Do probiotics actually do anything
Probiotics, manufactured mixtures of "good bacteria" that help digest food, have become a growing multibillion-dollar industry. But do they work?
There is an invisible universe hidden inside your body, it’s called the gut microbiome — a vast array of trillions of intestinal bacteria, hundreds of different species. They help digest your food in exchange for a warm, safe place to live. And we are only now starting to discover the gut microbiome plays a much larger role in our lives than we ever imagined.
Some of those bacteria found inside us are replicated in commercially manufactured mixtures called “probiotics.” You see them on grocery and pharmacy shelves, and they’re recommended by your friends and often, by doctors like me.
But do probiotics actually do anything? To find out, first you need to know about the gut microbiome.
Dr. Jeff Gordon: This is a snapshot of the microbiome.
Dr. Jon LaPook: And then this is the trillions of bacteria there. They’re represented by the different colors.
Dr. Jeff Gordon at Washington University in St. Louis is recognized as “the father of the microbiome.” He has spent decades exploring the mysteries of the bacterial community in our gut.
Dr. Jeff Gordon: It’s a collection of microbes that are able to coexist with us in ways that still are unclear.
Dr. Jon LaPook: Why are they there in the first place?
Dr. Jeff Gordon: They help process the food that we consume, but they do a lot more than that. They make Vitamins. We think about vitamins as only being in food. they’re able to produce essential amino acids, they’re able to talk to our immune system and help educate the immune system.
Dr. Jon LaPook: That’s different than I think the way a lotta people think about the intestinal track. It’s sorta like a tube, and the food comes in and it goes out, and that’s it. But you’re saying there’s much more of an interaction?
Dr. Jeff Gordon: We’re coming to understand that much more clearly. and this capacity to process– the food that we consume is linked to our health as well as our disease states.
Research suggests a healthy microbiome may reduce the risk of diseases like cancer and diabetes. And in a landmark experiment, Dr. Gordon and his team made a lean mouse fatter by giving it the bacteria of a fat mouse.
Dr. Jon LaPook: Are you saying that part of the cause of obesity might be the types of bacteria that are in the gut, in the microbiome?
Dr. Jeff Gordon: I am saying that. And we see that individuals who are obese have a less diverse microbial community compared to individuals who are lean.
Dr. Jon LaPook: Is there evidence that you could take the microbiome that’s associated with a lean person, transfer it to somebody who’s overweight, and it might somehow help them to become thinner?
Dr. Jeff Gordon: There’s a lot of work– going on right now, trying to test that hypothesis.
Right now, the microbiome is an area of hot research. Doctors are already treating illness by manipulating gut bacteria. A potentially life-threatening infection of the colon called C. Diff. has been successfully treated by moving bacteria from the gut of a healthy person to the gut of somebody who’s sick.
And millions of people are trying to improve their microbiomes themselves using probiotics, so-called “good bacteria.” But here’s the problem: there’s a lot of conflict among scientists about whether probiotics provide any benefit at all.
Dr. Patricia Hibberd: Over the years there have been so many studies of various probiotics saying “it’s good for this.” The next study says, “it’s not good for this.” And truly, it’s chaos.
Dr. Patricia Hibberd is an infectious disease specialist and a professor of medicine at boston university.
Dr. Hibberd has reviewed hundreds of studies in the medical literature about probiotics. She has also done her own studies and told us there’s not enough high quality research to recommend off-the-shelf probiotics for the medical problems for which they’re commonly used.
Dr. Patricia Hibberd: The whole idea that maybe throwing in good bacteria that we would take by mouth that hopefully would land in the right places in the GI tract and work with the immune system. We just don’t know how to do any of that.
Dr. Jon LaPook: But right now, there is a multi-billion dollar industry that’s growing.
Dr. Patricia Hibberd: Yes.
Dr. Jon LaPook: And people are out there buying this stuff.
Dr. Patricia Hibberd: Right.
Dr. Jon LaPook: So, is there convincing evidence that commercially available probiotics have been found to be beneficial for reducing diarrhea from antibiotics?
Dr. Patricia Hibberd: No.
Dr. Jon LaPook: Treating irritable bowel syndrome?
Dr. Patricia Hibberd: No.
Dr. Jon LaPook: Decreasing allergies?
Dr. Patricia Hibberd: No.
But probiotics are suggested as a remedy for all those things… and more.
Your digestive system has billions of bacteria. But life can throw them off balance.
Restoring that balance of bacteria in the gut microbiome is just one goal touted by makers of probiotics, a $50 billion global industry sold to us in capsules, popsicles, cereal, tea and some yogurt. And we’re told probiotics can even help your dog.
Many physicians and patients believe probiotics are worth trying, and many believe they work.
One of those physicians is Dr. Dan Merenstein. He’s a professor of family medicine at Georgetown University. And he’s on the board of a non-profit, industry-financed group that promotes probiotic science.
Dr. Merenstein is doing a clinical trial backed by the National Institutes of Health testing a probiotic cocktail. He’s trying to see if it can prevent diarrhea in children taking antibiotics, a remedy other researchers have tried with mixed results.
Dr. Dan Merenstein: I think the data is there. I recommend probiotics mainly for people who are on antibiotics and for people with irritable bowel disease.
Dr. Jon LaPook: I wonder what our viewers are thinking right now, right? They’re hearing you saying, it definitely helps, probiotics and others are saying, there’s no good evidence that it helps. Are they throwing a brick through the television screen just about now?
Dr. Dan Merenstein: …they are but they have been throwing a brick, you know, for the last 20 years when we tell them everyone needs Vitamin D, and everyone needs, you know, Echinacea for colds, or zinc for colds. I think it’s difficult to be a consumer because things change so quickly. But I think we need more probiotic research.
Read full interview.