Hydrogen sulfide can often be the missing link for people who have treated their SIBO but haven’t seen their symptoms resolve.
This article will help you understand this gas a little better and what steps to take to see if it’s appropriate to you.
So you’ve been through the biphasic diet to fix your IBS, SIBO and gut health issues and have worked hard to get to the retest to see how things have gone.
You feel better than you did when you started. However, the complete remission hasn’t arrived. When this type of thing happens, it can make you and your practitioner dubious about what could be in the retest results.
Surprisingly, the SIBO breath test results come back clear!
Ninety-nine per cent of the time, it’s what we’re looking for, combined with an improvement in the quality of your day.
Fear not if you are in the one per cent of people who find themselves in this position. The reason may be totally normal and now measurable.
That reason is the presence of another group of bacteria along with the hydrogen and methane producers. Instead of producing the two gases mentioned above, this group of bacteria forms another gas, hydrogen sulfide.
Until the last few years, hydrogen sulfide has been challenging to measure due to its sensitive nature in lab testing. It does, though, present with some specific symptoms. Let’s look deeper into this sulphur-forming bacteria and some solutions.
Bacteria that produce hydrogen sulfide are a classic example of the transcension of seeing bacteria as good or bad.
Let me explain.
When introducing the results of stool tests to my patients, I often start by suggesting that we are moving past bacteria as being good or bad. Sure, gram-negative bacteria such as Klebsiella spp, for example, can bring inflammation and acute infection.[1] However, most of the time, we are more concerned with high or low bacteria levels and ensuring things are balanced.
Hence, SIBO is called a small intestinal bacterial overgrowth rather than an infection.
More often than not, high levels of bacteria cause issues and low levels are not enough. This “sweet spot” is what we refer to as a U-shaped curve.
Hydrogen sulfide bacteria are an essential component of the microbiota.
Furthermore, the hydrogen sulfide created has numerous therapeutic benefits in the body, specifically within the digestive system. So much, so that hydrogen sulfide has been extensively researched in the hope of new medication options.
For example, early research in animals suggests that hydrogen sulfide versions of nonsteroidal anti-inflammatory drugs, such as Panadol, are more effective than the original versions and cause significantly fewer gastric issues.[2]
It seems as if this also might be the case with the common pharmaceutical drug, mesalamine, often used in inflammatory bowel conditions such as ulcerative colitis.[3]
In the digestive system, hydrogen sulfide produced by the bacteria we are looking at can reduce inflammation.
It does this via strengthening the component of the immune system that defends your digestive lining, called the mucosal defence.[4] Some studies have labelled hydrogen sulfide as the bridge between this mucosal defence and the microbiome reducing inflammation to a point where it’s a primary focus for healing gastric ulcers.[5]
If hydrogen sulfide is so essential to our digestive and immune systems, why is it a problem?
Excellent question. Higher levels of hydrogen sulfide bacteria are associated with ulcerative colitis, Crohn’s disease and irritable bowel syndrome.[6]
Certain situations can exponentially increase hydrogen sulfide-producing bacteria.
The first is diet.
A high-meat diet increased hydrogen sulfide production by up to fifteen times.[7] In contrast, decreasing meat and dietary protein intake reduced the growth and production of hydrogen sulfide bacteria.[8]
One particular amino acid from dietary protein, cysteine and the bacteria it’s connected to are some common species you might see tested in a comprehensive stool test.
For example, Fusobacterium, Clostridium, Escherichia, Salmonella, Klebsiella, Streptococcus, Desulfovibrioand Enterobacter are all connected with hydrogen sulfide, hence the connection with dietary protein intake.[9]
Dairy and saturated fat intake also contribute to the increased abundance of the hydrogen sulfide bacteria species listed above, specifically the main one, Desulfovibrio.[10]
One particular type of prescriptive diet for IBS can increase hydrogen sulfide bacteria.
Yep, and this is where we start to see why the standard SIBO treatments may not be the complete solution. Especially if you are one of the people, I mentioned at the beginning of this article with negative SIBO results without experiencing a change in symptoms.
Low FODMAP diets can increase hydrogen sulfide bacteria![11]
This increase automatically means a higher FODMAP diet for treating hydrogen sulfide bacteria, already a significant part of the difference between typical SIBO and the type of overgrowth we’re discussing here.
For now, though, we can see some key connections with diet, unintentional, the majority of the time, building these hydrogen sulfide bacteria.
As the hydrogen sulfide begins to increase, so can diarrhoea-based IBS symptoms.
Studies released in 2016 have already confirmed that breath tests with hydrogen sulfide levels that differ from healthy subjects can help to explain the origin of SIBO.[12] This difference was primarily in cases of IBS-D.
This higher prevalence of hydrogen sulfide in IBS-D is down to higher levels of hydrogen sulfide bacteria, increasing motility[13] (think the conveyor belt your food travels on to get to the toilet), especially when there is a disturbance in the bacterial diversity of the digestive system.
Remember all of the species we mentioned above? Well, if there are high levels of all of them, this is where that increased motility makes more sense.
Higher levels of hydrogen sulfide can also have cellular consequences.
These elevated levels interfere with how your cells create energy and increase the body’s natural rusting process – oxidative damage.
For those who like some science on these things, increased levels of hydrogen sulfide impair the production of adenosine triphosphate or ATP, an essential component of your energy production.[14]
Does anyone get fatigued with their IBS?
When people’s fatigue doesn’t clear up during their SIBO treatment, this is a definite sign that something else is interfering.
The big problem with these high hydrogen sulfide cellular effects is the increased colonic inflammation and damage.[15]
This inflammation and damage are why higher hydrogen sulfide levels can cause ulcerative colitis and Crohn’s disease.[16]
Interestingly, early research also associates the Desulfovibrio species with periodontitis and obesity. However, this research is unclear for now.[17]
How do I know if hydrogen-sulfide bacteria contribute to my SIBO and IBS?
We’ve touched on some of the main symptoms already. If your IBS is diarrhoea dominant, then that’s an initial clue. Research, though, is still confirming this as constipation-dominant IBS found high levels of hydrogen sulfide breath tests in one study.[18]
Having odorous gas, particularly strong-smelling farts, can also be a sign.
There can also be histamine-based problems such as skin issues or pain sensitivity. However, these are primarily clinical symptoms and haven’t been confirmed in the research yet.
Interestingly, another critical marker you might know if you have had some blood tests is low Zinc levels. Zinc has been one of the minerals shown to bind to hydrogen sulfide, and this classically deficient mineral can play a significant role in managing hydrogen sulfide.[19]
An easier way to find out about hydrogen sulfide and SIBO, in general, is to test it.
Stool testing can now identify the Desulfovibrio species and the other sulphur species we looked at earlier in the article. Often this can be a fast-tracked way to get a clearer outlook on what’s happening.
If you are in the US, the good news is that the Trio Smart breath test measures all three gases we see in SIBO; hydrogen, methane and now hydrogen sulfide!
You can also explore your body’s ability to deal with sulphur by looking at your genetics, specifically the CBS gene, which can give some indications there for you.
An important note on rushing to treat hydrogen sulfide dominance is to ask why it’s high in the first place.
I mentioned the positive effects of this gas earlier in the article for a few reasons. The first was to try and dispel the idea of bacteria being good and bad. The second was to help with the understanding that maybe hydrogen sulfide, especially if measured in a breath test, is there in higher levels for a reason.
Hydrogen sulfide is exceptionally anti-inflammatory for the digestive system. In the case of stool exams that come back with higher levels of other inflammation markers, it could be the result of an adaptation to the inflammation present in the gut.
It could actually be trying to help!
In this case, I tend to agree with my colleagues about leaning on testing too much and not treating the whole picture regarding the digestive system.
When the hydrogen sulfide is high because of inflammation, it’s most likely that they correct themselves when the inflammation is dealt with.
I guess I’m trying to say that all this is not as cut and dry as it seems.
However, if you are the person who has gone through your SIBO protocol and still has symptoms, I hope this article offers some reassurance that there are reasons why this might be the case.
Better still, they can be measured and acted upon to free you from those gut issues for good.
Hope this helps xx
References
[1] Paczosa MK, Mecsas J. Klebsiella pneumoniae: Going on the Offense with a Strong Defense. Microbiol Mol Biol Rev. 2016;80(3):629-661. Published 2016 Jun 15. doi:10.1128/MMBR.00078-15
[2] Blackler RW, Motta JP, Manko A, et al. Hydrogen sulphide protects against NSAID-enteropathy through modulation of bile and the microbiota. Br J Pharmacol. 2015;172(4):992-1004. doi:10.1111/bph.12961
[3] Fiorucci S, Orlandi S, Mencarelli A, et al. Enhanced activity of a hydrogen sulphide-releasing derivative of mesalamine (ATB-429) in a mouse model of colitis. Br J Pharmacol. 2007;150(8):996-1002. doi:10.1038/sj.bjp.0707193
[4] Shen F, Zhao CS, Shen MF, Wang Z, Chen G. The role of hydrogen sulfide in gastric mucosal damage. Med Gas Res. 2019;9(2):88-92. doi:10.4103/2045-9912.260650
[5] Magierowski M, Magierowska K, Kwiecien S, Brzozowski T. Gaseous mediators nitric oxide and hydrogen sulfide in the mechanism of gastrointestinal integrity, protection and ulcer healing. Molecules. 2015;20(5):9099-9123. Published 2015 May 19. doi:10.3390/molecules20059099
[6] Singh SB, Lin HC. Hydrogen Sulfide in Physiology and Diseases of the Digestive Tract. Microorganisms. 2015;3(4):866-889. Published 2015 Nov 12. doi:10.3390/microorganisms3040866
[7] Magee EA, Richardson CJ, Hughes R, Cummings JH. Contribution of dietary protein to sulfide production in the large intestine: an in vitro and a controlled feeding study in humans. Am J Clin Nutr. 2000;72(6):1488-1494. doi:10.1093/ajcn/72.6.1488
[8] Magee EA, Richardson CJ, Hughes R, Cummings JH. Contribution of dietary protein to sulfide production in the large intestine: an in vitro and a controlled feeding study in humans. Am J Clin Nutr. 2000;72(6):1488-1494. doi:10.1093/ajcn/72.6.1488
[9] Blachier F, Andriamihaja M, Larraufie P, Ahn E, Lan A, Kim E. Production of hydrogen sulfide by the intestinal microbiota and epithelial cells and consequences for the colonic and rectal mucosa [published correction appears in Am J Physiol Gastrointest Liver Physiol. 2021 Apr 1;320(4):G484]. Am J Physiol Gastrointest Liver Physiol. 2021;320(2):G125-G135. doi:10.1152/ajpgi.00261.2020
[10] Wolf, P., Cummings, P., Shah, N., Gaskins, H.R. and Mutlu, E. (2015), Sulfidogenic Bacteria Abundance in Colonic Mucosa is Positively Correlated with Milk and Animal Fat Intake and Negatively Correlated with Mono and Polyunsaturated Fatty Acids. The FASEB Journal, 29:598.10. https://doi.org/10.1096/fasebj.29.1_supplement.598.10
[11] Rey FE, Gonzalez MD, Cheng J, Wu M, Ahern PP, Gordon JI. Metabolic niche of a prominent sulfate-reducing human gut bacterium. Proc Natl Acad Sci U S A. 2013;110(33):13582-13587. doi:10.1073/pnas.1312524110
[12] Banik GD, De A, Som S, et al. Hydrogen sulphide in exhaled breath: a potential biomarker for small intestinal bacterial overgrowth in IBS. J Breath Res. 2016;10(2):026010. Published 2016 May 10. doi:10.1088/1752-7155/10/2/026010
[13] Jimenez M, Gil V, Martinez-Cutillas M, Mañé N, Gallego D. Hydrogen sulphide as a signalling molecule regulating physiopathological processes in gastrointestinal motility. Br J Pharmacol. 2017;174(17):2805-2817. doi:10.1111/bph.13918
[14] Cooper CE, Brown GC. The inhibition of mitochondrial cytochrome oxidase by the gases carbon monoxide, nitric oxide, hydrogen cyanide and hydrogen sulfide: chemical mechanism and physiological significance. J Bioenerg Biomembr. 2008;40(5):533-539. doi:10.1007/s10863-008-9166-6
[15] Roediger WE, Babidge WJ. Nitric oxide effect on colonocyte metabolism: co-action of sulfides and peroxide. Mol Cell Biochem. 2000;206(1-2):159-167. doi:10.1023/a:1007034417320
[16] Singh SB, Lin HC. Hydrogen Sulfide in Physiology and Diseases of the Digestive Tract. Microorganisms. 2015;3(4):866-889. Published 2015 Nov 12. doi:10.3390/microorganisms3040866
[17] Singh SB, Lin HC. Hydrogen Sulfide in Physiology and Diseases of the Digestive Tract. Microorganisms. 2015;3(4):866-889. Published 2015 Nov 12. doi:10.3390/microorganisms3040866
[18] Guo HZ, Dong WX, Zhang X, Zhu SW, Liu ZJ, Duan LP. Zhonghua Nei Ke Za Zhi. 2021;60(4):356-361. doi:10.3760/cma.j.cn112138-20200731-00725
[19] Mitsui T, Edmond LM, Magee EA, Cummings JH. The effects of bismuth, iron, zinc and nitrate on free sulfide in batch cultures seeded with fecal flora. Clin Chim Acta. 2003;335(1-2):131-135. doi:10.1016/s0009-8981(03)00288-2
