Doctor's Note

Check out these videos on gut bacteria:
Stool pH and Colon Cancer
Gut Feelings: Probiotics and Mental Health
Preventing Ulcerative Colitis with Diet
Carnitine, Choline, Cancer and Cholesterol: The TMAO Connection
The Leaky Gut Theory of Why Animal Products Cause Inflammation

And check out my other videos on weight loss

For some context, please check out my associated blog posts: Boosting Gut Flora Without Probiotics and How Probiotics Affect Mental Health.

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.

  • Michael Greger M.D.

    Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out the other videos on weight loss. Also, there are 1,449 other subjects covered in the rest of my videos–please feel free to explore them as well!

  • 2RHealth

    For vegans who don’t eat yogurt, what is a good source for probiotics? Probably not Kimchi, as you noted its harmful effects in another video!

    • Michael Greger M.D.

      Commercial yogurt of any kind (soy, rice, cow, or coconut) is an insufficient source of the level of probiotic bacteria found effective in treating diarrheal illnesses, inflammatory bowel disease, and irritable bowel syndrome. A plant-based diet appears to naturally modulate one’s gut flora, but if you need to bring out the big guns for therapeutic usage or to repopulate your gut after a round of antibiotics, allow me to refer you to the advice of one of my medical mentors, Dr. Michael Klaper, who has some great probiotic tips and insight.

      • Art

        Thanks for all of your information. But I was wondering, what about kefir grains? There are milk kefir grains and also water kefir grains used to ferment beverages. And do you know of any reliable comparison of yogurt and kefir, such as how many organisms are found in homemade yogurt and kefir? Thanks again.

  • Carl B. Nelson

    Dr. Greger, many thanks for your fine, concise, science based videos on so many subjects. My wife is battling stage 4 breast cancer. Due to the experience we’ve had I decided to put together a blog ( to share resources I found that have helped my wife to save others from some of the distress we’ve experienced. Many of your videos dealing with cancer are posted on my blog.

    Here’s my question: I’ve probably heard over a hundred times people recommending the fruit and a tea (made from the leaves) of the soursop fruit tree. The common phrase is that it’s “10,000 times more powerful than chemo” (it’s even on YouTube). There’s clearly a bucket of hyperbole in that statement but I’m wondering if the sheer volume of people that place such faith in this magical fruit indicate that there’s at least some truth to the legends. Have you heard of any studies that shed some light of science on this legend? I’d appreciate your help in evaluating if it would be worth including this fruit (and tea from its leaves) in my wifes cancer management treatment plan.

    We are following predominately the integrative treatment system advocated by Dr. Keith Block (author of Life Over Cancer).

  • Nicole Lucas Haimes

    Can you please help guide me for what are the best sources of probiotics? Pills, yoghurt, Kefir? It would be valuable to know this, short of going for a fecal transplant. Thanks!

    • Nicole Lucas Haimes

      P.S. I love your posts, and appreciate your hard work and service. Thank you for all you do!

  • David

    Among Dr. Greger’s Greatest Hits:

    2003: About time for an updated version/Eh Dr. Greger?

    THANK YOU DR. GREGER: Devotee/7:00 Central/Weedays/Every Week/for past several years

    The David

  • M

    I’m posting here because I don’t know where else to go. I don’t have any plant based doctors in my area and I’m really struggling with the effects of this diet. I just can’t seem to lose any weight. I’m almost 30 years old, 5’8, 145lbs and I’ve been vegan for almost a year now. I’m being honest when I say that I’ve been eating as clean as possible this past year. High carb, low fat, lots of fruits/vegetables/whole grains, minimal processed food and oil (maybe 1-2 times a month), 1800-2000cals a day. I do 1 hour of yoga every day and 30-40 minutes of cardio 4 times a week. I haven’t lost a single pound. It’s really frustrating to be eating the healthiest diet on the planet and consistently working out without seeing any physical changes. I’ve also had a lot of stomach issues (gas, intense bloating, constipation which is crazy considering all the fiber I eat, etc.)

    My mom, who went vegan a couple of months after I did, has GAINED 40lbs. She’s in her early 50s, has never been overweight, and she walks/climbs stairs daily. I know this sounds crazy and it is! We are both so, so frustrated. I’ve read How Not to Die, I’ve read The Starch Solution. I don’t know what we’re doing wrong but it’s so discouraging. Not to mention really difficult to promote plant based eating when you’re gaining weight or unable to lose it. People are always commenting about my mom’s weight and telling her to go back to eating meat (which will never happen because we are both ethical vegans!) We’ve tried cutting out smoothies, cutting down on calories, eating more vegetables than carbs but nothing seems to work.

    I so want to be one of those people who magically loses 20 pounds on this diet but it’s just not happening. ANY suggestions or help would be greatly appreciated. Especially for my mom who has ALWAYS been slim, this has been a huge shock for her physically and emotionally.

    • san

      You are 65 kg’s?. Thats not fat , wtf lol

    • san

      Oh and do you have a lot of stress in your life?. Seems like it, an unhealthy obsession with weight loss, maybe also other areas of stress I dont know?. Stress makes it very hard to lose weight

  • Stefanie

    I had problems with my stomach so a naturepath recommended a stool test. And I had “bad” bacteria in them. They recommended probiotics to me and I took them. After I used all of the package I stopped taking them. And it started again after a while. Even though I was vegan for a while back then. So my doctor again (without testing my stool again) said to me I should take them again. I bought them and now I take half a package each day. But then I was afraid my stomach might rely on the bacteria instead of creating them itself. So I take them every 2 – 3 days. How long should I keep taking them? I hit a weight plateau for months now and I try to think of every little thing that might cause this.