Obesity and associated metabolic disorders have become highly prevalent diseases worldwide, and the human gut microbiota, due to its influence on host energy metabolism, has been attributed an important role therein. This pilot study explores host-microbiota relationships in men and women affected by various types of glucose metabolism disorder. Among 20 individuals aged 58 to 71 years with either normal glucose tolerance, prediabetes, or type 2 diabetes mellitus the gut bacterial communities were compared based on barcoded 454 sequencing of 16S rRNA genes amplified from stool samples. We found that specific microbiota groups were relatively enriched or reduced in different metabolic states. Further, positive or negative associations with clinical manifestations of metabolic disease suggest that these organisms indicate and possibly contribute to metabolic impairment or health. For instance, a higher prevalence of Erysipelotrichaceae and Lachnospiraceae was found associated with metabolic disorders, and the Holdemania and Blautia genera correlated with clinical indicators of an impaired lipid and glucose metabolism. The Bacteroidetes and groups therein, by contrast, displayed inverse relationships with metabolic disease parameters and were found relatively enriched in participants not diagnosed with metabolic syndrome or obesity. Further, the prevalence of specific Clostridia and Rikenellaceae members also pointed towards a healthier metabolic state. Links with diet as an intermediate factor included positive and negative associations of Lachnospiraceae with relative consumption rates of fat and carbohydrates, respectively, and positive associations of Turicibacteraceae with the consumption of protein. Identifying critical roles of major gut microbiota components in metabolic disorders has important translational implications regarding the prevention and treatment of metabolic diseases by means of preventing or reversing dysbiosis and by controlling exacerbating diet and life style factors particularly in sensitive population groups.

Iron deficiency is a common cause of reactive thrombocytosis, however, the exact pathways have not been revealed. Here we aimed to study the mechanisms behind iron deficiency‐induced thrombocytosis. Within few weeks, iron‐depleted diet caused iron deficiency in young Sprague–Dawley rats, as reflected by a drop in hemoglobin, mean corpuscular volume, hepatic iron content and hepcidin mRNA in the liver. Thrombocytosis established in parallel. Moreover, platelets produced in iron deficient animals displayed a higher mean platelet volume and increased aggregation. Bone marrow studies revealed subtle alterations that are suggestive of expansion of megakaryocyte progenitors, an increase in megakaryocyte ploidy and accelerated megakaryocyte differentiation. Iron deficiency did not alter the production of hematopoietic growth factors such as thrombopoietin, interleukin 6 or interleukin 11. Megakaryocytic cell lines grown in iron‐depleted conditions exhibited reduced proliferation but increased ploidy and cell size. Our data suggest that iron deficiency increases megakaryopoietic differentiation and alters platelet phenotype without changes in megakaryocyte growth factors, specifically TPO. Iron deficiency‐induced thrombocytosis may have evolved to maintain or increase the coagulation capacity in conditions with chronic bleeding. Am. J. Hematol. 89:524–529, 2014. © 2014 Wiley Periodicals, Inc.

Quantitative PCR (qPCR) and community fingerprinting methods, such as the Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis,are well-suited techniques for the examination of microbial community structures. The use of phylum and class-specific primers can provide enhanced sensitivity and phylogenetic resolution as compared with domain-specific primers. To date, several phylum- and class-specific primers targeting the 16S ribosomal RNA gene have been published. However, many of these primers exhibit low discriminatory power against non-target bacteria in PCR. In this study, we evaluated the precision of certain published primers in silico and via specific PCR. We designed new qPCR and T-RFLP primer pairs (for the classes Alphaproteobacteria and Betaproteobacteria, and the phyla Bacteroidetes, Firmicutes and Actinobacteria) by combining the sequence information from a public dataset (SILVA SSU Ref 102 NR) with manual primer design. We evaluated the primer pairs via PCR using isolates of the above-mentioned groups and via screening of clone libraries from environmental soil samples and human faecal samples. As observed through theoretical and practical evaluation, the primers developed in this study showed a higher level of precision than previously published primers, thus allowing a deeper insight into microbial community dynamics.