From the Guidelines
Sulfur-producing bacteria in the GI tract Certain sulfur-producing bacteria, such as Desulfovibrio 1, have been found to reside in the human gut.
Key Characteristics of these Bacteria
- These bacteria are known to produce hydrogen sulfide gas as a byproduct of their metabolism, which can have both beneficial and harmful effects on the host.
- Desulfovibrio species, for example, are sulfate-reducing bacteria that can contribute to the production of hydrogen sulfide in the gut 1.
Importance of Balance in the Gut Microbiome
- It is essential to note that an overgrowth of these bacteria can lead to an imbalance in the gut microbiome, potentially causing gastrointestinal symptoms.
- Maintaining a balanced gut microbiome through a healthy diet and lifestyle is crucial to preventing an overgrowth of sulfur-producing bacteria.
Key Points to Consider
- The production of hydrogen sulfide by Desulfovibrio has been linked to increased intestinal permeability and potentially carcinogenic effects 1.
- A healthy balance of the gut microbiome is necessary to prevent the overgrowth of sulfur-producing bacteria and maintain overall gut health.
From the Research
Sulfur-Producing Bacteria in the GI Tract
- The human intestinal bacterium Bilophila wadsworthia is a key source of hydrogen sulfide (H2S) production in the gut, as identified in a study published in 2019 2.
- Desulfovibrio species, such as Desulfovibrio desulfuricans and Desulfovibrio alaskensis, are also sulfur-producing bacteria that reside in the GI tract, with a unique glycyl radical enzyme (GRE) enabling their energy metabolism 2.
- Other sulfidogenic bacteria, including Escherichia, may also contribute to H2S production in the gut, particularly in the context of inflammatory bowel diseases (IBD) 3.
Mechanisms of Sulfur Production
- The taurine desulfonation pathway in Bilophila wadsworthia involves the reduction of sulfoacetaldehyde to isethionate, which is then cleaved to sulfite and acetaldehyde by a GRE, ultimately leading to H2S production 2.
- Sulfate-reducing bacteria, such as Desulfovibrio species, use molecular hydrogen and lactate as electron donors and sulfate as the terminal electron acceptor to produce H2S 4.
- The enzymatic desulfhydration of cysteine by heterotrophic bacteria also contributes to H2S production in the gut 4.
Implications for Human Health
- The overgrowth of sulfidogenic bacteria, including Bilophila wadsworthia and Desulfovibrio species, has been linked to various diseases, including inflammatory bowel diseases and colorectal cancer 3, 5, 6.
- High concentrations of H2S produced by these bacteria can disrupt the integrity of the intestinal epithelium and mucus barrier, triggering inflammation and contributing to disease pathology 5, 6.