The intestinal microbiome in type 1 diabetes. Clinical and Experimental Immunology 2014, 177: 30–7. Helminths in the hygiene hypothesis: sooner or later?

Clinical and Experimental Immunology 2014, 177: 38–46. www.selleckchem.com/products/AP24534.html The recent epidemics of obesity and type 2 diabetes mellitus (T2DM) in western societies have challenged researchers to investigate the underlying pathophysiological mechanisms [1]. Although genetic factors and lifestyle contribute significantly to the susceptibility of these metabolic disorders, the role of intestinal microbiota as potential partaker in the development of obesity and subsequent insulin resistance has only recently gained momentum [2]. Trillions of bacteria are present in the human gastrointestinal tract containing at least 1 × 1014 bacteria made up of from 2000 to 4000 different species of (an)aerobic bacteria. Among these indigenous bacterial populations (major phyla: Bacteroidetes, Firmicutes, Actinobacteria

and Proteobacteria), commensal anaerobic species also are thought to have a significant influence in host structure and function. In adults, the commensal microbial communities are LDE225 price relatively stable, but can undergo dynamic changes as a result of its interactions with diet, genotype/epigenetic composition and immunometabolic function. Moreover, differences in intestinal microbiota composition in the distal gastrointestinal tract appear to distinguish lean Exoribonuclease versus obese individuals, suggesting that intestinal dysbiosis contributes to the development of obesity and its consequences [3, 4]. In line with this, Cani et al. demonstrated that a lower abundance of Gram-positive, short chain fatty acid butyrate-producing anaerobic bacteria was associated with endotoxaemia, chronic inflammation and development of insulin resistance in mice [5]. However, the question remains as to whether these changes in intestinal microbiota composition are the cause or consequence of human obesity. In this respect, faecal bacteriotherapy or faecal transplantation has been proved to be a highly effective and successful treatment for patients with

several diseases [6]. The hypothesis behind the faecal bacteriotherapy rests on the concept of bacterial interference, in which pathogenic microbes are replaced by beneficial communities. We subsequently used this faecal transplantation model in a randomized control trial to test whether gut microbiota are related causally with human metabolism. Male insulin-resistant subjects with metabolic syndrome received solutions of stool from lean donors, and a significant improvement in peripheral insulin resistance was observed in conjunction with altered (small) intestinal microbiota composition [7]. These include an increase in short chain fatty acid (SCFA) butyrate-producing intestinal bacteria, including Roseburia and Faecalibacterium spp. in faeces as well as small intestinal Eubacterium halli.