Hydrogen-rich water alleviates constipation by attenuating oxidative stress through the sirtuin1/nuclear factor-erythroid-2-related factor 2/heme oxygenase-1 signaling pathway.

Abstract

Using a loperamide-induced constipation model in Sprague-Dawley rats, this study examined the effects of ad libitum hydrogen-rich water (HRW) consumption. HRW improved 24-hour stool output, fecal water content, and charcoal propulsion rate, while restoring intestinal mucus layer thickness, c-kit expression, and enteric neuron counts. 16S rDNA sequencing revealed correction of gut microbiota dysbiosis, and non-targeted serum metabolomics identified associated metabolic abnormalities. Colonic oxidative stress markers (ROS, MDA) were reduced and superoxide dismutase activity was elevated through upregulation of the SIRT1/Nrf2/HO-1 signaling pathway. Intraperitoneal injection of the SIRT1 inhibitor EX527 reversed these benefits, confirming pathway dependence. In NCM460 cells, two identified serum metabolites—β-leucine and traumatic acid—upregulated SIRT1 and attenuated H2O2-induced oxidative stress, suggesting a mechanistic link between HRW-driven metabolite shifts and antioxidant signaling.

Mechanism

HRW activates SIRT1, which in turn induces Nrf2 and HO-1 expression, reducing colonic ROS and malondialdehyde levels and restoring intestinal motility. Serum metabolites β-leucine and traumatic acid further upregulate SIRT1, reinforcing antioxidant signaling.