Relationship between oral microbiota and chronic kidney disease: facts and perspectives.

BACKGROUND: The human microbiome comprises the microorganisms inhabiting the body, with the oral cavity representing the second most densely colonized site after the colon. Periodontal disease-associated oral bacteria are more common in patients with kidney disorders than in the general population. Oral dysbiosis disrupts host-microbiota homeostasis and promotes destructive periodontal inflammation, which has been linked to chronic kidney disease (CKD). However, current interventional evidence, including randomized controlled trials, remains limited by small sample sizes, short follow-up, heterogeneous periodontal interventions, inconsistent renal endpoints, limited blinding, and inadequate adjustment for confounders such as smoking, glycemic control, and medication use. Thus, causality between oral microbiota modulation and CKD progression remains unproven.

METHODS: This review synthesizes current evidence on the mechanisms by which oral microbiota influence various forms of nephropathy, with a particular focus on the impact of periodontitis (PD) on the progression of renal disease.This review summarizes evidence on mechanisms by which oral microbiota and periodontitis may contribute to nephropathy and renal disease progression.

RESULTS: Oral dysbiosis may affect CKD through systemic inflammation, endothelial dysfunction, and oxidative stress. It may also promote abnormal IgA1 glycosylation in IgA nephropathy and contribute to immune dysregulation and persistent inflammation in glomerulonephritis.

CONCLUSION: Periodontitis-associated oral dysbiosis may contribute to renal disease pathogenesis and progression. Clarifying these mechanisms could support preventive and therapeutic strategies for patients with nephropathy.