Safety Assessment of Indigenous Probiotic Strain Lactobacillus plantarum Mut-7 Using Sprague Dawley Rats as a Model

Lactobacillus plantarum Mut-7 is a probiotic candidate isolated from gatot, traditional fermented cassava from Java, Indonesia. This study aimed to evaluate safety aspects of high dose consumption of L. plantarum Mut-7 (10¹¹ CFU/ml/day) on Sprague Dawley rats for 21 days. Twenty four female rats were randomly divided into 4 groups; initial condition group (P.0), control group (P.1), skim milk group (P.2) and probiotics group (P.3). All groups followed adaptation phase of 7 days, followed by treatment phase of 21 days for P.1, P.2 and P.3. The results showed that supplementation of high dose of L. plantarum Mut-7 did not have detrimental effects on general health, organ weight, hematology and histology parameters of treated rats. Feed intake and body weight showed no significant difference between groups. L. plantarum Mut-7 can survive in gastrointestinal tract of rats, resulting in an increased population of L. plantarum in the fecal matter and the digesta of treated rats. Bacterial translocation of L. plantarum Mut-7 was not detected in the blood and organ of treated rats as confirmed by rep-PCR with BOXAIR primer and further 16S RNA gene sequencing analysis. Twenty-six isolates from blood and organs of treated rats had low-level similarity (<75%) to that of L. plantarum Mut-7, with 10 isolates were further analyzed and found that none of them belong to L. plantarum. Although this study was limited to the use of animal study, the findings are useful to support the safety assessment of the use of L. plantarum Mut-7 as a probiotic according to the abovementioned parameters.