The state of the gut microbiome is influential on health, perhaps as much as exercise. The balance of microbial populations shifts with age, reducing beneficial metabolite production, and increasing inflammation. Experiments in animals have shown that resetting those populations towards a more youthful configuration can improve health and extend life. Producing of a greater understanding of how exactly microbial populations produce changes in health is a work in progress, and today's research is an example of one approach, correlating microbial populations with blood metabolites. Many such metabolites have known associations with aspects of health and aging, which will hopefully guide future research to more effective approaches to intervention.
Human gut microbiota produce a variety of molecules, some of which enter the bloodstream and impact health. Conversely, dietary or pharmacological compounds may affect the microbiota before entering the circulation. Characterization of these interactions is an important step towards understanding the effects of the gut microbiota on health. In this cross-sectional study, we used deep metagenomic sequencing and ultra-high-performance liquid chromatography linked to mass spectrometry for a detailed characterization of the gut microbiota and plasma metabolome, respectively, of 85,83 participants invited at age 50 to 64 from the population-based Swedish CArdioPulmonary bioImage Study.
Here, we find that the gut microbiota explain up to 58% of the variance of individual plasma metabolites and we present 997 associations between alpha diversity and plasma metabolites and 546,819 associations between specific gut metagenomic species and plasma metabolites in an online atlas. We exemplify the potential of this resource by presenting novel associations between dietary factors and oral medication with the gut microbiome, and microbial species strongly associated with the uremic toxin p-cresol sulfate. This resource can be used as the basis for targeted studies of perturbation of specific metabolites and for identification of candidate plasma biomarkers of gut microbiota composition.