Malproduction of endogenous hydrogen gas in COVID-19.

Abstract

COVID-19 is associated with extensive alterations in gut microbiota composition, including a reduction in hydrogen-producing bacterial species, which may lead to decreased endogenous dihydrogen (H2) output. As a biologically active gaseous molecule, H2 exerts cytoprotective, antioxidant, anti-inflammatory, and antiapoptotic effects. This review proposes that diminished H2 production could contribute to disease progression and severity in COVID-19. Exogenous H2 supplementation is discussed as a potential approach to restore physiological H2 levels, with the possibility of combining H2 measurement and supplementation as a combined diagnostic and interventional strategy. The paper also situates H2 alongside other gasotransmitters such as nitric oxide and hydrogen sulfide in the context of COVID-19-related gaseous signaling disruption.

Mechanism

COVID-19-induced gut dysbiosis reduces the abundance of H2-producing bacteria, lowering endogenous dihydrogen levels. Because H2 normally exerts antioxidant, anti-inflammatory, and antiapoptotic effects, its deficiency may impair host defense mechanisms and contribute to disease worsening.