Human microbiota aredistinctcommunities of microorganisms that resides at different body niches. Exploration of the human microbiome has become a reality due to the availability of powerful metagenomics and metatranscriptomic analysis technologies. Recent advances in sequencing and bioinformatics over the past decade help providea deep insight into the nature of the host-microbial interactions and identification of potential deriver genes and pathways associated with human health, well-being, and predisposition to different diseases.In the present review, we outline recent studies devoted to elucidate the possible link between the microbiota and various type of diseases. The present review also highlights the potential utilization of microbiota as a potential therapeutic option to treat a wide array of human diseases. This article is

In this study, we attempted to evaluate the clinical significance of T helper 1 (Th1)/T helper 2 (Th2) ratio in patients with myelodysplastic syndrome (MDS), five refractory anaemia (RA), four refractory anaemia with ringed sideroblasts (RARS), 31 refractory cytopenia with multilineage dysplasia (RCMD), nine refractory anaemia with excess blast-1 (RAEB-1) and seven refractory anaemia with excess blast-2 (RAEB-2). Intracellular interleukin-4 (Th2 cytokine) and interferon-gamma (Th1 cytokine) production was assessed in CD4+ T lymphocytes activated by phorbol 12-myristate 13-acetate and ionomycin using flow cytometry. Mean Th1/Th2 ratios in each MDS group were as follows: RA/RARS, 8.8 (95% CI, 5.8-11.8), RCMD, 14.7 (95% CI, 9.5-19.9), RAEB-1, 10.6 (95% CI, 4.6-16.6), RAEB-2, 12.8 (95% CI, 3.0-22.7) and control 12.8 (95% CI, 9.6-16.1). There were no significant differences in Th1/Th2 ratio in the RA/RARS, RCMD, RAEB-1 and RAEB-2 subgroups when compared to controls. Because Th1/Th2 ratio in the RCMD group was widely distributed, we divided RCMD patients according to Th1/Th2 ratio into three groups (low, normal and high Th1/Th2 groups). There were no differences in severity of cytopenia among the three above groups. However, the percentage of CD8 cells in the low Th1/Th2 group was significantly lower than those in the high group (P < 0.01). These data suggest that Th1/Th2 imbalance induces CD4/CD8 imbalance, and serves as a marker of the biological interplay in immune regulation.

The expansion of natural CD4(+) Tregs may contribute to the suppression of CD8 through the Th1-mediated immune response in MDS. The low CD8/Foxp3 ratio is a characteristic feature in MDS. To determine whether the expansion of CD4(+) Tregs contributes to the progression of MDS subtypes into more aggressive subtypes, more MDS cases and further follow-up are required.

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BackgroundClostridium difficile infection (CDI) is not generally reported to public health authorities in the Middle East and its true prevalence remains largely unknown. The aims of this study were to determine the prevalence of CDI and its associated ribotypes among C. difficile isolates in Qatar. Influence of age and correlation with other risk factors e.g. proton pump inhibitor use, antibiotic use, existence of chronic conditions, etc was also investigated for CDI positive patients.MethodsA total of 1,532 patients with suspected CDI were recruited from two hospitals between 2011 and 2012. C. difficile was identified using glutamate dehydrogenase (GDH) lateral flow assay and toxins A and B Enzyme Immunoassay (EIA). The C. difficile positive samples were then cultured for PCR-ribotyping.Results122 of the 1,532 (7.9%) samples from individual patients were identified as C.difficile positive; and 79 of these were viably cultured (~65%). From these, 36 different PCR ribotypes were isolated, of which strains 258 (6 [7.6%]), 01/014/046 (5 [6.3%]), and 011/053/056/107 (4 [5%]) were the most prevalent. The prevalence of PCR-ribotype 027 was 1.3% (n = 1). An age of ≥65 years and treatment with proton pump inhibitors correlated with higher frequency of CDI. Treatment with third generation cephalosporins (50 [41%]) and piperacillin/tazobactam antibiotics (55 [45.1%]) was most frequently associated with CDI.ConclusionThe most common C. difficile ribotype identified in Qatar was 258, which is different from those found in North America, Europe and Asia. The prevalence of CDI was higher in Qatar than Europe; though comparable to other Middle Eastern countries. These findings underscore the importance of local surveillance to detect and control C. difficile infection.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2334-14-502) contains supplementary material, which is available to authorized users.