Antidiarrheal potential of Lactobacillus strains isolated from pharmaceutical formulations for the treatment of pediatric diarrhea

The consumption of probiotics in the prevention and treatment of diarrhea have been clinically justified, comprehensive studied and explored in many products around the world. In Pakistan, recommendation of probiotic formulations is being emerged to control the increased mortality and morbidity from diarrhea under 5 years of age children. The objective of the study was to evaluate the antimicrobial potential of isolated Lactobacillus strains against diarrheagenic Escherichia coli. Twelve strains were isolated from different probiotic pharmaceutical formulations available in Pakistan. Physiological and biochemical characteristics of isolates were analyzed. Selective media was used for the growth of probiotic isolates and E. coli. Agar spot and well diffusion methods were employed to evaluate the antimicrobial activity of isolates and measured as a zone of inhibition (mm). Changes in cell morphology was observed by Scanning Electron Microscopy. Statistical analysis was adopted with a level of significance p<0.05. L. reuteri (28 mm) and L.plantarum (26 mm) showed significant inhibitory actions against E. coli due to increased organic acids and bacteriocins formations. Rest of isolates exhibited mild to moderate activity with an average inhibition (20 mm). L. sporogenes demonstrated weak antagonistic behavior. Use of multiple strains of Lactobacillus along with L. reuteri or L.plantarum as a therapeutic agent or in nutritional supplements could be a novel approach for the prevention and treatment of pediatric diarrhea.