Dietary fiber increases survival in influenza-infected mice by setting the immune system at a healthy level of responsiveness, according to a preclinical study published in the journal Immunity.
A high-fiber diet blunts harmful, excessive immune responses in the lungs while boosting antiviral immunity by activating T cells. These dual benefits were mediated by changes in the composition of gut bacteria, leading to an increase in the production of short-chain fatty acids (SCFAs) through the microbial fermentation of dietary fiber.
“The beneficial effects of dietary fiber and SCFAs on a variety of chronic inflammatory diseases, including asthma and allergies, have received substantial attention in recent years and have supported momentum toward their use in clinical studies,” says senior study author Benjamin Marsland of Monash University. “But we were concerned that these treatments might lead to a general dampening of immune responses and could increase susceptibility to infections.”