What Your Gut Microbiota Says About Mood, Thyroid, and More - Dr. Michael Ruscio, DC

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What Your Gut Microbiota Says About Mood, Thyroid, and More

Surprising findings on how your gut health correlates with subclinical hypothyroidism, rheumatoid arthritis, depression, H. Pylori, and more

By now, you have likely heard about the connection between your gut and other organs like your thyroid, brain, and liver. This episode has the latest findings about these unique connections, particularly between: 

  • Depression and gastrointestinal symptoms 
  • Gut microbiota and mood disorders 
  • Gut dysbiosis and rheumatoid arthritis 
  • IBS and hypnotherapy 
  • GI infections and post-infectious IBS
  • Histamine intolerance and gut dysbiosis 
  • SIBO and subclinical hypothyroid

… and a lot more. Tune in to the episode for gut health research updates.

In This Episode

Intro… 00:08
Digestive symptoms and depression… 01:40
Gut dysbiosis in rheumatic diseases… 07:00
H pylori treatment… 08:16
Hypnotherapy for IBS… 12:51
Post-infectious irritable bowel syndrome… 14:26
Dysbiosis in patients with histamine intolerance… 16:39
Mediterranean diet for Crohn’s disease… 18:29
GERD in those with IBS… 20:00
SIBO breath testing… 24:03
SIBO and hypothyroidism in pregnant women… 28:16
Exercise for leaky gut… 30:21
Glutamine supplementation with low FODMAP… 32:10
Outro… 34:14

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Hey everyone. Welcome back to Dr. Ruscio, DC radio. This is Dr. Ruscio, DC and let’s talk about gut health research. I’ve been trying to break down the research that we cover to one podcast dedicated to probiotic research, another podcast (as this one will be) to a broader gut health research category that does not involve probiotics, a third type of podcast that covers research on thyroid and female hormone health, and then a fourth that is essentially related to diet, lifestyle, sleep, vitamin D, exercise, and is more of a potpourri, if you will. So today we’ll go into gut health updates that are not probiotic in nature.

➕ Full Podcast Transcript


Welcome to Dr. Ruscio, DC radio, providing practical and science-based solutions to feeling your best. To stay up to date on the latest topics, as well as all of our prior episodes, make sure to subscribe in your podcast player. For weekly updates, visit DrRuscio.com. That’s DRRUSCIO.com. The following discussion is for educational purposes only and is not intended to diagnose or treat any disease. Please do not apply any of this information without first speaking with your doctor. Now let’s head to the show.

Dr Ruscio, DC:

Hey everyone. Welcome back to Dr. Ruscio, DC radio. This is Dr. Ruscio, DC and let’s talk about gut health research. I’ve been trying to break down the research that we cover to one podcast dedicated to probiotic research, another podcast (as this one will be) to a broader gut health research category that does not involve probiotics, a third type of podcast that covers research on thyroid and female hormone health, and then a fourth that is essentially related to diet, lifestyle, sleep, vitamin D, exercise, and is more of a potpourri, if you will. So today we’ll go into gut health updates that are not probiotic in nature.

Dr Ruscio, DC:

And the first study was a review of NHANES data, so population-based survey data, essentially looking at just under 32,000 individuals followed for 11 years compared to healthy controls. Those who had moderate to severe depression had higher rates of digestive symptoms, diarrhea, constipation, stomach illness, bowel liquid (sounds fun), or bowel mucus. So not surprising that we see in this very well-performed NHANES data set that people who have depression have a higher occurrence of digestive symptoms. This is the gut-brain connection. This should not be news, necessarily, to our audience because we’re on the cutting edge of this, but it’s great to see more and more data here now at the population observational level. Really showing that even when we get this sample size high up as to almost 32,000, in this case, we’re seeing yes, there is a signal that the gut and the brain function together. And we know from much of the research that we’ve discussed on the podcast that while this is bidirectional—gut can impact brain and brain can impact gut—it seems that the more common direction is problems in the gut cause problems with cognitive and neurological function. And again, this is symptoms. People had diarrhea, constipation, what have you, and they were more depressed.

Dr Ruscio, DC:

Let’s contrast this with the next study. That was a systematic review of 44 studies looking at about 2,500 psychiatric patients versus 2,400 healthy controls. They didn’t find any difference in microbiota diversity, at least at the alpha level. There were some differences in short-chain fatty acid levels and in the levels of lactic-acid- producing bacteria. So more evidence showing that the gut relates to depression. But one of the things I want to point out here is sometimes there there’s an over, I think, focusing on diversity scores. And while yes, there is a trend, that trend of diversity mapping onto health doesn’t always follow or doesn’t always point in the direction of there being an association. And in this case, lower short-chain fatty acids, interesting to see higher levels of lactic acid producing bacteria. Also interesting to see could that mean overgrowth, maybe, right? But this is a stool sampling. So stool sampling will not tell you what’s going on in the small intestine. But something is awry in the gut is what we can take away from this systematic review. Again, looking at 44 studies and about 2,500 patients versus 2,500 controls showing again, diversity didn’t matter, didn’t change, but other findings like short-chain fatty acid and lactic-acid producing bacteria levels did.

Dr Ruscio, DC:

Now one thing just as an aside, be careful that if you see low levels of short-chain fatty acids on a stool test, that doesn’t always mean that eating to directly treat that number increase short-chain fatty acids is the best path. Especially if you have preexisting digestive symptoms, diarrhea, bloating, constipation, abdominal pain, you may make yourself worse by doing so. It’s not to say you can’t, and it’s not to say you couldn’t try a higher fiber, higher vegetable diet. This will be beneficial for some, but it’s important to continue to flag that some of the conventional and traditional nutritional advice, more fruit and vegetables, more fruits and vegetables, more fiber. It’s not always the right advice. And this is most relevant in those with active digestive symptoms.

Dr Ruscio, DC:

And so just to provide a little bit of an antidote to the commonplace dietary recommendations, remember that something like the low FODMAP diet, that we’ve discussed in the past, is according to the American college of gastroenterology (I believe that was the association I’m quoting from a podcast ago) that the low FODMAP diet is one of the most evidence-based diets for irritable bowel syndrome. And by definition, this diet will reduce prebiotic and fiber consumption. Other data has found a benefit between lowering FODMAPs and mood or clarity to some extent. So just important to keep in mind and want to flag for you, just because this study found lower levels of short-chain fatty acids, it does not necessarily mean that treating that number directly will get you the most healthy.

Dr Ruscio, DC:

Okay. The next study looked at gut dysbiosis in rheumatic diseases; systematic review looking at 92 observational studies and about 12,000 participants. And what they found here was compared to healthy controls, rheumatic patients had a alpha diversity that was lower. So they had less diversity than did their healthy counterpoint or counterparts. So this is one study showing that diversity did map on with disease states, such as rheumatoid arthritis, systemic lupus, gout, [and] fibromyalgia. Now, again, what you do about that has to be handled more on a clinical and individual level, but it tells us that in this case, there is some correlation between diversity and health. But remember, we don’t want to treat the diversity directly. We want to treat the person. Because there’s a growing argument to be made, that the diversity that you see is a byproduct of the health of the host and not exclusively tied to the level of fiber and prebiotic intake that the individual has.

Dr Ruscio, DC:

The next study looked at H pylori, and what happens to the stomach or the gastric microbiota after eradication of H pylori. This was another systematic review and meta-analysis. And by the way, I hope that you’re queuing in on the fact that a lot of these studies we’re covering are systematic reviews, meta-analyses, or clinical trials. And this is because we want to, and I want to, serve up to you, so to speak, curate for you the best research. What I don’t care about is saying, “Hey, person on our research team, go find a bunch of studies that support X, Y, Z, (what I think) and I don’t care how good they are.” Rather, this is just us picking out the best quality studies from the ongoing flowing river of research and selecting for you the best studies, the highest quality studies and me peppering in a little bit of my commentary.

Dr Ruscio, DC:

So this study, again, systematic review with meta-analysis of nine studies, about 550 patients were treated for H pylori. And they found that the stomach or gastric microbiota diversity improved and persisted for six months. And likely what’s happening here, the gastric microbiota, although not not a ton of bacteria are going to be hanging out in the harsh high acid environment of the stomach, but there is a microbiota there, nonetheless. And if one organism, H pylori, overgrows, it pushes out the other organisms, hence lower diversity. So by weeding, so to speak, the H pylori you allow the garden to have this more diverse growth, hence the improvement in diversity that persisted six months after eradication.

Dr Ruscio, DC:

The next study looked at the effect of H pylori treatment on autoimmune diseases. And essentially the finding here was that when compared to those who were untreated, those who received treatment for H pylori had a slightly higher rate of inflammatory bowel disease and a slightly higher rate of autoimmune diseases, but conversely had lower rates of all-cause mortality (death from any cause).

Dr Ruscio, DC:

So what’s interesting here is that there’s these seemingly discordant findings, you have a lower chance of death but a higher chance of auto-immunity. However, as we discussed in the podcast in the past with Moises Velasquez-Manoff, who wrote An Epidemic of Absence, there is likely this biological trade off where we get rid of more organisms, you have a lower chance of dying, but getting rid of those organisms deprives you of the training that your immune system needs to prevent autoimmune diseases, which includes inflammatory bowel disease. So I think it’s important to keep this in mind because it’s not a, “antibiotics are bad and we need to go back to the farm,” it’s not a all to one side or all to the other. The hunter gatherer environment had a lot of merit, but there was a higher incidence of infant death.

Dr Ruscio, DC:

And this is where antibiotics can help. But you trade a little bit there for incidents of autoimmune diseases and inflammatory conditions. Right now, the pendulum’s almost undeniably too far in the sterile hygiene direction, and we need to tip it back more to center. But I just want to provide some context and some mooring that we want to understand that there’s not necessarily a perfect, it’s just trying to arrive at the balance point compromise that’s going to be the best. And, again, in the spirit, I want to be careful that people don’t develop this unnecessary fear of all antibiotics all the time, because that would also be incorrect.

Dr Ruscio, DC:

Okay. The next study is a randomized control trial looking at hypnotherapy for IBS. And what was interesting here in this study of about 120 patients, they looked at group hypnotherapy as compared to one-on-one individual hypnotherapy and all of the groups improved and all of the groups showed or demonstrated similar levels of improvement.

Dr Ruscio, DC:

So what’s so interesting here is that if you’re thinking about hypnotherapy, you could save some money and find a group hypnosis class and rest assured—at least from this one randomized control trial—that you’ll likely get the same outcome, but for a lower cost using hypnosis. And this really hits at the mind-body, or maybe we could say the brain or psychology to gut connection. Whether you get there via meditation, limbic retraining, hypnosis, the important thing is to have something that you’re doing to try and reduce stress [and] get yourself into a parasympathetic state. And this is one more evidence point for a therapy, hypnosis, that can improve IBS symptoms. So there’s the brain to gut, hypnosis to gut, and also quality of life.

Dr Ruscio, DC:

The next study was a narrative review that looked at post-infectious irritable bowel syndrome. Remember that one of the ways IBS develops is someone has a bout of food poisoning, travelers diarrhea, acute gastroenteritis, they’re throwing up, having diarrhea—unpleasant, we’ve all probably been there, it’s not fun—and then after that clears, there are some lingering symptoms, as in IBS. Altered bowel function, improvement of symptoms after a bowel movement, abdominal pain, and some bloating, as some of the most hallmark symptoms of IBS. What’s, I think, important to mention is that it’s not everyone. And this study found that post infectious IBS developed in 11.5% of individuals. The most common organisms were Shigella Vibrio and Giardia as the causal organisms. And this is just one more evidence point in the camp of post infectious IBS. And Mark Pimentel has done some really fantastic and elegant work here, dissecting the mechanism, but also remember that you shouldn’t be afraid to travel.

Dr Ruscio, DC:

And the odds are in your favor that if you do come down with a bout of Traveler’s diarrhea or food poisoning, that you won’t be impacted. You have an 85% chance that you won’t and a 11.5% chance that you will. Also remember that probiotics can be used to reduce the incidents of travel’s diarrhea. Refaximin can also. However, I would much rather someone takes a probiotic with them than takes an antibiotic, especially depending on how often you’re traveling. Full disclosure, Rifaximin has been demonstrated to be safe upon multiple uses or via repeat administration. However, it seems quite prudent to say use probiotics preventatively rather than antibiotics.

Dr Ruscio, DC:

Okay. The next study looked at intestinal dysbiosis in patients with histamine intolerance. This was a small study, 12 histamine intolerant patients versus 14 healthy controls, and stool samples were collected on all of these participants. The histamine intolerance patients had more deficiencies in diamine oxidase, and they also had higher levels of histamine-secreting bacteria. Not surprising. Question is what do we do about that? Well, we know a low histamine diet can improve diamine oxidate levels, even if you’re not super strict with it. I suspect, even though this has been challenged, that a low FODMAP diet may do the same thing or at least help with some of the dysbiosis.

Dr Ruscio, DC:

Probiotics clearly help because remember probiotics help to address dysbiosis. So the overgrowth of some of these histamine-secreting bacteria and things like SIBO and reduce leaky gut and have been shown to be antihistamine, even if they contain a small amount of histamine in them, they have a net antihistamine effect. And of course, antimicrobial therapy can also be effective as can elemental dieting. So there’s really a whole number of therapies on offer for histamine intolerance, including even immunoglobulins. So lot of options out there, but this study does a good job of documenting that intestinal dysbiosis underlies histamine intolerance.

Dr Ruscio, DC:

All righty, the next study looked at the effect of the Mediterranean diet on Crohn’s disease. This was a systematic review of five studies in about 83,000 Crohn’s patients. And those who followed a Mediterranean diet had improved Crohn’s disease symptoms, lower fecal calprotectin (inflammatory marker), and lower CRP (c reacitve protein), another inflammatory marker. Great news. If you have Crohn’s disease, there are a few different diets on offer: Mediterranean, low FODMAP, paleo, low flex. So important to mention this, the people in the Mediterranean diet were eating grains and they were eating gluten. So you can see improvements in an autoimmune condition, Crohn’s, when eating gluten. This is important to keep in mind because we don’t want to shoehorn people into recommendations just because some people do clearly have a problem with gluten, it doesn’t mean everyone does. Even someone with an autoimmune condition affecting their gut. So keep this in mind. There’s a handful of diets on offer. Well, there’s many, many, many diets on offer. I think there’s a handful that are really worthwhile to explore and consider, even those that have a moderate to high carbon take and call for consumption of grains.

Dr Ruscio, DC:

This next study was fascinating in my opinion, looking at GERD, gastroesophageal reflux, in those who also have IBS. And of course there’s going to be some overlap between these two. They wanted to see what happened both from a symptom and mechanism perspective when people were given either placebo (rice noodles) or high FODMAP wheat noodles. So you have both gluten and wheat. And they found that in the group receiving the wheat noodles, so gluten plus FODMAP, there was a relaxation of the lower esophageal sphincter, increased gas production, and increased GERD.

Dr Ruscio, DC:

Specifically the gas included higher levels of hydrogen and methane, and this correlated with a progressive relaxation of that lower esophageal sphincter and more symptoms. So what’s likely happening here, or what’s been documented here, is what the SIBO community had speculated was happening for a while, which is you have this sphincter or this valve at the bottom of your throat that’s the doorway from your throat into your stomach, and it should be a doorway that only opens when food is trying to go from the esophagus into the stomach. And it shouldn’t be open for business all the time. It should be closed afterwards. The SIBO community has postulated that SIBO increased gas, increased gas pressure, increased pressure against the valve, the valve gets pushed open, the contents reflux, you have GERD. And that’s what this study is demonstrating, that the increased gas correlated with a relaxation of that LES, that lower esophageal sphincter.

Dr Ruscio, DC:

This is one of the reasons why a low FODMAP diet or an elimination diet are a good idea for GERD. And also probiotics. Amongst other therapies, but this would be a good place to start.


Hi, everyone. If case you are in need of help, or would like to learn more, I wanted to quickly point out what resources are available to you. “Healthy Gut, Healthy You”, my book and your complete self-help guide to healing your gut. If you’re not a do-it-yourselfer there is always the clinic and myself or any one of our doctors would be more than happy to help you. And as a quick aside there, we just had accepted for peer review a six-part case series where in we demonstrated the gut-thyroid connection and how crucially important it is to make sure you are not overlooking someone’s gut health as it pertains to thyroid health and thyroid symptoms more broadly. Through the clinic we also offer health coaching and, independent of the clinic, if you’re reading the book or need some general advice, we offer health coaching also. There’s our store where you can find our Elemental Diet line, our probiotic line, and other health and gut-supportive supplements. And finally, there is our clinician’s newsletter, the FFHR, AKA the Future of Functional Health Review database with research reviews, case studies, and other helpful resources for healthcare providers. Everything for any of these resources can be found at the overview page DrRuscio.com/resources. That’s DrRuscio.com/resources.

Dr Ruscio, DC:

Alrighty, this next study was interesting. It looked at hydrogen and methane SIBO breath tests and how they correlate with SIBO. And the long story short here, they found that patients with IBS were less likely to have SIBO. This is counter to much of the evidence, but it’s important to point this out. Why? Well it’s a contradictory finding. Okay. It’s good to showcase both sides of the evidence. Yes, I’m with you. However, there’s another component to this, which is if you have a SIBO breath test, it does not 100% guarantee you will have symptoms. The most recent meta-analysis found a correlation between a positive SIBO breath test and IBS symptoms of roughly 50%. Now we can argue over, well, it would be higher if we use lactulose. And we could counter argue that, well, there’s going to be false positives. And we could counter argue that [with] we should use aspirate sampling directly. Okay? All that arguing back and forth. You still don’t get to a 100% correlation between SIBO breath test positive status and symptoms.

Dr Ruscio, DC:

Why does this matter? Because if you’re feeling good and you have a positive SIBO breath test, take the win. Right? Take the win symptomatically, meaning you don’t need to treat, treat, treat, treat, treat down to a negative test. At least not in my opinion. And I quote often a systematic review, now from probably about five years ago, that concluded there does not seem to be clear utility in serial, repeat breath testing. But rather the best path—and now this is me mixing in some of my speculation—the best path is to treat the individual until you get to full symptomatic resolution.

Dr Ruscio, DC:

Because knowing that someone has SIBO, that’s your step one. Okay. We’ve identified this good. Now we move forward and we personalize care to you to try to get you to zero symptoms or as close as we can. Now, do we need a SIBO breath test to say, well, probiotic triple therapy was helpful but not fully adequate. No. Do we need a SIBO breath test to say now we graduate to herbal antimicrobials. No. Do we need a SIBO breath test, another test, with every one of these steps beyond the baseline test? Do we need another SIBO breath test to tell us to do an elemental diet? No. Do we need a SIBO breath test to tell us to try enzymes or HCL? No. Do we need a SIBO breath test to tell us now to use immunoglobulin? No. So we want to go through the care and really use and personalize the different therapies that gets you feeling as well as we can. And then perhaps as an endpoint, we can do confirmatory, retesting.

Dr Ruscio, DC:

But midstream, so to speak, I do not see the SIBO breath test giving us precision for, “well, we’ve got to use immunoglobulin as compared to elemental diets as compared to X, Y, Z.” Some make that claim and make that argument. I think it’s tea leaf reading, if I’m being honest. Probably done, as I think most clinicians are doing, with the best intentions, but there’s this backdrop of really getting too zoomed in and treating the numbers. And this is something that costs a lot of money, right? If someone needed to go through, let’s say six to eight months of treatment to fully resolve their symptoms, they could have done four breath tests through that course. And at $200 to $250 a pop, I mean, yeah, this is a thousand dollars plus or minus to the course of someone’s care. Which is why we’re using the test, yes, baseline, but not using them midstream to try to confirm if we’re on the right track or not, other than some exceptional circumstances.

Dr Ruscio, DC:

This next study ties together an area that we often connect the dots between. And I think has historically been a bit underserved, but this is starting to change a bit, which is the connection between the gut and the thyroid. And in this case, small intestinal bacterial overgrowth was looked at as it pertains to subclinical hypothyroidism in pregnant women. Now remember subclinical hypothyroidism is when your TSH is elevated slightly above the reference range, but not to a very high degree. So it’s a cut off of 4.5. You might have a five or a six or a seven or an eight, but you haven’t gone above the, “okay, now we have to do something cut off,” which is roughly 10.

Dr Ruscio, DC:

And in this study of 224 pregnant women who also had this mildly elevated TSH, they found that the prevalence of SIBO was about 20% higher, 57% versus 32%. There was also a higher degree of TPO antibodies in that group. So this study is associating SIBO and hypothyroidism. And we’ve discussed other research in the past that has associated these two together also, so interesting to see more information there pouring in. And remember if you are having a thyroid problem, yes, thyroid hormone and direct thyroid supports are part of the care, of course, but don’t forget the importance of your gut. And this permeates multiple domains—thyroid, hormone, medication absorption, antibody levels, and symptoms.

Dr Ruscio, DC:

The next study looked at the impact of a 12-week exercise program on biomarkers of leaky gut. And in this small 41 patient study, gut permeability was assessed before and after an exercise program that was 12 weeks in duration, combining aerobic exercise with resistance training. They found that an increase in cardio respiratory fitness, as VO2 max, was associated with lower gut permeability or less leaky gut.

Dr Ruscio, DC:

So really important to keep this in mind, everyone listening to this probably understands that exercise impacts multiple systems of the body in a positive way. But I think important to reiterate that exercise has been shown to positively impact the gut microbiota. And here we have an evidence point showing probably the even more important point of the ability of exercise to reduce leaky gut. So if you are not exercising or every once in a while, do whatever you can do to be more consistent with the habit, especially if you’re trying to improve your gut health. And of course, exercise will help not only with that, but with mood vigor, self-esteem energy, sleep, mental clarity. So just a, I guess, a public service announcement there to get back to exercise if you have drifted out of the habit.

Dr Ruscio, DC:

Alrighty, let’s do one more. And this study looked at the effect of glutamine supplementation and how it affects or enhances the effect of a low FODMAP diet in those with IBS. 50 patients were randomized to receive a low FODMAP diet plus placebo or a low FODMAP diet plus 15 grams of glutamine. And after six weeks, the low FODMAP plus glutamine diet had significant improvements in IBS symptoms, a 58% reduction.

Dr Ruscio, DC:

So important to keep this in mind that when we combine therapies, in this case a low FODMAP diet plus glutamine, we can get a better outcome. And this is one of the starting points at the clinic we use with most patients would be some iteration of a low FODMAP diet. Sometimes it’s paleo low FODMAP. Sometimes it’s standard low FODMAP. Sometimes it’s vegetarian low FODMAP. [Then] some other lifestyle recommendations, plus probiotictriple therapy—unless a person’s very sensitive and then we’ll give them the three different bottles separately and have them start one at a time. And oftentimes we will also use gut rebuild nutrients, which contains glutamine amongst a few other compounds, like zinc and aloe, to help with repair of the lining of the gut. And this works quite well. And this is one study, just showing that you can get more out of a diet if you leverage it with other therapies. Now there’s a balance here, right? There is such a thing as too much. But I feel that to be a good starting point. And from the signal that we get in the clinic, that seems to be working pretty well.

Dr Ruscio, DC:

All right. Well, I hope you found this episode helpful and I will look forward to speaking with everyone next time. Take care, guys. Bye bye.


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➕ Dr. Ruscio’s, DC Notes

Association Between Gastrointestinal Symptoms and Depression in a Representative Sample of Adults in the United States: Findings From National Health and Nutrition Examination Survey (2005-2016)

  • 31,191 adults followed over 11 years
  • Compared to healthy controls, participants with moderate-to-severe depressive symptoms had higher rates of: 
    • Diarrhea (OR 1.7) 
    • Constipation (OR 2.7)
    • Stomach illness (OR 1.8) 
    • Bowel liquid (OR 2.1)
    • Bowel mucus (OR 2.8) 
  • Commentary: This large study highlights the gut-brain connection. 


A systematic review of gut microbiota composition in observational studies of major depressive disorder, bipolar disorder and schizophrenia

  • 44 studies, 2510 psychiatric patients, 2407 healthy controls 
  • Compared to healthy controls, psychiatric patients had: 
    • NO difference in microbiota alpha-diversity between groups
    • Greater microbiota beta-diversity 
    • Lower levels of SCFA-producing bacteria
    • Higher levels of lactic acid-producing bacteria
  • Commentary: Mental health disorders may be related to the composition of the gut microbiome. 


Gut dysbiosis in rheumatic diseases: A systematic review and meta-analysis of 92 observational studies

  • 92 observational studies, 11,998 participants
  • Compared to healthy controls, microbiome alpha-diversity was lower in patients with:
    • Rheumatoid arthritis (Moderate effect size)
    • Systemic lupus erythematosus (Large effect size) 
    • Gout (Moderate effect size) 
    • Fibromyalgia (Small effect size) 
  • Commentary: Dysbiosis is associated with various rheumatological diseases. Keep in mind this is an observational study.


Effect of Helicobacter Pylori Eradication on Human Gastric Microbiota: A Systematic Review and Meta-Analysis

  • 9 studies, 546 participants with H. pylori, treated with either triple or quadruple eradication therapy
  • Eradication of H. pylori led to improved gastric microbial alpha diversity, and these improvements persisted 6 months later
  • Commentary: Eradicating H. pylori may have beneficial effects on gastric dysbiosis. 


Effects of Helicobacter pylori treatment on the incidences of autoimmune diseases and inflammatory bowel disease in patients with diabetes mellitus

  • Observational study of 79,181 participants with H. pylori or peptic ulcer disease, categorized by:
    • Untreated H. pylori in healthy controls
    • Untreated H. pylori in diabetic participants
    • Treated H. pylori in diabetic participants
  • Compared to untreated H. pylori, those who received treatment experienced: 
    • Higher rates of autoimmune diseases (5.1% treated vs 3.56% untreated)
    • Higher rates of IBD (5.6% vs 3.21%)
    • Lower rates of all-cause mortality (HR 0.9) 


Randomised clinical trial: individual versus group hypnotherapy for irritable bowel syndrome

  • 119 IBS patients randomized to individual or group hypnotherapy 
  • After 6 months, both groups experienced:
    • Improved IBS symptom scores (-116 individual vs -98 group) 
    • Similar response rates (>50 point IBS symptom score) (69% vs 57%) 
    • Improved quality of life 
  • Commentary: Hypnotherapy can improve IBS symptoms whether in a group or individual setting. 


Postinfection Irritable Bowel Syndrome

  • Narrative review
  • Post-infectious (PI) IBS develops in approximately 11.5% of acute gastroenteritis (AGE) cases
  • Infections most commonly associated with developing PI-IBS include:
    • Shigella
    • Vibrio cholerae
    • Giardia lamblia 
  • Commentary: A significant percentage of IBS diagnoses may be due to a history of GI infection. 


Intestinal Dysbiosis in Patients with Histamine Intolerance

  • 12 histamine intolerant (HIT) patients, 14 healthy controls
  • Stool samples were collected on all participants
  • Compared to healthy controls, HIT patients had greater:
    • Diamine oxidase (DAO) deficiency (83% of HIT patients) 
    • Histamine-secreting bacteria (staphylococcus, proteus, clostridium perfringens, enterococcus faecalis, enterobacteriaceae)
  • Commentary: This small study showed patients with HIT have greater dysbiosis and lower DAO. This supports the hypothesis that HIT begins in the gut. 


Mediterranean diet diminishes the effects of Crohn’s disease and improves its parameters: A systematic review

  • 5 studies, 83,564 Crohn’s disease (CD) participants 
  • Greater adherence to a mediterranean diet was associated with:
    • Improved CD symptoms
    • Lower fecal calprotectin
    • Lower hsCRP 
  • Commentary: A mediterranean diet may be a useful option for patients with CD. 


Gastroesophageal Reflux Disease (GERD) Patients with Overlapping Irritable Bowel Syndrome (IBS)

  • Cross-over study of 8 patients with overlapping GERD-IBS (non-constipation)
  • Randomized to either breakfast and lunch that contained either:
    • Control (rice noodle)
    • High FODMAP (wheat noodle)
  • Measured the following after ingestion of the meals:
    • Postprandial transient lower esophageal sphincter relaxation (TLESR)
    • Intestinal gas production
    • GERD/GI symptoms
  • FODMAP ingestion was associated with:
    • Higher H2 and CH4 levels
    • More TLESR
      • Higher H2 gas production correlated with TLESR
    • More postprandial regurgitation (2.9 vs. 0.4
    • More bloating (7.0 vs. 3.1)
    • Satiety (7.7 vs. 3.5)
    • Belching (3.8 vs. 1.1) 
  • Commentary: FODMAP ingestion was related to greater gas production, esophageal sphincter relaxation, and GI/GERD symptoms. 


Hydrogen and methane breath test results are negatively associated with IBS and may reflect transit time in post-surgical patients

  • 525 glucose breath tests performed over 3 years
  • 16% positive for hydrogen, 8% positive for methane
  • Patients w/ IBS (HR  0.17) and those with a higher body mass index (HR = 0.93) were LESS likely to have a positive test
  • Patients who underwent the test post-surgically were more likely to have a positive test (HR  2.76)
  • Commentary: This study contradicts the most recent meta-analysis that shows an association between IBS and SIBO. 


Small Intestinal Bacterial Overgrowth in Subclinical Hypothyroidism of Pregnant Women

  • 224 pregnant women w/ subclinical hypothyroidism (SCH), 196 euthyroid pregnant women
  • Lactulose breath test and thyroid function tests performed in all women
  • Pregnant women w/ SCH had:
    • HIGHER rate of SIBO (57% vs 32%)
    • Higher CRP (7.8 vs 4.7)
    • More GI symptoms
    • Higher TPO antibodies (32 vs 11)
    • Higher TSH (5.9 vs 5.3) and lower fT4 (13.5 vs 14.1)
  • Commentary: SIBO is associated w/ SCH.


Impact of 12-week exercise program on biomarkers of gut barrier integrity in patients with coronary artery disease

  • 41 participants, measured gut permeability markers before and after exercise program
  • After 12 week exercise program (aerobic exercise and resistance training):
    • Increase in cardiorespiratory fitness (VO2 max) was associated with lower gut permeability levels
  • Commentary: A foundational practice such as regular exercise can lead to improved gut health. 


Glutamine Supplementation Enhances the Effects of a Low FODMAP Diet in Irritable Bowel Syndrome Management

  • 50 IBS patients, randomized to:
    • low FODMAP diet + placebo
    • low FODMAP diet + glutamine (15 g/d)
  • After 6 weeks, the low FODMAP diet + glutamine group had significant improvement in IBS symptoms (58% reduction)
    • Improvement in IBS-severity score of more than 45% was observed in 88% (vs 60% in low FODMAP + placebo)
  • Commentary: Adding glutamine supplementation to a low FODMAP diet is superior to a low FODMAP diet alone.  This is one of the mainstays of our clinic model.

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