In-Vitro Prebiotic Analysis of Microbiota Accessible Pectic Polysaccharides

Pectin is a diverse polysaccharide comprising of polygalacturonic acid, rhamnogalactouronan, and neutral polysaccharides (arabinan and arabinogalactan) as side chains or branches. They are resistant to salivary amylase and gastric juice. In the present study the prebiotic potentials of different pectic derived substrates were performed by using intestinal cultures and measuring the growth, change in pH and short chain fatty acid, (SCFA) production. Arabinan, arabinogalactan, and rhamnogalacturonan were fermented by probiotic bacteria such as Bifidobacterium breve, Bi. longum, Bi. bifidum, and Bacteroides thetaiotaomicron (commensal bacteria). While, polygalacturonic acid was fermented by Ba. fragilis, Ba. thetaiotaomicron, and Ba. uniformis. All the screened bacteria significantly decreased the pH from 7 to 5 (pH difference of ≈ 2), which clearly indicated that the above bacteria produced the enzymes necessary for the digestion of the pectic derived polysaccharides. The SCFA profiles of the above screened bacteria clearly demonstrated the production of lactate, acetate and propionate which are the key metabolites involved in maintaining gut health and prevention of several intestinal diseases. Thus, pectic polysaccharides hold potential application in food industry as prebiotic ingredients or dietary fibers.