Obesity and NAFLD: the role of bacteria and microbiota

Clin Liver Dis. 2014 Feb;18(1):59-71. doi: 10.1016/j.cld.2013.09.002. Epub 2013 Oct 24.

Abstract

There are trillions of microorganisms in the human intestine collectively called gut microbiota. Obesity may be affected by the gut microbiota through energy harvesting and fat storage by the bacteria. Small intestinal bacterial overgrowth is also responsible for endotoxemia, systemic inflammation, and its consequences including obesity and nonalcoholic fatty liver disease (NAFLD). Relationship between gut microbiota and NAFLD is also dependent on altered choline and bile acid metabolism and endogenous alcohol production by gut bacteria. Further evidence linking gut microbiota with obesity and NAFLD comes from studies showing usefulness of probiotics in animals and patients with NAFLD. This article reviews the relationship among gut microbiota, obesity, and NAFLD.

Keywords: Endotoxemia; Intestinal permeability; Nonalcoholic fatty liver disease; Nonalcoholic steatohepatitis; Probiotics; Small intestinal bacterial overgrowth; Toll-like receptors.

Publication types

  • Review

MeSH terms

  • Animals
  • Cytokines / physiology
  • Fatty Liver / etiology*
  • Fatty Liver / microbiology*
  • Fatty Liver / physiopathology
  • Humans
  • Immunity, Innate
  • Inflammasomes / physiology
  • Inflammation / physiopathology
  • Insulin Resistance
  • Intestines / microbiology
  • Intestines / physiopathology
  • Microbiota*
  • Non-alcoholic Fatty Liver Disease
  • Obesity / complications*
  • Obesity / microbiology*
  • Obesity / physiopathology
  • Probiotics / therapeutic use
  • Toll-Like Receptors / physiology

Substances

  • Cytokines
  • Inflammasomes
  • Toll-Like Receptors