Oral Probiotic Activities and Biosafety of Lactobacillus gasseri HHuMIN D

Abstract

Background Specific probiotic bacteria may have inhibitory effects against oral pathogens. Lactobacillus spp. have been researched worldwide and are used in probiotics, but due to difficulties with laboratory cultivation of and experimentation on oral microorganisms, there are few reports of Lactobacillus spp. being isolated from the oral cavity and tested against oral pathogens. This research aimed to determine the safety and inhibitory impacts of L. gasseri HHuMIN D as a potential oral probiotic with biotherapeutic capabilities against oral pathogens. Results The microbial and genetic characteristics of L. gasseri HHuMIN D were evaluated in this research. A 5% dilution of L. gasseri HHuMIN D culture supernatant exhibited 88.8% inhibition against halitosis-producing anaerobic microorganisms and L. gasseri HHuMIN D exhibited powerful inhibitory effects on the growth of every harmful oral bacterium tested. Unfortunately, other oral bacteria affected the growth of L. gasseri HHuMIN D, suggesting a poor proliferative response to most co-cultures. Hydrogen peroxide production by L. gasseri HHuMIN D reached 802 µmol/L after 12 hours and gradually diminished until 24 hours. It efficiently aggregated with P. catoniae and S. sanguinis, and completely supressed S. mutans-manufactured artificial dental plaque. L. gasseri HHuMIN D’s KB cell adhesion capacity was 4.41 cells per cell, and the cell adhesion of F. nucleatum and S. mutans diminished strongly in protection and displacement assays. L. gasseri HHuMIN D was evaluated for safety using ammonia and biogenic amine development, hemolytic property and mucin degradation testing, antibiotic susceptibility, and whole genome sequencing (WGS). Conclusion Our results suggest that L. gasseri HHuMIN D may be a safe, bioactive, lactobacterial food ingredient, starter culture, and/or probiotic microorganism for human oral health.

Two novel lactic acid bacteria, Limosilactobacillus fermentum MN-LF23 and Lactobacillus gasseri MN-LG80, inhibited Helicobacter pylori infection in C57BL/6 mice

“…28 L. fermentum and L. gasseri can release anti-microbial agents such as bacteriocins, 29,30 biosurfactant 31,32 and hydrogen peroxide. 33,34 In line with this, our results showed that LF23 and LG80 fermentation supernatants could significantly inhibit the growth of H. pylori and reduce H. pylori infection in vivo, indicating that they can metabolize and produce bacteriostatic substances. In the case of excluding the influence of acid, the fermentation supernatant of LAB can also significantly inhibit the growth of H. pylori, indicating that in addition to the secretion of organic acids, it can also produce other antibacterial substances.…”

The metabolites of lactic acid bacteria: classification, biosynthesis and modulation of gut microbiota

“…Probiotic characteristics; antimicrobial activity; innate immune responses in epithelial cells [131,132] Bacteremia [133] Lactobacillus gasseri Probiotic characteristics; used in food industry as supplements; inhibit increase in body weight and adipose tissue weight [134,135] Liver abscesses [136]…”