Safety aspects and beneficial features of lactobacilli isolated from Lebanese Baladi goat milk

The microbiological and physicochemical parameters of Lebanese goat milk from the “Baladi” breed were evaluated and twenty-eight lactobacilli were isolated and examined in vitro for their probiotic potential. Initially, Lactobacillus isolates were examined for safety issues and exhibited diverse susceptibility to commonly used antibiotics while none was hemolytic. Subsequently, Isolates showed variable antimicrobial activity towards a range of spoilage and pathogenic bacteria. Regarding their performance in conditions simulating the human gastrointestinal tract, all isolates remained unaffected at pH 3 and in the presence of bile salts (0.5% (w/v)) for 3 hours. Based on their survival at pH 2.5 for 3 hours, 10 isolates were selected for the adhesion assay. Low adhesion was observed to HT-29 and Caco-2 cells. Co-cultivation of THP-1 cells with specific isolates indicated a tendency for anti-inflammatory modulation shown by an increase in IL10 mRNA levels. Further analysis for probiotic properties indicated partial bile salt hydrolase activity for all isolates (n=28). Isolates were identified by 16S rRNA sequence and were affiliated to the Lactobacillus casei group. Overall, by applying in vitro tests, a select number of presumptive Lactobacillus rhamnosus strains showed promising probiotic features from the Lebanese Baladi goat milk. This is the first report about safety and beneficial characterization of Lactobacillus strains isolated from Baladi goat milk from Lebanon.