Microorganisms in Fermented Foods and Their Contribution to Oral Health: A Narrative Review

Fermented foods contain diverse microorganisms that may influence oral microbial ecology and contribute to oral health. This narrative review aimed to examine the current evidence regarding microorganisms present in fermented foods and their role in oral health promotion. Twenty relevant clinical, experimental, observational, and review studies published between 2016 and 2026 were identified through a structured literature search and critically synthesized according to major thematic areas, including oral microbiota modulation, dental caries prevention, periodontal health, probiotic delivery systems, and evidence from review articles. The findings appear to indicate that fermented food-derived microorganisms may reduce cariogenic and periodontal pathogens, modulate oral biofilms, improve gingival health, and promote microbial homeostasis. Yogurt, kefir, fermented dairy products, and kimchi-derived microorganisms were the most frequently investigated sources. Emerging evidence further suggests that the benefits of these microorganisms are linked to ecological regulation of the oral microbiome and host–microbe interactions rather than direct antimicrobial activity alone. Microorganisms associated with fermented foods may therefore represent promising functional dietary components for supporting oral health and complementing preventive oral healthcare strategies. Further well-designed clinical studies are needed to establish strain-specific recommendations and explore the potential of postbiotic applications in dentistry.