EVALUATION OF THE ANTIULCER AND ANTIDIARRHEAL POTENTIAL OF LACTIC ACID BACTERIA ISOLATED FROM YOGURT IN ULCER AND DIARRHEA INDUCED IN WISTAR RATS

Abstract

This study investigates the antiulcer and antidiarrheal potential of lactic acid bacteria (LAB) isolated from commercially available yogurt in Wistar rats. Three LAB strains, Lactobacillus paracasei (Y1), Lactobacillus rhamnosus (Y2), and Streptococcus thermophilus (Y3), were identified through biochemical tests and 16S rRNA sequencing. For the antiulcer study, rats were pre-treated with LAB strains for seven days before inducing gastric ulcers with indomethacin. Ulcer index and gastric juice parameters were assessed. For the antidiarrheal study, diarrhea was induced using castor oil, and the effects of LAB pre-treatment on fecal output, consistency, and intestinal transit time were evaluated. GC-MS analysis identified bioactive compounds that may contribute to the observed therapeutic effects. Results showed that L. paracasei (Y1) significantly reduced ulcer index by 65% (p<0.05) and increased gastric mucus production by 40% compared to the control group. L. rhamnosus (Y2) reduced diarrhea severity by 50% (p<0.05) and normalized intestinal transit time. S. thermophilus (Y3) showed moderate improvement in both ulcer and diarrhea parameters. Bioactive compounds such as lactic acid, acetic acid, butyric acid, and reuterin were identified, which may contribute to the protective effects. These findings suggest that LAB isolated from yogurt possess significant antiulcer and antidiarrheal properties, with L. paracasei and L. rhamnosus exhibiting the most promising effects.