Review article: short chain fatty acids in health and disease

Abstract

Short chain fatty acids (SCFAs) have been the subject of much research over the past few decades. They play a vital role in maintenance of colonic integrity and metabolism. They are produced when dietary fibre is fermented by colonic bacteria. SCFAs are avidly absorbed in the colon, at the same time as sodium and water absorption and bicarbonate secretion. Once absorbed, SCFAs are used preferentially as fuel for colonic epithelial cells and have trophic effects on the epithelium. Clinically, SCFAs have been studied as possible therapeutic agents in diversion colitis, ulcerative colitis, radiation proctitis, pouchitis and antibiotic‐associated diarrhoea. Although some promising effects have been observed in uncontrolled studies, a specific therapeutic role for SCFAs remains to be defined. SCFAs may be the effector of the beneficial role of fibre in prevention of colon cancer.

Microbiota and the control of blood-tissue barriers

“…57 Furthermore, certain SCFAs may lower the risk of developing gastrointestinal disorders, cancer and cardiovascular disease. 58 SCFAs enter cells both by simple diffusion and through the action of transporters of monocarboxylates and other solutes. Several investigations in the gut of rodents have demonstrated that the SCFAs act as messengers between the gut microbiome and the host 59 promoting the formation of regulatory T-cells (Treg) and regulating immune functions.…”

Effect of Synbiotic Therapy on Gut–Derived Uremic Toxins and the Intestinal Microbiome in Patients with CKD

“…In fact, treatment with oral-activated charcoal to adsorb ammonia resulted in significant reduction of endotoxemia and plasma concentration of inflammatory cytokines, chemokines, and adhesion molecules in animals with reduced kidney function (14). Disruption of the intestinal epithelial tight junction by heavy influx of urea and expansion of urease-possessing bacteria is compounded by the reduced production of short-chain fatty acids, which compromises viability of colonic epithelial cells, because short-chain fatty acids generated from fermentation of carbohydrates by the symbiotic bacteria are the major source of nutrients for colonic epithelial cells (15). Increased formation of toxic metabolites (IS, PCS, and trimethylamine-N-oxide) and disruption of the intestinal epithelial barrier, changes in the gut milieu, and the resulting microbial dysbiosis play a major role in the pathogenesis of systemic inflammation, a likely important contributor to morbidity and mortality in the CKD population (16).…”

Short-chain fatty acids induced autophagy serves as an adaptive strategy for retarding mitochondria-mediated apoptotic cell death

“…1 The molar ratio among the three major SCFAs is B60:25:15 for acetate (2C):propionate (3C):butyrate (4C). 2 SCFAs are reported to induce differentiation, growth arrest and apoptosis in colon cancer cells.…”