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The Link Between Gut Bacteria and Common Diseases

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The Link Between Gut Bacteria and Common Diseases

Oct 28, 2014

Once thought to only help digest food, the microbiome plays a role in a host of processes. Dr. Kathleen Boynton specializes in research to discover how these microorganisms that inhabit our bodies affect other systems. She discusses probiotics, immune response, and what can happen when our microbiome is disrupted or leaks into other parts of our body.

Episode Transcript

Dr. Miller: Bacteria that live with us in our gut, the microbiome. We're going to talk about that next on Scope Radio.

Announcer: Medical news and research from University of Utah physicians and specialists you can use for a happier and healthier life. You're listening to The Scope.

Dr. Miller: Hi. I'm here with Dr. Kathleen Boynton. She is a professor in the department of medicine, and she is a specialist in gastroenterology, diseases of the gut.
We're here today to talk about the microbiome. Kathleen, tell us about the microbiome. My understanding is that we have billions and billions of bacteria living with us, and we need them to live with us as they need us. We work in a symbiotic relationship, and when those become disturbed and the relationship between the bacteria that live normally in our gut is disturbed, that can create problems.

Dr. Boynton: Yeah, this is sort of the topic where I think where do I start with the story. We've known for a long period of time that we have bacteria in our gut. It was traditionally thought that these bacteria just helped with the breakdown of food and that they prevented more damaging bacteria from inhabiting the gut. Currently, we recognize that they do so much more. They train our immune system how to react to infection throughout the body.

Dr. Miller: So, it's not just that these bacteria create that unsavory gas that everybody talks about.

Dr. Boynton: That's right.

Dr. Miller: There's a lot more to it than that.

Dr. Boynton: Yes. They can produce a whole host of chemicals that may work in our best interest or may lead to most of the common diseases that we're seeing in our clinics these days.

Dr. Miller: We've adapted to bacteria as they have to us for millions of years. I mean they're in all animal guts. Some of our listeners might think that bacteria in our colon seems strange. In fact, that's quite normal. What is abnormal is a change in the concentration of this bacteria or introduction of other pathogenic or disease causing bacteria into that biome. Would that be right?

Dr. Boynton: That's correct.

Dr. Miller: Your area of study seems to be much more focused on new ideas about the microbiome and what that's doing for us. When that's disturbed, there could be far reaching problems that are related. Maybe you could talk about that a little bit.

Dr. Boynton: Yes. That's exactly correct. What is so surprising to us is that a disruption or disturbance in the microbiome can literally create diseases that are remote from the gut. There are studies on diabetes that talk about it's associated with a disturbance in the microbiome, or autism, or Parkinson's. Traditionally, we had thought that those were two independent organs that never spoke to each other.

Dr. Miller: These are concepts that we still need to prove, right, those associations...

Dr. Boynton: That is correct, yes.

Dr. Miller: ...epidemiologic or population based associations. I would suspect that there's still work that needs to be done in that area.

Dr. Boynton: Oh, much work that needs to be done. The fundamental issues are not even addressed. We don't know what those bacteria are. We don't know how many of them have any role in our health and well being. As general concepts, we can determine that some people have a reduction in the diversity of the bacteria, and that that is definitely associated with a lot of the diseases that we study in the gut and outside the gut.

Dr. Miller: Irritable bowel is a problem for a lot of people. I know you deal with that in your practice. Is there an association between abnormalities in the microbiome and irritable bowel disease that we know about, or is that still too early to say?

Dr. Boynton: Probably the biggest association we've identified is with inflammatory bowel disease. In that case, your immune system is attacking the bacteria. The bacteria lies on the surface of the intestine. Those patients get inflammation.
Recently, there has been identification of a gene marker, that means a genetic malfunction, in patients who have irritable bowel. That's different than inflammatory bowel. Those patients have a disturbance in their microbiome coupled with the fact that they have leakiness in the gut, which means all those chemicals made by this abnormal microbiome have the ability to leak out of the gut and travel around and cause a lot of uncomfortable associations for IBS patients.

Dr. Miller: Some of the patients that I see will come in asking about leaky gut. Is that related to an abnormality in the microbiome? Can you talk about that a little bit for folks that are listening.

Dr. Boynton: Yes. We don't know a lot about leaky gut, because it's a brand new phenomenon. We know it exists. We know that in concept our gut should be what we call impenetrable, meaning that it doesn't allow chemicals that are made in the gut to escape and get to the rest of the body.
We also have realized that common things we do in our culture, for instance taking an aspirin or a non-steroidal, can lead to this leakiness. All the sudden the foods you eat may get into your bloodstream, or the chemicals made by your microbiome. In association to that, we've noticed that some of the chemicals that are made by the microbiome have the ability to create the symptoms that are part of irritable bowel.

Dr. Miller: For folks that are listening, what should they take home from this? Should they be thinking about taking probiotics? Is that something that patients should do to keep their microbiome health, or are we not yet at that stage where we can say?

Dr. Boynton: We have a lot of pieces. We think we can put them together. We think it makes sense. But, there are so many fundamental aspects that we still don't know. We don't know what the critical bacteria are in terms of each of these diseases. We don't know when they're in the pill form and you swallow them, do they even make it out of the stomach, or does the acid break it down. The companies that are producing probiotics are right in the sense that we think there is a future for probiotics, but we don't know which ones and in what format.

Dr. Miller: Still a lot of work to be done.

Dr. Boynton: A lot.

Dr. Miller: It sounds like the microbiome, if I think about it simplistically, is a nice coating in the gut to protect the lining so that barrier remains permeable only to certain things that get into our system that we need and keeps a lot of perhaps bad things, pathogens and toxins, out. Without that bacteria layer which primarily resides in the colon, we could be in trouble.

Dr. Boynton: Absolutely. In addition, the microbiome helps us absorb our calories, and probably most importantly to people who have immune related diseases, it trains our immune system. It teaches the immune system this is something that's called a pathogen, meaning a bad thing, I have to destroy it, versus this is part of my body, I need to ignore it. It may be that defects in this training process are what lead to immune related diseases. It doesn't figure out the distinction.

Dr. Miller: To wrap it up, it sounds like the microbiome is extremely important. We've known that for a long time. How we can help maintain a healthy microbiome, there remains work to be done, and future research is underway.

Dr. Boynton: That's correct.

Dr. Miller: Thank you very much.

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