MUC5AC and inflammatory bowel disease: An increase in Desulfovibrio genus bacteria in the gut, which produce excess H2S (accounting for 60% of gut H2S) [54], contributed to intestinal mucin degeneration (this result aligns with a decrease in goblet cells producing mucin) and inflammation associated with inflammatory bowel disease, while beneficial Verrucomicrobia (which produce important short-chain fatty acids for gut health and immune function) typically abundant in healthy individuals were reduced [43].