Introduction

The oral cavity is a complex biological environment harboring hundreds of microbial species that maintain a delicate balance to support host health. Among these, Prevotella nanceiensis emerges as a significant member of the salivary microbiome. Rather than acting as a simple commensal, this species often serves as a biological marker for ecosystem stability, with its abundance shifting significantly in response to both preventive health states and pathological transitions.

Location of Microbe

Oral Ecosystem

Prevotella nanceiensis is primarily located within the oral cavity, where it is found as a constituent of the free salivary microbiome and the broader oral microbial community.

Behavior During Dysbiosis

Oral Ecosystem

In the oral ecosystem, P. nanceiensis exhibits contrasting patterns during dysbiosis. It is often depleted in conditions associated with periodontitis and SARS-CoV-2 infections. Conversely, it shows enrichment in specific malignant contexts, such as oral squamous cell carcinoma.

Disease Associations

Oral Ecosystem

The association of Prevotella nanceiensis with oral health is multifaceted and depends on the specific clinical context:

• Dental Caries: This species is strongly associated with a healthy, caries-free state in early childhood. In 1-year-old children, a higher relative abundance of P. nanceiensis is identified as a biomarker for those who remain caries-free by age two, suggesting a protective role or association with a resilient oral environment.
• Oral Squamous Cell Carcinoma (OSCC): In contrast to its role in caries prevention, P. nanceiensis is found to be elevated in patients with OSCC. Research suggests that its higher abundance may influence the progression of these malignancies through the modulation of inflammatory signaling.
• Periodontal Disease: A lower abundance of P. nanceiensis is observed in individuals with generalized periodontitis compared to periodontally healthy adults, marking it as a potential biomarker for the loss of periodontal health.
• Viral Infections: Evidence indicates a consistent depletion of P. nanceiensis in the oral microbiome of individuals during SARS-CoV-2 infections, reflecting a shift in the microbial ecology during the infection phase.

Foods Supporting Healthy Balance

Maintaining a balanced oral ecosystem requires a focus on diet and hygiene to support beneficial microbial abundance and prevent dysbiosis. While specific foods for P. nanceiensis are not isolated, general principles of oral microbiome health include:

• Reduction of Refined Sugars: Limiting the intake of fermentable carbohydrates reduces the growth of acidogenic bacteria, which may help preserve the abundance of protective species like P. nanceiensis, especially in children.
• Fiber-Rich Vegetables: Diets rich in complex fibers support a diverse microbial community, which is essential for maintaining gut barrier integrity and overall systemic health, often reflecting in the oral cavity.
• Probiotic-Rich Foods: Incorporating fermented foods may help maintain a diverse oral environment, preventing the overgrowth of opportunistic pathogens.
• Hydration: Adequate water intake ensures optimal saliva flow, which is critical for the distribution and survival of commensal bacteria in the free salivary microbiome.

Actionable Insights

Based on current metagenomic evidence, the following insights can help maintain oral microbial balance:

• Early Caries Monitoring: Since P. nanceiensis is a biomarker for caries-free status in infants, maintaining high oral hygiene standards in early childhood may help preserve this protective microbial profile.
• Inflammation Management: Given the association between P. nanceiensis enrichment and OSCC-related inflammation, regular dental screenings for premalignant lesions are essential for early detection.
• Periodontal Care: Regular professional cleanings and scaling can help mitigate the dysbiosis associated with the depletion of beneficial taxa like P. nanceiensis.
• Holistic Health Awareness: Be aware that systemic events, such as viral infections or metabolic surgeries, can transiently reshape the oral microbiome and influence the abundance of commensal species.

Conclusion

Prevotella nanceiensis serves as a complex indicator of oral health, acting as a marker of resilience against dental caries in children and a sign of periodontal stability in adults. However, its association with inflammatory processes in oral squamous cell carcinoma highlights that the impact of this microbe is highly dependent on the specific niche and the overall state of the host's immune system. Understanding the balance of P. nanceiensis within the oral ecosystem is key to transitioning from reactive treatment to preventive microbiome management.