Changes of saliva microbiota in the onset and after the treatment of diabetes in patients with periodontitis

Abstract

The relationship between type 2 diabetes mellitus (T2DM) and oral microbiota is still insufficiently recognized. In the present study, we compared the salivary microbiome of nondiabetic individuals, treatment-naïve diabetic patients, and diabetic patients treated with metformin or a combination of insulin and other drugs. The α- and β-diversity demonstrated significant differences in the salivary microbiome between the nondiabetic people and patients with a history of diabetes, while little divergence was found among individuals with a history of diabetes. After characterizing the effects of periodontitis on the microbial composition of each group, the salivary microbiome of the treatment-naïve diabetic patient group was compared with that of nondiabetic people and the metformin/combined treatment groups. The results revealed changes in the contents of certain bacteria after both the onset and the treatment of diabetes; among these differential bacteria, Blautia_wexlerae, Lactobacillus_fermentum, Nocardia_coeliaca and Selenomonas_artemidis varied in all processes. A subsequent correlational analysis of the differential bacteria and clinical characteristics demonstrated that salivary microbes were related to drug treatment and certain pathological changes. Finally, the four common differential bacteria were employed for distinguishing the treatment-naïve diabetic patients from the nondiabetic people and the treated patients, with prediction accuracies of 83.3%, 75% and 75%, respectively.

Association between metabolic syndrome and periodontitis: The role of lipids, inflammatory cytokines, altered host response, and the microbiome

“…Type 2 diabetes alters the subgingival and salivary bacterial profile of individuals (Table 4 ) by decreasing diversity and richness. 194 , 195 , 196 , 197 , 198 , 199 This is consistent with data observed within the gut microbiome. 74 , 189 , 190 , 191 , 200 When evaluating the subgingival microbiome, not only is the diversity decreased in individuals with type 2 diabetes, but when these individuals are further divided by adequate or inadequate glycemic control, there is a notable further decrease in the microbiome diversity in those with inadequate glycemic control (hemoglobin A1c ≥ 8%).…”

“…Type 2 diabetes alters the subgingival and salivary bacterial profile of individuals (Table 4) by decreasing diversity and richness 194‐199 . This is consistent with data observed within the gut microbiome 74,189‐191,200 .…”

“…77 Although the diversity of the subgingival and supragingival microbiome decreases when subjects with type 2 diabetes are compared with normoglycemic individuals, the bacterial shift in individuals with periodontitis is less prominent in type 2 diabetes subjects than in normoglycemic individuals. 195,196,202 There is not much consensus regarding the specific differences in the microbiome (Table 4). However, individuals with diabetes had a higher total taxa of Saccharibacteria (TM7), Aggregatibacter, Neisseria, Gemella, and Eikenella.…”

“…Although the diversity of the subgingival and supragingival microbiome decreases when subjects with type 2 diabetes are compared with normoglycemic individuals, the bacterial shift in individuals with periodontitis is less prominent in type 2 diabetes subjects than in normoglycemic individuals. 195 , 196 , 202 …”

“…Nonetheless, the supragingival microbiome is different in patients with type 2 diabetes without medications and those being treated with metformin or with a combination of medications. 196 Another study by the same group 196 evaluated the salivary microbiome of normal weight, obese, and obese/type 2 diabetes children (aged 10‐19 years), noting that there was minimal difference in the alpha diversity among these groups. This study supported a modest link between periodontal inflammation and type 2 diabetes in the pediatric population.…”