The Relationship Between the Human Genome and Microbiome Comes into View

Area of Science:

• Human health and disease
• Microbiome research
• Genetics and genomics

Background:

• The human microbiome, comprising trillions of microbes, plays a crucial role in health and disease.
• Microbiome composition is influenced by host genetics, environmental factors (diet, exposures), and develops with the host.
• Understanding the interplay between host genetics and the microbiome is essential for predicting health outcomes.

Purpose of the Study:

• To explore the influence of human genetic variation on the composition of the microbiome.
• To investigate the challenges and emerging associations in genome-wide association studies (GWASs) for microbiome phenotypes.
• To emphasize the need for integrating microbiome data into studies of genotype-environment-microbiome interactions.

Main Methods:

• Review of existing studies on microbiome heritability and genetic associations.
• Analysis of genome-wide association studies (GWASs) linking human genetic variants to microbiome composition.
• Cross-population comparisons of identified genetic-microbiome associations.

Main Results:

• A subset of gut microbes shows heritability, indicating genetic determination by the host.
• Genome-wide association studies (GWASs) for microbiome phenotypes have faced challenges due to study size and analytical differences.
• Consistent associations found across populations, notably between higher levels of Bifidobacteria and the lactase nonpersister genotype.

Conclusions:

• Human genetic variation significantly influences the microbiome.
• The association between Bifidobacteria and the lactase nonpersister genotype is a key example of host-microbe genetic interaction.
• Incorporating microbiome analysis into future research is crucial for a comprehensive understanding of human disease susceptibility.