(P20-016-23) Effects of an Apiaceous or Cruciferous Vegetable on the Infant Gastrointestinal Microbiota and MicroRNA Expression: A Randomized Control Feasibility Trial

Objectives: The infant complementary diet influences gastrointestinal (gut) microbiota composition, playing a key role in host health. The objectives of this study were to determine the effects of an apiaceous or cruciferous vegetable on the infant gut microbiota and microRNA (miRNA) expression.

Methods: In this randomized, control trial, infants (N=11) were randomized to control, carrot (apiaceous), or broccoli (cruciferous) feeding groups and consumed their assigned puree on days 1, 2, and 3 along with their milk diet (human milk or infant formula); the control group continued their milk diet only. Genomic DNA was extracted from fecal samples on days 0, 2, 4, and 6 and assessed via long-read sequencing (ShorelineBiome, Farmington, CT). Total RNA was extracted from fecal samples on days 0 and 4 for miRNA profiling (Nanostring, Seattle, WA). Differences among feeding groups were assessed using linear mixed effects models for alpha diversity and taxon relative abundance, and PERMANOVA for beta diversity; linear models assessed for miRNA differences. Due to small sample size, p≤0.1 and as needed, adjusted for 10% false discovery rate.

Results: Shannon diversity was decreased in the carrot group compared to control on days 2 and 4 (all p≤0.1). Conversely, there was a trend for species richness to increase in carrot compared to control on day 4 (p=0.11). Carrot and broccoli samples differed by Weighted Unifrac distance (p=0.02). In the carrot group, Streptococcus was increased at day 4 compared to control and at day 4 and 6 compared to broccoli (all p≤ <0.1). In the carrot group compared to control, a decrease in miR-25-5p and an increase in miR-200a-3p, -362-3p, and -378i (all p≤0.1) were observed. In the broccoli group compared to control, a decrease in miR-502-5p and -590-5p and an increase in miR-200a-3p and -362-3p (all p≤0.1) were observed.

Conclusions: Feeding carrots resulted in a microbial community characterized by a decrease in more abundant organisms and an increase in less abundant organisms; the highest increase in genera (Streptococcus) was observed in the carrot group. In both the carrot and broccoli groups, miRNAs associated with both decreased inflammation and tumor proliferation were increased compared to control.

Funding Sources: The University of Delaware Predoctoral Summer Fellowship, Delaware INBRE, the State of Delaware, and the Delaware Biotechnology Institute