Interplay between host genetics and gut microbiome composition in the Japanese population.

Area of Science:

• Human Genetics
• Microbiome Research
• Population Genomics

Background:

• Host genetics play a crucial role in shaping gut microbiota composition.
• Understanding these host-microbiome interactions is vital, particularly in non-European populations.
• Previous research has often overlooked population-specific genetic influences on the gut microbiome.

Purpose of the Study:

• To investigate the associations between host genetic variations and gut microbiome composition in a Japanese cohort.
• To identify specific genetic variants linked to microbial taxa and metabolic pathways.
• To evaluate the impact of different methodologies on microbiome data reproducibility.

Main Methods:

• Whole-genome sequencing of 306 Japanese individuals.
• Shotgun metagenomic sequencing for gut microbiome profiling.
• Genome-wide association studies (GWAS) and Phenome-wide association studies (PheWAS).

Main Results:

• Significant genetic associations were found with specific bacterial taxa and pathways, though not reaching stringent genome-wide significance.
• Replication of previously reported associations proved challenging, even within Japanese populations.
• A variant in the OR6C1 gene (rs5798345-CA) was linked to increased abundance of Bacteroides uniformis.
• Methodological differences in sample processing and DNA extraction substantially affected microbiome composition and reproducibility.

Conclusions:

• Host genetics influence gut microbiota composition in the Japanese population.
• Methodological standardization is critical for enhancing reproducibility in microbiome studies.
• Identifying host genetic variants associated with microbial communities advances understanding of host-microbiome interactions.