Researchers assessed the overall diet quality of 1,175 postmenopausal women by calculating their Healthy Eating Index 2020 (HEI-2020) scores based on a food frequency questionnaire. The HEI-2020 measures diet quality by reflecting adherence to the 2020 Dietary Guidelines for Americans.

While HEI-2020 scores were linked to the composition of the oral microbiome they did not affect its diversity. However specific components of the HEI-2020 were associated with both the diversity and composition of the oral microbiome. For instance higher intake of vegetables and protein foods correlated with more diverse oral microbiomes while greater consumption of dairy and added sugars was linked to less diversity.

Previous studies have looked at how individual foods or nutrients relate to the oral microbiome but people don’t consume nutrients in isolation foods are often eaten together their intake can be correlated and their health effects may interact says Yihua Yue PhD, the study's first author who conducted the research during her doctoral studies in epidemiology at UB’s School of Public Health and Health Professions.

This is why we focused on overall diet quality to get a more comprehensive view of dietary explains Yue now a postdoctoral research fellow at the Cleveland Clinic. Our goal was to examine how diet quality as measured by the Healthy Eating Index correlates with the bacteria found in the oral cavity. We wanted to see if there were significant differences in the diversity and composition of the oral microbiome between those with high and low-quality diets.

Research has linked periodontal disease with an increased risk of conditions such as cancer cardiovascular disease and other chronic diseases associated with inflammation including age-related macular degeneration notes Amy Millen PhD, corresponding author and associate professor in the Department of Epidemiology and Environmental Health at UB.

However the question remains whether this association is causal.

What we do know Millen says is that nutrition is a risk factor for many diseases with inflammatory causes. Our research team has been investigating whether nutrition both specific nutrients and diet patterns can influence periodontal disease. Since oral bacteria play a causal role in periodontal disease we hoped that by examining the link between diet quality and the oral microbiome we could further understand how diet contributes to the development of periodontal disease or other conditions like dental caries.

The HEI-2020 includes 13 components each representing a different aspect of diet quality. While higher more favorable scores for these individual components are generally recommended for overall health Yue notes that this doesn’t necessarily mean these components have consistent effects on the composition of the oral microbiome.

Our findings suggest that the Dietary Guidelines for Americans recommendations particularly regarding sugar vegetables seafood, and plant-based proteins, may influence the oral microbiome Yue adds. These results provide valuable evidence for the U.S. Department of Agriculture to consider when evaluating the relevance of the HEI-2020 in the context of oral health.

The authors acknowledge that while the study focused on postmenopausal women, its findings are particularly relevant to this group, as they are at higher risk for gum disease and tooth loss due to hormonal changes and aging. Future studies may benefit from including a broader range of participants with diverse dietary habits and lifestyle factors.

Source: https://www.buffalo.edu/grad/news.host.html/content/shared/university/news/news-center-releases/2025/04/yue-millen-diet-quality-oral-microbiome.detail.html