# Engineered Lactobacillus reuteri for scavenging reactive oxygen species and modulating oral microflora in periodontitis therapy

## TL;DR

Scientists engineered a probiotic bacteria to reduce mouth inflammation and fight gum disease by sticking to the right place and reducing harmful stress chemicals.

## Contribution

A ROS-responsive adhesive polymer was engineered in Lactobacillus reuteri to enhance colonization and antagonize pathogens in periodontitis.

## Key findings

- Engineered Lactobacillus reuteri effectively alleviates local oxidative stress in periodontitis.
- The treatment reduces the abundance of pathogenic bacteria in the subgingival microbiome.
- The engineered probiotic shows good biocompatibility and safety for potential clinical use.

## Abstract

The onset and progression of periodontitis are closely associated with subgingival dysbiosis and excessive localized oxidative stress. While some oral probiotics exhibit certain inhibitory effects on periodontitis-related pathogens, they often struggle to effectively colonize and antagonize these pathogens due to the complex oxidative stress at the site of periodontitis. In this study, we engineer Lactobacillus reuteri with a reactive oxygen species (ROS)-responsive adhesive polymer (phenylboric acid-dopamine-hyaluronic acid) (LR@PDH). In the periodontitis microenvironment, this polymer can consume ROS and then expose the phenolic hydroxyl group of dopamine, promoting the selective adhesion and colonization of Lactobacillus reuteri at the site of inflammation to antagonize pathogens. The results show that, compared to conventional probiotic therapy, inflammation-responsive adhesive Lactobacillus reuteri effectively alleviates local oxidative stress, reduces the abundance of pathogenic bacteria in the subgingival microbiome, and inhibits the progression of periodontitis. Additionally, its good biocompatibility and safety highlight its potential as a therapeutic approach for clinical treatment of periodontitis.