The Antimicrobial Effects of Lactobacillus Plantarum and Lactobacillus Rhamnosus Isolated from Local Kefir Buttermilk on Oral Pathogens

Tooth decay is one of the most common diseases, and Streptococcus mutans and Porphyromonas gingivalis have been found to play an effective role in causing advanced tooth decay. Due to the increase in antibiotic resistance of bacteria, the use of probiotics has been investigated to reduce pathogenic bacteria in the oral cavity. The purpose of this study is to investigate the effect of probiotics isolated from traditional kefir dough on the two main causes of tooth decay.

Two common species Lactobacillus plantarum and Lactobacillus rhamnosus were confirmed by using microbiological techniques (phenotypic and molecular). The antimicrobial effects of these probiotic on Streptococcus mutans (ATCC 35668) and Porphyromonas gingivalis (ATCC 32277) was investigated by welling method and then the compounds present in their culture supernatant were identified by gas chromatography Mass spectrometry (GC-MS).

The experiments showed that Lactobacillus plantarum and Lactobacillus rhamnosus had a significant antimicrobial effect on Streptococcus mutans and Porphyromonas gingivalis and it can may be used as a suitable candidate to control the disease. Lactobacillus plantarum decreased gtfB gene expression by 0.001 fold change and brpA gene expression by 0.007 fold change, also Lactobacillus rhamnosus decreased gtfB gene expression by 0.01 fold change and brpA gene expression by 0.04 fold change. Also, GC-MS showed the presence of Pyrrolidione, Furanone, Benzoic acid, Icosane, Nonadecane derivatives in the supernatant of the tested probiotics.

Considering the antimicrobial properties of bacteria isolated from traditional kefir buttermilk, they can be used as traditional probiotic strains with antimicrobial effect in fermented foods.