Antagonistic properties of potential probiotics, Lactiplantibacillus plantarum BO1 and Lacticaseibacillus paracasei BUM6 on pathogenic bacteria causing oral disease

Lactic acid bacteria (LAB) of the family Lactobacillaceae, produces certain metabolites, such as extracellular proteins, exopolysaccharides, bacteriocins and lipoteichoic acids which affecting the health and physiology of the host by strengthening the epithelial cells barrier, metabolic and antibacterial effects and modulating the host immune system. In the present day, probiotics can be used as medications and alternatives to drugs since bacteria can develop resistance to drugs. This research aimed to evaluate the antagonistic properties of the potential probiotic strains, Lactiplantibacillus plantarum strain BO1 and Lacticaseibacillus paracasei strain BUM6 against several oral pathogenic bacteria and to compare two methods used for detection of antagonistic properties of both strains. The determination of antagonistic properties of the LAB against the oral pathogenic bacteria, Streptococcus mutans, Streptococcus sanguinis, and Enterococcus faecalis was carried out using two methods, agar spot assay and disc diffusion assay. Both methods detect the antagonistic properties of the LAB by measuring the inhibition zone around the LAB colonies. Larger inhibition zone indicates stronger inhibition ability. Compared to the control, Lactiplantibacillus plantarum (BO1), Lacticaseibacillus paracasei (BUM6) and the combination of the LAB were all inhibiting the growth of oral pathogenic bacteria. Greater inhibition zone can be observed using the agar spot assay. The study also includes coaggregation assay to determine the aggregation activity between the LAB and the oral pathogenic bacteria which correlates to the antagonistic effects of the potential probiotic strains. The higher coaggregation activities indicate more effective inhibition of pathogenic bacterial adhesion. This experiment can be applicable for further research to create a new therapeutic agent using lactic acid bacteria as probiotics, being an alternative to conventional drugs for oral products and medication.