Assessment of Filifactor alocis and Porphyromonas gingivalis Levels in Subgingival Plaque of Patients with Type 2 Diabetes Mellitus with and without Periodontitis: A Case-Control Study

Introduction: Periodontitis, a chronic inflammatory condition, is influenced by microbial dysbiosis and the host’s immune response. Type 2 Diabetes Mellitus (T2DM) represents a significant public health challenge in India and exacerbates periodontal inflammation due to hyperglycaemia, compromised immune regulation, and increased oxidative stress. Key pathogens such as Porphyromonas gingivalis and Filifactor alocis, an emerging anaerobe, are known to play a central role in disease progression, especially in diabetic individuals, where their coexistence appears more pronounced. Despite this, there is a significant gap in comparative data on the presence of these bacteria in the subgingival microbiome of diabetic patients with and without periodontitis. Aim: This study investigates the levels of Filifactor alocis (F. alocis) and Porphyromonas gingivalis (P. gingivalis) in subgingival plaque samples from patients with T2DM with and without periodontitis. Materials and Methods: This case-control study was conducted at the Departments of Periodontics and General Medicine, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India from September to December 2022. Ethical clearance was obtained (IEC No: CSP/22/JUL/114/429). The study included 24 T2DM patients aged 30-60 years, with 12 having periodontitis and 12 without, based on the American Academy of Periodontology (AAP) 1999 criteria. Clinical parameters (Plaque Index, Bleeding on Probing (BOP), Periodontal Probing Depth (PPD), Clinical Attachment Loss (CAL), Periodontal Inflamed Surface Area (PISA), Periodontal Epithelial Surface Area (PESA), fasting/Postprandial Blood Sugar (PPBS), and subgingival levels of P. gingivalis and F. alocis (via species-specific qPCR) were evaluated. Data were analysed using SPSS v23 with the Mann-Whitney U test and Spearman correlation; significance was set at p-value ≤0.05. Results: Periodontitis patients exhibited significantly higher mean values for BOP, plaque index, PPD, CAL, PISA, and PESA (p-value <0.05). Lower Ct values (indicative of higher bacterial loads) of both P. gingivalis and F. alocis were observed in the periodontitis group, although differences were not statistically significant. A significant positive correlation was found between P. gingivalis levels and Fasting Blood Sugar (FBS) (r=0.617, p-value=0.032). No significant correlations were found between F. alocis levels and clinical or glycaemic parameters. Conclusion: These findings underscore the synergistic role of these pathogens in periodontal inflammation and their potential impact on glycaemic control, highlighting the importance of integrated oral and systemic care.