The oral microflora in obesity and type-2 diabetes

Abstract

BackgroundType 2 diabetes mellitus (T2DM) is prevalent in people with obesity. It has been proposed that these conditions are related to specific features of the microflora of the mouth and lower gastrointestinal (GI) tract. Hyperglycemia often resolves quickly after Roux-en-Y gastric bypass (RYGB) but the role of the GI microflora cannot be examined easily because of reduced intestinal mobility. We propose that the study of microorganisms present in the mouth of patients undergoing RYGB will contribute to our understanding of the role of bacteria in the pathogenesis of T2DM.ObjectiveTo conduct a feasibility study to examine differences in oral microbes in obese patients with and without T2DM and to determine whether it is feasible to measure changes after gastric bypass surgery.MethodsIndividuals with morbid obesity (n=29), of whom 13 had T2DM, were studied. Oral rinses, stool samples, and blood samples were obtained before RYGB, and oral rinses and blood samples were obtained at 2 and 12 weeks postsurgery.ResultsPrior to surgery, participants with T2DM had slightly higher total levels of oral bacteria than those without diabetes. Those with HbA1c > 6.5% had rather lower levels of Bifidobacteria in the mouth and stool. At 2 weeks post-RYGB, patients with T2DM were able to reduce or discontinue their hypoglycemic medications. Stool samples could not be obtained but oral rinses were readily available. The levels of oral Bifidobacteria had increased tenfold and levels of circulating endotoxin and tumor necrosis factor-alpha had decreased.ConclusionsThe study of oral bacteria before and after RYGB is feasible and should be tested in larger patient populations to increase our understanding of the role of microorganisms in the pathogenesis of obesity and T2DM.

Association of the oral microbiome with the progression of impaired fasting glucose in a Chinese elderly population

“…For each sample 38,706 ± 4,321 (mean ± SD) high quality reads were obtained. OTUs (7,263) were obtained at 97% identity. A total of 13 phyla, 22 classes, 37 orders, 82 families, and 152 genera were detected through taxonomic assignments based on the Greengenes Database.…”

“…Therefore, the oral microbiota represents a relevant target for further investigation. Prior studies have revealed a structural shift in the oral microbiome in patients with diabetes compared to healthy controls [7,8]. The dysbiosis of the oral microbiota is highly associated with the development of periodontal disease, which can induce higher level of inflammation locally and systemically, and then contribute to aggravation of hyperglycemia [9].…”

Review: Maternal health and the placental microbiome

“…1) [80]. Outside pregnancy, obesity was associated with dental caries [81], imbalanced oral microflora [82], differences in cervical microflora [83] and profound changes in the gut microbiota [84e87]. Therefore it can be hypothesized that maternal obesity and/or excess gestational weight gain may lead to dysbiosis in the placental microbiota.…”

The Microbiome at Other Mucosal Sites

“…These mechanisms activate the prothrombotic cascades in the bloodstream, causing atheromas (Kebschull et al, 2010), and they become a risk factor for coronary heart disease (Ueno et al, 2012). In addition, the presence of Bifidobacteria in oral samples has been related with diabetes mellitus type 2 (Shillitoe et al, 2012).…”