Gut microbiota and its mysteries

Indian J Med Microbiol. 2019 Apr-Jun;37(2):268-277. doi: 10.4103/ijmm.IJMM_19_373.


Gut microbiota are microorganisms that inhabit the gut; they coexist peacefully with the host, thereby contributing to the health and well-being of individuals. Bacteroidetes and Firmicutes largely dominate the gut microbial flora. The intestinal flora promotes intestinal mucosal integrity, provides essential nutrients such as vitamins and enzymes, protects the body against pathogens and produces antimicrobial peptides such as defensins, C-type lectins, cathelicidins, they also play an active role in the innate and adaptive immune system. Gut microbial flora plays an active role in the synthesis of short-chain fatty acids such as butyrate, propionate and acetate. Gut microbiota also plays a significant role in the cognitive and behavioural functions of the host. A balanced gut microbiota shifts to dysbiosis, due to intake of high fat or sugar or other factors like sedentary lifestyle. The dysbiosis of the gut results in increased permeability, endotoxaemic, insulin resistant, systemic inflammation, adiposity and metabolic disorders such as type 2 diabetes mellitus, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, irritable bowel disorder, colorectal cancer, etc. A prudent lifestyle modification, added on with use of probiotics and prebiotic restore the normal flora of the gut, especially in patients with Clostridium difficle-associated diarrhoea, inflammatory bowel syndrome, liver disease and colon cancer. Faecal microbial transplant is an important therapeutic tool in many illness related with the gut. Thereby, understanding the gut microbial signatures in various diseases yields various novel therapeutic targets. Human gut microbiota has a prognostic, diagnostic and therapeutic potential which is recognised worldwide.

Keywords: Faecal transplant; gut microbiota; obesity; probiotics; type 2 diabetes mellitus.

Publication types

  • Review

MeSH terms

  • Animals
  • Biodiversity
  • Diabetes Mellitus, Type 2 / etiology
  • Diabetes Mellitus, Type 2 / metabolism
  • Diabetes Mellitus, Type 2 / therapy
  • Diet
  • Disease Management
  • Disease Susceptibility*
  • Exercise
  • Female
  • Gastrointestinal Microbiome*
  • Humans
  • Life Style
  • Male
  • Obesity / etiology
  • Obesity / metabolism
  • Obesity / therapy
  • Research