In vitro and In vivo Safety Assessment of Bifidobacterium longum BBMN68, A Potential Probiotic Isolated from Healthy Centenarians

摘要

Bidifobacterium longum BBMN68 (BBMN68) is a potential probiotic, which was selected from centenarians feces isolates in Bama. To evaluate the strain's safety, antimicrobial susceptibility, mucin degradation activity, bacterial translocation activity and acute toxicity were investigated. The results of the distribution of inhibition zone diameters showed that BBMN68 were susceptible to most of the antibiotics except for aminoglycoside. Based on recovery of mucin carbohydrate and SDS-PAGE analysis of mucin glycoprotein in liquid medium, BBMN68 had no mucinolytic activity. No viable bacteria were recovered from blood and tissue samples of mice, and no treatment-associated illness or death was observed. Acute oral toxicity study showed that the strain had no toxic reaction with mice, and the mice maximum tolerable dose of BBMN68 frozen cultures was greater than 4.6x10~(11) cfu/kg bw/day. The results obtained in this study suggest that consumption of BBMN68 at a normal dose should be safe for human, BBMN68 may be exploited as a probiotic in food and dairy industry.