The influence of polyunsaturated fatty acids on probiotic growth and adhesion

The establishment of the intestinal microflora, and probiotic bacteria, may control the inflammatory conditions in the gut. As polyunsaturated fatty a cids (PUFA) possess antimicrobial activities, they may deter the action of probiotics. We assessed whether free linoleic, gamma -linolenic, arachidoni c. alpha -linolenic and docosahexaenoic acids at physiological concentratio ns in the growth media would influence the growth and adhesion of Lactobaci llus GG (probiotic), Lactobacillus casei Shirota (probiotic) and Lactobacil lus bulgaricus (dairy strain). Higher concentrations of PU FA (10-40 mug PU FA ml(-1)) inhibited growth and mucus adhesion of all tested bacterial stra ins, whilst growth and mucus adhesion of L. casei Shirota was promoted by l ow concentrations of gamma -linolenic acid and arachidonic acid (at 5 mug m l(-1)). respectively. PUFA also altered bacterial adhesion sites on Caco-2 cells. Caco-2 cells grown in the presence of arachidonic acid were less adh ered to by all three bacterial strains. Yet, L. casei Shirota adhered bette r on Caco-2 cells grown in the presence of cc-linolenic acid. As the adhesi on to mucosal surfaces is pivotal in health promoting effects by probiotics . our results indicate that the action of probiotics in the gut may be modu lated by dietary PUFA. (C) 2001 Federation of European Microbiological Soci eties. published by Elsevier Science B.V. All rights reserved.