Intestinal bacteria release metabolic by-products that support antibody-producing immune cells.

Gut microbes produce short-chain fatty acids as they digest dietary fibre. Chang Kim and his colleagues at Purdue University in West Lafayette, Indiana, treated cultured B cells with the fatty acids and found that this enhanced the expression of genes that help the cells to develop into antibody-producing factories known as plasma B cells. The treatment also increased the cells' metabolism, helping to support the energy-consuming process of making antibodies.

Mice fed a low-fibre diet were more susceptible than other animals to infection by the pathogen Citrobacter rodentium and had weaker immune responses. Treating the mice with short-chain fatty acids or dietary fibre increased antibody production and reversed this immune deficiency.

Cell Host Microbe (2016)