Detection and Quantification of Probiotic Strains in Clinical Fecal Samples of Healthy Adults by Real-time PCR

INTRODUCTIONA randomized, double-blind, placebo-controlled, crossover clinical study (NCT01879098) on healthy, middle-aged adults investigated the effects of three probiotic strains, Bifidobacterium animalis subsp. lactis B94, Lactobacillus plantarum HA119, and Bacillus subtilis R0179 on bile acid metabolism, satiety, and inflammation. In order to substantiate positive outcomes, probiotic strains must persist during transit through the gastrointestinal tract of participants. The objective of this sub-study was to detect and quantify HA119 and R0179 at the strain level in fecal samples using previously designed primers for real-time PCR (qPCR). METHODOLOGYParticipants of the clinical study were randomized to receive one capsule per day of a probiotic strain or placebo for six weeks. Following a four week washout period, participants were crossed to the other treatment (probiotic to placebo or placebo to probiotic). Fecal samples were collected at the baseline and final time points of each intervention for ...