Effect of Dietary Supplementation with Lactobacillus Strains in Non-Dairy Matrices on Colonic Metabolic Activities: A Clinical Trial

Background: Gut microbiota has beneficial effects on intestinal mucosa. It enhances immunity and produces metabolites that influence general health. This study aimed to evaluate the effect of dietary intervention with multi-strain potential probiotic Lactobacilli on functional metabolic colonic activities in healthy adult males. Furthermore, the study introduces dates and biscuits as non-dairy matrices for administration of probiotic Lactobacilli. Methods: The crossover study included eleven adult male volunteers, who were assigned to three different interventions consecutively, with each intervention lasting for 21 days. The participants were given biscuits with probiotics, followed by biscuits with placebo, and lastly dates with probiotics. Each phase was followed by a month of washout period. The consumed biscuits and dates contained probiotics with a total daily dose of 1.68 x 108 and 3.3 x 108 colony forming units, respectively. Before and after each test period, the volunteers were clinically examined and stool samples were collected. The samples were examined for Lactobacillus count, short chain fatty acids, secretory immunoglobulin A, ammonia contents, and stool pH using standard techniques. Results: After daily consumption of probiotics, a significant increase in fecal secretory immunoglobulin A and short chain fatty acids were observed, with associated significant decrease of fecal ammonia contents. As a whole, colonic metabolic functions were significantly improved. Conclusion: Biscuits and dates proved to serve as efficient matrices for delivery of live probiotics. The used probiotic Lactobacillus strains have positive impact upon metabolic functions of the colon in healthy adults.