[Methanogen and human gut health--A review].

Methane is produced exclusively through anaerobic fermentation of both endogenous and exogenous carbohydrates by methanogens. Methane production is detectable in about one third of healthy adult individuals. In recent years, many studies have found that methanogens played an important role in maintaining stability in the gut microbiota. Researches have paid much attention on the metabolism of the methane in the gut. The relationship between methane and intestinal dysfunction has also been investigated. The number of methanogens in irritable bowel syndrome patients is different when compared with the normal individuals. Besides, methanogens are potentially linked with obesity. This article reviewes the role of methanogens in gastrointestinal homeostasis and intestinal diseases (irritable bowel syndrome, colon cancer), as well as the relation between methanogens and obesity.