Characteristics of the gut microbiota in adult patients with type 1 and 2 diabetes based on the analysis of a fragment of 16S rRNA gene using next-generation sequencing.

Abstract

Introduction Scientific data indicate a possible influence of gut microbiota on the development of type 1 and type 2 diabetes mellitus (T1DM and T2DM, respectively). Sequence analysis of 16S ribosomal RNA identified several hundred bacterial species of the intestinal ecosystem, most of which cannot be cultured. Objectives We aimed to evaluate gut microbiota composition in adult patients with T1DM and T2DM and establish a link between microbiological test results and patients' clinical data. Patients and methods We examined DNA isolated from fecal samples in 3 groups: healthy volunteers (n = 23), patients with T1DM (n = 22), and patients with T2DM (n = 23). Next‑generation sequencing was performed on the MiSeq platform. Results At the phylum level, the Firmicutes bacteria prevailed (>77%) in all groups. At the taxonomic levels L2 (phylum) and L6 (genus), significant differences were demonstrated in bacterial profiles, particularly in the T2DM group. A negative correlation was observed between several genera of bacteria and the percentage of glycated hemoglobin A1c in the T2DM group, while a positive correlation was revealed between bacteria belonging to the genus Bifidobacterium and high‑density lipoprotein cholesterol levels in both T1DM and T2DM groups. Conclusions Our results provide grounds for conducting research in the field of gut microbiota in order to develop individualized therapy for patients with diabetes based on modifying the microbiota composition, as a new method for controlling glycemia. Next‑generation sequencing allows a rapid identification of the DNA of all bacteria present in the sample and their taxonomic classification.

Metagenomic Analysis of Duodenal Microbiota Reveals a Potential Biomarker of Dysbiosis in the Course of Obesity and Type 2 Diabetes: A Pilot Study

“…In the work by Salamon et al, after sequencing isolates from stool samples, a similar relationship, but one of average severity, was observed in both patients with type 1 (r = 0.46; p = 0.03) and type 2 (r = 0, 43; p = 0.03) diabetes [21]. These observations confirm the relationship between the genus of Bifidobacterium and HDL concentration in animal studies [22][23][24].…”

Dependence of Colonization of the Large Intestine by Candida on the Treatment of Crohn’s Disease

“…However, the authors did not analyze the influence of the treatment type on the observed change in mycobiota. Similar results were obtained by Standaert-Vitse et al (2009) where CD patients were more frequently and more heavily colonized by C. albicans than the patients in the control group. As it was found in our study, the group undergoing biologic therapy showed significantly higher colonization with Candida spp.…”

“…The increasing occurrence of Crohn's disease and the decreasing age of patients stimulate researchers to find out the causes behind this illness (Benchimol et al 2017;Ng et al 2017). Although, until now, it has not been possible to associate a particular microorganism with CD etiology, microbial participation is still considered crucial, besides genetic and immunological disorders, for induction or intensification of inflammation in the gastrointestinal tract (Gosiewski et al 2012;Wright et al 2015). However, there is still insufficient knowledge concerning the role of fungi in the course of CD, as well as the impact of the treatment on gastro-intestinal colonization with fungi of the genus Candida in IBD patients.…”

“…Crohn's disease (CD) together with ulcerative colitis belongs to the group of disorders known as inflammatory bowel diseases (IBD). The etiology of Crohn's disease still remains not fully explained, although the changes in the composition and distribution of intestinal microbiome seem to play a crucial role in the development and persistence of inflammation in the gastrointestinal tract (Kostic et al 2014;Scarpellini et al 2015). It is still under debate if the changes in the microbiome in IBD are a cause or a consequence of inflammation.…”

“…As mentioned above, studies are available in the literature that concern changes in the bacterial flora of the human gastrointestinal tract in the course of IBD; however, there are few articles describing the study of anti-Candida antibodies and methods based on the fungi cultures (McKenzie et al 1990;Standaert-Vitse et al 2006;Standaert-Vitse et al 2009). Hence, the primary objective of the present study was to determine if there are quantitative differences in Candida fungi (by quantitative real-time PCR (qPCR)) between pediatric patients with CD and healthy controls.…”