# Microbial genetic composition regulates host social behavior

## TL;DR

This study shows that genetic changes in gut bacteria can affect the social behavior of a host organism, offering new insights into how microbes influence brain function.

## Contribution

The study identifies specific E. coli gene mutations that alter C. elegans social behavior through the TGF-β signaling pathway.

## Key findings

- 370 E. coli gene knockout strains were found to reduce C. elegans social behavior.
- Mutations in the L-tyrosine biosynthesis pathway significantly affect social aggregation via TGF-β signaling.
- The findings emphasize the role of microbial genetic variation in host neurobehavioral interactions.

## Abstract

The co-evolutionary relationship between gut microbiota and their hosts is influenced by microbial genetic variation, which enables adaptation to host environmental changes, modifies metabolic processes, and refines host–microbiota interactions. Investigating how gut microbial genetic variations influence host neurobehavior can provide insights into the pathogenesis of neurological disorders. In this study, we screened a comprehensive single-gene knockout library of Escherichia coli (E. coli) and identified 370 mutant strains that reduced social behavior in Caenorhabditis elegans (C. elegans). Notably, five mutations in the L-tyrosine biosynthesis pathway significantly alter the social aggregation behavior of C. elegans via the TGF-β signaling pathway. These findings highlight the importance of considering both microbial genetic variation and community composition in the examination of gut microbe-host neurobehavioral interactions. The establishment of this relationship provides a reference and experimental basis for the development of genetically engineered probiotics aimed at regulating host behavior.