Introduction

The human oral cavity is a complex ecosystem harboring a diverse array of microorganisms that play critical roles in maintaining health. Among these is Campylobacter hominis, a species whose presence and abundance can fluctuate based on the state of the host's oral environment. Understanding how this microbe interacts within the oral biofilm is essential for grasping the dynamics of microbial balance and the onset of dysbiosis.

Location of the Microbe

Oral Ecosystem

In the oral cavity, Campylobacter hominis is found within dental biofilms, specifically inhabiting the pit and fissure sites of the teeth where plaque accumulates.

Behavior During Dysbiosis

Oral Ecosystem

In the oral ecosystem, C. hominis shows a distinct pattern during dysbiosis; it is observed to be relatively more abundant in individuals who are caries-free compared to those with active dental caries.

Disease Associations

Oral and Upper Respiratory Associations

Within the oral ecosystem, Campylobacter hominis is associated with a state of health regarding dental caries. Metagenomic analysis of dental plaque in adolescents reveals that this species is more abundant in caries-free groups, suggesting it may be part of a balanced microbial community that resists the development of pit and fissure caries. Conversely, its relative abundance decreases in the presence of active caries, where other species like S. mutans become dominant.

Beyond the dental biofilm, C. hominis has been associated with the upper respiratory tract (URT) during systemic challenges. Research indicates that this microbe is more abundant in adults with SARS-CoV-2 infection, particularly in those exhibiting a high viral load, suggesting a shift in the URT microbiome during viral infection.

Foods Supporting Healthy Balance

Maintaining a balanced oral and systemic microbiome depends heavily on dietary patterns that discourage the overgrowth of opportunistic pathogens and support commensal diversity. A diet rich in whole fruits, vegetables, and lean proteins—aligned with high Healthy Eating Index (HEI) scores—is associated with a more favorable microbial profile. Reducing the intake of refined grains and added sugars is particularly critical for the oral ecosystem, as excessive fermentable carbohydrates drive the dysbiosis associated with dental caries.

Increasing the consumption of fiber-rich foods supports the overall gut-oral axis, promoting an environment where beneficial microbes can thrive. Furthermore, ensuring adequate intake of vitamins and minerals supports the host's immune response and gut barrier integrity, which indirectly influences the stability of other microbial niches, including the oral cavity.

Actionable Insights

Strategies for Microbial Management

• Prioritize Low-Sugar Diets: Limit the consumption of sweet drinks and refined snacks to prevent the shift toward a caries-active microbiome.
• Consistent Oral Hygiene: Regular brushing and flossing help manage the accumulation of plaque in pit and fissure sites, maintaining a healthy microbial balance.
• Nutritional Quality: Focus on a high-quality diet rich in proteins and micronutrients, as higher dietary quality scores in caregivers have been linked to more favorable microbial abundances in offspring.
• Support Immune Health: Since shifts in C. hominis abundance have been noted during respiratory infections, maintaining overall systemic health through balanced nutrition is key to microbial stability.

Conclusion

Campylobacter hominis serves as an interesting marker of microbial balance within the oral ecosystem. Its higher abundance in caries-free individuals suggests a role in a healthy, stable dental biofilm, while its presence in the upper respiratory tract during viral infections highlights its responsiveness to host health status. Maintaining this balance requires a multifaceted approach, combining rigorous oral hygiene with a nutrient-dense diet low in refined sugars. By focusing on ecosystem diversity and stability, we can support a microbiome that promotes long-term preventive health.