Low FODMAP Diets for Gut Health?

Low FODMAP Diets for Gut Health?

Producer Potts  0:08  

The low FODMAP diet seems to be gaining traction again as a solution for a slew of gut health issues. What are low FODMAPs and are there any benefits or harm in avoiding them long term as a dietary template?

Dr. Sarah  0:30  

interesting that they’re gaining in popularity. So FODMAPs are a class of carbohydrates, mainly types of fiber that are highly fermentable. So FODMAP actually stands for fermentable oligosaccharide, disaccharide, monosaccharide and polyols, which are like sugar alcohols. So the thing they have in common is they tend to have a lot of fructose in them. They tend to be great food for our gut bacteria, and they’re really like high fermentability, meaning our gut bacteria can use them as food and produce things like gas and short chain fatty acids as a result of their metabolism. It’s the high bacterial activity and the products of that bacterial activity that’s actually responsible for symptoms that look like irritable bowel syndrome, so symptoms that people find are sometimes alleviated by a low FODMAP diet would include gas, bloating, diarrhea, constipation, excess flatulence, belching, which is the technical term for when your stomach makes rumbling noises, which is my fun fact of the day. So all of those symptoms can be helped by a low FODMAP diet. The challenge is, there’s quite a few studies, actually, even you know, quite recent studies, like done over the last five to 10 years that have shown that low FODMAP diets actually cause undesirable shifts in the gut microbiome, both in healthy like controls for these studies, as well as people with irritable bowel syndrome. So it’s kind of a catch 22 because irritable bowel syndrome is a disease of exclusion, so, or diagnosis of exclusion, so, if you have GI symptoms, and it’s not inflammatory bowel disease or celiac disease or diverticular disease or an ulcer, or, you know, cancer, if it’s none of those other things, then you go, congratulations, You have an irritable bowel. And as somebody who has gone through this diagnostic process, I can say, Yeah, I know that’s why I came here in the first place. Doc, thanks so much for letting me know I have the thing that I let you know that I have. And then we did all that testing, and you were like, you have the thing you know you have, then we can’t do anything about it other than treat the symptoms. So it is a very frustrating condition to have. It definitely erodes quality of life. People tend to either have IBS C, where the C stands for constipation, or IBS D, where the D stands for diarrhea. But some people have both, and kind of swing between both, and it seems to be potentially multifactorial. It tends to have multiple different causes that end up in the same symptoms. So for some people, it can be GI symptoms that are related to a stress related mental health disorder. So it can be related to anxiety. For other people, it might be related to what’s called gut dysbiosis, which is the technical term for any imbalance in the gut microbiome, the community of bacteria and fungi and archaea that live in our digestive tract. So if we have the wrong kinds of microbes in our gastrointestinal tract, the wrong relative balance of different species, then living in the wrong locations. And that can kind of refer to like the large intestine versus different segments of the small intestine, but it can also refer to living in the middle versus closer to the edges of the digestive tube. So any kind of imbalance in that community can cause GI symptoms that can result in a diagnosis of irritable bowel syndrome. So the challenge with a low FODMAP diet is that, yes, like, if you just decrease the food for those bacteria, they’re producing less of the gas and short chain fatty acids that are driving the symptoms, so it can alleviate symptoms. However, FODMAPs are incredibly important. What’s called substrate means food for the most beneficial, important species that we can have in our gut. Microbiomes, lactobacillus species, Bifidobacterium species. So when we starve the imbalance right, maybe the undesirable species that are causing all this excess production of gas that is causing symptoms, we’re also starving the good guys. So some of the most important foods for supporting a healthy gut microbiome are high FODMAP foods, right foods like onions, brussel sprouts, broccoli, some of those vegetables that are high FODMAPs are known in a variety of different studies to improve the composition of the gut microbiome. And so now we have these studies where they put healthy people and people with IBS on a low FODMAP diet, they measure what happens to the symptoms. And by the way, not everyone has symptom resolution on a low FODMAP diet, only a subset of people do. So it’s not like it’s a guarantee, if you have IBS, that you go low FODMAP, that it’s going to get better. For some people, it gets worse on low FODMAP. So just FYI, it’s not a solution that works for everybody. It’s a solution that works for a subset of people, and potentially people who only have, like one type of gut dysbiosis or gut microbiome imbalance that responds to this and other types don’t, and other potential causes of IBS that don’t relate to our gut bacteria don’t, right? That’s probably what’s going on there. But the problem is, when you starve the bad guys. This also happens on diets like gaps and SCD which include reducing starches in addition to FODMAP type foods, if you starve the bad guys, you also starve the good guys, and so you end up worsening that imbalance over time, or developing a different kind of imbalance. And so studies have shown when people are on a low FODMAP diet for as little as a few weeks, they have reduced levels of lactobacillus, Bifidobacterium, Faecalibacterium prausnitzii, Akkermansia muciniphila, which are really, really, really important. They’re like keystone species of bacteria. They’re some of the most important probiotics that we can have in our gut microbiomes. So low fiber diets reduce the growth of these really important bacteria. They do things like reduce the production of short chain fatty acids, so that is a metabolic byproduct of our gut bacteria that is really beneficial for us, but also helps to control the entire gut environment, because it lowers the pH. So we actually want slightly acidic-like contents of our digestive tract. All of the good bacteria like to live in a slightly acidic environment, whereas a lot of the pathogens, like E coli, thrive on a closer to a neutral pH or even basic environment. It’s actually one of the reasons why I don’t love alkaline water, because it neutralizes acids that are really beneficial for digestion and also beneficial for supporting a healthy gut microbiome. So we’ll just throw that can of worms into this video and see what happens in the comment section. But, but, yeah, that’s the challenge. With a low FODMAP diet it can cause symptom resolution at least in the short term, but even over the short term, it can worsen the underlying problem that is direct that causes those symptoms. So it doesn’t actually help to correct the gut dysbiosis that may be at least one of the possible causes of irritable bowel syndrome. So I’m not a doctor. I’m not an expert in treating gut dysbiosis or small intestinal bacterial overgrowth or any of the other things that can be causing irritable bowel syndrome. But my understanding of like, what the current sort of standard of practice is, is to use low FODMAP diets as a short term intervention to reduce symptoms and help restore some quality of life while doing something else to address the underlying challenge, so that something else might be in the case of small intestinal bacterial overgrowth, It might be a non absorbable antibiotic like Rifaximin. In the case of just an imbalance, it might be prescription probiotics, it might be diet changes, it might be lifestyle changes, it might be some diagnostics to rule out other possible things going on. So and then the standard of practice would be to slowly reintroduce back FODMAPs, so adding as little as maybe a teaspoon per day of some of these types of foods, maybe starting with something like sauerkraut that has a lot of the good probiotics in it, in addition to FODMAPs. And then slowly increasing, going. Up every couple of days, because those gut bacteria do take a couple of days to kind of re establish an equilibrium every time you make a diet change, so inching up slowly to kind of re establish a really healthy gut microbiome over time. All of that being said, That is my understanding of the standard of practice. Again, I am not a doctor. This would be a situation where you want to work with somebody who’s an expert in this field, and somebody who’s not just recommending a long term low FODMAP diet, if they’re recommending a long term low FODMAP diet, unless you have something like fructose malabsorption, which is a whole separate thing. If that is not the fructose malabsorption has not been diagnosed. There’s not a reason for anyone to recommend a long term low fat diet. So that would be a sign to me, anyways, that that is not the expert that I would want to work with. So finding somebody who has experience in treating irritable bowel syndrome with a combination of diet changes as well as other strategies, would be my recommendation. There’s so many really, really beneficial foods that are eliminated on a low FODMAP diet. It’s not a sustainable approach unless absolutely medical, not medical, medically necessary. And again, that is a very small percentage of the people who are being recommended a low FODMAP diet, and why, I’m kind of surprised and a little dismayed that it’s gaining popularity again, as a cure all.

Producer Potts  11:32  

Yeah, wow. Um, that was so much information, and I loved all of that. I learned so much in such a short period of time, that’s amazing.