Periodontitis in Patients With Severe Obesity: From the Oral and Gut Microbiota Dysregulation to the Visceral Adipose Tissue Inflammatory and Metabolic Disorders.

Patients with severe obesity and periodontitis exhibited oral microbiota dysbiosis characterized by increased abundance of bacteria from the red and orange complexes.

• Study enrolled 39 patients with severe obesity: 23 with periodontitis and 16 without periodontitis
• Subgingival microbiota composition was examined to characterize the oral dysbiosis
• Red and orange complex bacteria are known periodontal pathogens including Porphyromonas gingivalis
• The dysbiosis was assessed in the subgingival (below the gumline) environment

Patients with periodontitis showed significantly worsened periodontal clinical parameters compared to obese patients without periodontitis.

• Five periodontal parameters were assessed: plaque index, bleeding index, gingival recession, probing depth, and clinical attachment level
• All measured periodontal parameters were worse in the periodontitis group
• These parameters are standard clinical measures used to assess severity of periodontal disease
• The study population comprised patients with severe obesity enrolled prior to bariatric surgery

Salivary IL-6 levels were higher in obese patients with periodontitis compared to those without periodontitis.

• IL-6 is a pro-inflammatory cytokine reflecting local oral inflammatory response
• Salivary inflammatory response was specifically examined as part of the study design
• This finding links periodontal infection to a measurable local inflammatory signal in saliva
• IL-6 elevation is consistent with the known inflammatory nature of periodontitis

Fecal microbiota of obese patients with periodontitis showed a higher proportion of the Proteobacteria phylum and changes in the functional profile of gut bacteria.

• Fecal microbiota composition was assessed by metagenomic analysis
• Proteobacteria phylum includes many gram-negative potentially pathogenic bacteria
• Functional profile changes in gut bacteria were detected beyond compositional differences
• This finding suggests that oral periodontitis is associated with gut microbiota dysregulation, potentially through bacterial translocation or indirect systemic effects

Periodontitis in obese patients was associated with higher circulating concentrations of anti-P. gingivalis IgG, total cholesterol, and lipoprotein (a).

• Anti-P. gingivalis IgG antibodies in plasma indicate systemic immune response to the key periodontal pathogen Porphyromonas gingivalis
• Elevated total cholesterol and lipoprotein (a) indicate altered lipid metabolism associated with periodontal infection
• Lipoprotein (a) is an established cardiovascular risk marker
• These markers were measured in plasma collected during bariatric surgery
• The findings suggest that periodontal infection during obesity contributes to systemic metabolic dysregulation

Periodontitis was associated with enhanced production of TLR2, MyD88, and TGF-β as well as higher activities of SOD and catalase antioxidant enzymes in visceral adipose tissue.

• Epiploon visceral adipose tissue was collected during bariatric surgery for analysis
• TLR2 and MyD88 are innate immune signaling molecules involved in pattern recognition and inflammatory pathways
• TGF-β is a pleiotropic cytokine involved in inflammation and fibrosis
• SOD (superoxide dismutase) and catalase are key antioxidant enzymes, and their elevated activity suggests increased oxidative stress in adipose tissue
• These findings demonstrate that periodontal infection has metabolic and inflammatory consequences reaching the visceral adipose tissue

Porphyromonas gingivalis may exert systemic effects both directly by translocating into the bloodstream and indirectly by deregulating the gut microbiota, potentially aggravating obesity-related complications.

• This dual mechanism (direct translocation and indirect gut microbiota dysregulation) was a central hypothesis framing the study
• The study used both oral and gut microbiota profiling to assess both pathways simultaneously
• Anti-P. gingivalis IgG elevation in plasma supports the concept of systemic immune exposure to this pathogen
• The connection between periodontal pathogens and gut microbiota has implications for understanding how oral health affects systemic disease in obesity