(LB03-12-26) Associations Between Nutrient Adequacy and Microbial Diversity and Composition Among Generally Healthy Adults

Objectives: Dietary components influence gut microbial diversity and composition, but the extent to which meeting established nutrient requirements is associated with gut microbial characteristics is not well understood. This study examined relationships between nutrient adequacy and the stool microbial diversity and composition.

Methods: An exploratory analysis was conducted using samples from 3 clinical trials. Dietary intake (assessed by 24hr dietary recall) and stool samples (analyzed with 16S rRNA sequencing) collected pre-study were used for analysis. Nutrient requirements were based on EAR and AI by age and sex. Adequacy was determined using the cut-off method for all nutrients with EAR (calcium, thiamin, riboflavin, niacin, folate, copper, iron, magnesium, phosphorus, selenium, zinc, and vitamins A, D, E, C, B6, and B12) and AI (potassium, sodium, fiber, vitamin K, and choline) values. Aggregate nutrient adequacy scores were calculated by adding the total number of EARs and AIs met for each participant. Associations between nutrient adequacy and microbial community within sample (alpha) diversity were tested with linear regression and between sample (beta) diversity was tested with permutational analysis of variance. Associations between nutrient adequacy and abundance of microbial taxa were tested with linear regression after centered-log transformation. Models were adjusted for age, sex, body mass index, and study.

Results: The total analytical sample included 130 participants. Most participants (54.6%) achieved adequate intake of at least 15 of 22 adequacy nutrients. The aggregate nutrient adequacy score was positively associated with the abundance of Eubacterium Xylanophilum group. The abundance of Lachnospiraceae Frisingicoccus was negatively associated with the aggregate nutrient adequacy score. Several other taxa were associated with achieving the EAR/AI for calcium, fiber, folate, phosphate, and vitamins A, D, E. No other associations were observed between nutrient adequacy and alpha- or beta-diversity metrics.

Conclusions: Nutrient adequacy may relate to stool microbial composition in generally healthy adults. Larger studies are needed to examine how nutrient adequacy may modify the microbial diversity and composition.

Funding Sources: This secondary analysis was partially funded by AG1.