Journal Article

Genetic determinants of gut microbiota composition and bile acid profiles in mice

Keller, Mark P., Broman, Karl W., Rabaglia, Mary E., Yandell, Brian S., Stapleton, Donald S., Attie, Alan D., Rey, Federico E., Amador-Noguez, Daniel, Boehm, Frederick J., Traeger, Lindsay L., Barrett, Kelsey L., Schueler, Kathryn L., Russell, Jason D., Gatti, Daniel M., Kemis, Julia H., Coon, Joshua J., Churchill, Gary A., Linke, Vanessa

2019

Overview

The microbial communities that inhabit the distal gut of humans and other mammals exhibit large inter-individual variation. While host genetics is a known factor that influences gut microbiota composition, the mechanisms underlying this variation remain largely unknown. Bile acids (BAs) are hormones that are produced by the host and chemically modified by gut bacteria. BAs serve as environmental cues and nutrients to microbes, but they can also have antibacterial effects. We hypothesized that host genetic variation in BA metabolism and homeostasis influence gut microbiota composition. To address this, we used the Diversity Outbred (DO) stock, a population of genetically distinct mice derived from eight founder strains. We characterized the fecal microbiota composition and plasma and cecal BA profiles from 400 DO mice maintained on a high-fat high-sucrose diet for ~22 weeks. Using quantitative trait locus (QTL) analysis, we identified several genomic regions associated with variations in both bacterial and BA profiles. Notably, we found overlapping QTL for Turicibacter sp. and plasma cholic acid, which mapped to a locus containing the gene for the ileal bile acid transporter, Slc10a2. Mediation analysis and subsequent follow-up validation experiments suggest that differences in Slc10a2 gene expression associated with the different strains influences levels of both traits and revealed novel interactions between Turicibacter and BAs. This work illustrates how systems genetics can be utilized to generate testable hypotheses and provide insight into host-microbe interactions.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Akkermansia / Animals / Antibacterial agents / Bacteria / Bacteriology / Bile / Bile acids / Bile Acids and Salts - blood / Bile Acids and Salts - metabolism / Biochemistry / Biological Variation, Population - genetics / Biology and Life Sciences / Cecum / Cholic acid / Collaborative Cross Mice / Composition / Deoxycholic acid / Fecal microflora / Female / Firmicutes - growth & development / Funding / Gastrointestinal Microbiome - physiology / Gene expression / Genes / Genetic aspects / Genetic diversity / Genetic research / Genetics / Genomes / Gut microbiota / High fat diet / Homeostasis / Hormones / Intestinal microflora / Laboratories / Male / Mediation / Medicine and Health Sciences / Menopause / Metabolic Networks and Pathways - genetics / Metabolism / Metabolites / Mice / Microbiota / Microbiota (Symbiotic organisms) / Microorganisms / Models, Animal / Novels / Nutrients / Organic Anion Transporters, Sodium-Dependent - genetics / Organic Anion Transporters, Sodium-Dependent - metabolism / Physiological aspects / Physiology / Population genetics / Quantitative genetics / Quantitative trait loci / Quantitative Trait Loci - genetics / Software / Strains (organisms) / Sucrose / Supervision / Symporters - genetics / Symporters - metabolism / Verrucomicrobia - growth & development