A Mediterranean Diet Intervention Reduces the Levels of Salivary Periodontopathogenic Bacteria in Overweight and Obese Subjects

Abstract

The human oral cavity is a complex ecosystem, and the alterations in salivary microbial communities are associated with both oral and nonoral diseases. The Mediterranean diet (MD) is a healthy dietary pattern useful for both prevention and treatment of several diseases. To further explore the effects of the MD on human health, in this study, we investigated the changes in the salivary microbial communities in overweight/obese subjects after an individually tailored MD-based nutritional intervention. Healthy overweight and obese subjects were randomized between two intervention groups. The MD group (Med-D group) increased their MD adherence during 8 weeks of intervention while the control diet (control-D) group did not change their dietary habits. The salivary microbiota was assessed at baseline and after 4 and 8 weeks of intervention. Despite no observed changes in the overall salivary microbiota composition, we found a significant decrease in the relative abundances of species-level operational taxonomic units annotated as Porphyromonas gingivalis, Prevotella intermedia, and Treponema denticola in the Med-D group compared to that in the control-D group after 8 weeks of intervention, which are known to be associated with periodontal disease. Such variations were significantly linked to dietary variables such as MD adherence rates and intakes of animal versus vegetable proteins. In addition, increased levels of Streptococcus cristatus were observed in the Med-D group, which has been reported as an antagonistic taxon inhibiting P. gingivalis gene expression. Our findings suggest that an MD-based nutritional intervention may be implicated in reducing periodontal bacteria, and an MD may be a dietary strategy supportive of oral homeostasis. IMPORTANCE Changes in dietary behavior with increased adherence to a Mediterranean diet can determine a reduction of periodontopathogenic bacterial abundances in the saliva of overweight subjects with cardiometabolic risk due to an unhealthy lifestyle, without any change in individual energy intake, nutrient intake, and physical activity.

Mediterranean diet: a nutrient‐packed diet and a healthy lifestyle for a sustainable world

“…To date, numerous scientific studies have shown that the MD protects from cardiovascular diseases 54–59 and certain types of cancer, 60–63 increases longevity, enables healthy aging 64‐70 and improves mental health and quality of life. Immunity boosting by adherence to an MD lifestyle is also reported by several authors, 71,72 as well as the diet's positive effects on metabolic syndrome and obesity, 73–78 diabetes 56,79–81 and hypertension. 82,83 .…”

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

“…These results are observed in specific populations. The adoption of the Mediterranean diet in a group of overweight/obese subjects led to a significant decrease in periodontal pathogens such as P. gingivalis , P. intermedia and T. denticola in the saliva [ 205 ]. The Okinawan-based nordic diet improved the general and periodontal health in diabetic patients [ 206 ].…”

Distribution of Antibiotic Resistance Genes in the Saliva of Healthy Omnivores, Ovo-Lacto-Vegetarians, and Vegans

“…Nevertheless, in the latter investigation [10], diet-related biomarkers which distinguished omnivore vs. non omnivore volunteers were identified, thus supporting what was previously reported by Takeda et al [56] on the contribution of environmental factors in the modulation of salivary metabolomics profiles. In a more recent study, the increased consumption of plant foods through a Mediterranean diet caused a decrease in salivary levels of potential periodontopathogenic bacteria [11].…”

“…Thus far, a plethora of taxa are known to colonize the human oral cavity in either a suspended (planktonic state) or attached (biofilm) state [ 2 , 3 , 4 , 5 ]. In the past decade, research efforts have focused on determining those factors modulating the complexity of this peculiar microbiota, such as geographical location [ 6 ], clinical conditions [ 7 , 8 ], obesity [ 9 ], and even dietary habits and intakes [ 10 , 11 , 12 ].…”