Preventing the Common Cold with Probiotics?

· ·
4.6/5 - (44 votes)

Though prebiotics may be preferable, probiotics may reduce the risk of upper respiratory tract infections.

Discuss
Republish

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

Babies delivered via Caesarean section appear to be at increased increase for various allergic diseases. The thought is that “[v]aginal delivery leads to the first colonization of the gut with maternal vaginal bacteria, while c-section babies are deprived of this natural exposure, and exhibit a different gut flora.” This is supported by research noting that a disturbance in maternal vaginal flora during pregnancy may be associated with early asthma in their children. This all suggests our natural gut flora can affect the development of our immune system for better, or for worse.

In adulthood, two studies published back in 2001 suggested that probiotics could have “systemic immunity-enhancing effects.” Subjects were given a probiotic regimen between weeks three to six, and saw a significant boost in the ability of their white blood cells to chomp down on potential invaders. And, what’s interesting is that even after the probiotics were stopped, there was still enhanced immune function a few weeks later, compared to baseline. The same boost was found in the ability of their natural killer cells to kill cancer cells. And, similar results were also found using a different probiotic strain.

Now, improving immune cell function in a petri dish is nice, but does this actually translate into people having fewer infections? For that, we had to wait another ten years. But, now we have randomized, double-blind, placebo-controlled studies showing that those taking probiotics may have significantly fewer colds, fewer sick days, and fewer symptoms.

The latest review of the best studies to date found that probiotics, such as those in yogurt, soy yogurt, or supplements, may indeed reduce one’s risk of upper respiratory tract infection. But, the totality of evidence is still considered weak, so it’s probably too early to make a blanket recommendation.

Unless one has suffered a major disruption of gut flora by antibiotics, or an intestinal infection—unless one is symptomatic—with, like, diarrhea, or bloating, I would suggest focusing on feeding the good bacteria we already have—by eating so-called prebiotics, such as fiber.

After all, as we saw before, who knows what you’re getting when you buy probiotics? They may not even be alive by the time you buy them. They also have to survive the journey down to the large intestine. Altogether, these points suggest that the advantages of prebiotics—found in plant foods—outweigh those of probiotics.

And, by eating raw fruits and vegetables, we may be getting both. Fruits and vegetables are covered with millions of lactic acid bacteria, some of which are the same type used as probiotics. So, when studies show eating more fruits and vegetables boosts immunity, prebiotics and probiotics may both be playing a role.

Please consider volunteering to help out on the site.

Images thanks to Sofa-King and William Brawley via flickr

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

Babies delivered via Caesarean section appear to be at increased increase for various allergic diseases. The thought is that “[v]aginal delivery leads to the first colonization of the gut with maternal vaginal bacteria, while c-section babies are deprived of this natural exposure, and exhibit a different gut flora.” This is supported by research noting that a disturbance in maternal vaginal flora during pregnancy may be associated with early asthma in their children. This all suggests our natural gut flora can affect the development of our immune system for better, or for worse.

In adulthood, two studies published back in 2001 suggested that probiotics could have “systemic immunity-enhancing effects.” Subjects were given a probiotic regimen between weeks three to six, and saw a significant boost in the ability of their white blood cells to chomp down on potential invaders. And, what’s interesting is that even after the probiotics were stopped, there was still enhanced immune function a few weeks later, compared to baseline. The same boost was found in the ability of their natural killer cells to kill cancer cells. And, similar results were also found using a different probiotic strain.

Now, improving immune cell function in a petri dish is nice, but does this actually translate into people having fewer infections? For that, we had to wait another ten years. But, now we have randomized, double-blind, placebo-controlled studies showing that those taking probiotics may have significantly fewer colds, fewer sick days, and fewer symptoms.

The latest review of the best studies to date found that probiotics, such as those in yogurt, soy yogurt, or supplements, may indeed reduce one’s risk of upper respiratory tract infection. But, the totality of evidence is still considered weak, so it’s probably too early to make a blanket recommendation.

Unless one has suffered a major disruption of gut flora by antibiotics, or an intestinal infection—unless one is symptomatic—with, like, diarrhea, or bloating, I would suggest focusing on feeding the good bacteria we already have—by eating so-called prebiotics, such as fiber.

After all, as we saw before, who knows what you’re getting when you buy probiotics? They may not even be alive by the time you buy them. They also have to survive the journey down to the large intestine. Altogether, these points suggest that the advantages of prebiotics—found in plant foods—outweigh those of probiotics.

And, by eating raw fruits and vegetables, we may be getting both. Fruits and vegetables are covered with millions of lactic acid bacteria, some of which are the same type used as probiotics. So, when studies show eating more fruits and vegetables boosts immunity, prebiotics and probiotics may both be playing a role.

Please consider volunteering to help out on the site.

Images thanks to Sofa-King and William Brawley via flickr

Doctor's Note

Probiotics do play an established role in helping to prevent antibiotic-associated diarrhea, and may speed recovery from acute gastroenteritis; see Preventing & Treating Diarrhea with Probiotics. When should they be taken? That’s the subject of Should Probiotics Be Taken Before, During, or After Meals? 

Update: In 2017, I released a new video on probiotics. See: Culture Shock – Questioning the Efficacy and Safety of Probiotics. 

How else might we reduce our risk of getting an upper respiratory infection? See:

You can watch a video of white blood cells actually chomping down on foreign invaders in Clinical Studies on Açaí Berries. A must-see for biology geeks!

See all of my videos on the common cold on the topic page.

The immune-boosting fruit and vegetable video I reference is Boosting Immunity Through Diet. See also Kale & the Immune System, and Boosting Immunity while Reducing Inflammation.

For further context, check out my associated blog posts: Probiotics & Diarrhea; Probiotics During Cold Season?; How Should I Take Probiotics?; How Probiotics Affect Mental Health; and Top 10 Most Popular Videos of 2013.

What are The Benefits and Side Effects of Probiotic Supplements? Check out the video.

If you haven't yet, you can subscribe to our free newsletter. With your subscription, you'll also get notifications for just-released blogs and videos. Check out our information page about our translated resources.

Subscribe to our free newsletter and receive the Purple Sweet Potato Longevity Smoothie recipe from How Not to Age.

Previous Video

Preventing & Treating Diarrhea with Probiotics

Next Video

Should Probiotics Be Taken Before, During, or After Meals?

Pin It on Pinterest

Share This