Xenobiotic Metabolism and Gut Microbiomes

PLoS One. 2016 Oct 3;11(10):e0163099. doi: 10.1371/journal.pone.0163099. eCollection 2016.


Humans are exposed to numerous xenobiotics, a majority of which are in the form of pharmaceuticals. Apart from human enzymes, recent studies have indicated the role of the gut bacterial community (microbiome) in metabolizing xenobiotics. However, little is known about the contribution of the plethora of gut microbiome in xenobiotic metabolism. The present study reports the results of analyses on xenobiotic metabolizing enzymes in various human gut microbiomes. A total of 397 available gut metagenomes from individuals of varying age groups from 8 nationalities were analyzed. Based on the diversities and abundances of the xenobiotic metabolizing enzymes, various bacterial taxa were classified into three groups, namely, least versatile, intermediately versatile and highly versatile xenobiotic metabolizers. Most interestingly, specific relationships were observed between the overall drug consumption profile and the abundance and diversity of the xenobiotic metabolizing repertoire in various geographies. The obtained differential abundance patterns of xenobiotic metabolizing enzymes and bacterial genera harboring them, suggest their links to pharmacokinetic variations among individuals. Additional analyses of a few well studied classes of drug modifying enzymes (DMEs) also indicate geographic as well as age specific trends.

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Bacteria / classification
  • Bacteria / enzymology
  • Bacteria / genetics*
  • Child
  • Child, Preschool
  • Enzymes / genetics
  • Enzymes / metabolism*
  • Ethnicity / genetics
  • Female
  • Gastrointestinal Microbiome / genetics*
  • Gene Expression Regulation, Bacterial
  • Gene Expression Regulation, Enzymologic
  • Humans
  • Inactivation, Metabolic / genetics*
  • Infant
  • Infant, Newborn
  • Male
  • Metabolic Networks and Pathways / genetics
  • Metagenome / genetics
  • Middle Aged
  • Xenobiotics / metabolism*


  • Enzymes
  • Xenobiotics

Grants and funding

Three of the authors (AD, TSG and SSM) are employed in a commercial company, namely Tata Consultancy Services Ltd. However, the company provided support only in the form of salaries for authors, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.