Hydrogen gas ameliorates acute alcoholic liver injury via anti-inflammatory and antioxidant effects and regulation of intestinal microbiota

Alcoholic liver disease (ALD) is a globally prevalent liver-related disorder characterized by severe oxidative stress and inflammatory liver damage, for which no effective treatment is currently available. Hydrogen gas (H2) has been demonstrated to be an efficient antioxidant in various diseases in animals as well as humans. However, the protective effects of H2 on ALD and its underlying mechanisms remain to be elucidated. The present study demonstrated that H2 inhalation ameliorated liver injury, and attenuated liver oxidative stress, inflammation, and steatosis in an ALD mouse model. Moreover, H2 inhalation improved gut microbiota, including increasing the abundance of Lachnospiraceae and Clostridia, and decreasing the abundance of Prevotellaceae and Muribaculaceae, and also improved intestinal barrier integrity. Mechanistically, H2 inhalation blocked activation of the LPS/TLR4/NF-κB pathway in liver. Notably, it was further demonstrated that the reshaped gut microbiota may accelerate alcohol metabolism, regulate lipid homeostasis and maintain immune balance by bacterial functional potential prediction (PICRUSt). Fecal microbiota transplantation from mice that had undergone H2 inhalation significantly alleviated acute alcoholic liver injury. In summary, the present study showed that H2 inhalation alleviated liver injury by reducing oxidative stress and inflammation, while also improving intestinal flora and enhancing the intestinal barrier. H2 inhalation may serve as an effective intervention for preventing and treating ALD in a clinical context.