As well as hydrogen and methane SIBO (small intestine bacterial overgrowth), there’s a third type — hydrogen sulfide SIBO.
The trio-smart test is the first SIBO breath test that can help detect and distinguish hydrogen sulfide SIBO from the other two types.
All the SIBO types likely have a similar trajectory and require similar treatment, so though it can be helpful to know what type you have, it’s not essential for treatment.
The best approach to hydrogen sulfide SIBO treatment (and other types of SIBO) is to look at the gut holistically rather than focusing too narrowly on a specific lab finding.
Learning you have SIBO (small intestinal bacterial overgrowth), can be both a worry and a relief — the latter because it can help to explain the unpleasant symptoms, such as diarrhea, constipation, bloating, fatigue, and brain fog, you’ve been experiencing.
A new type of SIBO, hydrogen sulfide SIBO, has recently become a popular topic of conversation within the gut health world. But what is hydrogen sulfide SIBO, and does it require a different approach to treatment?
It’s likely that specialized approaches, such as low sulfur diets or avoiding sulfuric medications, are not necessary for this type of SIBO (and may actually distract from helpful treatments).
In this article, we’ll look deeper into what hydrogen sulfide SIBO is, the value of breath testing, why a bigger picture approach to gut healing is important, and how to treat SIBO symptoms in general.
What Is SIBO?
SIBO is short for small intestinal bacterial overgrowth. As the name suggests, this is when abnormal amounts of normal gut bacteria start to grow in the small intestine, a part of the digestive tract where they would not normally be present (most bacteria reside in the bowel, or large intestine).
You may have come across complicated protocols to eradicate SIBO, but it doesn’t need to be the scary diagnosis it’s sometimes made out to be. In fact, SIBO is really just a lab finding that indicates a particular type of dysbiosis or gut microbiome imbalance.
Like all types of gut bacteria imbalances, your SIBO will start to improve when you look at your gut health holistically.
SIBO can generally be categorized as:
Hydrogen sulfide dominant
These categorizations refer to the main types of gases that the bacterial overgrowth in your small intestine produces. Technically speaking, some say that the methane-predominant version should be referred to as intestinal methanogen overgrowth, not SIBO, as the microorganisms that produce methane, known as methanogens, belong to the classification archaea, not bacteria. However, for our purposes, it certainly still counts as a form of SIBO.
Symptoms of SIBO
As with any form of gut dysbiosis, digestive symptoms (gas, bloating, belching, reflux, flatulence, abdominal pain, diarrhea, and constipation), are among the most common SIBO symptoms, along with non-digestive symptoms like fatigue, brain fog, and joint pain.
The table below shows the different types of SIBO and the gut symptoms they tend to be most associated with:
People with irritable bowel syndrome (IBS) and inflammatory bowel disease are much more likely than people without these conditions to be diagnosed with SIBO, according to high quality meta-analyses. For example:
When 50 clinical studies were pooled, more than one-third of IBS patients tested positive for SIBO and IBS patients were nearly five times more likely to test positive for SIBO compared to healthy people [4 Trusted SourcePubMedGo to source].
Until quite recently we only really knew about hydrogen and methane SIBO. However, hydrogen sulfide SIBO is a third type that may be present in some people.
In hydrogen sulfide SIBO the patient, or rather the microbes in the patient’s gastrointestinal tract, produce more hydrogen sulfide gas (colloquially known as rotten egg gas, due to its sulfurous odor), than is normal or healthy.
There is a view held by some individuals and practitioners that more specialized treatments specifically targeting hydrogen sulfide, like low sulfur diets and avoiding sulfuric medications, will help people with this type of SIBO to get better more quickly.
However, neither the available research nor my clinical experience have provided a clear reason to address hydrogen sulfide SIBO or its symptoms any differently than we would methane or hydrogen dominant SIBO cases.
Nevertheless, being able to test for and identify hydrogen sulfide SIBO — which until recently hasn’t been possible — can give answers to patients with uncomfortable symptoms that have so far been impossible to pin down.
Testing for SIBO
Testing for hydrogen and methane SIBO has traditionally been done by breath testing, immediately following the consumption of a measured sugar or carbohydrate solution. Humans don’t usually produce hydrogen or methane gas on the breath, unless they have malabsorption issues, so when these gases are identified, it usually means that bacteria in the gut are producing them [17 Trusted SourcePubMedGo to source].
Unfortunately, hydrogen sulfide is not tested for on traditional SIBO breath tests. That’s why a new test, called the Trio-Smart, is potentially exciting. It is the first that can identify hydrogen sulfide too.
Trio-Smart is also a breath test, but it detects and measures all three of the SIBO gases (hydrogen, methane, and hydrogen sulfide).
Downsides of Lab Testing
My clinical philosophy has increasingly been to take a cautious approach to diagnosing with functional medicine lab testing, because often, expensive tests fail to actually add much to the clinical picture or help make a patient feel better.
While often carried out with the best of intentions by those practising naturopathic or functional medicine, excess or unnecessary tests may just encourage a reductionist approach — i.e., the focus ends up on just one lab marker, and how to improve it, rather than thinking about the patient as a whole and considering the entirety of their symptoms.
When it comes to breath testing specifically, there can also be issues interpreting results if the clinician doesn’t have extensive experience with these tests. Problems that arise can include:
False positives from breath analysis carried out beyond the accuracy cut off point, which is at around 80-90 minutes after carbohydrate consumption [19 Trusted SourcePubMedGo to source].
Advantages of the TrioSmart Test
That said, the Trio-Smart test, which has been developed in collaboration with SIBO researcher Dr. Mark Pimental, does have the potential to add value to existing SIBO diagnosis and treatment pathways.
The advantage of the Trio-Smart test is that it provides a more complete picture of what’s going on with your bacterial overgrowth, and may help prevent false negatives as it tests for all three gases. It can be used to monitor what is happening with SIBO before and after a gut-healing diet and probiotic treatment, for example.
Hydrogen Sulfide SIBO Diet
If you’ve been diagnosed with hydrogen sulfide SIBO, or indeed any type of SIBO, the most important thing to consider is your diet. This means finding a diet that allows you to have and maintain a healthy environment in your gut.
Sometimes highly restrictive, detoxification-style dietary regimens are recommended straight off for SIBO, but a softer approach with diet is better for most people.
With that in mind, and given the huge overlap between SIBO and IBS, the low FODMAP diet is often an effective (and easier) place to start.
One review of 10 clinical trials found that the low-FODMAP diet led to clinical response in 50–80% of patients with IBS symptoms [20 Trusted SourcePubMedGo to source]. This review also found that the low-FODMAP diet resulted in several positive changes in the microbiome, and in overall gut health, including:
A less leaky gut
Reduced histamine (a marker of an overzealous immune system)
An advantage of the low-FODMAP diet is that though it may be somewhat restrictive at first, over time, as your SIBO improves, you should gradually be able to reintroduce and tolerate foods that were previously problematic.
Does a Low Sulfur Diet Help Hydrogen Sulfide SIBO?
Though people with hydrogen sulfide SIBO are sometimes told to go on a strict low-sulfate, low-sulfur diet, no studies exist to show that this is actually of benefit for this condition.
In general, research on low sulfur diets for gut health is limited. One 2004 study found that high-sulfur foods (which include many common protein foods) was associated with relapses in inflammatory bowel disease [24 Trusted SourcePubMedGo to source].
While it’s always worth experimenting to find the diet that works best for you, avoiding high sulfur foods based only on your lab results (rather than your symptoms or reactions to those foods) might end up distracting you from the bigger picture.
If you have hydrogen sulfide SIBO, it’s best to stick with where the diet research is strongest, which, as per the above, is around a healthy less processed diet that takes into account potential food sensitivities (like low FODMAP).
While it has become a popular opinion that probiotics don’t help SIBO (because they add extra bacteria into the system) this is simply wrong. In fact many studies show taking probiotics can bring benefits for all types of SIBO.
A meta-analysis summarizing 18 clinical trials concluded that probiotics are an effective treatment for SIBO. Specifically, probiotics reduced bacterial overgrowth and hydrogen concentrations, and improved symptoms, including abdominal pain [20 Trusted SourcePubMedGo to source].
Research has shown that multispecies probiotics work better than single species for IBS [27 Trusted SourcePubMedGo to source, 28 Trusted SourcePubMedGo to source]. To add to this body of research and start to develop a better scientific picture of this treatment approach, we’re currently running a clinical trial using the above triple therapy regimen for those with all three types of SIBO.
The three types of probiotics appear to work together like the legs of a three-legged stool. If the stool only has one or two legs, it’s likely to be unstable. With three legs, the stool is able to stay upright.
A Note About Prebiotics
Although probiotics get the green light for use by people with SIBO, the same can’t be said for prebiotic foods and supplements (fibers such as inulin and fructooligosaccharides that stimulate bacterial growth).
Though prebiotics can be good for people with robust gut health, they can also be potent producers of hydrogen in the gut‚ which is bad news for many people with SIBO [29 Trusted SourcePubMedGo to source].
Other Hydrogen Sulfide SIBO Treatments
Here are some other treatments that you may want to try further down the road if you need more help to feel fully recovered from SIBO. It’s usually best to only introduce these one at a time, a few weeks apart.
Always remember that how your symptoms change is generally more important than changes in lab test results.
SIBO treatment often uses antibiotic therapy with Rifaximin, which reduces unwanted gut bacteria in both the small and large intestine [30 Trusted SourcePubMedGo to source].
Elemental diets were developed as a medical food for patients with severe digestive issues. They include nutrients broken down into their constituent parts (e.g. amino acids rather than proteins).
Most research into elemental diets has focused on inflammatory bowel disease [33 Trusted SourcePubMedGo to source]. However, one intriguing study saw lactulose breath tests normalize in 80% of SIBO patients after two weeks on the elemental diet [34 Trusted SourcePubMedGo to source]. Sixty-five percent of patients in the same study saw an improvement in their IBS symptoms.
Elemental diets can be used in flexible ways to manage SIBO symptoms. For example, getting 50% of your calories from elemental meals still reduces gut symptoms and flares [35 Trusted SourcePubMedGo to source].
In other words, if you want to just replace breakfast or lunch with an elemental diet, that can still help your gut.
Bismuth, which is an active ingredient in Pepto Bismol, and also sold in some health supplements, is another option to try for hydrogen sulfide SIBO. It purportedly has anti-sulfur actions, but has more convincing research in the areas of:
Prokinetics are supplement and prescription medications that help improve your gut motility (i.e. they encourage food to move through your digestive tract in a timely manner).
Supporting gut motility with prokinetic supplements or even with prokinetic prescription medication, (such as low dose neomycin, or prucalopride) — may reduce frequency of SIBO relapse. It’s certainly worth discussing this option with your doctor or functional medicine practitioner, to see if prokinetics are right for you.
Tying It All Together
To recap, hydrogen sulfide SIBO is a type of SIBO that can now be diagnosed with a lab breath test. This can help patients and practitioners better identify the problem, but there’s likely no need for a special set of treatments for this specific SIBO type.
Instead it’s important to work on improving your overall gut health with diet and probiotics, followed by antimicrobials and other therapies if necessary.
Singer-Englar T, Rezaie A, Gupta K, Pichetshote N, Sedighi R, Lin E, et al. Sa1219 – Validation of a 4-Gas Device for Breath Testing in the Determination of Small Intestinal Bacterial Overgrowth. Gastroenterology. 2018 May;154(6):S-281. DOI: 10.1016/S0016-5085(18)31300-3.
Pimentel M, Hosseini A, Chang C, Mathur R, Rashid M, Sedighi R, et al. Fr248 EXHALED HYDROGEN SULFIDE IS INCREASED IN PATIENTS WITH DIARRHEA: RESULTS OF A NOVEL COLLECTION AND BREATH TESTING DEVICE. Gastroenterology. 2021 May;160(6):S-278. DOI: 10.1016/S0016-5085(21)01391-3.
Chen B, Kim JJ-W, Zhang Y, Du L, Dai N. Prevalence and predictors of small intestinal bacterial overgrowth in irritable bowel syndrome: a systematic review and meta-analysis. J Gastroenterol. 2018 Jul;53(7):807–18. DOI: 10.1007/s00535-018-1476-9. PMID: 29761234. Trusted SourcePubMedGo to source
Shah A, Morrison M, Burger D, Martin N, Rich J, Jones M, et al. Systematic review with meta-analysis: the prevalence of small intestinal bacterial overgrowth in inflammatory bowel disease. Aliment Pharmacol Ther. 2019 Mar;49(6):624–35. DOI: 10.1111/apt.15133. PMID: 30735254. Trusted SourcePubMedGo to source
Pimentel M, Wallace D, Hallegua D, Chow E, Kong Y, Park S, et al. A link between irritable bowel syndrome and fibromyalgia may be related to findings on lactulose breath testing. Ann Rheum Dis. 2004 Apr;63(4):450–2. DOI: 10.1136/ard.2003.011502. PMID: 15020342. PMCID: PMC1754959. Trusted SourcePubMedGo to source
Podas T, Nightingale JMD, Oldham R, Roy S, Sheehan NJ, Mayberry JF. Is rheumatoid arthritis a disease that starts in the intestine? A pilot study comparing an elemental diet with oral prednisolone. Postgrad Med J. 2007 Feb;83(976):128–31. DOI: 10.1136/pgmj.2006.050245. PMID: 17308218. PMCID: PMC2805936. Trusted SourcePubMedGo to source
Parodi A, Paolino S, Greco A, Drago F, Mansi C, Rebora A, et al. Small intestinal bacterial overgrowth in rosacea: clinical effectiveness of its eradication. Clin Gastroenterol Hepatol. 2008 Jul;6(7):759–64. DOI: 10.1016/j.cgh.2008.02.054. PMID: 18456568. Trusted SourcePubMedGo to source
Patil AD. Link between hypothyroidism and small intestinal bacterial overgrowth. Indian J Endocrinol Metab. 2014 May;18(3):307–9. DOI: 10.4103/2230-8210.131155. PMID: 24944923. PMCID: PMC4056127. Trusted SourcePubMedGo to source
Fialho A, Fialho A, Kochhar G, Schenone AL, Thota P, McCullough AJ, et al. Association between small intestinal bacterial overgrowth by glucose breath test and coronary artery disease. Dig Dis Sci. 2018 Feb;63(2):412–21. DOI: 10.1007/s10620-017-4828-z. PMID: 29110161. Trusted SourcePubMedGo to source
Ní Chonchubhair HM, Bashir Y, Dobson M, Ryan BM, Duggan SN, Conlon KC. The prevalence of small intestinal bacterial overgrowth in non-surgical patients with chronic pancreatitis and pancreatic exocrine insufficiency (PEI). Pancreatology. 2018 Jun;18(4):379–85. DOI: 10.1016/j.pan.2018.02.010. PMID: 29502987. Trusted SourcePubMedGo to source
Fu P, Gao M, Yung KKL. Association of Intestinal Disorders with Parkinson’s Disease and Alzheimer’s Disease: A Systematic Review and Meta-Analysis. ACS Chem Neurosci. 2020 Feb 5;11(3):395–405. DOI: 10.1021/acschemneuro.9b00607. PMID: 31876406. Trusted SourcePubMedGo to source
Mathur R, Chua KS, Mamelak M, Morales W, Barlow GM, Thomas R, et al. Metabolic effects of eradicating breath methane using antibiotics in prediabetic subjects with obesity. Obesity (Silver Spring). 2016 Mar;24(3):576–82. DOI: 10.1002/oby.21385. PMID: 26833719. PMCID: PMC4769647. Trusted SourcePubMedGo to source
Basseri RJ, Basseri B, Pimentel M, Chong K, Youdim A, Low K, et al. Intestinal methane production in obese individuals is associated with a higher body mass index. Gastroenterol Hepatol (N Y). 2012 Jan;8(1):22–8. PMID: 22347829. PMCID: PMC3277195. Trusted SourcePubMedGo to source
Mathur R, Amichai M, Chua KS, Mirocha J, Barlow GM, Pimentel M. Methane and hydrogen positivity on breath test is associated with greater body mass index and body fat. J Clin Endocrinol Metab. 2013 Apr;98(4):E698-702. DOI: 10.1210/jc.2012-3144. PMID: 23533244. PMCID: PMC3615195. Trusted SourcePubMedGo to source
Guo HZ, Dong WX, Zhang X, Zhu SW, Liu ZJ, Duan LP. [The diagnostic value of hydrogen sulfide breath test for small intestinal bacterial overgrowth]. Zhonghua Nei Ke Za Zhi. 2021 Apr 1;60(4):356–61. DOI: 10.3760/cma.j.cn112138-20200731-00725. PMID: 33765706. Trusted SourcePubMedGo to source
Losurdo G, Leandro G, Ierardi E, Perri F, Barone M, Principi M, et al. Breath Tests for the Non-invasive Diagnosis of Small Intestinal Bacterial Overgrowth: A Systematic Review With Meta-analysis. J Neurogastroenterol Motil. 2020 Jan 30;26(1):16–28. DOI: 10.5056/jnm19113. PMID: 31743632. PMCID: PMC6955189. Trusted SourcePubMedGo to source
Rezaie A, Buresi M, Lembo A, Lin H, McCallum R, Rao S, et al. Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus. Am J Gastroenterol. 2017 May;112(5):775–84. DOI: 10.1038/ajg.2017.46. PMID: 28323273. PMCID: PMC5418558. Trusted SourcePubMedGo to source
Staudacher HM, Whelan K. The low FODMAP diet: recent advances in understanding its mechanisms and efficacy in IBS. Gut. 2017 Aug;66(8):1517–27. DOI: 10.1136/gutjnl-2017-313750. PMID: 28592442. Trusted SourcePubMedGo to source
Marsh A, Eslick EM, Eslick GD. Does a diet low in FODMAPs reduce symptoms associated with functional gastrointestinal disorders? A comprehensive systematic review and meta-analysis. Eur J Nutr. 2016 Apr;55(3):897–906. DOI: 10.1007/s00394-015-0922-1. PMID: 25982757. Trusted SourcePubMedGo to source
Schumann D, Klose P, Lauche R, Dobos G, Langhorst J, Cramer H. Low fermentable, oligo-, di-, mono-saccharides and polyol diet in the treatment of irritable bowel syndrome: A systematic review and meta-analysis. Nutrition. 2018 Jan;45:24–31. DOI: 10.1016/j.nut.2017.07.004. PMID: 29129233. Trusted SourcePubMedGo to source
Altobelli E, Del Negro V, Angeletti PM, Latella G. Low-FODMAP Diet Improves Irritable Bowel Syndrome Symptoms: A Meta-Analysis. Nutrients. 2017 Aug 26;9(9). DOI: 10.3390/nu9090940. PMID: 28846594. PMCID: PMC5622700. Trusted SourcePubMedGo to source
Jowett SL, Seal CJ, Pearce MS, Phillips E, Gregory W, Barton JR, et al. Influence of dietary factors on the clinical course of ulcerative colitis: a prospective cohort study. Gut. 2004 Oct;53(10):1479–84. DOI: 10.1136/gut.2003.024828. PMID: 15361498. PMCID: PMC1774231. Trusted SourcePubMedGo to source
Zhong C, Qu C, Wang B, Liang S, Zeng B. Probiotics for Preventing and Treating Small Intestinal Bacterial Overgrowth: A Meta-Analysis and Systematic Review of Current Evidence. J Clin Gastroenterol. 2017 Apr;51(4):300–11. DOI: 10.1097/MCG.0000000000000814. PMID: 28267052. Trusted SourcePubMedGo to source
Soifer LO, Peralta D, Dima G, Besasso H. [Comparative clinical efficacy of a probiotic vs. an antibiotic in the treatment of patients with intestinal bacterial overgrowth and chronic abdominal functional distension: a pilot study]. Acta Gastroenterol Latinoam. 2010 Dec;40(4):323–7. PMID: 21381407. Trusted SourcePubMedGo to source
Leventogiannis K, Gkolfakis P, Spithakis G, Tsatali A, Pistiki A, Sioulas A, et al. Effect of a Preparation of Four Probiotics on Symptoms of Patients with Irritable Bowel Syndrome: Association with Intestinal Bacterial Overgrowth. Probiotics Antimicrob Proteins. 2019 Jun;11(2):627–34. DOI: 10.1007/s12602-018-9401-3. PMID: 29508268. PMCID: PMC6541575. Trusted SourcePubMedGo to source
Ford AC, Quigley EMM, Lacy BE, Lembo AJ, Saito YA, Schiller LR, et al. Efficacy of prebiotics, probiotics, and synbiotics in irritable bowel syndrome and chronic idiopathic constipation: systematic review and meta-analysis. Am J Gastroenterol. 2014 Oct;109(10):1547–61; quiz 1546, 1562. DOI: 10.1038/ajg.2014.202. PMID: 25070051. Trusted SourcePubMedGo to source
Gatta L, Scarpignato C. Systematic review with meta-analysis: rifaximin is effective and safe for the treatment of small intestine bacterial overgrowth. Aliment Pharmacol Ther. 2017 Mar;45(5):604–16. DOI: 10.1111/apt.13928. PMID: 28078798. PMCID: PMC5299503. Trusted SourcePubMedGo to source
Chedid V, Dhalla S, Clarke JO, Roland BC, Dunbar KB, Koh J, et al. Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth. Glob Adv Health Med. 2014 May;3(3):16–24. DOI: 10.7453/gahmj.2014.019. PMID: 24891990. PMCID: PMC4030608. Trusted SourcePubMedGo to source
Chen C, Tao C, Liu Z, Lu M, Pan Q, Zheng L, et al. A Randomized Clinical Trial of Berberine Hydrochloride in Patients with Diarrhea-Predominant Irritable Bowel Syndrome. Phytother Res. 2015 Nov;29(11):1822–7. DOI: 10.1002/ptr.5475. PMID: 26400188. Trusted SourcePubMedGo to source
Tsertsvadze A, Gurung T, Court R, Clarke A, Sutcliffe P. Clinical effectiveness and cost-effectiveness of elemental nutrition for the maintenance of remission in Crohn’s disease: a systematic review and meta-analysis. Health Technol Assess. 2015 Mar;19(26):1–138. DOI: 10.3310/hta19260. PMID: 25831484. PMCID: PMC4781042. Trusted SourcePubMedGo to source
Pimentel M, Constantino T, Kong Y, Bajwa M, Rezaei A, Park S. A 14-day elemental diet is highly effective in normalizing the lactulose breath test. Dig Dis Sci. 2004 Jan;49(1):73–7. DOI: 10.1023/b:ddas.0000011605.43979.e1. PMID: 14992438. Trusted SourcePubMedGo to source
Takagi S, Utsunomiya K, Kuriyama S, Yokoyama H, Takahashi S, Iwabuchi M, et al. Effectiveness of an “half elemental diet” as maintenance therapy for Crohn’s disease: A randomized-controlled trial. Aliment Pharmacol Ther. 2006 Nov 1;24(9):1333–40. DOI: 10.1111/j.1365-2036.2006.03120.x. PMID: 17059514. Trusted SourcePubMedGo to source
Daghaghzadeh H, Memar A, Mohamadi Y, Rezakhani N, Safazadeh P, Aghaha S, et al. Therapeutic Effects of Low-dose Bismuth Subcitrate on Symptoms and Health-related Quality of Life in Adult Patients with Irritable Bowel Syndrome: A Clinical Trial. J Res Pharm Pract. 2018 Mar;7(1):13–21. DOI: 10.4103/jrpp.JRPP_17_56. PMID: 29755994. PMCID: PMC5934982. Trusted SourcePubMedGo to source
Alharbi SA, Mashat BH, Al-Harbi NA, Wainwright M, Aloufi AS, Alnaimat S. Bismuth-inhibitory effects on bacteria and stimulation of fungal growth in vitro. Saudi J Biol Sci. 2012 Apr;19(2):147–50. DOI: 10.1016/j.sjbs.2012.01.006. PMID: 23961173. PMCID: PMC3730766. Trusted SourcePubMedGo to source
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!
Transform your health
Every product is science-based, validated by real-world use, and personally vetted by Dr. Ruscio, DNM, DC.