Regulation of gut microbiota by vitamin C, vitamin E and β-carotene.

Vitamin C (VC), vitamin E (VE) and β-carotene (βC) are representative dietary antioxidants, which exist in daily diet and can increase the antioxidant capacity of body fluids, cells and tissues. The health benefits of vitamins like VC, VE and βC are widely demonstrated. Given that the strong associations between the gut microbiota and host health or a range of diseases has been extensively reported, it is important to explore the modulatory effects of known vitamins on the gut microbiota. Herein, this article reviews the effects of VC, VE and βC on the gut microbiota. Totally, 19 studies were included, of which eight were related to VC, nine to VE, and six to βC. Overall, VC, VE and βC can provide health benefits to the host by modulating the composition and metabolic activity of the gut microbiota, improving intestinal barrier function and maintaining the normal function of the immune system. Two perspectives are proposed for future studies: i) roles of known antioxidant activity of vitamins in regulating the gut microbiota and its molecular mechanism need to be further studied; ii) causal relationships between the regulatory effects of vitamins on gut microbiota and host health still remains to be further verified.