Beyond live microorganisms, inanimate microorganisms and their components can also confer a health benefit on the host. A panel of experts under the auspices of the International Scientific Association for Probiotics and Prebiotics (ISAPP) updates the definition and scope of postbiotics.

Irritable bowel syndrome is one of the most common disorders diagnosed by gastroenterologists. Peppermint oil, specific probiotics, psyllium supplementation, first-line IBS dietary advice, and a low FODMAP diet can aid in improving IBS symptoms.

Fermented foods are a known source of lactic acid bacteria. A high-throughput sequencing analysis of food and human metagenomes proves that fermented foods are a source of lactic acid bacteria for the gut microbiome, and that abundance is shaped by both age and lifestyle.