Environment dominates over host genetics in shaping human gut microbiota.

Area of Science:

• Human Microbiome Research
• Genetics and Host-Microbe Interactions

Background:

• Understanding factors influencing human gut microbiome composition is crucial.
• The precise contribution of host genetics to microbiome diversity remains unclear.

Purpose of the Study:

• To investigate the association between host genetics, ancestry, and gut microbiome composition.
• To identify key environmental factors driving microbiome variability.
• To assess the impact of microbiome data on predicting human traits.

Main Methods:

• Analysis of genotype and microbiome data from 1,046 healthy individuals.
• Comparison of microbiome composition across different genetic ancestries and household contacts.
• Statistical modeling to correlate microbiome variability with diet, drugs, and anthropometric measurements.

Main Results:

• Gut microbiome composition showed no significant association with genetic ancestry.
• Host genetics had a minor influence on microbiome composition.
• Significant microbiome similarities were observed among genetically unrelated household members.
• Diet, drugs, and anthropometric measurements explained over 20% of microbiome variability.
• Microbiome data improved prediction accuracy for traits like glucose levels and obesity.

Conclusions:

• Environmental factors, particularly diet and household sharing, are stronger determinants of gut microbiome composition than host genetics or ancestry.
• Microbiome profiling enhances the prediction of host traits beyond genetic and conventional environmental data.
• Microbiome-targeted interventions show promise for diverse genetic backgrounds to improve clinical outcomes.