Screening Potential Probiotic Characteristics of Lactobacillus brevis Strains In Vitro and Intervention Effect on Type I Diabetes In Vivo

Diabetes has become the third most serious threat to human health, after cancer and cardiovascular disease. Notably, Lactobacillus brevis is the most common species of LAB that produces γ-aminobutyric acid (GABA). The aim of this study is to clarify the effect of time, strain types, antibiotic concentrations, different levels of pH, and intestinal juices in aerobic or anaerobic conditions and the effect of interactions between these factors on the potential properties of KLDS 1.0727 and KLDS 1.0373, furthermore, antagonistic activity against foodborne pathogens. Moreover, another aim is to study the capability of KLDS 1.0727 and KLDS 1.0373 strains as gad gene carriers to express GABA that reduce the risk of type 1 diabetes in C57BL/6 mice as diabetic models. The obtained results exhibited the surprising tolerance of Lactobacillus brevis strains in vitro digestion models mimicking the conditions of the gastrointestinal tract, further, large antagonistic activity against foodborne pathogeneses. In vivo results displayed the significant effect on glucose level reduction, blood plasma, and histological assays of mice organs. As recommended, the use of Lactobacillus brevis strains should be widely shared in the market as a natural source of GABA in pharmaceutical and food applications.