Effects of Dietary Selenium Supplementation on Intestinal Barrier and Immune Responses Associated with Its Modulation of Gut Microbiota

TLDR

Selenium intake variations influence gut barrier and immune responses, yet the role of Se‑related microbiota on gut health remains underexplored. The study compared the effects of Se‑deficient, Se‑adequate, and Se‑supranutritional diets on the gut microbiota of mice. Fecal microbiota transplantation was performed to isolate the microbiota’s role, demonstrating that dietary Se modulates gut barrier and immune responses through changes in the microbiota. Se deficiency produced a microbiota profile that increased susceptibility to DSS‑induced colitis and Salmonella infection, whereas adequate or supranutritional Se intake optimized the microbiota to protect against these intestinal dysfunctions.

Abstract

Variations in selenium (Se) intake have been reported to affect the barrier function and immune responses in the gut. Previous studies mainly focused on the role of Se itself or its metabolites, while the influences of the Se-intake-related microbiota on gut health were not thoroughly studied. This study compared the effects of different dietary Se supplementation (Se-deficient, Se-adequate, and Se-supranutritional) on the gut microbiota of mice. Fecal microbiota transplantation (FMT) was further conducted to bypass the effect of Se itself and provided direct evidence that the effects of dietary Se supplementation on the intestinal barrier and immune responses are associated with its modulation of the gut microbiota. Deficient Se supplementation can result in a phenotype of gut microbiota that is more susceptible to dextran sulfate sodium (DSS)-induced colitis and Salmonella typhimurium infection. Sufficient or supranutritional Se intake can optimize the gut microbiota for protection against these intestinal dysfunctions.