The gut microbiome field has evolved beyond characterizing which organisms are present to understanding what those organisms produce — the metabolome. Postbiotics, defined by the International Scientific Association for Probiotics and Prebiotics (ISAPP) in 2021 as "preparations of inanimate microorganisms and/or their components that confers a health benefit on the host," represent the third wave of microbiome therapeutics after probiotics and prebiotics.
Key Postbiotic Classes and Their Mechanisms
Short-chain fatty acids (SCFAs — acetate, propionate, butyrate): produced by fermentation of dietary fiber by colonic bacteria. Butyrate is the preferred energy source for colonocytes, maintains gut barrier integrity, suppresses NF-κB inflammatory signaling, and induces regulatory T cells — linking dietary fiber intake to reduced colorectal cancer risk, reduced IBD disease activity, and improved metabolic health. Low SCFA producers correlate with obesity, type 2 diabetes, and inflammatory bowel disease. Lipoteichoic acids and peptidoglycans from gram-positive bacterial cell walls: immune-modulating effects through TLR2 signaling. Bacteriocins: antimicrobial peptides produced by beneficial bacteria that competitively inhibit pathogen colonization. Urolithins (produced from ellagitannin metabolism by gut bacteria): urolithin A activates mitophagy (selective removal of damaged mitochondria) — in human RCTs, urolithin A supplementation improved muscle endurance in older adults, linking gut metabolite production to aging and sarcopenia.
Clinical Applications
Heat-killed Lactobacillus preparations (postbiotics proper): LactoB (heat-killed L. paracasei) reduces eczema severity in children — equivalent efficacy to live probiotic in direct comparisons, with superior shelf stability. Heat-killed L. rhamnosus GG reduces allergy symptoms in double-blind trials. Tributary butyrate: oral and rectal butyrate supplementation shows benefit in mild-moderate ulcerative colitis in RCTs. For facilities managing patients with IBD, metabolic disease, or elderly sarcopenic patients, our nutrition catalog includes therapeutic nutrition products supporting gut health, and our patient care section includes products for nutritional support in gastrointestinal conditions.
