Coaggregation of oral pathogens by postbiotic lactobacilli.

INTRODUCTION

Coaggregation may reduce the abundance of bacteria in physiological fluids, such as saliva, as aggregated bacteria are cleared more easily than planktonic cells. This study aimed to identify Lactobacillus strains that coaggregate with oral pathogens with the perspective of using this approach to improve oral health.

MATERIAL AND METHODS

Coaggregation of 719 postbiotic strains with target pathogens , , and intermedia was quantified by absorbance. Coaggregation efficacy of selected strains with clinical isolates and in the presence of other salivary bacteria was determined by flow cytometry. Brightfield and confocal microscopy were applied to characterize the size and structure of coaggregates. Pangenome analysis was used to identify genomic regions potentially involved in the coaggregation activity.

RESULTS

Two strains, Lacticaseibacillus rhamnosus 1B06 and Lacticaseibacillus paracasei 8A12, coaggregated efficiently with all three target pathogens and clinical isolates of the same species even in the presence of other salivary bacteria. The coaggregation capability of the selected Lactobacillus strains was unique and could not be reproduced with other genetically similar lactic acid bacteria of the same species.

CONCLUSION

Lactobacillus strains capable of coaggregating oral pathogens were identified as promising candidates for the development of new postbiotic ingredients for oral hygiene products.