Synbiotic combination of Lactobacillus rhamnosus NCDC 298 and short chain fructooligosaccharides prevents enterotoxigenic Escherichia coli infection

This study aimed to examine the role of fructooligosaccharides (FOS), inulin and maltodextrin as prebiotics on aggregation characteristics of putative probiotic Lactobacillus rhamnosus NCDC 298 strain. Same prebiotics were assessed alone for their anti-adhesive effect against enterotoxigenic Escherichia coli (ETEC) followed by its synergistic synbiotic effect on ETEC virulence to HT-29 intestinal cell lines. The effect of prebiotics on autoaggregation and coaggregation property of probiotic strain was studied by comparing absorbance over an interval of time. FOS was found to enhance autoaggregation and coaggregation characteristics of L. rhamnosus NCDC 298 with ETEC. Anti-adherence effect of prebiotics towards ETEC was determined by cultural method. Adherence inhibition percentage was occurred maximum in presence of inulin followed by FOS, having non-significant relationship in-between. Synergistic effect of both probiotics and prebiotics against ETEC virulence were seen by comparing cyclic AMP (cAMP) and cyclic GMP (cGMP) levels with controls. Significant decrease in both the cyclic nucleotides were recorded in presence of FOS with L. rhamnosus NCDC 298. Fructooligosaccharide influenced adhesion characteristics of L. rhamnosus NCDC 298 with anti-virulence activity against ETEC, both alone and as synbiotic combination. Hence this combination can be further used to develop prophylactic anti-diarrheal formulation.