Biomedical Applications of Gut Stem Cells: Gaining First- Hand Insights for Developing Therapy for the Future

The gut (gastrointestinal tract) is a series of hollow organs joined in a long, twisting tube from the mouth to the anus [1]. The GI tract comprises the foregut, midgut, and hindgut, and each region gives rise to different tissues and organs. For example the foregut endoderm gives rise to the epithelium of the oral cavity, pharynx, esophagus, stomach, liver, pancreas, and proximal duodenum. The midgut and hindgut endoderm gives rise to the epithelium of the distal duodenum, jejunum, ileum, colon, rectum, and anal canal along with the epithelial lining of the bladder and urethra [2]. The role of the gut is not restricted to process food. Over the years, researchers have successfully deciphered many of the key aspects of gut i.e. gut is endowed with a range of sensory receptors that activate four major effector systems i.e. the enteroendocrine system, the nervous system, the gut immune system, and the non-immune defense systems [3]. With all its folds, villi, and microvilli, gut is arguably the largest surface in the body [4]. Gut has been described as ‘the largest endocrine organ in the body (gastrin, cholecystokinin or CCK, secretin, somatostatin, ghrelin, bombesin, and gastrin-releasing peptide (GRP). These hormones released by the enteroendocrine cells which can act locally as well as on other cells (including immune cells), nerve endings, or organs at remote sites including pancreatic islets and the CNS [5]. Around 40 neurotransmitters of the same classes as those found in the brain also been reported in Gut. Most importantly; in the era of personalized medicine we have given lot of emphasis to both of our genome and the second genome i.e. “Microbiome”. The human body consisting of >100 trillion (1014) microbial cells moreover, it has been estimated that <10% of DNA found in the human meta-organism derives from Homo sapiens origin [6]. Recent studies suggest microbiome in our digestive tract can play a profound role in our overall health including depression, anxiety, autism, schizophrenia, obesity, cancer and irritable bowel syndrome etc. Considering the importance of the microbiome Human Microbiome Project (HMP) [7] and the European Metagenomics of the Human Intestinal Tract (MetaHIT) Consortium has been established [8]. The recent findings suggest human gut microbiome altered by antibiotic use, with age, host Volume 1 Issue 3 2016