(LB01-19-25) Restriction of Insulinogenic Amino Acids Alters the Gut Microbiota Composition in a Neonatal Piglet Model

Objectives: We recently demonstrated that insulinogenic amino acids (IAA), i.e., Leu, Ile, Val, Thr, Phe, Arg, and Ala, restriction improves insulin sensitivity in neonatal piglet model. It is unknown whether gut microbiome is required for metabolic benefits of IAA restriction. As the first step, it is imperative to determine whether gut microbiota is altered with dietary IAA restriction. The objective of this study was to assess the effect of IAA restriction on gut microbiota composition in neonatal piglets.

Methods: One-week-old piglets were assigned into one of three dietary groups for three weeks: 1) Non-restricted (NR): 0% IAA restricted; 2) R50: 50% IAA restricted; and 3) R75: 75% IAA restricted. At the completion of the study, colon samples were collected, DNA isolated and sequenced for 16S rRNA followed by taxonomic classification. Weighted and unweighted UniFrac plots were generated to asses the overall variation in bacterial composition (beta diversity). To assess the richness and evenness of the bacterial community in each sample, alpha-diversity analysis was performed. LDA with LEfSe was done to identify the differences in the bacterial abundance of the colon contents between groups.

Results: The weighted and unweighted UniFrac plots showed some significant separation and clustering in bacterial communities among groups. There was significant differences in alpha diversity indices, Observed, ACE and Chao1, when comparing the NR to R50 and R50 to R75. Overall, at genus level, relative to NR, R75 and R50 had a higher abundance of Bacteroides. LDA with LEfSe showed a greater proportion of Prevotellaceae family in NR compared to R50 and R75 while the colon contents of R50 and R70 were more enriched in Veillonellaceae family.

Conclusions: Previous research has provided evidence on a potential link between increased abundance of Prevotellaceae and insulin resistance as well as the possible influence of Veillonellaceae family on improving insulin sensitivity. Given the greater enrichment of Prevotellaceae in NR and Veillonellaceae in R50 and R75 groups, the improved insulin sensitivity following IAA restriction may be associated with changes in these bacterial communitie in the gut.

Funding Sources: >Grant no. 2021-67016-33399/project accession no. 1024334 from the USDA-NIFA.