Probiotic property and biological activities of Bifidobacterium animalis subsp. lactis TISTR 2591 isolated from Thai population

Abstract

Bifidobacterium animalis subsp. lactis TISTR 2591 (B. L TISTR) isolated from Thai newborn babies and identified regarding 16S rDNA analysis. Its probiotic property was assessed on hemolytic activity, antibiotic susceptibility, gastric acid and bile resistance capacity, antimicrobial activity and adhesion ability. The biological properties of B. L TISTR were evaluated on blood metabolic parameters (cholesterol, glucose and insulin levels) and metabolic genes expression. The obtained results indicated that B. L TISTR has no hemolytic activity. Its adhesion ability to intestinal epithelium of Caco-2 and HT-29 cell lines is greater than that of the two commercial strains (B. lactis and L. reuteri). No antibiotic resistance property of B. L TISTR was found on eight antibiotics tested. Moreover, it possesses antimicrobial activity against twelve pathogenic bacteria covering seven intestinal pathogens, two oral pathogens and three skin pathogens. It was found that B. L TISTR could induce insulin sensitivity in adipose tissue that was related with reducing glucose. Also, it was shown that cholesterol level in plasma B. L TISTR fed mice decreased significantly. Expression of three metabolic genes including Srebp-1c, Glut4 and Ucp1 was found. These three genes are involved in gluconeogenic control, insulin sensitivity and cholesterol and fatty acid metabolism, respectively. We examined Il10 and Nos2 expression in Peyer’s patches from intestinal and found an induction of Il10 expression. We also found that Nos2 expression decreased in B. L TISTR fed mice. These observations suggest that B. L TISTR may improve immune system and reduce inflammation activity which in turn providing prevention of intestinal inflammation.