Doctor's Note

If whatever gut flora enterotype we are could play an important role in our risk of developing chronic diet-associated diseases, the next question is can we alter our gut microbome by altering our diet? And the answer is -- diet can rapidly and reproducibly alter the bacteria in our gut, the subject of my next video, How to Change Your Enterotype.

These are part of a new expanded series on the microbiome that I’ll be unfolding in the coming months. Make sure you catch the first four in this series:

Who we have living in our gut may also play a role in autoimmune diseases. See Why Do Plant-Based Diets Help Rheumatoid Arthritis?

If you haven't yet, you can subscribe to my videos for free by clicking here.

To post comments or questions into our discussion board, first log into Disqus with your account or with one of the accepted social media logins. Click on Login to choose a login method. Click here for help.

  • Noe Marcial

    wow interesting!. but i don’t quite understand so animal protein associate food feeds the blues ( Bacteroides) and the reds are feeding by fructose , carbohydrates, glucose, sucrose are the good ones Prevotella? but in this case eat just pure sugar may bee good to feed the good bacterias and help to prevent colon cancer, i can not believe that! probably i misunderstood something..

    • mixis

      Good and bad are too simple to describe what’s going on in the gut. One species may be good in one environment and bad in another and also good in one aspect and harmful in another. At this point people are just starting to map the landscape and I don’t think the map is good enough for navigating yet. In my simplistic view, I’d rather serve bacteria that feed on plant matter than the ones that do well on animal tissue.

      • Noe Marcial

        i think it is a good conclusion. I hope that don’t came any sugary pill to feed the good bacteria.. and instead people eat more plant based

      • Ray Tajoma

        If the bacteria feed on animal-tissue (meat), won’t they eat the lining of the gut, and eventually the whole individual from inside ?

        • Brynda Jolly Bechtold

          I think dead tissue and living tissue is a factor.

    • Alexandre

      maybe its no so much the carb and more the fiber envolving the carbs:

  • Noe Marcial

    It is Prevotella it is hotter than Bacteroides?if it is like that it have any impact the temperature of the food to feed the good types of bacterias?

    • mixis

      There is no information about temperature but the map reads like a weather forecast where red indicates high values and blue low values. In this case the values stand for correlation. For example, if you took a random stool sample and found mostly Bacteroides, you’d expect to also find those food components that are red in the Bacteroides column. Or you pick a nutrient and expect to find bacteria that are coloured red in that row and few of the blue ones.

      • Noe Marcial

        thank you!

  • Julie

    “I’m often asked what the most striking thing I’ve experienced or learned while working among the Hadza hunter-gatherers of Tanzania. Aside from their breathtaking contact with the microbial world around them, I would have to say their near-constant daily nibbling of dietary fiber has been a real eye opener.” –Jeff Leach of the Human Food Project. He goes on to say that 4-48 month old Hadza children eat up to 150 grams of fiber per day.
    Not surprisingly, American vegans eat more fiber than Paleo or any other group.

    • Joe Caner

      150 grams of fiber a day! We are so very far removed from that way of eating. One needs to be diligent to get 75 grams of fiber per day on a modern WFPB diet eating from the produce and dried bulk bin section of your grocery store. The Hadza easily get twice that much just consuming sufficient calories from wild foods. Selective breeding has significantly reduced fiber content of domesticated crops.

    • Thea

      Julie: That’s fascinating. Thanks for sharing! (Oh, if only my diet was as healthy as those 4-48 month olds.)

    • Lawrence

      Julie, that really is a very interesting read, and coming from a Paleophile it is even that much stronger. I learned several things that I thought might add something to today’s discussion.

      First, although I have been looking at these things a lot, I had never heard the term ‘box-and-whisker plot’ and wanted to nail down once-and-for-all how to interpret these things. Here’s a great explanation:

      Next, I had never heard of Baobab fruit (what these Hadza kids were being weaned on), and so here is a nice explanation:

      And, wouldn’t you know, Baobab fruit is now being touted as a new ‘superfood:’
      (Future Dr. Greger video?)
      (Maybe when my current supply of amla powder runs out…)

      And, finally, a quote from the last paragraph…
      “If I had to pick one thing – among the myriad of dietary decisions we are faced with on a daily or weekly
      basis – making our colonic environment more acidic would be at the top of the list. By doing so, our more
      acidic colons will mean better barrier function (less leaky gut), a more hostile environment for potentially
      pathogenic bacteria, and a greater diversity of microbes.”

      …and the science from Dr. Greger to put this quote into perspective:

  • Veganrunner

    What a book Dr Greger! I’ve ordered 6 books as Christmas presents this week. Every family that comes over for Christmas Eve dinner is getting a copy.

    • I’m so glad you like it!!!

      • guest

        What role does dairy consumption and egg consumption play in today’s video and topic?

        • Joseph Gonzales R.D.

          I would say based on the maps from this video that dairy and egg consumption being rich in protein with no fiber fit into the bacteriodes category.

          • guest

            Yeah, good point, but consider how this might not be the case if the dairy is eaten at the same meal with a bunch of veggies, beans, fruit, etc. – I’m mostly vegan and have no agenda here other than looking at this in the bigger picture, which possibly is that plant matter in the gut simultaneously with animal matter might negate the findings revealed in today’s video. Thoughts?

          • Rami Najjar – NF Moderator

            In the video following this one, a vegan was put on an omnivorous diet than back to a vegan diet, bacteriodes appeared during the omnivorous while prevotella re-emerged when going back to vegan. This suggests that a mixed diet likely encourages bacteriodes more than prevotella.

  • susanco

    Here’s someone who changed his gut to Prevotella recently, and the key was the WFPB diet, not the scale – lol:
    See you at the WF in Annapolis Dr. G! Can’t wait :) Your book is the bomb!

  • jjpowers

    I’m confused. In a previous video ( Bacteroidetes was associated with being “bonier” and in this video the enterotype called Bacteroides it is associated with eating fat and protein. But what happened to firmicutes? Firmicutes seemed to be a desirable class of bacteria to host and in this video it has taken a back seat. Am I confusing enterotypes with phylum or are similar names being used – Bacteroides and Bacteroidetes?

  • jjpowers

    I’m confused. In a previous video
    Bacteroidetes was associated with being “bonier” and in this video the enterotype called Bacteroides it is associated with eating fat and protein. But what happened to firmicutes? Firmicutes seemed to be an undesirable class of bacteria to host and in this video it has taken a back seat. Am I confusing enterotypes with phylum or are similar names being used – Bacteroides and Bacteroidetes?

    • Joseph Gonzales R.D.

      I too was thinking of that video – Tipping Firmicutes to Bacteroidetes – and noticed that this video doesn’t mention firmicutes. Does anyone know if this group of bacteria are lumped into another category? The firmicutes appear harmful. I’ll wait a bit for other folks to weigh in and then see if Dr. Greger can help us.

      • HemoDynamic, MD – NF Volunteer

        See my Comment above and give me your input as well if you can. Thanks!

        • Joseph Gonzales R.D.

          Thank you! I was trying to figure out where those fit in and re-watched the firmicutes video and others in the Doctor’s Note. My original response said more of that I wasn’t sure, and then I saw that graph. Your response is much better to understand and lays out the different phylums with importance to focus on Provotella. If we’re both off someone correct us.

          • HemoDynamic, MD – NF Volunteer

            I figured it out! Look at my new answer to jjpowers.

          • Vegan Taxonomist

            Hi Joseph: I think you ARE off on this one. See my comment above for more detail. In the Wu et al. (2011) study Prevotella is positively correlated with dietary glycemic load and negatively correlated with insoluble fiber, i.e. it is a marker of a diet high in refined carbohydrates. A number of Firmicutes genera are correlated with nutrients from whole plant foods, including the genera Roseburia and Butrycicoccus. As mixis said so well, the map we have so far from microbiome research is not yet good enough for navigation.

          • Joseph Gonzales R.D.

            Thanks for replying! Did you see Hemo’s answer? I am sure it’s better than mine please see if that helps? One thing we can agree on, as mixis said, “the map we have so far from microbiome research is not yet good enough for navigation.”

            However, we still know more than we did 5 years back and the research is growing.

      • Leslie

        Wonder what role omega 3/6 ratio might play on gut bacteria. This a big deal or no, in your opinion?

    • HemoDynamic, MD – NF Volunteer

      I’m confused too but a quick look at the studies shows that Provotella is in the Bacteriodies phylum meaning Provotella is a Bacteriodies bacterium. So without looking further (I will later today) you want to have Bacteriodies but with a predominance of Provotella. You don’t want Firmicutes however. Look at the graph at the bottom of this link and you will see the Phylum’s color coded and see what I am talking about. Gut Phylum Graph
      I could be completely wrong though.

    • HemoDynamic, MD – NF Volunteer

      OK, here it goes. The answer is in the deTAILS.

      You have to remember some basic Biology here.

      First we must discuss Taxonomy which is the arrangement method we use in the world to place order to things.

      From Biology you might remember the Hierarchy of Kingdom, Phylum, Class, Order, Family, Genus, Species.
      Nearly every biology student has learned a famous sentence to remember this sequence: King Philip Came Over For Good Sex :-) (The Capital letters represent the first letter in the Taxonomy hierarchy list).

      From the top down in Hierarchy the list looks like this:



      Class: ___BacterioDETES______BacterioDETES

      Order: ___BacterioDALES______BacterioDALES



      Species:__BacterioDES spp.____Prevotella spp. (spp.=species)

      So in todays Video Dr. Greger is discussing different geni (genuses). We want more of the Genus Prevotella!

      In the Prior video Tipping FirmiCUTES to BacteroiDETES” He is discussing Phyla and we want more of the Phylum BacterioDETES.

      So to sum up we want more of they gut phylum of BacterioDETES over FirmiCUTES and within that phylum we want more of the Genus PrevotelLA over BacterioDES. And how do you do that? Eat more plants!

      Payments accepted———-In gratitude. ;-) Phew! As I wipe the seat from my brow!

      • Thea

        Dr. HemoDynamic: That’s super, super helpful! You did a great job of clarifying this confusing topic.

      • jjpowers

        Thank you for the explanation. It is much appreciated. Now I’ll understand more when the taxonomy terms are used. My last biology class was in high school in ’75 so this is new to me. I find the results of the studies of our gut bacteria interesting – especially about faecal transplant affecting obesity.

        Yes, this makes sense and since I’ve never even seen one bacteriodetes nor a prevotella, I’ll continue to follow what you mention in your summary: “Eat more plants!” Thanks!

      • plant_this_thought

        I will henceforth watch my phyla and geni closely! :)

      • Lawrence

        So – at the risk of beating a dead Equus caballus – according to your nifty Taxonomy tree, Lactobacillus acidophillus is a species within the phylum Firmicutes, something we want to reduce. Then, what’s all this marketing hype about yogurt and such with this miracle probiotic? Well, after a romp through Pubmed, I found this meta-analysis that suggests that L. acidophillus is ineffective for treating virtually all of the conditions that eating probiotic yogurts is supposedly marketed for. (Why am I not surprised?)

        This meta-analysis does point to one study that shows benefits of taking L. acidophillus in combination with Bifidobacterium longum in mitigating the deleterious effects of taking a specific antibiotic.

        I’m certainly no expert, but I think I have learned enough to call ‘BS’ on probiotic yogurts and any marketing claims about the wondrous benefits of functional foods containing L. acidophillus. Our bottoms’ line should be the same as your bottom line, to simply eat more plants. Nice work, Dr. Hemo.

      • vegank

        Thank you Dr.HemoDynamic, don’t think I could afford to pay you but it all makes sense now !

        • HemoDynamic, MD – NF Volunteer

          You’re paid in full! Gratitude. :)

      • peseta11

        nicely done. But the plural of genus is genera, or genuses if you like; those romans were so arbitrary, as well as pushy!

        • HemoDynamic, MD – NF Volunteer

          Thank you!

      • HaltheVegan

        Excellent analysis Dr HemoDynamic.

        Another person mentioned that Dr Klaper has some info on this subject, too.
        At the following link, Dr Klaper says that the following types of Bacteria are beneficial:

        “There are a group of bacteria that are especially beneficial and I always look for these names on the label of any probiotic I purchase:
        Lactobacillus acidophilus
        Lactobacillus plantarum
        Lactobacillus. salivarius
        Lactobacillus. bulgaricus
        Lactobacillus casei
        Lactobacillus bifidus
        Lactobacillus rhamnosus
        Bifidobacteria longum

        Certain organisms appear to be especially beneficial for specific conditions:

        • Lactobacillus plantarum and L. casei have anti-inflammatory properties, making them especially valuable for people with inflammatory bowel disease, like Crohn’s disease or ulcerative colitis.

        • Lactobacilis acidophilus is valuable for rebalancing the bowel after taking antibiotics, and for thwarting recurring urinary infections in women.”

        This raises the questions: Where do these fit into the classification scheme that you mention (BacterioBACEAE, PrevotelLACEAE, or FirmiCUTES)?
        And are they really Good, Bad, or Neutral (ie. Just a waste of $) ?

        • D|F

          Yes, here comes the problem, in the study cited nearly all of the cultures in probiotics promote the seemingly negative bacteroids.

        • HemoDynamic, MD – NF Volunteer

          Nice read. Thanks for the link. I have been so blessed to be able to work with Dr. Klaper. Not only is he such a fantastic physician, he is such a kind, gentle and genuine Human being. Just like Dr. Greger!

  • plant_this_thought

    I feel like I have a consultation with my doctor each time a new NF video comes out. Imagine meeting with your doctor multiple times per week! The passion and excitement with which Dr. G pursues knowledge pertaining to MY health is positively infectious.

    • HemoDynamic, MD – NF Volunteer

      PTT, I got a comment from you in my email but I do not see it here on the message board. I think I got it all worked out regarding the confusion. See my answer to jjpowers, It’s in the deTAILS.

  • BB2

    Doc, what about water: is the chlorine in tap water likely to kill off some of our gut flora?

    I don’t feel comfortable filtering my tap water, by fear of modifying its ph and mineral profile, and I don’t feel comfortable with the “filter and remineralize” option, as I noticed some systems use natural alums to remineralize the water.

    So what I do is I just let it sit in a jar until the next day to have the chlorine evaporate; however, I don’t know if this is changing the bacterial content of the water. So on top of doing that, I also drink spring water sold in glass bottles (from presumably reputable companies). This way, I mitigate things…

    Any tips? Am I doing this right? Thank you!

    ps: I’m loving the book. “A doctor a day may keep the apples away”, that one is going to be a classic. :-)

    • Rebecca Cody

      I used to get my water from a spring that erupts from a pipe in a parking lot in downtown Olympia, but now I use a Berkey filter, which takes out chlorine, fluoride, and bacteria, but leaves the nutrient minerals like calcium in the water.

      • BB2

        Thanks for the info.

    • Joseph Gonzales R.D.

      I looked up some research by searching pubmed for “chlorine water + gut bacteria/microbiome” but did not find anything promising. Only a handful of animal studies, which cannot say much. We do have some videos and resources on water however to the extent of how chlorinated water effects gut health I have not found much.

      • BB2

        Thank you Joseph. Please keep us posted if anything shows up on your side!

        I was able to find this interesting opinion by Dr. Klaper – he mentions a few possible threats to the flora, including alcohol, tannic acid and chlorine. Basically, things that by nature have the ability to kill bacteria.

        I wonder to what extent we would have to avoid these things in order to protect the flora…

        • Lawrence

          BB2: This is a good posting. I think anyone who is now or is considering taking probiotics should read Dr. Klaper’s words. These probiotics are expensive, and even under ideal circumstances it is difficult to know if one is wasting their money (opinion withheld). And, as Dr. Greger has shown us, getting one’s advice from the health-food clerk is not the way to go:

          Dr. Klaper’s advice seems very sound, although I do like my morning coffee and will most likely never give that up. Though, I do now take it completely black thanks to sage advice from Wade Patton and my personal war on fructose.

          A couple things caught my eye that I want to highlight (quotation marks indicate Dr. Klaper’s words). First,
          “Sacchromyces boulardii, a beneficial member of the yeast family, is effective in stopping diarrhea, either from antibiotics, radiation to the pelvis, or ‘travelers’ diarrhea.’ It can be used as a preventative if one is traveling to a destination where contracting traveler’s diarrhea is a strong possibility, in which case it can be started 2 to 3 days before departure and taken each day while traveling.”

          This applies to a discussion on this thread about travelers d., but it also is salient because I know someone who is suffering from the after-effects of pelvic radiation. I found a study that addresses the efficacy of Sacchromyces boulardii here:

          The section ‘Factors that determine efficacy of Saccharomyces boulardii as a probiotic’ has some good information that underscores the difficulty even for researchers, let alone the average consumer, in knowing what one is buying.

          And, finally, in an earlier posting I came to the conclusion that commercial probiotic yogurts were a marketing gimmick:

          It’s nice to get an independent confirmation of my suspicions from someone who actually knows what they are talking about:
          “This is one reason why I think eating yogurt as a probiotic is pointless. Standard, commercial yogurt is pasteurized to kill bacteria before it is sold – so most brands are useless as a probiotic source. The ‘cultured’ or ‘bacteria-fortified’ yogurt products usually have a few million organisms, at best. Thus, you would need to consume dozens of tubs of yogurt to equal the bacterial numbers in a good probiotic.”

        • Joseph Gonzales R.D.

          I have much respect for Dr. Klaper he is an expert on probiotics and how to test if their active.

        • Thea

          BB2: I just got around to reading Dr. Klaper’s article. Very interesting!!!

          But I ended up with a similar question as you. The part that really caught my eye is that he included teas in the list. NutritionFacts has several videos showing healthy outcomes from drinking teas. So, a page which tell me to minimize tea drinking leaves me confused. I wonder how many items on the list fall into the category as being a good theory, but not actually tested on live humans???

          (Aside: That’s one thing I particularly like about NutritionFacts. Article’s like Dr. Klaper’s are great and important because they can help guide us when evidence is lacking, as it is for so many questions. But Dr. Greger gives us the information when there *is* evidence to back up an idea. It’s not always black and white, but I feel I’m more able to go to the bank with this type of information. For all I know, Dr. Klaper has similar evidence to back up his claims. But I don’t see it on that article…)

    • Fred

      The local water dept had the bright idea to soften ALL the water…so despite evidence that drinking hard water is a cardiovascular positive….they chose to favor their washing machines over their health…replacing the calcium/mag with salt.

      I use carbon filters for drinking and for showers get rid of chlorine…etc..


      Berkefeld gravity filter rain water must be the most economical answere for drinking water? I have been doing this for more than a couple of decades and my Kefir duva thrive on it as well.

  • HemoDynamic, MD – NF Volunteer

    I find this new area of research absolutely fascinating and I am so glad you are covering it now. In fact this reaseach has really made me nearly stop all my antibiotic prescribing unless absolutely necessary. And if I do have to Rx (prescribe) ABX’s(antibiotics) then I always Rx probiotic’s. Remember if you take probiotics you only need a short burst of them for 1-2 weeks (after you have finished the ABX’s) and it is imperative that you take them with a high fiber meal (eg. Beans, Greens and Grains) within 20 minutes or the probiotics don’t take hold (die) and you just poop them out.

    If anyone is interested in testing their own microbiome you can order the kit from Robynne Chutkan, MD’s websites (she is one of the leading researchers in this field) here. Microbiome Testing Kit It’s not cheap but it is very interesting.

    Thanks again for bringing this information to the world!!!!!

    • plant_this_thought

      Would you prescribe an antibiotic for ordinary traveler’s diarrhea, or would you encourage your patient to just ride it out?

      • jj

        Activated Charcoal do not travel anywhere without a supply of activated charcoal for internal use both as a preventive and as a treatment for Traveler’s Diarrhea and other Gastro-Intestinal problems. We have not found another single product that works so effectively as activated charcoal for the treatment of traveler’s diarrhea and more and more savvy travelers, vacationers, explorers, missionaries, and foreign development workers are making sure it is one of the first things they pack.

      • HemoDynamic, MD – NF Volunteer

        PTT, by ordinary I’m assuming you mean most common cause of Traveler’s diarrhea.

        First we must understand what causes TD. There are 3 causes of Traveler’s diarrhea and they are Bacteria (80-90% of cases caused by ingestion of bacterially contaminated food or water with E. coli–the most common pathogen in 50-60% of cases), and parasites and viruses.

        Treatment depends on the bug suspected to be causing the Traveler’s diarrhea (TD) and the severity. Mild cases (diarrhea with 1 or 2 unformed stools in 24 hours without additional symptoms such as fever, nausea, vomiting, cramps usually need no treatment other than supportive care (eg. fluids). Severe cases (greater than 3 loose stools in <24 hours and additional symptoms may require treatment.

        If the cause is bacteria (the most common cause) we can use antibiotics and if the cause is parasitic we can use antiparasitic drugs.

        In the case of viral TD such as rota-virus in children and infants, or Norovirus in adults (eg. Cruise ships) antibiotics don't work so supportive care is all we can do (eg. fluids, fluids, fluids and immodium if needed). Some severe cases may need IV (Intravenous) hydration at a doctors office, urgent care or hospital.

        Also another big risk factor for getting TD is taking medicines like Prilosec, Pepcid, Nexium, Protonix etc. because they decrease the stomach acid you make which is protective in that it can kill these bacteria, parasites and viruses before they cause any problems. All the better reason to eat plant based and not have gastric reflux from all the meat and diary consumption which leads to people taking these medications and placing themselves at even greater risk for TD.

        Also suspicion as to the cause is raised by the region that has been visited which can aid one in determining what is the potential cause. People that play in lakes, rivers and streams can get Giardia a common parasite. If you went to Mexico and Picked up Montezuma's Revenge it is most likely a strain of E. coli. And if you are on a cruise ship Norovirus is a common cause of TD in that environment.

        I hope this helps.

        • plant_this_thought

          Thanks for taking the time to compose this long reply. It’s clear that diarrhea is a symptom of a number of different infections, not a single entity.

          “If the cause is bacteria (the most common cause) we can use antibiotics…”

          It’s confusing to me that E. coli has different strains, some of which are normal gut inhabitants and some of which are pathogens. I’m not sure how antibiotics can knock out one without similarly affecting the other. In another reply you say that our normal flora are highly resilient. Is this not also true of disease-causing strains? Perhaps our immune systems play a role in favoring the healthy over the unhealthy as the population restores itself after the antibiotic assault?

    • Rebecca Cody

      I’ve started eating more home fermented sauerkraut, kimchi, water kefir and kombucha. I’ve noticed that I’m making a lot less gas from eating beans, and thinking all the gut bacteria I’m implanting may be the reason.

      • Joseph Gonzales R.D.

        There are ways to prepare beans to help lower gas. Check out these videos and Q&As on beans and gas and the video on Beans and Gas: Clearing the Air.


          Beans and Gas,soaking and rinsing beans daily until they start to sprout reduces the wind problem. Useing a savoury foods dressing of shredded red cabbage and beetroot + kelp powder immersed in cyder vinegar, which will modestly firment, helps as well;After some time the vinegar may form a new ‘mother’ on top;so is clearly happy with the arrangement :-).

        • Rebecca Cody

          Thanks for that. I’ve heard that before, but never tried it. Now I will, and I’m glad it takes so little.

          For anybody interested, and who has or wants to spend the $$$ for a pressure cooker,

      • vegank

        Putting a strip of Konbu kelp (dried seaweed) does help. I get them at a Japanese or general Asian food store.
        I’ve never tried these but apparently putting some fennel, cumin or a slice of ginger in the cooking water solves the problem.

        • Rebecca Cody

          Thanks. Kombu is available at my local food co-op and the others are in my pantry already. I’ve also read that epazote works and I even grew an epazote plant, dried the leaves and they, too, are in my pantry. I guess it’s time for a little science experiment to find out which works best for me.

          • vegank

            I’ve never heard of Epazote, but after searching I discovered that it’s available from the Seed shop I normally
            buy vegetable seeds ! Apparently used with mexican chilli .Thanks to you too !

  • plant_this_thought

    I am curious what effect antibiotics have had on our microbiome, whether the multiple heavy courses of these I have taken when treating Delhi belly have perhaps wiped out some beneficial species. I am completely WFPB, and I take lots of probiotics, but these supplements consist of only a handful of strains. I guess the question this video provokes is: Is there anything we can do (short of fecal transplant from an Amazonian aboriginal) to return our guts to a state of nature?

    • HemoDynamic, MD – NF Volunteer

      See the note I left above for a testing kit. Nice thing about your microbiome is it is resilient and if you are eating WFPB you should be doing just fine.

    • plant_this_thought

      I’m also curious whether exposure to healthy, non-Western bacteria causes diarrhea. In other words, when we travel to non-western countries and get sick and receive antibiotics treatment, are we missing out on acquiring a more diverse microbiome?

  • Filipe Coimbra

    Amazing, amazing video! Thank you once again Dr. Michael Greger and to the rest of the NF team.

  • Wade Patton

    Once again, a strike against colonoscopy for everyone. Prevention trumps detection. Every single time.

  • robert jones

    when you become a vegan does your enterotype change?

  • brock_sam_son


  • Brux

    What happens to the individual if you try to change, or your diet forces a change on you? It this something your body just passively accepts, or does the bacteria try to fight you in some way to preserve its bacteriological dominance? Can bacteria have anything to do with food cravings?

    • AllVegan

      I am sure it would if it could. Kinda like a bacterial little shop of horrors. However it is the bacteria you feed which becomes dominant.

    • Rebecca Cody

      I have read that an overgrowth of Candida Albicans causes sugar cravings.

    • jjpowers

      Here is a study that looks at hormones leptin and ghrelin and the gut bacteria and the relation with anorexia:

  • Dean Pomerleau

    Ubiome seems to have do its highest level classification in terms of Bacteroidetes & Firmicutes. Is it reasonable to assume Bacteroidetes corresponds to the Bacteroides enterotype and the Firmicutes represent the Prevotella enterotype that Dr. Greger speaks of in this video? I wondering, because I’m a whole-food vegan and uBiome tells me I have more Firmicutes than average, and less Bacteroidetes, which would make sense if the above correspondence is the same one Dr. Greger is talking about.



    • Dean Pomerleau

      Doing a little follow-up myself, it appears from diagram

      the tree of phylum and their contribution to the two enterotypes (the lowest split in the tree at the bottom of the diagram) is not very straightforward. So my simple classification of Bacteroidetes = Bacteroides enterotype and Firmicutes = Prevotella enterotype isn’t accurate.

      So does anyone know how to interpret the rather complex report that uBiome provides in order to determine one’s enterotype?



  • Jon McIntosh

    Anyone notice at 3:47, “…surprisingly, Bifidobacterium species was generally positively associated with increased risk of colon cancer.” ?

    Many probiotic supplements contain Bifidobacterium species, and according to the “Probiotic” report at Bifidobacterium is “effective” in the treatment of diarrhea from antibiotics, viral infection, or chemotherapy, weight loss, H.pylori, and other conditions.

    Any comments from those knowledgeable on this subject? If we are on a mostly plant based diet are we better off passing on probiotics that contain Bifidobacterium species due to this “increased risk of colon cancer”?

    • HemoDynamic, MD – NF Volunteer

      I left this comment below but reposted for your convenience.

      In the study the two strains that were associated with increased risk of colon cancer were Bifidobacterium longum and B. angulatum. Go down to page 3 and see the bacterium that were found to have corrolations with colon cancer.

      It makes sense to want to stay away from Probiotics having these bacterium in them.

      But most importantly eating a healthy plant based diet that is full of prebiotics eliminates ones needs for any probiotics supplements. There is sometimes risk to taking things in pill form.

      But it is also important to understand that this is a new field of study and research and just because these bacteria are associated with increased risk doesn’t mean they cause colon cancer. Corrolation doesn’t mean causation an important statement to remember!

      It could be the ratio’s of those bacterium that cause the problems such as Dr. Greger had explained in his video, Tipping Firmicutes to Bacteriodetes

      • plant_this_thought

        “Today, Young is teaching his students to think not about “bad” and “good” bugs, but rather good and bad communities of microbial organisms.”

        The last section of this paper: , entitled “IMPACT OF MICROBIOME ON GASTROINTESTINAL HEALTH” is a case study that is highly illuminating to our discussion. The final section, “Resilience of Gut Microbial Community Structure” is particularly apropos.

    • Leonid Kalichkin

      I suppose they could be helpful (if they actually reach the gut and settle there) for people with Bacteroides type. Having an established gut flora enterotype is better than having a disrupted one. If you are following a plant-based diet, you would better find probiotics with Prevotella.

  • Rebecca Cody

    I read of an experiment where fat rats were given an enema (picture that!) of skinny rats’ microbiome and they became thin, while the opposite happened as well. So this is probably telling us one of the reasons is because of the distribution of plant based bacteria vs animal based bacteria. But what about those of us who don’t lose weight on a WFPB diet?

    • Charzie

      Now how do I proposition a skinny person about this topic? LOL! I getcha, though I have lost a whole lot of weight since going WFPB and am really faithful to the principles, (I have to be, I was diabetic) I can’t get anywhere near the weight I should be…short of starving myself…which is not gonna happen! So instead of being “morbidly obese” (hate that term!) I’m borderline fat! LOL! My BMI is around 29-30.

      • Rebecca Cody

        Charzie, good for you! I do have trouble avoiding added fat, though I eat less and less. In reading Dr G’s book, I notice the serving sizes of foods he recommends are modest. Maybe I’d lose that 20 pounds if I stuck with his quantities. Most WFPB recipes I see, like those of Dr McDougall’s, have huge servings. Bigger than either my husband or I could possibly eat. Dr Fuhrman talks about how people eating this way eat more calories but lose weight.

      • Fred

        If it will make you feel better:

        “Our results showed that those over the age of 65 with a BMI of between 23 and 33 lived longer, indicating that the ideal body weight for older people is significantly higher than the recommended 18.5-25 ‘normal’ healthy weight range.”

        Research done on those following the SAD diet?

        My BMI is around 28…I’d “go on a diet” except that the stress of trying might kill me…..

        • largelytrue

          These citing authors link the study findings with a longstanding hypothesis that sarcopenia is an important confounder in this type of association; the elderly who lose weight or maintain a low BMI tend to do so in ways that produce a loss of muscle mass, which has its own hazards (notably falls). Specifically they cite another study as evidence that both sarcopenia and obesity contribute to mortality, and that the preference is to have neither.

      • SeedyCharacter

        You are too funny, Charzie! The old term for “borderline fat” is “pleasantly plump.” I like “ample,” “luscious,” and “curvy.” I eat much less and much better than I used to but after my second child my metabolism seemed to have switched–I now conserve calories like crazy.

        BTW, I just figured out how to upload my pic. If you squint really hard, you’ll be able to see “Tofu” on my shirt. It says “Save a Cow. Eat Tofu.” If you want one of your own, go to this cool website:

        • Charzie

          My Greek buddy called me “zaftig”, which I guess pretty much equates to the terms you mentioned. And YES, having kids I gained 50 pounds with each pregnancy, couldn’t get rid of most of it, and had 12 kids! Kidding, just two…and that’s why!
          I love your shirt! It kind of reminded me of a Chick fil A billboard here, where they have a cow writing graffiti that says “Eat mor chikin” and I always want to alter it…turn the cow and a chicken upside down and scrawl “Eat more plants” lol

  • “Bifidobacterium species were generally positively associated with increased risk of colon cancer” ….I just looked at my expensive probiotics from Klaire Labs…. FOUR strains of Bifidobacterium: Bifidobacterium bifidum, Bifidobacterium longum, Bifidobacterium lactis and Bifidobacterium breve. Ughh

    • HemoDynamic, MD – NF Volunteer

      In the study the two strains that were associated with increased risk of colon cancer were Bifidobacterium longum and B. angulatum. Go down to page 3 and see the bacterium that were found to have corrolations with colon cancer.

      It makes sense to want to stay away from Probiotics having these bacterium in them.

      But most importantly eating a healthy plant based diet that is full of prebiotics eliminates ones needs for any probiotics supplements. There is sometimes risk to taking things in pill form.

      But it is also important to understand that this is a new field of study and research and just because these bacteria are associated with increased risk doesn’t mean they cause colon cancer. Corrolation doesn’t mean causation an important statement to remember!
      It could be the ratio’s of those bacterium that cause the problems such as Dr. Greger had explained in his video, Tipping Firmicutes to Bacteriodetes

      • Jon McIntosh

        thank you for your response!

  • gentlegreen

    I recently had to take a course of antibiotics (Trimethroprim) because of a UTI (prostate has now been found to be enlarged).
    My digestion has been sub-par ever since … wholefood vegan 33 years .. will my gut biota recover ?

    • Patricia

      I recommend the gastroenterologist Dr. Robynne Chutkan’s work for helping you get your gut microflora back in balance. You can checkout her website,, or read her book The Microbiome Solution. Rich Roll also had her on his podcast if you want to listen to an interview.

      • gentlegreen


        At last I have justification for not bathing excessively.:)

        • Patricia

          haha! I must confess, I am more drawn to her “eat clean” suggestions (especially including fermented foods and probiotics to restore microflora lost to antibiotics) than her “live dirty” ones, but I am trying to let go of my dirt and germ phobias…baby steps.

      • Melva

        So I am confused about fermented dairy, specifically Kefir? I understand that yogurt is essentially a dairy product that has been supplemented with a few strains of probiotics. As kefir has been fermented the milk sugars have been changed. Many experts writing about the microbiome are suggesting eating/drinking a wide variety of fermented products including Kefir. So I know that dairy is out, for many reasons,but I have not seen anything on fermented dairy products such as kefir.
        Thanks for any information on this.

  • Matthew

    why are there no provetella probiotic supplements? It could take years to reverse the enterotype without assistance. I would guess water fasting would speed up the process of reorganization by an order of magnitude or more

  • Bat Marty

    also who has bacteroidis produces also bad smell in the bathroom, right? and the Prevotella guys no, I bet…:-) (any studies there?)

  • MateuszSz

    is it possible to change from one to the other type ?

  • Andrey Yusupov, M.D.

    We already know than large meat consumption vs. veggie diet only raises your lifetime risk of colon cancer by 18% (thanks to that famous British study), which by all measures is a very small change when comparing incidence of an already rare event. So besides cool blue and red colors, and the above, is there any evidence to show that having one enterotype is beneficial over the other?

    • largelytrue

      Could you cite the particular study that you have in mind? Lifetime incidence of ~5% in developed countries doesn’t seem like a rare event to me, in any case, particularly when the consequences can be devastating to finances and quality/length of life.

      • Andrey Yusupov, M.D.

        3.1 Evidence from human studies
        CRC is the number one cause of cancer mortality in European non-smokers (Ferlay et al., 2013). Preventability estimates in the USA suggest that 50% of the cases of CRC could be avoided by improving the diet (nutrition) and physical activity (World Cancer Research Fund, 2009). Yet, uncertainty exists regarding the supposed link between meat consumption and CRC. For example, meat intake could explain a major part of the variation in the incidence of CRC, and then CRC should be less common among vegetarians than among meat eaters. However, the findings on these associations are inconsistent: one study found a lower incidence of CRC for vegetarians (Fraser, 1999), another found no difference between meat eaters and vegetarians (Sanjoaquin, Appleby, Thorogood, Mann, & Key, 2004), and yet another detected a lower incidence in the meat eaters (Key et al., 2009). Hence, the relationship seems to be complex and not only depend on the meat intake but also on the total composition of the diet.

        Link here:

        That should get you started. But, that 18 percent is the main study the WHO used for their recent statment. ie. 5 vs 7 out of 10,000 is about an 18% difference (going from a small risk to a small risk).

        5% lifetime risk of ANYTHING is quite rare. Women have a >15% lifetime risk of breast cancer, for ie. Which has a significantly less studied and more debated nutritional component than say CRC.

        • largelytrue

          The 18% that the WHO reported in its recent statement was an 18% increase in relative risk for each 50g/d processed meat. 50g/d processed (a little more than 1 hot dog) doesn’t exactly characterize the world’s most meat-heavy or processed meat-heavy diet.

          Why would I agree that “5% lifetime risk of ANYTHING is quite rare”? You’ve overstated your case and oversimplified the issue, I think.

          I agree that multiple factors are involved in the etiology of cancer and that we shouldn’t focus on one nutritional component to the exclusion of other influences. But we shouldn’t dismiss the preventability of this disease and the plausibility of the meat component of it.

          • Andrey Yusupov, M.D.

            Care to comment on the data I provide above showing that there are studies showing a higher risk of CRC in vegetarians, another study in meat eaters, and another no difference. In order words, the studies out there demonstrate conflicting results.

            Actually, a hot dog is an example of THE WORST type of meat ie. Most people would consume actual chicken, beef, or fish to a greater quantity than hot dogs generally. You just proved my point. Even if one were to comsume a hot dog or two per day for the rest of their darn life, 18% increased lifetime incidence of an already rare event is nothing mate. If you said 18% increased incidence annually thats a better argument.

            I am vegan for your information. But lets not overstate the significance of a finding. Facts are facts.

          • Andrey Yusupov, M.D.

            I didn’t note a single thing in this video, while educational, that would lead me to believe trying to have one microbiome is better or worse to another. (besides which bacteria has a cooler sounding name). If you did, I’m all ears.

          • largelytrue

            If you want to say that it’s fairly tentative work at this time, I’m inclined to agree with you. But if you are saying that he presented no evidence at all for that claim, I’m a bit at a loss for what to say.

          • Andrey Yusupov, M.D.

            We both agree on the first part of your statement. Well, if the evidence was so plain in sight and easy to see, surely you would have answered my simple question by now? :)

          • largelytrue

            Since it’s so simple and easy to see, and you have an MD. I thought you’d know to look for the source.

            Greger said:

            The reason this may matter is Bacteroides species are generally associated with increased risk of colon cancer, our second leading cause of cancer death, yet almost unheard of among native Africans. The differences in our gut flora may help explain why Americans appear to have more than 50 times the rate of colon cancer.”

            And while he was saying that, he pointed to this paper.

          • Andrey Yusupov, M.D.

            Short term memory loss much? I had already told you that 18% lifetime increased risk (that is from hot dogs not actual meat) of an already rare event (ie. a jump from 6 to 8 cases out of 10,000), is nothing given the risk benefit ratio. Most people don’t eat hot dogs every day. The unhealthiest people I know even don’t do this. Making this even a silly statistic. To put it in perspective for you, flying on a less safe airline (say rated 4/7 stars as opposed to 6 or 7/7 stars) will increase your risk of death by A LOT MORE THAN 18%. I would venture and say more like 300%+. People still fly on those airlines without obsessively checking airline safety ratings or even giving it a second thought, because risk of death in a commercial flight is already low. Why is this hard to grasp?
            Is there anything else than what we’ve already discussed above ad nauseum re: CRC that would be beneficial with one microbiome over another.

          • largelytrue

            And colon cancer is the second leading cause of cancer death, according to the statement from Greger that I just underscored. The absolute baseline risk that is amplified differs in the two cases, so I don’t know why you are pointing out that sometimes the relative increase in risk is greater in other situations. The dose dependent increase in RR is only part of the story. as is the risk of death by itself itself.

          • Andrey Yusupov, M.D.

            Sounds good. Does “may help explain” and “appear to have” sound like sound science to you? Do we have any real data showing that if YOU OR I have one microbiome vs another, we can reduce our risk of CRC by 50 times? Even by 10 times? We’ll just have to agree to disagree.

          • largelytrue

            Science is tentative, and proceeds with hypotheses that aren’t necessarily firmly reliable. It’s good to examine potential reasons for a 50 fold variation in cancer risk, don’t you think? A difference in the activity of gut flora is one of the potential factors. Looking at research on this potential factor is valuable, and when we look at research we can still treat it according to the weight of the evidence therein.

            Again, I don’t think I really disagree with you that this may be one of the areas where Greger’s argument is a little thin. For instance I find myself somewhat at odds with Greger over the idea that focusing on maximal antioxidant power is one of the most important nutritional concerns.

          • Andrey Yusupov, M.D.

            Agreed on both counts. I guess after watching Dr. McDougall laughably saying that Steve Jobs cancer metastasized at age 27 (3 years after the first cancerous cell of the original tumor) which is just nonsense. Two cancers of the same histology, of the same size, one may metastasize in 5 minutes while the other may in 50 years. He boiled down the entire field of cancer biology only to “doubling time”; that is not even 1% of the story. People actually come on youtube and believe these ‘experts’.
            Between that and my IGF-1 levels going up on a vegan diet, people (myself included) need to go on and just live their lives instead of worrying about the 18% increase or decrease yada yada. Experimenting is quite fun, though!
            I must be screwed since I drink (prooxidant) pu-erh and green tea, and even 1/4 tsp of turmeric in my morning shake was nasty!

          • Andrey Yusupov, M.D.

            Male Okinowans and male Sardinians ate meat. And they are some of or the longest living males EVER!! End of story. They ate more than 2% meat by most accounts. Not just on “special occasions”. I am a vegan telling you this. I don’t like when people inflate their personal decisions’ significance in order to help justify it.

          • largelytrue

            More than 2% meat? By what, calories? By how much more?

          • largelytrue

            You yourself said in your original post that the change in risk between a meat and veggie diet was 18%. I assumed that you believed that figure. Do you not believe it? Then why did you say it?

  • Panchito

    The gut flora is also related to brain chemistry, thinking, and even gene expression

    • Charzie

      This is only anecdotal because a load of people have had the same experience, but since I started consuming a lot of home fermented foods, I have noticed a dramatic improvement in not only digestion, but my mental state. Any actual research on this?

  • Panchito

    Just out of curiosity, does anybody has an opinion on the antimicrobial properties of copper, and how a high copper diet could shape the gut flora? Note: copper is widely used in organic farming

    • Thea

      Panchito: I don’t know about antimicrobial properties, but if memory serves (I don’t have access to the book right now), Dr. Barnard’s book on Power Foods For the Brain says that there is a correlation between copper in the brain and altzheimers. No proof of a cause-effect yet, but reason for caution.
      I was aware that copper is widely used in organic farming based on a post that Darryl made some time ago. I gave it a lot of thought and decided that I would pick a say copper organic apple or a roundup apple, but it’s sad to me that I don’t have more perfect, easier options.

  • Charzie

    Fascinating! This topic is really profound and exciting, thanks for covering it here!

    I am a huge proponent of fermentation after experiencing such positive effects from it, and I would love to see more research done on the benefits of this ages old practice. I’ve seen your past videos on kimchi and kombucha, but to be honest, one fatality in an AIDS patient from kombucha and some other nonspecific incidents leaves a whole lot of territory for confounding factors, and the conclusion was kind of sarcastic, not one of your best. (Sandor Katz, a big fermentation advocate and author of many excellent books on the topic, actually credits fermentation for his extended survival and good health, despite living with AIDS)

    The kimchi report and even the citation was very unspecific and overly generalized because you can PICKLE something with cheap distilled vinegar and a ton of salt and chemicals or whatever, but LACTO-FERMENTATION is a whole different animalcule , and I saw no differentiation between these two dramatically divergent methods of preservation! There are so many amazing topics covered here, but I feel like this one has been unfairly panned based on very tenuous info. In my personal experience, and certainly plenty of others, it has been nearly as life enhancing as ditching the crap foods and going WFPB. I often wondered if even the conflicting results pertaining to studies of drinking wine are problematic because they compare commercially manufactured wine with it’s multitude of marketing additives and questionable methods, with traditional, fermented wine created with natural processes. This is certainly no different from comparing fast food versus home cooked…just not the same, as we all know! Or even comparing the questionable potency/effectiveness of manufactured probiotic pills with the actual pre and probiotic rich, resplendent, fermented foods! I think our germphobic society is missing out on an amazing gift, everyone I know who’s tried them over time has had benefits, even if at first they complain of bowel issues! lol

    This isn’t me, but certainly could be:

    • Lawrence

      Wow, Charzie, your well-written and impassioned posting really got my attention. Donna Schwenk’s personal story was dramatic and compelling. And, while there are vegan kefirs, I don’t think I will go down that road. Something like this I will probably try:

      BTW, I’m a huge fan of Joseph Campbell. My interest in his life’s work in mythology and comparative religion was, for me, a life-altering experience. I have never looked at religion the same after experiencing his teachings. Here’s an introduction to Joseph Campbell and one of my favorite books:

      What the world needs now is LESS religion, not more. Hold on to the innate, humanist desire to help one another, but discard all the superstitious, stultifying nonsense. If people knew how contrived and plagiarized are the ‘Three Great Religions’ that are now tearing the world apart, they would be shocked. Unchanged most likely, but shocked nonetheless. (Want to talk about social isolation, try being a vegan AND an atheist.)

      • Charzie

        Thank you Lawrence, I’ve become passionate about fermenting for the reasons I stated and more! Either making rejuvelac or veggie fermentation is probably the easiest place to start, and despite the press for starter cultures (they do supposedly boost the # and amount of microbial strains), they are certainly not necessary! I am just too darn poor to afford them, but have never had any problems getting a batch going! (Once you get a good ferment, it’s a help to save a bit to add to your next one to speed it up.) That is what I find so amazing…like always, nature provides what we need… the balance of starter microbes for free, and with just a container to hold them and whatever you want to ferment, in a week or two you have this wonderful, nutritionally enhanced, entirely new tangy veggie creation that is not only delicious and preserved, but it can create magic in your body! You just chop or grate your veggies (or mix of them) of choice, stuff them into a jar, add enough (salted to taste) water to cover, whatever herbs and spices you like, make sure everything is under the water level, and leave some head space for fermentation action, seal the jar, set it on your counter and let her rip! Lacto-fermentation is an anaerobic process, so you want to keep things submerged. Depending on your household temps, in two or three days you should see some bubbling starting to happen, and the solids will start to try to rise up out of the liquid. Some people have fancy jars, crocks, airlocks, and so on, but I recycle used glass jars with lids, and once or twice a day I burp them to let out the built up pressure, and give it a good shake to settle the solids back down. Once the culture is active, taste your ferment every time you burp it and enjoy the process to gauge when you think it is ready. The longer it goes, the tarter and sourer it will become, and higher temperatures will speed things up, so it is different every time. The taste test determines when it’s done enough for you. Garlic half sour pickles can be done in one day, sweet fruits and veggies move along quick too, but in cool weather most veggies can go even months, though most of mine are done here in 5-10 days on average. Some people freak out about sterilizing the jars and utensils, etc, but the way I look at it is…our ancestors have been doing this for millennia, and I seriously doubt hygiene got a second thought, all they cared about was preservation! The cool thing is, unlike canning and the inherent risks of botulism etc, the microbes that are in ferments oust the bad guys!
        I live in Florida so unfortunately there is no cellar or cool storage, so into the fridge it goes…but will last forever because though dramatically slowed, fermentation will continue. The worst problem I’ve ever experienced was a patch of kahm yeast on the surface, a weird looking whitish scum that is harmless. (You can scrape off heavy accumulations…the flavor isn’t great…or just stir in lesser amounts). I get called the “mad scientist” because I am always making some new “experiment”, it is such a fun and satisfying endeavor! I won’t say everything has been delicious, but it really couldn’t be easier, you have nothing to lose and a whole lot to gain! My latest adventure was quite…inebriating! I grew some of the hibiscus Dr Gregor recommends for tea, and it makes these cool looking calyxes that the tea is made out of, not flowers as I thought. (They are called “Florida cranberries” here!) They grow like a weed and I planted a bunch, so I had a slew of them to utilize. I made tons of tea, juice, smoothies, dried them, shared them, and of course, fermented them! That was a lovely, intensely colored, alcoholic surprise! A probiotic buzz with a bevy of benefits! The first few sips were interesting, but after that it was awesome! Ha ha. I’m not a drinker and sensitive to alcohol anyway, but the stuff was pretty potent! I was just winging it so it could have probably been better, but I am definitely gonna have to refine or investigate the finer points of perfecting that process!
        I ramble, but I can’t help being so enthusiastic and excited about the topic! I’ve suffered with depression, anxiety, and severe IBS for most of my life, and though going WFPB helped reduce them and beat diabetes, obesity, severe arthritis and a slew of other chronic health issues, fermentation really took it to the next level. I can’t remember ever feeling so stable and happy, even despite an extended period of major life issues, including the death of my oldest son, that would have bottomed me out for sure! If I slack off and get lazy about creating new ferments for too long, I get a big wake up call, so it isn’t just wishful thinking, I’ve proven it to myself many times.
        So many of our foods that were traditionally fermented and replete with beneficial microbes and prebiotics are now processed with cheap shortcuts, pasteurized so they are shelf stable if they actually are fermented, chemicalized (if that’s even a word) to smithereens, and a pale shadow of what so many cultures still enjoy. Here in the US you either have to pay a fortune for the real thing or…you make it yourself easily for next to nothing, just a little time. But I think if you managed to read this novella, you definitely get the not so subtle enthusiasm I’ve developed for doing so!
        As for religion, without blowing up the board here, I totally agree that it is responsible for more divisive wars, death and suffering over the ages than any other single factor. One does not need the dogmatic programming of religion to be a decent, moral, human, and in fact the people I’ve come to respect the most for their character, have no affiliations. I was born into the “club”, but much to the horror of my mom, I regularly got kicked out of catechism for not assimilating the agenda and asking too many questions. I guess I’d consider myself an agnostic, because as a mere mortal I know I don’t have the capacity to deny, nor comprehend the forces and principles that govern and power the miraculous experience we call life.

        • HaltheVegan

          Charzie, with your knowledge and passion for fermenting, I think you’re ripe for starting a small Internet business … recipes for new fermenting techniques, starter cultures, etc. Who knows, it could grow into something really big :-)

          • Charzie

            Thanks Hal, I could sure use the cash, but I am so not business savvy or organized! I am working on a blog though…and can’t even get that off the ground! LOL

        • Lawrence

          Charzie, my heart tells me that you are a dear, sweet lady. I wish for you every kindness and good fortune that life has to offer.

          • Charzie

            Thank you so much, you are a kind heart!

    • Julie

      I totally agree with you, Charzie; fermented foods and health go hand in hand.

    • Panchito

      I have to say that hearing the name Sally Fallon in the linked video made me shudder. Just google her picture to see how diet advices can go wrong. She is the guru impersonation of total unhealthiness.

  • Wendy

    I watched it and found it interesting, I just don’t know what I am supposed to do with the information.

  • Matthew Smith

    For almost one year I ate only cornflakes, skim milk, and white rice, and juicy juice on Fridays and Saturdays. I was younger then. It was a very Spartan diet. They no longer make Total Cornflakes, which I loved. I think the vegan diet is very Spartan too. I would like to thank you for this website. It has let me live a more disease free life. I am a more sinful and indulgent man now, but I would commend any fasting that I do as a result of this diet to the temple.

    • Matthew Smith

      Is that what you eat on the Esselstyn diet?

    • Fred

      In my younger days I subsisted on a diet of rice and canned soup with occasional forays in to mac and cheese and spagetti mixes. I was cheap and I was stupid? This was for years at a time….

      Does remind me of the “rice diet” (?) that a doctor uses to cure whatever though.

      • Matthew Smith

        You are very abstemious. Thank you for sharing this. May eating less glamorous foods, as people do here, bless their religions or the religions that hold them.

    • Joe Caner

      Before adopting it, I had thought of a vegan diet as a one of depravation because it eliminated a whole category of foods from the menu, foods of animal origin. The beef, pork, chicken, dairy, eggs, lamb, turkey, fish, mollusks, crustaceans, game etc. that had featured so prominently banished from my plate.
      I was surprised that my diet become more varied on a vegan diet, not less because I replaced meat with with many different vegetables, grains and fruits.

      • Matthew Smith

        I love plants. I studied plants. I would love to be a researcher or expert in the Passionflowers, aroids, asclepiads, orchids, and birthworts. I like to go to the garden as much as possible and I like to garden. You would have to really love plants to be a Vegan. I like to think about biogeography and why plants grow where they do. I am interested in what plants say about the ice age we are in, as they display evidence of a recent large disturbance. It is possible an asteroid struck the Rocky Mountains around Yosemite creating the ice age we are in, and causing the extinction of the megafauna and many kinds of plants. The Earth before this incident was probably a giant grassland. Or perhaps it was a giant Sequoia forest, with only a small patch of rainforest in the high Chilean Andes. In America, we grow corn, soy, and pork. What does that say about us? How is this a part of our life? I think plants are a big part of our country, and we ignore it at our peril, celebrations of corn and soy and pork are probably all around us. Eating a diversity of plants is probably very good for you, as is eating a diversity of plants from a variety of places on the planet. Plants are probably very good for our genes. Plants grown on ideal soils probably provide everything needed for health. To be a vegan anybody would have to identify at least a couple of plants. Identifying plants is a valuable skill that makes the whole world a richer place. Did you know that 90 percent of the worlds world comes from grasses? Fifty percent from corn, wheat, and rice, and forty more percent from barley, oats, rye, sorghum, millet, and others. Only potatoes are a majority source of food that does not come from grass. We know very little about grass. In some parts of the world to eat literally means to eat rice. What does grain not add to the diet that vegetables and fruit do? What are root crops good for? What about nuts and seeds? Even leafy vegetables? How could the world provide for a diversity of plants to eat? I like to learn about plants by studying the plants I eat.

  • ali

    so does this say we should eat diff, mix it up or what ?

    • Tom Goff

      It argues that if you want to reduce your risk of colon cancer then you should aim to have mainly Prevotella species in your gut. This can be achieved by eating like native Africans rather than African Americans – ie eat a mainly plant based diet and avoid or minimise animal foods.

  • vegank

    Is there a source where we can find a list of food / prebiotics that is free of commercial agenda?

  • Delrumple

    Does anyone know if it is the factory meat sold to citizens that is responsible for the type of Microbiome Enterotype in the majority US citizens?

    I know antibiotics and steroids are a staple in the diet of most all the animals used in our meat industry, and they are fed grains (Beef) and other foods that are not in their natural diet. Almost all processed meats are Sausage, Bacon & ham and other prepared meats contain Sulphites which have attributed to increasing your chance of Colon cancer by 10%. While the video was interesting, I found it raised a lot of questions.

  • Rhombopterix

    I’ve searched the site for info on FODMAPs but found little. Are there others here trying to get a handle on this?

    • Rhombopterix

      Yes, I certainly wish to understand why some people, like my wife, have horrible consequences when some of this stuff hits her nether regions. We’ve worked through a long process of elimnation and add back one at a time…we have learned the legume is the worst. Really bad, not the usual complaint about flatulence…but major pain, IBS like symptoms, fatigue, nausea, errrm…leakage. Just misery. I hate that she cant get the good nutrition that comes from beans. We tried beano but that only helped a little.

      I kept pushing the wfpb diet and she kept getting sicker. Now, without beans but still eating WFPB she is much better…but still sick. I would like to amp up her butyrate levels but she eats a lot of fiber already. Grean leafys, buckwheat, millet, potato and steamed veg. thats pretty much her daily diet. Where’s Darryl? What happened to the scientists that used to be here? and Boomer …you know. Wheres the Seitan (remeber that hamburger commerical)? i mean is there any science on FODMAPs that guides peoples choices?


  • Vegan Taxonomist

    Dr. Greger missed the most interesting results from this article pertinent to whole foods plant-based eaters. The heat map in Fig. 1 (and the more detailed supplementary Fig S1) has TWO distinct clusters of nutrients that come from plants: Cluster 1) carbohydrates that can come from either whole or refined plant foods and cluster 2) fiber, folate, magnesium potassium, oxalic acid, phytic acid, etc. that are supplied only by whole plant foods. The genus Prevotella is correlated only with the first (according to Figure S1, only the glycemic load of the diet is statistically significant). Abundance of Prevotella is actually significantly negatively correlated with magnesium and insoluble dietary fiber (Fig. S1), suggesting that in this population (98 North Americans), high abundance of Prevotella is a marker of high ingestion of refined carbohydrates.Instead, other bacterial taxa are significantly correlated with whole plant food nutrients (cluster 2): phylum Proteobacteria, genus Betaproteobacteria and phylum Firmicutes, genera Roseburia and Butrycicoccus (Fig. S1).
    The separation of the population into two enterotypes seems to be driven by the absence of Prevotella from the microbiome of 67 of the 98 subjects. In those 31 subjects that had bothe Prevotella and Bacteriodes, there is a continuous distribution of abundance ratios between the two genera (Fig. S5). So Prevotella and Bacteriodes are NOT like chimpanzees and dolphins, they CAN and DO co-occur within the same gut in any ratio. As the authors state (Fig. S5 legend) “The clear gradient across the enterotype boundary emphasizes that the boundary is not sharply defined.”

    • Vegan Taxonomist

      I suspect the whole concept of “enterotypes” is based on under-sampling and clustering analyses that give too much weight to abundant taxa. See Knights et al (2014) doi:10.1016/j.chom.2014.09.013

      • Tom Goff
      • largelytrue

        I agree that there are huge pitfalls in research on gut flora. This stuff is trending currently because determining the relative amount of genetic sequences is getting really cheap, but the field is hugely complex and the temptation to oversimplify is always there. In other words, I’m inclined to say that one should expect that some of the hypotheses based on loose correlations and unspecific mechanisms will be overturned quite rapidly.

        I think that the concept of “enterotypes” may be a hasty reification by many (e.g. what’s clustering in the actual causal pathway?), but I’m not sure that clustering analyses typically give excessive weight to abundant taxa. The study of Greger’s that you are discussing looks like it essentially ignores the average abundance of taxa when weighting its clustering score in the method shown for figure 2.

        Nor do I think that giving roughly proportionate weight to abundant taxa is going to be that flawed, at least not as a first crack at the problem in the absence of other data. The more abundant a taxon is, the greater the effect it will have on the gut environment, all else being equal or equally unknown. Also, the data on very rare taxa are more likely to be suspect due to potential contamination.

        I haven’t already investigated this matter deeply myself, so I’d be interested if you could be more specific about what “excessive weight” to abundant taxa would look like in statistical terms and where you think it has been found.

        But again, I second your point that Bacteroides and Provetella can co-occur, and would add that it’s unreasonable to suppose that all Bacteroides are equally harmful just because of a course preliminary association. That’s not what was found in Greger’s citation on the harmful associations between bacteria in this genus and colorectal cancer rates.

        My rhetorical question is important, I think: what’s clustering, at what point in the mechanistic pathway? The SAD diet in its stereotypical form could be extreme enough to kill off a marker genus like Prevotella, but a sample based on more moderate forms of the diet could emphasize those points in the gray area between clusters from the prior analysis, showing no pattern of clustering. The outcome of clustering depends on the underlying distribution of causal factors, even when the underlying causal model is fixed. To see that discrete enterotypes are ‘real’ in-and-of themselves I’d want to see that even when the distribution of diets in the sample has no natural clustering, relatively discrete clusters are produced.

        That said, we should expect there to be some roughly discrete boundaries at some scale of resolution because the population density of an organism tends to respond to chemical inputs that are relevant to survival with an s-shaped curve. And even if apparently discrete enterotypes were due only to discrete clustering in the diet of a population, enterotypes would still be a useful model for discussing dietary behavior with that population, because they reflect the response to discrete dietary patterns within that population’s cultural practices. We could even distort our sampling in this case, to emphasize plausible practices that are not popular, but which science suggests should maybe be more popular. That is, noticing relatively sharp, clustery distinctions between the flora of WFPB vegans and people on a Prudent American diet would be useful, even if our sampling were totally unreflective of the rates at which these diets are practiced by the population.

  • sebastianlundh

    Good day Dr. Greger!

    I have a question regarding a study I read about recently, called “Diets supplemented with chickpea or its main oligosaccharide component raffinose modify faecal microbial composition in healthy adults.”; it says that a diet high in chickpeas didn’t result in more SCFA than the control diet, which worries me as I consume chickpeas daily to decrease my inflammation. Could you please tell me what you think about the study, and whether or not I should consume something else instead?

    Thank you!

  • How are sales of your wonderful book? We keep learning after 3+ years of daily visits to your site!

  • M. Burghart

    My findings have been that some people may have such a large amount of these cause excessive and chronic flatulence leaving the client/patient in a state of daily embarrassement. If a person has had severe diarrhea and abdominal issues thru their entire existence with a surmountable amount of pinworms and such, should we conclude that the client’s microbiome is also at risk for colon or stomach cancer? how can plant based diet actually help eliminate those parasites? thank you

  • Vegan4health

    I am dying to know where coconut oil fits in here. It is a confusing substance being both plant based and saturated.

    • Thea

      Vegan4health: NutritionFacts has covered coconut oil. The bottom line is that it is one of the plant foods that are not overall healthy, due in part as you say to the high saturated fat content.

      I’ll also point out that any pure/processed oil, whether coconut or otherwise would generally be devoid of all the good things that come with whole foods – like fiber, lots of phytonutrients, etc. So, it’s a general good rule of thumb to minimize any type of oil.

  • dr. jason buffington

    Dr Greger, I got my results from the American Gut Project showing my microbiome is 24.9% prevotella and only 8.1% Bacteroides, which I was happy with, being WFPB, but my Ruminococcaceae was 13.4%. Per the 2011 paper you referenced, it placed Rumino’s in with the Bacteroides, which would then mean I’m equal Prevotella and Bactereroides, confusing being WFPB?? But in my own research, I found a 2013 paper stating Lachnospiracaea (mine was 10.1%)and Rumino’s are highly specialized at breaking down complex plant matter, seems they should be grouped with the Prevotella? In that case, my ‘good’ are 48% vs 8% bacteroides, seems more logical. attached is my reference. thoughts??

  • Here are some new estimates on microbiome numbers. A ‘reference man’ (one who is 70 kilograms, 20–30 years old and 1.7
    metres tall) contains on average about 30 trillion human cells and 39
    trillion bacteria, say Ron Milo and Ron Sender at the Weizmann Institute
    of Science in Rehovot, Israel, and Shai Fuchs at the Hospital for Sick
    Children in Toronto, Canada. Their paper is currently under review at Nature.

  • Fernando Romero

    Hi doc, thank you so much for taking the time to inform. You are one of the reasons why we have continued to be vegan for as long as we have. Your research let’s us know we made the right choice.
    I know you have touched on the subject in other videos but I was hoping you can make one dedicated solely to ulcerative colitis. Not only stating why the vegan diet is the right choice but which foods within the vegan diet may be more helpful than others and which to stay away from. Thanks

  • Annetha

    Soon to be published in PNAS, research by Shuai Liu (U Calgary) links
    consumption of fatty, sweetened food to over-eating–changing mouse
    synapses at least. The effect is quick and lasts about a week–perhaps yet another way that the human body is prepared to take advantage of rich food–all too rare in ancestral conditions, but not when groceries stock paczki for a month and not just Fat Tuesday. :-(

  • vanrein

    This makes me wonder what happens to cattle or farmed fish that is fed with ground-up bones, fish meal and other protein-rich animal waste. Do such animals also change their enterotype, are they relatively ill due to it, and more filled with unhealthy nutrition (like cholesterol?) You’d almost think that the paleo thing for “lean, grass-fed beef” is on to something.

  • Hendrik

    According to a new study, some gut bacteria make it into our blood, where they can cause an inflammatory response, see the link at:-

    This gives another causal link between our gut microbiome, and some lifestyle diseases.