Exploring the relationship between dietary indices, gut microbiota, and health status in healthy, older individuals

authored by

Madeline Bartsch, Felix Kerlikowksy, Andreas Hahn, Shoma Berkemeyer, Sabrina Woltemate, Marius Vital, Mattea Müller

Abstract

Background: With increasing life expectancy, dietary choices are crucial for healthy aging. Objective: This study investigates associations between two dietary indices, the energy-adjusted Dietary Inflammatory Index (E-DII) and the healthful Plant-based Diet Index (hPDI), and biomarkers related to metabolic health and micronutrient status, focusing on the mediating role of gut microbiota. Methods: We conducted a secondary, exploratory analysis of baseline data from 129 community-based participants aged ≥70 years (median age: 75 years). Dietary indices were calculated from 3-day food protocols, and biomarkers were measured in blood samples. Cognitive and physical function were assessed using validated questionnaires, body composition was determined via bioimpedance, and fecal gut microbiota composition through 16S rRNA gene sequencing. Statistical analyses included multiple linear regression models, Permutational Multivariate Analysis of Variance, and mediation analysis. Results: We found no significant associations between the indices and gut microbiota diversity. However, red blood cell (RBC) folate and serum uric acid were significantly associated with E-DII (stand. β = −0.32 and 0.23, respectively, p < 0.01 and 0.01) and contributed to microbiota composition variance (R²= 0.01, Q = 0.21). Specific genera correlated with serum uric acid (Oscillibacter: coefficient = −0.01, Q = 0.24, Gemmiger: coefficient = −0.02, Q = 0.23) and RBC folate (Bacteroides: coefficient = 0.03, Q = 0.22), independent of dietary patterns. Conclusions: This study suggests that gut microbiota composition does not mediate the associations between a healthy plant-based or anti-inflammatory diet and metabolic health markers in a healthy, older population. However, microbial genera were associated with uric acid and folate concentrations independent of the investigated dietary patterns, indicating potential roles in folate and uric acid metabolism.

Organisation(s)

Institute of Food and One Health

External Organisation(s)

Osnabrück University of Applied Sciences
Hannover Medical School (MHH)

Type

Article

Journal

Nutrition and Healthy Aging

Volume

10

ISSN

2451-9480

Publication date

2025

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Food Science, Medicine (miscellaneous), Biochemistry, Nutrition and Dietetics

Sustainable Development Goals

SDG 3 - Good Health and Well-being

Electronic version(s)

https://doi.org/10.1177/24519502251365105 (Access: Open)