Microbiota alters the metabolome in an age- and sex- dependent manner in mice

Commensal bacteria are major contributors to mammalian metabolism. We used liquid chromatography mass spectrometry to study the metabolomes of germ-free, gnotobiotic, and specific-pathogen-free mice, while also evaluating the influence of age and sex on metabolite profiles. Microbiota modified the metabolome of all body sites and accounted for the highest proportion of variation within the gastrointestinal tract. Microbiota and age explained similar amounts of variation the metabolome of urine, serum, and peritoneal fluid, while age was the primary driver of variation in the liver and spleen. Although sex explained the least amount of variation at all sites, it had a significant impact on all sites except the ileum. Collectively, these data illustrate the interplay between microbiota, age, and sex in the metabolic phenotypes of diverse body sites. This provides a framework for interpreting complex metabolic phenotypes and will help guide future studies into the role that the microbiome plays in disease. Commensal microbes contribute considerably to mammalian metabolism. Here the authors report the relative contributions of microbiome, age and sex to metabolism throughout the body and uncover age- and sex- specificity in how microbes affect metabolite levels in mice.

Automated summary

Commensal bacteria play a significant role in mammalian metabolism. This study investigates the impact of microbiota, age, and sex on metabolite profiles in various body sites of mice. The microbiota has the highest influence on the gastrointestinal tract, while age and microbiota similarly contribute to urine, serum, and peritoneal fluid metabolome variations. Moreover, age mainly drives metabolome variations in the liver and spleen, while sex has a significant impact on all sites except the ileum.