Genomic Discoveries in Gut Microbes and Their Impact on Brain Behavior

In a groundbreaking study using Merino sheep as an animal model, researchers discovered that subtle genetic changes within gut microbes can influence brain-related behavior. By sequencing over 5,000 microbial genomes, including 3,500 previously unreported genomes, genetic changes in microbes were linked to neurobehavioral traits and metabolic processes in plasma associated with brain function.

Discovery of Microbial Genomes

Researchers reconstructed 5,253 microbial genomes from the gut, including 3,548 new species-level genomes. This discovery significantly expands the sources of microbial genomes in the digestive system of ruminant animals, providing deeper insights into microbial genetic diversity and its impact on overall health.

The study showed that precise genetic shifts, particularly in the Firmicutes and Bacteroidetes phyla, can lead to metabolic changes affecting active neural regulation and oxidative stress. These findings suggest that microbial genes can finely tune metabolism and cognition in the host, offering new perspectives on the connection between the microbiome, metabolism, and the brain.

The Link Between Microbes and the Brain

The study demonstrated a correlation between changes in microbial DNA (SNVs) and alterations in metabolism and exploratory behavior. For instance, a microbial genetic mutation was linked to the formation of brain-derived neurotrophic factor (BDNF), influencing curiosity and exploration.

Based on metagenomic sequencing data from fecal and rumen samples, the authors reconstructed 5,253 species-level assembled genomes, including 3,548 previously unreported genomes, significantly expanding the microbial genomic resources for the digestive system of ruminants.

Impact of Genetic Changes on Behavior

Using this database, the study described approximately 140 million single nucleotide variation (SNV) sites from 790 species. By correlating the phylogenetic evolutionary distances of these species with 21 neurobehavioral traits, the study found that hosts harboring different strains within the same species exhibited neurobehavioral differences.

Furthermore, by conducting an association analysis between microbial SNVs and host plasma metabolic processes, the study identified 34 significant associations between SNVs and metabolic processes, primarily centered in the Firmicutes and Bacteroidetes phyla, many of which are potentially new species.

Conclusion

This study suggests that genetic shifts in the microbial genome may be a significant driver of phenotypic differences in the host, revealing that microbial genetic changes can affect the host’s cognitive neural behavior by regulating metabolic processes. This discovery expands our understanding of the “microbiome-metabolism-brain” axis and provides a theoretical basis for developing targeted interventions aimed at the gut microbiome.