Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi

A certain type of SIBO, hydrogen sulfide, may be treated opposite to how we traditionally treat SIBO.  Eating more carbs, less fat and more FODMAPs might be better for this type of SIBO. This is one reason why listening to your body is so important.  Today I speak with Dr. Nirala Jacobi to elaborate.

Episode Intro

Dr. Michael Ruscio, DC: Hey everyone. Welcome to Dr. Ruscio Radio. This is Dr. Ruscio. Today, I’m here with Dr. Nirala Jacobi, the southern hemisphere queen of SIBO. Allison Siebecker’s southerly counterpart. And we’re going to be talking about hydrogen sulfide SIBO. So Nirala, welcome to the show.

Dr. Nirala Jacobi: Thanks so much for having me, Michael.

[Continue reading below]

Dr. R’s Fast Facts Summary

SIBO stands for Small Intestinal Bacterial Overgrowth

  • Altered bowel function (constipation/diarrhea)
  • Bloating, gas, pain
  • Other physical and mental symptoms can correlate with SIBO as well

SIBO is diagnosed using a breath test

  • Bacterial overgrowth creates gases (Hydrogen and Methane) that can be measured on the breath
  • Hydrogen gas feeds hydrogen sulfide SIBO
  • Hydrogen sulfide cannot be measured on a breath test

Hydrogen Sulfide (H2S) SIBO and symptoms

  • A type of SIBO that can’t currently be measured, testing coming soon
  • Rotten eggs smelling gas is suggestive
  • Common symptoms – nausea, diarrhea, bladder pain
  • When someone has GI symptoms but flat line H2 (lactulose) breath test



  • Bacteria to look for:
    • Desulfovibrio, Bilophila (both bile loving bacteria), Helicobacter, Streptococcus, etc.
    • Nirala’s Hydrogen Sulfide Master Class lays out the full list of bacteria to look for as well as how to treat.




  • Supplemental bile might be problematic
  • Be aware of the ingredients in your supplements, they may contain sulfur and sulfates and may actually contribute and act as a substrate for these organisms.
Dr. Ruscio Podcast
itunes-button Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - google music 100 Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - spotify button e1514412713726
In this episode…
Episode Intro … 00:00:40
What is SIBO … 00:04:16
Intro to Hydrogen Sulfide … 00:06:00
Indicators of H2S … 00:09:50
Symptoms … 00:12:45
Lab Testing … 00:14:50
Treatment … 00:15:10
Herbal Antimicrobials … 00:33:09
Episode Wrap Up …00:44:15

Download Episode  (Right click on link and ‘Save As’)

DrMR: Yeah, it’s great having you here. We’ve been crossing paths in the SIBO community for so long, I was saying before we started the recording, I’m shocked that it’s taken us this long to actually have you on the podcast. I’ve heard a lot of good things about your hydrogen sulfide SIBO and dysbiosis presentation at the most recent SIBO Symposium. Or, I guess the SIBO SOS, was it the SIBO SOS Summit, or the SIBO Symposium?

DrNJ: Actually the SIBO Symposium is in Portland, and I did it at the integrative SIBO Conference, which was in New Orleans.

DrMR: Gotcha. Thank you. So I heard some good things about that through the grapevine, and I said, perfect. This is a great chance for us to connect and discuss this more. So, really looking forward to jumping into that. But before we do, in case people haven’t heard of you, can you please tell everyone about your background and what you’re currently kind of up to?

Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - 51cREKoDx LDrNJ: Sure. I’m a naturopathic physician. I’ve been in practice for over 20 years. I started in Montana in primary care, and then moved to Australia about 13 years ago. And really was interested in SIBO when, I think like most of our SIBO practitioners, we’ve never heard of it until Dr. Allison Seibecker and Dr. Steven Sandberg-Lewis really brought it to our attention after Dr. Pimentel’s book, the IBS Solution, came out. And that was around 2011.

I was so fascinated with this subject, I’d never heard of it. It explained a lot while some people just didn’t improve with my very well-intentioned treatment protocol. And so I endeavored to learn everything about it. And because in Australia I wasn’t satisfied with the level of testing that was available, I started a testing facility, and then moved into practitioner education. And that’s really where my passion is.

It’s really evolved into a lot of, like I said, presentations, developing diets, like the biphasic diet and now the histamine biphasic diet. There’s a lot of movement in trying to solve these problems for our patients.

DrMR: Yeah. And you know, I was talking with someone the other day. And they said something that I thought was maybe counterintuitive if you spend much time in the health space. But it also made a lot of sense, which was, gosh, it seems like thyroid disorders are so straightforward, but the gut is so infinitely complex. You could paint a disagreement about that. I think there’s definitely some nuance with thyroid. But the more I thought about it, it really made me appreciate, it doesn’t seem complicated, I think, perhaps to you or I, because we eat, live, and breathe this.

But, gosh. When you think about all the different diets. All the different treatments. All the different points of dysfunction. The gut is pretty complex. And as you’re saying, it’s a constant evolution of trying to figure out the best way to get people healthy as quickly as possible.

DrNJ: Exactly. And I think as we understand more about microbiome involvement in why some people, for example, do better on one diet than another, the more complex it gets. And you go down into different rabbit holes all the time in your research. So it’s really fascinating.

What is SIBO?

DrMR: Exactly. So just in brief for people, if you haven’t heard of SIBO before, SIBO stands for small intestine bacterial overgrowth, and it’s a condition, like the name denotes, where you have an overgrowth of bacteria in the small intestine. And it’s been associated, to a varying degree, with the symptoms of IBS. Or I should say IBS-like symptoms. So your abdominal pain, bloating, altered bowel function, constipation, diarrhea, potentially in oscillation between the two. Abdominal pain, bloating, potentially reflux.

Breath Test StudyAnd definitely symptoms outside of the gut, also. But that’s just kind of the quick primer on SIBO. There’s this new type of SIBO that we’re learning about, which is hydrogen sulfide. I guess, Nirala, where do you want to launch us into the conversation on hydrogen sulfide?

DrNJ: OK. So let’s go back to SIBO, when we test for SIBO, we assess SIBO through breath testing Trusted SourcePubMedGo to source. Bacterial overgrowth creates gases that can be measured on the breath. We’re looking for hydrogen gas, and we’re looking for methane gas. So let’s concentrate on hydrogen.

Intro to Hydrogen Sulfide

Hydrogen gas serves also as a substrate or a fuel for another type of gas, called hydrogen sulfide, which cannot be measured on a breath test. So traditionally, in the SIBO world, we’ve really focused on hydrogen and methane. And we’ve treated them. We’ve treated our patients with very specific protocols that are specific to hydrogen, or methane. Now we are starting to realize. Or we have realized for some time that there is this hydrogen sulfide element that some people experience with SIBO that we can’t really properly assess, which is going to change probably at the end of this year, or very likely at the beginning of next year. Where we are going to be able to measure this third gas, hydrogen sulfide.

As hydrogen sulfide is produced by very specific bacteria that use the hydrogen to, like I said, make the hydrogen sulfide. When it’s overgrown in SIBO, hydrogen sulfide can cause diarrhea. It can cause bladder pain. It can cause body pain. Rashes. All sorts of things. But it’s actually more complicated than just hydrogen sulfide is bad and therefore we must kill it. Because it also has been shown to be beneficial in low amounts.

Any time we talk about SIBO that’s a pathological state, and we must treat it. But when you actually look at hydrogen sulfide, it’s really fascinating. Because it’s a really important substrate in very small amounts. So I don’t know how deep you want me to go, Michael. It’s really very interesting to know that you also produce hydrogen sulfide, inside of yourself, in terms of certain ways to produce hydrogen sulfide. Because it is so important. But when you have bacteria producing it in large amounts, it becomes problematic.

It’s sort of like a goldilocks gas. When you have it in small amounts, it’s beneficial. It can be anti-inflammatory. But when you have it in high amounts in the small intestine it can be problematic. And when you have it in high amounts in the large intestine it’s also problematic.

DrMR: You make, I think, an important point, which is that these things aren’t exclusively bad. But it’s rather, as you hinted with the great Goldilocks’ analogy, that it’s about balance. And so, again, just to reiterate that for the audience. It’s not all about just killing and getting rid of any kind of hydrogen sulfide gas in your system, or producing bacteria. Rather, maybe to use a bit of a more positive spun analogy. You want to give yourself some self-care. Maybe we don’t think of this like killing, but supporting your system back into a healthy balance.

Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - small intestineDrNJ: Exactly. With SIBO, I think Dr. Pimentel, who is a very well-known SIBO researcher, would argue that in SIBO, you must kill the bacteria that are overgrown in the small intestine because they’re not supposed to be there. But in the large intestine, we do, look at the physiology of the colon. You actually clear hydrogen sulfide 20 times more efficiently in the colon than in the small intestine. So that tells us, it’s supposed to be there in small amounts. And it helps with things like oxidation of butyric acid, and other short chain fatty acids.

Some thought to produce a new medication that combines nonsteroidal anti-inflammatories with hydrogen sulfide. Because it actually prevents the damage of the NSAID drugs on the mucosa. So we know that it can be beneficial in small amounts. I just really want to reiterate that. But because we’re talking about a pathological state, we can certainly move more into what happens when these bacteria are really overgrown.

Indicators of H2S

DrMR: Now, if a clinician is listening to this, or a patient is listening to this, and they’re trying to say, “How do I know if this is me or not?” what have you found to be potential indicators? I know, as just a few examples, to kind of start the conversation in this regard, that it’s been reported that the rotten egg smelly sulfur-like farts can be indicative. And I’ve seen different things shown in the literature in terms of, do people with traditional SIBO, hydrogen SIBO, have a higher incidence.

Gastroenterology JournalOne study has shown that people with SIBO have a higher incidence of hydrogen sulfide SIBO. And to your earlier point, we can test this in routine clinical practice. But it’s coming in not too long. There are some select research settings where we can measure. So that’s how we’ve been able to judge this. But, in other subgroups, they have found that people who are SIBO negative actually had a higher rate of hydrogen sulfide SIBO. So, this may answer the question of why some people are traditional SIBO breath test negative, negative hydrogen, negative methane, and also having symptoms. It might be hydrogen sulfide. But there also may be a correlation where those with hydrogen SIBO have a higher chance of having this hydrogen sulfide SIBO.

DrNJ: Yeah, as a substrate. Yeah. Hydrogen can be used by acetogens, and it can be used by methane producers. Hydrogen is just a raw substrate. And if you don’t have an overgrowth of either methanogens or hydrogen sulfide, you actually just have pure hydrogen overgrowth.

Sponsored Resources

DrMR: Hey everyone. Let’s talk about one of my favorite tests for digestive health, the GI map from Diagnostic Solutions, who has helped to make this podcast possible. Now, if you’ve been reading any of the case studies I’ve published in the Future of Functional Medicine Review clinical newsletter, you’ve likely seen that this test, the GI map, is a test I frequently use in my practice. Why?

Diagnostic SolutionsWell, one of my favorite things about this test is it has excellent insurance coverage. This is a few hundred dollars I save patients. This lab is also CLIA certified, which is essentially the quality assurance bureau for labs. So it’s important that these labs are being monitored, not cutting any corners. That’s where you get your CLIA certification.

Now, this test uses quantitative PCR technology, so it’s a DNA test. And you’ll get a good read on dysbiosis with this test, because they will assess and report out various types of bacteria, yeast, and parasites, including protozoa, worms, and amoeba. They also have some valuable and helpful clinical markers, like calprotectin, which can help rule in or out inflammatory bowel disease, and zonulin, a marker of leaky gut.

So head over to to learn more, and to order your tests.


DrMR: So how do you start to make the judgment of, does this person look like they potentially have hydrogen sulfide SIBO? What are some of the things you’re looking for in terms of history, or symptoms that make you suspicious?

DrNJ: So the class symptoms of excessive hydrogen sulfide is the belching and flatulence, as you’ve mentioned. Often with a rotten-egg smell. But it doesn’t always have to be like that. Clinically, I’ve not always found this to be the case. Sometimes, people don’t have the belching. But if you do have belching, and flatulence that’s very smelly, then it’s possible you have this issue.

Digestive ProblemsAlso, nausea is common, diarrhea. Diarrhea is often associated with hydrogen sulfide when it’s a SIBO case. But a lot of research actually correlates more the constipation type when you have the sulfur-reducing bacteria overgrown in the large intestine. So these are very specific organisms that produce hydrogen sulfide. And when it’s overgrown in the colon, we actually see more constipation. But classically, and clinically what we see on a breath test can be just a flat lining hydrogen on a lactulose breath test, not so much the glucose, because we expect that to be sort of flatlining towards the end. So more of a lactulose hydrogen flat curve. And classic signs and symptoms.

So it is a diagnosis of exclusion when it’s SIBO. But with LIBO, or large intestinal bacterial overgrowth, we can easily assess an overgrowth of the organisms that produce hydrogen sulfide, which are, the desulfovibrio are the main ones, and Bilophila wadsworthia, so really classic organisms that use a very primary sulfate reduction pathway. And that can be done either with, I’m not sure if I’m allowed to mention labs.

DrMR: Yeah go ahead.

Lab Testing

DrNJ: Like for example, the Genova GI affects assesses for this organism. And I like that one because it also looks at methanogens. So you can really get a good sense of what’s overgrown in the large intestine. But also UBiome or any lab that does a very good PCR assessment or DNA assessment of the microbiome can really help to determine if these organisms are overgrown. And it’s quite a different treatment from SIBO. Even if it’s overgrown in the small intestine.

Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - 9448181DrMR: And that’s what I want to ask you about. Now, I’m certainly open to the treatment needing to be different. There has been one study Trusted SourcePubMedGo to source published. And if there are other studies on treatment, please fill me in. I can’t claim to have done an exhaustive review. But I know there was one study that showed that traditional antibiotic therapy could work for hydrogen sulfide SIBO. Why is that you say the treatment is different. What data do we have that helps us answer this question?


DrNJ: Yes. And that’s a really good question. The thing with hydrogen sulfide is that actually antibiotic therapies, the organisms are often resistant to treatment. And so they are very good at creating, or being resistant to antibiotic treatment. And that was done in ulcerative colitis research, and things like that. I’m talking more, the way I treat hydrogen sulfide is, and I live in a country where, as a naturopathic physician, I cannot prescribe prescription medications. So I have to constantly think outside the box as to what I’m going to do.

But what my research uncovered is, first of all, when you have a hydrogen sulfide bacterial overgrowth. Again, those are very specific organisms. Unlike hydrogen production, you have a number of species of different bacteria. But with hydrogen sulfide, it’s pretty specific in terms of the Desulfovibrio, the Bilophila, and then you also have some secondary pathways where we see Helicobacter is often a hydrogen sulfide producer. And streptococcus and other organisms.

Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - 23898195But the primary ones can be treated actually quite differently. There was one study Trusted SourcePubMedGo to source that showed that a low-FODMAP diet was actually not very good for hydrogen sulfide overproduction, which I found really interesting, because our main diet that we use for SIBO utilizes some element of low fermentable carbohydrate diet.

So, that was really interesting for me. Now, granted, that was just one study. But one of the big elements people have to understand, especially with Desulfovibrio and Bilophila, they are bile-loving bacteria. And what that means is, if you have a very high-fat diet or you’re taking bile supplements or cholagogue herbs, they love that. They actually thrive in a very high-fat environment.

I’ve done hundreds and hundreds of stool tests that really corroborate that, where I see very high fecal fat, or even Bacteroidetes, which are also bile-loving organisms. And I see a very high level of Desulfovibrio.

Now, association obviously does not prove causation in just stool tests. But it does seem to bear out that people that are on a very high meat and fat diet do seem to have higher levels of this organism. So it’s interesting that this is also shown, then, that a low-FODMAP diet is counterproductive for these organisms.

Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - AdobeStock180191805SulfurAlso, I’ve found that in terms of treatment, now, I usually do a low-sulfur diet, meaning low meat, red meat in particular, low eggs or no eggs. There’s a whole list that you can find on my website that goes through foods to avoid. And just for a short period of time to see if you actually benefit from that. And then we usually use binders. Like bismuth or zinc acetate to reduce the numbers. Because remember, we don’t want to totally wipe them out. We just want to manage it. We want to reduce the output.

Now, when it comes to conventional medications, like I said, I don’t know the data. I think Dr. Pimentel was going to reveal some antibiotic therapy. I know that I’ve seen people use rifaximin, which of course is the main antibiotic used for SIBO. And it makes sense that if you use rifaximin and you kill organisms that produce hydrogen, that you would deprive the sulfur organisms of their fuel. So it’s possible that that actually works. And I certainly have seen that work. I’ve seen it also not work. So, the jury is still sort of out for me when it comes to what’s the perfect antibiotic cocktail for this situation.

DrMR: The piece on diet is really interesting. And it reminds me of why I think it’s so important for patients not to forget about listening to their bodies. One of the things I’m continually finding myself coaching patients on is not having this tunnel vision like approach to their healthcare. I’ve had SIBO, or I think I have SIBO, and so now everything I’m going to do for my health is going to be centered around the traditional SIBO recommendations.

And the problem with that is if there’s something occurring in that person that we can’t yet measure, and that condition, in this case, hydrogen sulfide SIBO might violate the rules of the traditional SIBO treatment paradigm, that person might be doing things that are inadvertently hurting them.

“Hydrogen sulfide SIBO might violate the rules of the traditional SIBO treatment paradigm, that person might be doing things that are inadvertently hurting them”Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - tweet e1540485375388

And why I say listening to your body, is there are plenty of patients, and I’m sure you can also relate to this, who notice they don’t do well on a low-carb diet. And yes, there are definitely patients who feel better on low-carb diets. Absolutely. But the point I’m making is some patients actually start eating some grains, start eating some starches, reducing their fat or even eating more FODMAPs. And some of these foods that traditional SIBO recommendations would tell you to avoid. But when people start eating these non-SIBO foods, they actually feel better.

Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - LowFODMAPGuide usewithweeklytipWhich, again, is why I recommend people, yes, look at the recommendations out there for SIBO if you have SIBO. But don’t pigeonhole yourself into only following those recommendations because there might be something else occurring. And if you listen to your body’s response, your body will usually lead you in the right direction.

DrNJ: That’s right. That’s correct. And I think the more we understand about the microbiome. About this incredible rainforest in our gut as to how the different species talk to each other. How they create a particular terrain that is very unique to each person. And we can’t generalize. And I think that’s sort of where we’re headed with a lot of digestive disorders, where we actually really individualize treatments. And I think that’s the closest we can get right now. Basically, looking at microbiome DNA and starting to understand how different bacteria respond. And it’s still in its infancy. There’s still a lot we don’t know.

DrMR: Exactly. And we’re getting there. Hopefully, there will come a point where we’ll be able to say, this is the exact probiotic you should take. This is the exact diet you should follow. But we’re not there. There are some early hints. And I’m sure you see this also. Sometimes patients get one diagnosis and their whole worldview can form to that diagnosis, and they forget about listening to their body.

And I think the carb piece is such a great example. Because that is one area where I’ve seen more patients just beat their head against the wall. They’ve been told that all carbs are bad. And for some patients, they see pretty cathartic levels of improvement just when they open up their diet and start pushing into some of these higher carb foods. Have you seen that same thing in some cases?

DrNJ: Absolutely. In fact, the case that I presented in New Orleans at this conference was exactly that. This was a patient that had fibromyalgia. She was in her 60s. Depression. Very longstanding constipation. And she’d been treated for SIBO for probably a year and a half, and was just not getting anywhere. And we did a stool test. We looked at her microbial diversity.

This is the other thing. When you have a very low level of bacterial diversity. Meaning, how many different species of plants do you have in your garden? That makes a big difference to how you’re going to respond to the different diets as well. And that’s why things are so individualized.

So what I did for her, we found that she had just astronomical levels of Desulfovibrio, the main sulfate-reducing bacteria. And she had virtually no short chain fatty acids at all. Nothing. Below detectable levels, which I’ve never seen before. So we completely changed her diet. From one day to the next. I told her to go on a vegan diet. And to go slowly with the fiber. She hadn’t had any fibers at all. And within four weeks, there was a dramatic improvement in her symptoms.

Now, it sort of waffled around. First it was really dramatic, and then we started to do some other things. And it kind of went back and forth for a while, as she adjusted. I then had to go from a vegan diet back to sort of more of a paleo diet, which was still high fiber. But some more protein. So we continually adjusted the diet, and obviously other treatments. But just to demonstrate that also if you’re given a diet, that doesn’t mean that’s it. You have to follow that forevermore. Things are dynamic. Especially when you’re dealing with trying to regrow your rainforest.

DrMR: Now, you mentioned certain species that you can detect on a stool test. And I’m wondering, do we have any data that has correlated elevations of these levels on stool tests to symptomatic presentation?

Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - 15747080DrNJ: Absolutely. There was one by Singh in 2015 Trusted SourcePubMedGo to source that showed absolutely sulfate-reducing bacteria were found in much greater number in constipation predominant IBS, and periodontitis, and pouchitis, and IBD, and obesity, as well, related to that. So there are studies out there that definitely correlate these specific organisms to pathology states.

DrMR: Have there been any looking at IBS?

DrNJ: Yeah, that’s the one I just mentioned. Especially in constipation dominant IBS.

DrMR: OK, gotcha. If I send you an email after, can you send me some of those links? Because I know people are going to ask. It would be great to beat them to the punch and put them in the…

DrNJ: Sure. Just put in Singh, hydrogen sulfide in physiology and disease of the digestive tract. 2015. That’s a really great one to have if you are inclined to read scientific studies. Because it goes through the whole, also how hydrogen sulfide is produced endogenously and exogenously.

That’s the other thing, some people have issues with hydrogen sulfide not necessarily because they’re suffering from a huge overgrowth. But because their own detoxification pathways of hydrogen sulfide are impaired. Because they have some DNA variant or SNP that is in the CBS pathway, which usually, cystathionine beta-synthase, which is a particular pathway that manages sulfur and turns sulfite into sulfate. So if you have a problem there, you can just accumulate hydrogen sulfide. And suffer the symptoms.

So this is what I mean. If you actually have a gas that you produce also internally, and externally by bacteria, it takes some sorting out a little bit.

DrMR: Sure. And we discussed with Heidi Turner in the past the low sulfur diet. And we’ve developed a handout for that. And I agree regarding the low sulfur diet, specifically for some people that is a shift they need to make. That one is also a bit counterintuitive for people, because again, you’re sometimes reducing these sulfur-rich, cruciferous family vegetables. And people have such a tendency to equate those to being health promoting foods. It’s not to say that they’re necessarily bad, but someone may need to reduce the intake of those at least while they’re trying to balance things out.

brussels sproutsDrNJ: Exactly. I’m not as strict. I do eliminate cruciferous vegetables. But if you go online and you search low sulfur diet, it can be exhaustive. You have to avoid everything. I’m actually more interested in the biggies. And I’ve found that to be sufficient in many cases.

What I’ve found is that some people, they have one food that’s a real problem. Like egg. Or kale. But they can manage the other ones. Obviously, onion and garlic are sort of in a class of themselves of problematic for anyone with SIBO. But they are also on that list. So very often, I just say, do it for a month. And see what foods, I start with the cruciferous. What can you manage there? By then, hopefully, they already have made some improvements.

DrMR: Do you feel a one-week low sulfur diet trial is long enough? That was something that Heidi and I had discussed. She, I think, she has far more experience with this than I do. Although, as I’ve been experimenting with it, it seems like a vital approach can be to have someone follow a bit more of a strict low sulfur diet for one week. If they’re going to improve, they’ll notice it by the one week. And then they can relax the boundaries a bit and be on a lower sulfur diet, rather than a strict low sulfur diet in the longer term. Are you noticing any kind of time response curve?

DrNJ: I do, and it’s true. Most people do respond positively within a weak. But bear in mind, I see really advanced cases. So there’s a lot of overlap of a lot of stuff. When they’re really ill, I usually allow for a little longer time. And I do other supportive measures. I give them molybdenum to help clear hydrogen sulfide. And I might give them binders and things like that.

View Dr. Ruscio’s Additional Resources

StudyDrMR: You mentioned a specific list of bacteria. Is that available somewhere on your site? I’d love to include, especially for practitioners who are going to be doing testing on their patients and would like to know what the hydrogen sulfide producing bacteria are. Is there a list somewhere we could point people to?

DrNJ: Yeah. My lecture, I’ve sort of turned it into a Master Class for practitioners that are listening. It’s called Hydrogen Sulfide in SIBO and LIBO. And it’s available on That’s the lecture that I gave with all the references and the treatments and the case examples, etc.

Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - 19709217But the study you want to look at that really went into was the one I mentioned before by Singh and Lin, called “Hydrogen Sulfide in Physiology and Disease of the Digestive Tract.” I think it was published in Microorganisms in 2015, I want to say. I referenced that study. It was really a great one that went into the different pathways. The main sulfur-reducing pathway Trusted SourcePubMedGo to source is something called dissimilatory sulfate reduction. And the second, lesser used one is desulfurization. And that’s used by other organisms, like streptococcus and Fusobacterium and salmonella, etc. They actually use it, they degrade the sulfur-containing amino acids, versus the primary pathway, where they actually produce hydrogen sulfide from the substrate from the foods that we mentioned.

Herbal Antimicrobials

Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - 14612249DrMR: Gotcha. So we talked about treatment. I should clarify more so herbal antimicrobial treatment. We touched on that. And I know there’s been discussion about bismuth Trusted SourcePubMedGo to source and/or zinc, especially bismuth potentially being a biofilm disruptor, or at least a synergistic. But what else are you noticing in terms of what we have to do differently with the herbal antimicrobial or like treatments when we’re looking at hydrogen sulfide Trusted SourcePubMedGo to source, specifically.

Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - Tile 9558280 BismuthDrNJ: I use mainly oil of oregano as an agent in and of itself. I haven’t found berberine to be effective, personally. I get the best results with the combination of diet. I have used bismuth and high zinc, usually acetate because acetate doesn’t get absorbed very well. So they say. So, I have to compound it.

But because it’s a normal organism, just like methanogens. Methanogens are not pathogens. And I’d actually say that hydrogen sulfide producers are probably more pathogenic than methanogens. But you just want to manage. You just want to weed your garden a little bit. So it’s about the reduction of levels so that things can be more in balance. So, I don’t go for total eradication.

DrMR: Ok. And are you using bismuth routine along with that? Do you lean more so towards zinc? Do you use them both together?

Funtional Medicine FormulationsDrNJ: I use zinc and bismuth, and I use oil of oregano for about 4 to 6 weeks. And I use the diet. And the other interesting thing, because I do a lot of microbiome testing. In those that have equol producing bacteria. Equol is a substance that’s produced by the metabolization of soy isoflavones into equol. And not everyone can do this. And that’s why soy is beneficial for some, and not beneficial for others.

But equol producing bacteria, like Adlercreutzia and the Eggerthella phylum is helpful to reduce both methane and hydrogen sulfide. Now, I’m just beginning to experiment with that. But to actually use soy isoflavones for both methane and hydrogen sulfide overgrowth.

DrMR: Interesting. Keep me abreast of that. If you feel there’s something there that’s worthwhile, let me know, and we can have you back on to expound upon that. Because that would be interesting to see how that pans out.

DrNJ: Yeah. That will be some time.

DrMR: I’m sure, yeah. The wheels turn slowly, I know.

DrNJ: Yeah, and then you’ve got to retest, and all that. It takes a while to get the data.

DrMR: All right, so we’ve laid out some things that I think are really important here that provide some nuance I suspect could be very helpful for people, which is the low-FODMAP diet is not always going to be a good idea. And what some people gravitate towards being a more paleo-like diet, which can be higher in fat, sometimes higher in meat, may also be problematic. And steering toward a lower sulfur diet may also be helpful. Another reason for not pigeonholing one diet in particular. But those nuances I think can definitely be helpful for people. And the bit about the oregano with the bismuth and the zinc also really helpful. And these, maybe subtle changes that people can make that may lead to significant difference.

Is there anything else that you think is important in the realm of hydrogen sulfide SIBO? I next want to ask you if there’s anything else that you’re excited about just generally. But anything else within the hydrogen sulfide that you think is worth mentioning?

DrNJ: Yeah. The main sort of take-home is what you’ve already mentioned in terms of just be aware that you may not follow a specific SIBO diet. You might actually have to increase your fibers. The other thing is, be aware of your supplements. A lot of people taking ox bile, or are really using supplements that also have a sulfate component. For example, you can get berberine sulfate. So, be aware that there are some supplements that contain sulfur and sulfates. So they may actually contribute and act as a substrate for these organisms.

Also, I think be aware if you’re somebody who just eats a lot of fat, because you are on a low-carb diet, you may inadvertently, if you have a problem with this particular situation of hydrogen sulfide. You might be making that situation worse with doing that.

DrMR: That’s a good point. Especially the bile piece. Thank you for reiterating that. We actually published one case study where the only thing we had to do to get this person well who was otherwise nonresponsive was just get her off bile. And also remember, for the audience, bile can also be a laxative. So it certainly can be helpful. But bile acid malabsorption diarrhea is a legitimate condition that can affect some people. So don’t think just because you saw a blog post talking about how bile supplementation can be helpful that it will always be helpful. And this may be a specific case where it may be a bit detrimental.

Treating SIBO with a High FODMAP Diet & Higher Carb Intake – How Hydrogen Sulfide SIBO Breaks The Rules with Dr. Nirala Jacobi - sibo doctor edu logo blue retinaDrNJ: Well, that’s why I think as practitioners, and my passion really is with practitioner education. Is to understand, really be on the cutting edge of microbiome science and start to really put the pieces together. Because I know a lot of practitioners that do stool testing, and don’t really know how to interpret a lot of the microbiome results that they’re receiving. So, just be aware of that and learn more about microbiome. We have a course, Microbiome Restoration, on The SIBO Doctor that really goes through a lot of these different things.

I think as a practitioner that focuses on digestive disorders, it really is important that you start to deal with those kinds of situations where people are completely different. When you look at the microbiome, and even though that person may have SIBO, you’re going to do a different diet for that person than the same exact person that has a totally different microbiome readout and they may also have SIBO. I don’t know if I explained that very well.

DrMR: Yep, you did.

DrNJ: When I started to really understand that, my whole practice changed. Also with SIBO treatment.

DrMR: I agree. That’s why one of the things I think is so important is just to keep an open mind. And even though I’m a big supporter of something like the low-FODMAP diet and I’ve defended that oftentimes of the critics who have criticized it for various reasons. I’m not dogmatic. Not everyone gets a low-FODMAP diet. Some people I tell them to get off the low-FODMAP diet for various reasons. So I think that’s incredibly well-said, learning how to navigate the nuance.

What else is exciting? Anything else you feel is worth mentioning? Any new treatments, new tests, anything else that’s exciting?

DrNJ: Well, the really, really exciting thing is that we will be getting, that’s what I understand from good sources, that we will have the ability to test for hydrogen sulfide very soon, and not just in a research setting. So stay tuned. I think that is coming. I also think that all of those exciting things, like pill cams and all that type of stuff that’s on the horizon is also very exciting and may give us more certainty as a practitioner with testing and so forth.

So those kinds of things are, to me as a practitioner, very exciting. And learning more and more about the incredible role of how the microbiome really works. And how they work in unison. It’s not just about the individual species, but how do they work together? That kind of stuff is always very exciting to me. Other than that, I don’t know. I’ve had such a big year, I’m kind of excited out.

DrMR: Fair enough. And you’re right about the pill cams and the smart capsules. At one point, I wouldn’t be shocked if at some point breath testing is considered obsolete because we have these smart pills that can just take multiple samples from multiple positions in both the large and small intestine and look at everything from fungus to bacteria to gas pressure to pH. It’s funny to think that maybe, who knows, if that’s 5 years away or 10 years away. I think the cost barrier will probably be the biggest one. But at some point, breath testing may be something that you learn about in history class. Medical history class.

DrNJ: Probably. I would not be surprised. And I’ve learned to really appreciate how to really interpret the breath test. And I still very confident with testing, even with lactulose. But I do understand that compared to more definitive data that you get from something like a pill cam or a pill sampler is just incredible that that’s even a possibility soon. So as a clinician, I’m excited about that.

DrMR: Same here.

DrNJ: You have to embrace that.

Episode Wrap-Up

DrMR: Well thank you for taking the time to discuss this. I’m really happy we had a chance to talk about this. Because I do think this is a nuance, especially because it’s a nuance that violates norms, that’s really important for people to hear about. So thank you again for taking the time and doing this work and research.

Tell people again where they can learn more? I know you have some practitioner training and self-help c courses. So please, let people know where they can find out more.

DrNJ: Yeah, thank you for that. My main education website is called there are courses on microbiome restoration. I go through SIBO treatment courses, with the biphasic treatment protocols. We also have a wonderful course coming up with Dr. Steven Sandberg-Lewis, he’s coming out to Australia to teach function GI physical exam skills for practitioners. So that’s in November. And I’m super excited about that. Because it’s really the missing link for a lot of practitioners who don’t put the hands on the patient enough. I think you can learn a lot from a proper physical exam. And also functional exams and reflexes and things like that. So I’m excited about that.

And there’s more for patients. There are free handouts. The biphasic diet. And so forth. So it’s really a hub. And then I have my clinic. But that’s in the countryside in northern New South Wales called the Biome Clinic. So that’s really my two main areas of focus. And then I have a testing service, as well, called SIBO test.

DrMR: Awesome. So knee deep in SIBO, SIBO, and gut, gut.

DrNJ: I know. I need a bit of a break from that. But it is fascinating, what can I say.

DrMR: Awesome. Well, Nirala, thank you again. Hopefully, our paths will cross at another SIBO conference here soon.

DrNJ: I’m sure they will, Michael. Keep up the good work.

DrMR: Thank you.

What do you think? I would like to hear your thoughts or experience with this.

Dr. Ruscio is your leading functional and integrative doctor specializing in gut related disorders such as SIBO, leaky gut, Celiac, IBS and in thyroid disorders such as hypothyroid and hyperthyroid. For more information on how to become a patient, please contact our office. Serving the San Francisco bay area and distance patients via phone and Skype.


I care about answering your questions and sharing my knowledge with you. Leave a comment or connect with me on social media asking any health question you may have and I just might incorporate it into our next listener questions podcast episode just for you!