Correlation between oral-gut microbiome laboratory findings and oral health in clinical dentistry-An Updated Review for Laboratory Professionals, Dentists, and Health Administrators

Background: The oral and gut microbiomes constitute the two largest microbial ecosystems in the human body and are closely interconnected through microbial translocation, immune signaling, and metabolic interactions. Alterations in either ecosystem lead to microbial dysbiosis associated with systemic inflammatory, metabolic, and neoplastic diseases.  Aim: This review aims to summarize current evidence on the bidirectional relationship between oral and gut microbiomes, highlight mechanisms underlying microbial transfer, and evaluate their relevance to disease progression and therapeutic strategies.  Methods: A comprehensive literature-based synthesis was conducted focusing on microbial composition, dysbiosis patterns, cross-ecosystem microbial migration, and mechanistic pathways involving bacteria, fungi, and viruses. The review further integrates findings from human studies and experimental animal models.  Results: The oral microbiome influences gut microbial diversity through translocation of pathogenic species such as Porphyromonas gingivalis and Streptococcus mitis, leading to reduced gut microbial richness and increased inflammatory taxa. Conversely, gut dysbiosis in inflammatory bowel disease and colorectal cancer induces significant shifts in oral microbial composition, enriching taxa such as Streptococcus and Actinomyces. Fungal and viral communities also exhibit cross-site transmission, contributing to disease-associated microbial remodeling and epithelial barrier disruption. Mechanistic pathways include direct microbial translocation, systemic dissemination, immune modulation, and metabolic reprogramming.  Conclusion: Oral–gut microbial interaction plays a central role in systemic health, contributing to inflammatory, metabolic, and neoplastic diseases. Understanding these mechanisms is essential for developing targeted interventions including periodontal therapy, probiotics, dietary optimization, and microbiome-based diagnostics.