Randomized controlled trial finds that type 2 diabetics given a diet high in fiber improved the secretion of hormones involved in insulin production (GLP-1) and lowered blood glucose levels (HbA1c) via changes in the gut microbiome.

Certain species of gut bacteria produced short-chain fatty acids such as acetate and butyrate which have been shown to improve glucose homeostasis by inducing gut production of glucagon-like peptide-1 (GLP-1) which in turn stimulate insulin secretion.