Oral dysbacteriosis in type 2 diabetes and its role in the progression to cardiovascular disease

Distribution characteristics of oral microbiota and its relationship with intestinal microbiota in patients with type 2 diabetes mellitus

Introduction

Type 2 diabetes mellitus (T2DM) has a high incidence rate globally, increasing the burden of death, disability, and the economy worldwide. Previous studies have found that the compositions of oral and intestinal microbiota changed respectively in T2DM; whether the changes were associated or interacted between the two sites and whether there were some associations between T2DM and the ectopic colonization of oral microbiota in the gut still need to be identified.

Research design and methods

We performed a cross-sectional observational study; 183 diabetes and 74 controls were enrolled. We used high-throughput sequencing technology to detect the V3-V4 region of 16S rRNA in oral and stool samples. The Source Tracker method was used to identify the proportion of the intestinal microbiota that ectopic colonized from the oral cavity.

Results

The oral marker bacteria of T2DM were found, such as Actinobacteria, Streptococcus, Rothia, and the intestinal marker bacteria were Bifidobacterium, Streptococcus, and Blautia at the genus level. Among them, Actinobacteria and Blautia played a vital role in different symbiotic relationships of oral and intestinal microbiota. The commonly distributed bacteria, such as Firmicutes, Bacteroidetes, and Actinobacteria, were found in both oral and intestine. Moreover, the relative abundance and composition of bacteria were different between the two sites. The glycine betaine degradation I pathway was the significantly up-regulated pathway in the oral and intestinal flora of T2DM. The main serum indexes related to oral and intestinal flora were inflammatory. The relative abundance of Proteobacteria in the intestine and the Spirochete in oral was positively correlated, and the correlation coefficient was the highest, was 0.240 (P<0.01). The proportion of ectopic colonization of oral flora in the gut of T2DM was 2.36%.

Conclusion

The dysbacteriosis exited in the oral and intestine simultaneously, and there were differences and connections in the flora composition at the two sites in T2DM. Ectopic colonization of oral flora in the intestine might relate to T2DM. Further, clarifying the oral-gut-transmitting bacteria can provide an essential reference for diagnosing and treating T2DM in the future.

Enrichment of Acid-Associated Microbiota in the Saliva of Type 2 Diabetes Mellitus Adults: A Systematic Review

It could conceivably be hypothesized that a link exists between an altered microbiota due to local hyperglycemia and the increased risk of caries in diabetes mellitus (DM). This systematic review aimed to perform a cross-study comparison into the salivary microbiota of adults with type 2 diabetes mellitus (T2D) compared to adults without T2D, particularly focusing on the abundance of acid-associated bacteria. This report follows PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). Studies using next-generation sequencing and other molecular techniques are included. The methodological quality of individual studies was assessed using appropriate Joanna Briggs Institute tools. The certainty of the evidence considering the effect direction was evaluated using the GRADE approach. From 2060 titles retrieved, 12 were included in the data synthesis, totalling 873 individuals with T2D and controls evaluated across the literature. Weighted averages of blood glucose levels (HbA1c—fasting blood glucose) were 8.21%—172.14 mg/dL and 5.12%—84.53 mg/dL for T2D and controls, respectively. In most studies, the relative abundance of acidogenic and aciduric bacteria was higher in diabetics when compared to their normoglycaemic controls. Whilst the evidence certainty was very low, there was a consistent Proteobacteria depletion and Firmicutes enrichment in T2D. As for the acid-associated genera, there was consistent enrichment of Lactobacillus and Veillonela for T2D. Tannerella/T. forsythia was enriched in T2D saliva, but the certainty is low. Further well-designed cohorts are needed to clarify the distribution of acid-associated microorganisms in the saliva of adults with T2D and how this can be clinically manifested (PROSPERO = CRD42021264350).

The Correlation between Type 2 Diabetes Mellitus and Cardiovascular Disease Risk Factors in the Elderly

With the improvement of people's living conditions and changes in social lifestyles, the incidence of type 2 diabetes is gradually increasing, and the number of people with diabetes and cardiovascular disease is also increasing. Based on this, the article collects basic information on 650 elderly patients with type 2 diabetes, of which 49.39% are between 60 and 70 years old, 32.46% are between 70 and 80 years old, and 18.15% are between 80 and 90 years old. Through the analysis of related cardiovascular disease risk factors, the correlation between the elderly cardiovascular disease risk factors and type 2 diabetes is explored. The results showed that the correlations between smoking history, diastolic blood pressure, total cholesterol, low-density lipoprotein cholesterol, and the risk of type 2 diabetes in the elderly were 0.987, 0.956, 0.971, and 0.940, respectively. It can be seen that these factors are highly correlated with the risk of type 2 diabetes in the elderly, and smoking history has the strongest correlation, indicating that high levels of smoking may be a key pathogenic factor in the onset of type 2 diabetes. The correlation of other factors is lower than 0.8, indicating that other factors are additional risk factors for the disease. After that, the p value was 0.01, and the difference test was passed, which proved the accuracy of the model.

Nutrition as a Key Modifiable Factor for Periodontitis and Main Chronic Diseases

Nutrition is recognized as an essential component in the prevention of a number of chronic diseases, including periodontal disease. Based on these considerations, a better understanding is required regarding how the diet, and more particularly the intake of macronutrients and micronutrients, could impact the potential relationship between nutrition and periodontal diseases, periodontal diseases and chronic diseases, nutrition and chronic diseases. To overcome this complexity, an up-to-date literature review on the nutriments related to periodontal and chronic diseases was performed. High-sugar, high-saturated fat, low-polyols, low-fiber and low-polyunsaturated-fat intake causes an increased risk of periodontal diseases. This pattern of nutrients is classically found in the Western diet, which is considered as an ‘unhealthy’ diet that causes cardiovascular diseases, diabetes and cancers. Conversely, low-sugar, high-fiber and high-omega-6-to-omega-3 fatty acid ratio intake reduces the risk of periodontal diseases. The Mediterranean, DASH, vegetarian and Okinawa diets that correspond to these nutritional intakes are considered as ‘healthy’ diets, reducing this risk of cardiovascular diseases, diabetes and cancers. The role of micronutrients, such as vitamin D, E, K and magnesium, remains unclear, while others, such as vitamin A, B, C, calcium, zinc and polyphenols have been shown to prevent PDs. Some evidence suggests that probiotics and prebiotics could promote periodontal health. Periodontal and chronic diseases share, with a time delay, nutrition as a risk factor. Thus, any change in periodontal health should be considered as a warning signal to control the dietary quality of patients and thus reduce the risk of developing chronic diseases later on.

IDF Diabetes Atlas: Diabetes and oral health - A two-way relationship of clinical importance

The current scientific evidence for the bi-directional associations between oral health and diabetes is summarized. The universal biologic mechanisms and demographic and behavioral risk drivers underlying these associations in both directions are also described. Dysglycemia, even slightly elevated blood sugar levels, adversely affects oral health, manifesting itself in several oral diseases and conditions. In the opposite direction, any oral infection with its subsequent local and systemic inflammatory responses adversely affects blood glucose levels. Moreover, painful, mobile, or missing teeth may lead to intake of soft food items representing a sub-optimal diet and hence poor nutrition, and thereby contribute to incident type 2 diabetes or to poorer glucose control in existing diabetes. Treatment of inflammation related oral conditions, such as non-surgical periodontal treatment and extraction of infected teeth, can lead to a clinically significant decrease in blood glucose levels. Attention to infectious oral diseases and referral to dental care professionals for treatment can therefore be an important novel tool for medical care professionals in preventing and managing diabetes mellitus. Dental professionals can detect unrecognized potential dysglycemia and refer for medical examination. Such interprofessional, patient centered care may contribute to improved health, wellbeing, and quality of life in people with diabetes.