Hydrogen-producing intestinal bacteria

Hydrogen-producing intestinal bacteria represent a diverse functional group of anaerobic microorganisms, including genera such as Bacteroides, Clostridium, Ruminococcus, and Escherichia coli, that generate molecular hydrogen (H2) as a metabolic byproduct of carbohydrate fermentation. Molecular hydrogen is increasingly recognized as a therapeutic gaseous signaling molecule with significant antioxidant, anti-inflammatory, and cytoprotective properties, capable of neutralizing hydroxyl radicals and modulating gene expression. In a healthy state, these bacteria maintain redox balance within the gut; however, their overgrowth in the small intestine is a primary cause of Small Intestinal Bacterial Overgrowth (SIBO) and Irritable Bowel Syndrome (IBS), leading to excessive gas production and gastrointestinal distress. Therapeutic interventions target this group either to enhance H2 production for systemic benefits—using agents like acarbose or prebiotics—or to suppress their activity using targeted antibiotics like rifaximin to treat malabsorptive or functional bowel disorders. Clinical assessment of these bacteria is standardly performed using the hydrogen breath test, which measures exhaled H2 as a proxy for intestinal fermentation activity.

Other names

Hydrogen-producing microbiotaH2-producing gut bacteriaHydrogenogenic bacteriaHydrogen-producing gut flora

Modulation of bacterial fermentation through the provision of non-digestible carbohydrate substrates (prebiotics), inhibition of host carbohydrate-digesting enzymes to increase distal substrate availability, or direct reduction of bacterial populations via non-absorbable antibiotics.