title: Do interactions between gut ecology and environmental chemicals contribute to obesity and diabetes?
abstract: BACKGROUND
  Gut microbiota are important factors in obesity and diabetes, yet little is known about their role in the toxicodynamics of environmental chemicals, including those recently found to be obesogenic and diabetogenic.
  
  
  OBJECTIVE
  We integrated evidence that independently links gut ecology and environmental chemicals to obesity and diabetes, providing a framework for suggesting how these environmental factors may interact with these diseases, and identified future research needs.
  
  
  METHODS
  We examined studies with germ-free or antibiotic-treated laboratory animals, and human studies that evaluated how dietary influences and microbial changes affected obesity and diabetes. Strengths and weaknesses of studies evaluating how environmental chemical exposures may affect obesity and diabetes were summarized, and research gaps on how gut ecology may affect the disposition of environmental chemicals were identified.
  
  
  RESULTS
  Mounting evidence indicates that gut microbiota composition affects obesity and diabetes, as does exposure to environmental chemicals. The toxicology and pharmacology literature also suggests that interindividual variations in gut microbiota may affect chemical metabolism via direct activation of chemicals, depletion of metabolites needed for biotransformation, alteration of host biotransformation enzyme activities, changes in enterohepatic circulation, altered bioavailability of environmental chemicals and/or antioxidants from food, and alterations in gut motility and barrier function.
  
  
  CONCLUSIONS
  Variations in gut microbiota are likely to affect human toxicodynamics and increase individual exposure to obesogenic and diabetogenic chemicals. Combating the global obesity and diabetes epidemics requires a multifaceted approach that should include greater emphasis on understanding and controlling the impact of interindividual gut microbe variability on the disposition of environmental chemicals in humans.
authors: Department of Microbiology and the Institute for Comparative and Environmental Toxicology, Cornell University, Ithaca, New York 14853, USA.
authors: Suzanne M
authors: SM
authors: Snedeker
authors: Anthony G
authors: AG
authors: Hay
mesh_terms: D000818:Animals; D003920:Diabetes Mellitus / Q000139:chemically induced / Q000453:epidemiology* / Q000378:metabolism* / Q000382:microbiology; D004785:Environmental Pollutants / Q000378:metabolism* / Q000493:pharmacokinetics / Q000633:toxicity; D005260:Female; D041981:Gastrointestinal Tract / Q000378:metabolism / Q000382:microbiology*; D006801:Humans; D008297:Male; D051379:Mice; D009765:Obesity / Q000139:chemically induced / Q000453:epidemiology* / Q000378:metabolism* / Q000382:microbiology; D051381:Rats; D015262:Xenobiotics / Q000378:metabolism / Q000493:pharmacokinetics / Q000633:toxicity
chemical_list: D004785:Environmental Pollutants; D015262:Xenobiotics