Familial Patterns of Oral–Gut Dysbiosis and Systemic Markers in Periodontitis

Aim: To investigate whether periodontitis in parents is associated with differences in the faecal microbiome and systemic markers in both themselves and their children. Methods: Eighty participants were divided into four groups (n = 20): parents with periodontitis (PP); healthy parents (PC); and their respective children (CP, CC). Clinical periodontal parameters were recorded. Saliva and faecal bacterial DNA were analysed via 16S rRNA sequencing. Salivary lactoferrin, faecal calprotectin, gingival crevicular fluid cytokines (IFN-γ, IL-10, IL-17, IL-1β, IL-4, TNF-α) and urinary intestinal permeability markers (claudin-2, -3, -4, haptoglobin) were quantified. Results: Parents with periodontitis showed distinct faecal microbiota profiles, which were mirrored in their children and significantly differed from controls. Claudin-2 levels were elevated in both PP and CP groups (p < 0.05) and positively correlated with the oral dysbiosis index and the faecal Firmicutes/Bacteroidetes ratio. Conclusions: Parental periodontal health appears to influence the faecal microbiome and systemic markers in the offspring. These findings highlight a potential pathway for oral–gut microbial transmission and its relevance to systemic health, warranting further investigation.