Dietary effects on the functional diversity of the gut microbiome in children

The human gut is home to trillions of microbial cells whose functions are essential for normal human physiology. However, little information exists on the quantitative relationships between diet and gut microbial community composition and function, particularly in multi-ethnic populations of children. To address this knowledge gap, we will link dietary features of children with the functional diversity of gut microbial communities in a diverse population living within the greater Los Angeles area. Specific Aims: Aim I: Characterize the functional diversity of gut (fecal) microbial communities of ?96 children between the ages of 2-9 years of age using shotgun metagenomic sequencing. Aim II: Link functional diversity of gut microbiomes to demographic and quantitative dietary data. Approach: During the summer of 2014, 131 children from 93 different families were consented and contributed at least one fecal sample for microbiome analysis. Most of the children (n=101) provided three fecal samples and dietary recalls and in total, we collected 345 samples. We are currently using 16S rRNA gene sequencing to link the taxonomic diversity of each sample to dietary features. To characterize the functional diversity of these communities, we will use shotgun metagenomic sequencing on the Illumina HiSeq 2500 platform. Dietary data have been converted to quantitative measures of macronutrients (e.g., %protein, %carbohydrates (including fiber), %fats) and micronutrients using a dietary analysis program called the Automated Self-administered 24-hour Recall (ASA24). Findings of this study will provide a deeper understanding of environmental factors that contribute to childhood obesity, particularly in low-income, multi-ethnic populations. By focusing our work on young children, the potential for impact on disease prevention and health promotion over the life course will be maximized.