Dietary Habits of 2- to 9-Year-Old American Children Are Associated with Gut Microbiome Composition

Background The human gut microbiome is recognized as an important determinant of human health, yet little is known about how dietary habits are related to the microbiome in post-weaned, pre-pubescent children. Objective The goal of this work was to link quantitative dietary intake with microbiome features in a diverse population of children consuming a predominantly Western diet. Design This was a cross-sectional study. Participants/settings English- or Spanish-speaking families with healthy children between the ages of 2 and 9 years were recruited from a community-based, early childhood learning center in suburban Los Angeles, California between June and September 2014. Main outcome measures Children included in the analyses (n=75) contributed three fecal samples and three quantitative 24-hour dietary recalls using the multiple-pass method with an average of 5.7 days between samples. Microbial communities of each fecal sample were characterized using Illumina sequencing of the 16S ribosomal RNA gene. Dietary recalls were analyzed using the Automated Self-Administered 24-Hour Recall Dietary Assessment Tool. Statistical analysis performed Associations between dietary factors and microbiome features were assessed using the Kruskal-Wallis test, Spearman rank correlations, or permutational multivariate analysis of variance. For demographic and health-related variables, χ2 analyses were used to test for differences between age groups for categorical variables. Results Our results show that age is correlated with three metrics of microbiome diversity (P0.05). Likewise, the relative abundance of several bacterial taxa were linked to consumption of particular food groups and/or nutrients, as illustrated by the positive associations between total fruit (Pfalse discovery rate<0.05) and fiber (Pfalse discovery rate