A Deep Dive on Hydrogen Sulfide SIBO: Symptoms, Testing and Treatment

Welcome to The Perfect Stool: Understanding and Healing the Gut Microbiome. This is your host, Lindsey Parsons, and today I'm going to be talking about a topic that I've only touched on briefly in the course of other podcasts, which is hydrogen sulfide, SIBO, or small intestine bacterial overgrowth. But before I do that, I just wanted to remind you that if you haven't yet followed or subscribed to the show, be sure to do so. If you'd like my free ebook, Finding Your Root Cause Through Stool and Organic Acids Testing, you can get that by signing up for my newsletter at HighDesertHealthCoaching.com. And if you haven't yet done my quiz on which stool test would help you get to your root cause, you can find a link in the show notes and take that. Now on to the show. So I've done multiple other shows on SIBO and IBS. So do see episode 36, IBS Treatment: Addressing an Irritable Bowel Naturally, and episode 83, Recurrent SIBO: Symptoms, Causes, Testing, and Treatment, for an in-depth treatment of all types of SIBO and IBS. But today I'm going to focus on hydrogen sulfide SIBO, which is abbreviated H2S SIBO. So you know how when you learn a new word, all of a sudden you hear it being used all the time? That's kind of what's going on right now with me and hydrogen sulfide SIBO. It kind of feels like everyone I've seen lately has suspected or diagnosed hydrogen sulfide SIBO. And it's funny because before now it wasn't that common in my experience, but I'm starting to recognize the type. And if I had to say one thing that tells me that someone might have hydrogen sulfide SIBO other than a positive breath test or stool test showing elevated levels of hydrogen sulfide producers, or what are called sulfate-reducing bacteria, it's how miserable my clients are. From a painful gurgling abdomen and gut known as increased visceral sensitivity, to bloating and distension, to excessive burping, to urinary urgency, a burning bladder or interstitial cystitis, to systemic inflammation, rampant food intolerances, and often histamine reactions. My hydrogen sulfide SIBO clients are just some of the worst suffering. Other symptoms you might see include weight loss, postprandial hypotension, meaning low blood pressure after meals, weight loss, an elevated heart rate, exercise intolerance, brain fog, or insomnia. And then the classic symptom, of course, is diarrhea or loose stool. Hydrogen sulfide overgrowth is also associated with ulcerative colitis, Crohn's disease, and colorectal cancer, so definitely not something you want to let fester. And what I'm finding surprisingly is that some of my toughest cases of what I thought was an overgrowth of methanogens is in fact an overgrowth of hydrogen sulfide alone or in combination with methanogens. And this is because while the overwhelmingly common presentation of hydrogen sulfide is diarrhea or loose stool, it can also present with constipation if there's an overgrowth in the large intestine, or if you have a simultaneous overgrowth of methanogens, which pretty much always cause constipation. The classic example of this is someone with a mixed-type IBS where constipation is the usual presentation,, but then occasionally there will be bouts of attacks where they'll have diarrhea and often also all-over body pain or extreme abdominal pain, often requiring a trip to the emergency room. And what a lot of these clients have in common, if they have constipation, is that they have slowly but surely stopped eating everything besides meat, or meat and a limited number of vegetables, maybe a very limited quantity of rice. And they've often have histamine intolerance or signs of sulfur intolerance, like like the inability to stand cruciferous vegetables or alliums like onions, garlic, shallots, chives, and leeks, which have sulfur. A few have noticed they don't tolerate red meat, which is particularly high in sulfur. Ironically, all of this may actually stem from a, a deficit of sulfur, which is a new theory I'm testing out, so I'll get back to you on that. But this is theorized because of the impact of glyphosate on food, which impairs a pathway in gut microbes called the shikimate pathway. This pathway produces the very important amino acids L-tryptophan, our serotonin precursor, and L-phenylalanine and L-tyrosine, our dopamine precursors, as well as other nutrients. And it's been shown that glyphosate also impedes sulfur production by causing a deficiency in molybdenum, a cofactor for the enzyme sulfite oxidase, which produces sulfate. Then if you have homozygous copies of the CBS, or cystathionine beta synthase, enzyme, which drives the recycling of sulfur-containing compounds, you may have too much unusable sulfur in your body, which can lead to sensitivities, while simultaneously having a deficiency of sulfur. But suffice it to say that hydrogen sulfide is a very important component in the human body, playing roles in inflammatory, neuromodulatory, immune, endocrine, vascular, and respiratory actions. But at high levels, it becomes toxic to cells inhibiting cytochrome oxidase, a heme protein, which is an important enzyme in the electron transport chain in our mitochondria, which is the way we produce energy in the cells. It also damages the intestinal mucosa and inhibits the oxidation or use of butyrate to feed the colonocytes, or cells lining the colon. So upregulating hydrogen sulfide production in the gut may be a compensatory mechanism. I'll have to get back to you on my experiments with that later. So which bacteria produce hydrogen sulfide? There's actually a lot of common genuses of bacteria that produce hydrogen sulfide, it turns out, including Escherichia, as in E. coli, which is not just the pathogenic E. coli you've heard of but also includes many commensal species; Klebsiella, which is known as the big histamine producer; Proteus species; and Citrobacter freundii, but not all Citrobacters, all of which are part of the family Enterobacteraceae. Some of which are hydrogen sulfide producers. Also the genuses Streptococcus and Staphylococcus, which I see elevated on virtually every GI map I see. Pseudomonas, H. pylori, Salmonella, some Clostridium, and Yersinia enterocolitica. But the two that have been the most highlighted as, as potentially overgrown and relevant to the hydrogen sulfide SIBO picture are Desulfovibrio species and Bilophila wadsworthii. The interesting thing is that hydrogen sulfide producers come from a number of different phyla including Delta Proteobacteria, Proteobacteria, Pseudomonoda, Thermo— desulfobacteriota, Fusobacteriota, and one genus from the phylum Euryarchaea called Archaeoglobus. And while most are gram-negative, one genus Desulphomaculum is gram-positive and is a spore-former. But the majority of the sulfate-reducing bacteria are from the genus Desulfovibrio, around 66%, hence why you see those species listed separately on the new version of the GI Map under the heading Commensal Overgrowth Microbes, right above Methanobacteraceae, the methanogens responsible for EMO or intestinal methanogen overgrowth. And then Bilophila wadsworthii is in the class Dysulfuvibrionia and the order Dysulfuvibrioniales, but a different genus. And can I just say bacteria nomenclature is really confusing even for me. And then finally, Fusobacteria, which is from the phylum Fusobacteriota and the family Fusobacteriaceae, is another one that's well known to be problematic in hydrogen sulfide SIBO, including Fusobacterium nucleatum, known to be responsible for periodontal disease and all sorts of other mischief. So what do hydrogen sulfide producers eat? Next thing you may want to know is that hydrogen sulfide producers Most of them use hydrogen as a fuel source. That's H2 through a process called oxidation. The hydrogen is coming from other gut bacteria which produce hydrogen, which you'll certainly be familiar with as the more common type of SIBO. And while hydrogen gas is odorless, hydrogen sulfide gas is smelly like rotten eggs. But again, one of the difficulties in recognizing hydrogen sulfide overgrowth is that many people with it will not say they have gas, smelly gas, or gas that smells like rotten eggs. Or they'll only occasionally have gas like that, like after they've had a meal heavy in animal fat that really feeds the hydrogen sulfide producers. But other sulfate reducers use different fuel sources or multiple fuel sources. So for example, Bilophila wadsworthii metabolizes the amino acid taurine. Fusobacterium, Desulfovibrio, E. coli, and Klebsiella metabolize the amino acid cysteine and methionine, which makes finding food to eat much more complicated because, you know, amino acids, proteins, but I'll get to that in a minute. The other thing you might want to know is that methanogens also use hydrogen as a fuel source. So although you may be negative in a breath test for hydrogen, if you have methanogens and/or hydrogen sulfide producers overgrown, if you kill them off, you may end up with hydrogen overgrowth. So don't think that it's likely to be a one-and-done program to get rid of these pathogens. Sometimes it requires several rounds of treatment with testing in between to see where you are. So how do you test for hydrogen sulfide SIBO? There is actually only one breath test out there that tests for all three possible gases in SIBO, or EMO, including hydrogen sulfide. It's called the TRIO Smart Test, and that's only available in the US as far as I know, possibly in Canada too with a doctor's prescription, but you can order it yourself in the US. Stool tests like the GI-MAP or GI-FX can also point to the presence of hydrogen sulfide SIBO in conjunction with symptoms, when you see elevated bacterial markers for hydrogen sulfide producers. You can find all these tests in my Rupa Health Lab Shop if you're in the US, which is linked in the show notes. Although I have been partial to the GI Map in working with clients, I'm beginning to think that the Trio Smart might make more sense for clients who are constipated, both because you can differentiate between the rarer hydrogen sulfide SIBO overgrowth with constipation, or find out if it's present alongside E. moe intestinal methanogen overgrowth. And because then you can track the level of methanogens and determine exactly how bad the overgrowth of methanogens is and have some sense of how long a treatment protocol someone might need. With the GI Map, you're just seeing stool levels, which isn't necessarily indicative of small intestine levels. But if you happen to have taken a SIBO breath test that only included hydrogen and methane, the sign that you might have a hydrogen sulfide issue is that you have a flat line or no growth on either of those other gases. I've also heard that you can use sulfite urine testing strips to test for the presence of free sulfites, which may help you diagnose hydrogen sulfide SIBO, but I don't know the details of how to use the strips this way. So how do you treat hydrogen sulfide SIBO? So the bad news for those of you who are on a paleo or carnivore type diet is that the diet for hydrogen sulfide SIBO is actually a plant-based diet. To start with, you want to reduce your animal fat completely. And ideally your animal protein as well, other than fermented dairy, which seems to be helpful in reducing levels of Bilophila wadsworthii per two studies, one on probiotic yogurt consumption and the other on consumption of a fermented milk product. There may also be benefits for yogurt and kefir consumption in the reduction of Fusobacteria, as an in vitro study found they inhibited its growth. But no animal foods ideally for 3 to 4 weeks then you can start reintroducing those foods one by one, starting with the lowest fat types. But otherwise, you'll want to decrease fat entirely for 2 to 3 weeks, definitely avoiding butter and tallow and lard and fatty cuts of meat. And coconut oil and coconut milk are in moderation, are okay after your initial low-fat period. And small amounts of olive oil or omega-3s are the best choice for fat throughout. MCT oil should also be okay in that initial period and afterwards, as it doesn't require bile for absorption. You also want to avoid simple sugars or high fructose and focus on whole foods with lots of fiber. And then avoid animal protein as much as possible. So basically, you'll have to incorporate sources of protein that are not animal-based, but not including soybeans or quinoa if you have overgrowth of Fusobacterium dysulfidibrio, E. coli, or Klebsiella, as those two foods are high in cysteine and they feed on cysteine. You want to sustain this diet until such time as you're feeling better. And if the sulfur-containing vegetables like garlic, leeks, onions, shallots, and shallots, and cruciferous vegetables bother you, you should limit those as well. Now, if you're one of the unlucky ones who has both a hydrogen sulfide overgrowth and a methane overgrowth and a high level of constipation, you may be asking, what can I eat? Especially if that coincides with histamine issues and food intolerances. In those circumstances, I tend to recommend a diet that's more in between with a limited quantity of low-fat sources of animal protein like chicken breasts, white fish, and shrimp, with low-fat fermented dairy, nuts, seeds, and any high-fiber carbohydrate foods you don't react to like lentils, chickpeas, or beans, starting with small quantities and working your way up, as well as fruits and veggies you can tolerate. Another option, of course, is doing an elemental diet, which consists of just a liquid diet for 2 to 3 weeks, which most likely you'd wanna combine with antimicrobial supplements in order to help it along. I did a podcast on Elemental Diets, which is episode 100, called Give Your Gut a Break. This may seem like a scary idea if you do have trouble keeping on weight, but in fact, my guests from that episode, Debbie and Roy Steinbach, maintained that people maintain or gain weight if they have trouble putting on weight while on the diet, but people wanting to lose weight simultaneously lost weight. So it's good for any weight circumstances. Or you may just use the Elemental Diet shakes as a supplement to the food you're eating in order to make sure you're not losing weight or to replace 1 to 2 meals a day. You can find the Physician's Elemental Diet powder in my Fullscript dispensary. So what supplements should you avoid with hydrogen sulfide SIBO? So as you're decreasing sulfur in your diet, you're also going to want to avoid supplements with sulfur or bile. This includes ox bile, bitters, bile-stimulating herbs, carrageenan, and additives with sulfur, glucosamine, and chondroitin sulfate. You should avoid protein powders with high levels of sulfur amino acids like taurine, cysteine, and methionine, although collagen is okay. And then of course avoid NAC, which is N-acetyl cysteine, glutathione, and anything with a thiol or sulfur group. Thiol, that's T-H-I-O-L, or sulfur group, including alpha lipoic acid. Thiamine or B1 and biotin also have sulfur, so avoiding high doses of those might be a good idea, but really they're usually dosed in milligrams, so it's not a huge food source compared to, say, amino acids. Also, certain probiotics are known to produce hydrogen sulfide, so best to avoid those, including Lactobacillus reuteri BR11, Lactobacillus delbrueckii ATC4797, and possibly Bacillus subtilis, which is a spore-based probiotic. There are a couple of others that produce hydrogen sulfide, L. plantarum 299v and L. rhamnosus GG, But I've heard recommendations and studies in which foods or supplements with those strains were helpful in hydrogen sulfide SIBO. So the jury is still out on that for me. So which supplements are helpful for hydrogen sulfide SIBO? So first, there's several herbs that are helpful, including Gymnostemma, Codonopsis, and Korean ginseng, which is Panax ginseng. Then minerals may be deficient that are necessary for repairing bodily processes that aren't working properly. In particular molybdenum, 50 to 150 micrograms per dose, but no more than 500 micrograms a day, or a multi-mineral supplement. I like the Jigsaw Essential Blend Multi-Mineral that's in full script cuz it has zinc, copper, selenium, and molybdenum, all in good doses, all of which are recommended for hydrogen sulfide SIBO. Then hydroxocobalamin, a form of B12, is also recommended as opposed to methylcobalamin, a form I recommend to most clients because of the presence of MTHFR SNPs. And beyond that, butyrate is important, although go easy on it if there's constipation, only taking one 300-500 milligram pill every 3 days if you're constipated to start, and then maybe moving up to maybe one a day. If you're not constipated, you can use a higher dose supplement like my Tributrin Max, which is 750 milligrams of Tributrin, 1 to 3 daily, decreasing if you get constipated, or any other Tributrin or core biome-based product, although you need more of a lower-dosed butyrate supplement or tributyrin supplement. Then the prebiotic FOS is also helpful, 2 grams a day with meals. If you don't react to that, be careful not to choose one with inulin though, as many people with SIBO are reactive to that. And finally, something I'm recommending to most people these days, serum bovine immunoglobulins, which help bind to and remove gut pathogens without impacting commensal bacteria. The dose that's been studied is 5 grams a day, which is recommended in 2 doses of 2.5 grams on an empty stomach. Usually first thing in the morning and last thing before bed. And let me not fail to mention good old Pepto-Bismol or a generic equivalent or a supplement containing bismuth, which is known to help with hydrogen sulfide. MDs will use 500 milligrams of bismuth 3 to 4 times a day with hydrogen sulfide SIBO in addition to Rifaximin, the antibiotic often used in SIBO. There's only one product in Fullscript with bismuth. That isn't full of dyes and additives like Pepto-Bismol that you might be trying to avoid. And it's called Biofilm Phase 2 Advanced, and it has 200mg of bismuth in 2 of them, along with some other stuff though that may not be great in hydrogen sulfide SIBO, like alpha lipoic acid. I'm just beginning to experiment with this product, so I'll let you know how it works out in a subsequent podcast. And also, I shouldn't fail to mention that exercise and stress management are also important in managing hydrogen sulfide SIBO. Well, I hope this helps some of you get to the bottom of your gut health or all-over body suffering and find a way out. As usual, I'm here if you need me and need more help figuring out what's going on with you, from understanding testing to educating you on protocols used by practitioners. You can set up a free 30-minute breakthrough session with me through a link in the show notes, or I offer individual consultations as well. If you'd like to support the show, you can make a regular donation on Patreon, buy vetted high-quality supplements from my full script dispensary, or links in the show notes to iHerb, Bulk Supplements, or Amazon. Or give me a 5-star review on Apple Podcasts. To reach out to me in other ways, I have a Gut Healing Facebook group for asking questions, or I'm on Instagram, Pinterest, TikTok, and X. Links for all those are in the show notes or on my website, HighDesertHealthCoaching.com. Thanks for listening, and here's wishing you all the perfect stool.