Is Sulfur the Cause of Your IBS?

In my experience as a clinical nutritionist, there is an underlying cause behind irritable bowel syndrome (IBS). The tricky part can be finding out what that is. One of those causes can be hydrogen sulfide (H₂S).

What is sulfur?

Amino acids are basic building block molecules that combine to form proteins. Some are made by your body, and some have to come from food. The sulfur amino acids are methionine and cysteine. Methionine must come from the diet, and your body makes cysteine from methionine. These amino acids create the metabolites homocysteine, glutathione, and hydrogen sulfide.^1,2

High intake of H₂S causes mucus disruption and inflammation. It also may contribute to the development of cancer and inflammatory bowel disease (IBD). And it can cause increased epithelial gut permeability, also known as leaky gut!^1,2

There are 2 major sources of H₂S:^1,2

1. The sulfur amino acids found in high-protein foods such as red meat, cheese, milk, fish, nuts, and eggs, and inorganic sulfate in brassica vegetables like cabbage and kale
2. Preservatives in processed foods, particularly commercial breads, beers, sausages, and dried fruit

Research shows that limiting sulfur may reduce the risk for colon polyps and cancer. Limiting sulfur also may reduce chronic gut inflammation, which contributes to IBD, such as ulcerative colitis, and small intestinal bacterial overgrowth (SIBO). Limiting high-sulfur foods may prevent cardiovascular disease as well.^1,2

Is a diet low in sulfur amino acids right for you?

Tell your doctor if you have a family history of colon polyps or colorectal cancer, or a personal or family history of ulcerative colitis. Also, your gas may be a clue to how much H₂S is in your gut due to its pungent "rotten egg" odor.

Suggestions for maintaining a low-sulfur diet

It’s not just the total sulfur content of your diet but the specific type of sulfur that matters. Try the following steps to reduce problematic sulfur in your diet:^1,2

• Limit meat, dairy, and eggs, as they are high in sulfur amino acids.
• Remove processed foods – especially processed meat such as bacon and sausage – processed breads, and dried fruit, as they contain large amounts of sulfate as a food additive.
• Cut out alcohol with additives, like wine and beer.
• Proceed with caution with cruciferous vegetables! Cruciferous vegetables (like cabbage, broccoli, cauliflower, and kale) are rich in sulfur-containing glucosinolates. Their intake has been linked to less sulfur-metabolizing bacteria but also reduced colon cancer risk.

The bottom line

A high-sulfur diet, either from sulfur amino acids or sulfate additives, results in too much toxic H₂S gas. This gas can cause inflammation, leaky gut, IBS symptoms, and stinky gas! Reducing sulfur-containing foods may help you manage your IBS symptoms. But, as always, talk to your healthcare provider before making changes to your diet.