Relations of gut microbes with various metabolic disorders

Gut is a shelter for various microbes where they live symbiotically with the host. In this symbiotic relationship, these microbes utilizes the resources from the host to survive and in return regulates the metabolic machinery of the host. In hosts, exposure to these microbes begins at the time of birth and works as building blocks of infant gut microbiota and overall health in future. Several factors influences the colonization of microbes inside the infant gut, such as, mode of delivery, the diet of infant (selective substrates), treatment of antibiotics, enrichment of selective microbes and external environment.

The gut microbiota contribute to immune tolerance (by eliminating invading pathogens), intestinal homeostasis and healthy metabolism.  http://www.nature.com/nri/journal/v9/n5/execsumm/nri2515.html   http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3337124/ 

Dysbiosis, means disruption of the regular gut microbial composition. This is associated with the various disorders such as:

1) Immune diseases: atrophy, asthma, multiple sclerosis, systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), experimental autoimmune encephalomyelitis and type -1 diabetes. For details read http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3337124/   

2) Intestinal diseases: irritable bowel syndrome (IBS), inflammatory bowel diseases (IBD) (including ulcerative colitis and Crohn’s disease), necrotizing enterocolitis and colon cancer. For details read http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3667473/ 

3) Metabolic diseases: type-2 diabetes, atherosclerosis and obesity for details read  http://diabetes.diabetesjournals.org/content/62/10/3341.full   http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4483604/ 

4) Cardiovascular diseases: metabolic interaction between host and microbes in the development of cardiovascular diseases is the new field of study. For details read  http://www.nature.com/nm/journal/v18/n8/abs/nm.2895.html 

5) Liver diseases: alcoholic liver disease and hepatocarcinogenesis. For detail read  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4323444/ 

6) Blood diseases: haematopoiesis and hematologic disorders. For detail read  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4504946/   http://www.bloodjournal.org/content/126/3/311?sso-checked=true 

7) Brain diseases: role of gut microbiota in the regulation of anxiety, mood, cognition and pain has been discussed.  http://www.nature.com/nrn/journal/v13/n10/full/nrn3346.html   http://www.ncbi.nlm.nih.gov/pubmed/25390799  

The field is growing rapidly as facilitated by new, faster and cheaper sequencing technologies. Now, researchers are more interested and trying to find out how the specific microbes related with the disease phenotype? Understanding of host-microbes interactions using metabolomics approaches help us to understand the complete mechanism.