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OMED Health

Reducing the Levels of Hydrogen Sulfide In the Gut


An excess of hydrogen sulfide in the gut causes dysbiosis and inflammation, resulting in diarrhea, constipation, bloating and/or fatigue, which are all typical symptoms of those suffering from irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO).  

However, elevated levels of hydrogen sulfide in the gut are difficult to diagnose and treat due to the limited scientific research and test availability on this gas. 

Read our blog, hydrogen sulfide and how it is related to gut health.

At present, in the UK it is not possible to routinely measure hydrogen sulfide for SIBO or IBS via breath testing and caution should be taken if a service refers to a result of a gas that is not measured. However, our latest research is looking promising for the launch of a hydrogen sulfide breath test, watch this space! 

Read our blog: What is SIBO? 

So, if a clinician confirms that the levels of hydrogen sulfide in your gut are abnormal, what are the best treatment options for you? One of the most common suggestions would be to follow a low-sulfur diet or avoid sulfuric medications to help reduce the number of hydrogen sulfide-producing bacteria in the gut, but there is a lack of studies that look at this in more detail.  

What causes hydrogen sulfide in the breath?

Decreasing the amount of sulfur-rich foods in the diet can be tricky, as sulfur is present in two essential amino acids, methionine and cysteine, in fact, those following a vegan diet or who are elderly, often suffer from low sulfur levels. While the diet is the only source of methionine in humans, cysteine can be produced from methionine via a metabolic pathway (1). Methionine and cysteine play an essential physiological role within the body and a deficiency can contribute to several health issues such as contribute to obesity, heart disease, Alzheimer’s, and chronic fatigue (2). It can also exacerbate a variety of conditions including skin complaints, gastrointestinal concerns, and arthritis (2). 

There is plenty of crossover between high-sulfur foods and the FODMAP diet. Examples of high-sulfur foods are eggs, poultry and fish, and allium plants such as garlic, onions, and leeks, as well as cruciferous vegetables like kale, cabbage, and broccoli. Following a low FODMAP is often recommended for those suffering from SIBO and IBS but everyone and their gut microbiome is unique. Therefore, one of the best approaches is to experiment with diet and foods and eliminate different foods for a period to try and determine what triggers your symptoms alongside real-time monitoring of gas production via a breath test. Remember it is best to consult with a dietitian or nutritionist before making drastic changes to your diet. 

Read our blog: How is FODMAP related to Gut Health? 

As SIBO is caused by the overgrowth in bacteria, it is often treated with antibiotics such as rifaximin, which could also help contribute to lower the number of sulfur-producing bacteria in the gut. However, as there is not as much research in this area, further study is needed to better understand this connection.  

Read our blog: SIBO Treatment Options 

You may have heard of Pepto Bismol, which has the scientific name of bismuth subsalicylate, as another option to try to treat hydrogen sulfide SIBO. Bismuth subsalicylate binds to hydrogen sulfide in the gut, reducing the presence of the gas and alleviating symptoms (3). This study saw a 95%  reduction in the hydrogen sulfide produced in fecal samples after patients consumed bismuth subsalicylate four times a day for 3-7 days.   

Hydrogen sulfide is just one of the informative gases that can provide information about your gut health and help you to get a diagnosis of a particular disorder. Hydrogen and methane are two other gases produced by the microbiota in your gut, and measuring the levels of these gases via a breath test can help gain a wealth of insight into the process within your gut, thus aiding the diagnosis of other digestive health conditions, such as SIBO and carbohydrate malabsorption.  

Our at-home device the OMED Health Breath Analyzer that measures hydrogen and methane anytime, anywhere will be launched later this year.  Paired with the OMED Health App, this allows you to monitor your microbiome on the go, as well as track lifestyle factors such as sleep, diet, and exercise over time. This can help you to pinpoint exactly what is causing your gut health problems and give you back control. Join the waitlist today to get the latest updates. 


  1. Kabil O, Vitvitsky V, Banerjee R. Sulfur as a signaling nutrient through hydrogen sulfide. Annual review of nutrition. 2014 Jul 17;34:171-205. DOI: 10.1146/annurev-nutr-071813-105654.
  2. Deficiency of sulfur and inability to detox [Internet]. [cited 2023 Aug 3]. Available from: https://www.fammacademy.org/beta/index.php?route=pavblog/blog&id=22
  3. Suarez FL, Furne JK, Springfield J, Levitt MD. Bismuth subsalicylate markedly decreases hydrogen sulfide release in the human colon. Gastroenterology. 1998 May 1;114(5):923-9. DOI:10.1016/s0016-5085(98)70311-7.

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