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. 

Role of Gut Microbiome in the Regulation of Host Metabolism

Microbes are integral part of our routine life as they live in a constant association with the host to regulate the metabolism. Collection of microbes present at the epithelial surface and cavities of our body such as stomach are known as human associated microbiome/microflora. Bacteria are the predominant part of the microflora, however, some amount of virus, fungi and protozoans also present. The most complex community ever studied is the human distal gut microbiome, which contained 1,000 different microbial species across human populations. These microbes contain millions of different genes, largely more than the total number of host genes. Now a days, several research groups are working on how gut dysbiosis is related with the various metabolic disorders such as obesity, diabetes, IBD, cancer etc. This is quite interesting filed to know how microbes are interacting with each other or with the host in order to attain healthy or diseased phenotype. Since, the microflora is very complex and dynamic, and it is known to have a profound influence on the human metabolism. This vast diversity of the human-associated microbes poses a big challenge in the field of medical science. 

Recently, an interesting report published on the following topic "Modern Life Depletes Your Gut Microbes in a Number of Different Ways". 

http://articles.mercola.com/sites/articles/archive/2015/05/06/modern-life-depletes-gut-microbes.aspx