Influence of Prolonged Whole Egg Supplementation on Insulin-like Growth Factor 1 and Short-Chain Fatty Acids Product: Implications for Human Health and Gut Microbiota.

The gut microbiota exert a profound influence on human health and metabolism, with microbial metabolites playing a pivotal role in shaping host physiology. This study investigated the impact of prolonged egg supplementation on insulin-like growth factor 1 (IGF-1) and circulating short-chain fatty acids (SCFAs). In a subset of a cluster-randomized trial, participants aged 8-14 years were randomly assigned into three groups: (1) Whole Egg (WE)-consuming 10 additional eggs per week [ = 24], (2) Protein Substitute (PS)-consuming yolk-free egg substitute equivalent to 10 eggs per week [ = 25], and (3) Control Group (C) [ = 26]. At week 35, IGF-1 levels in WE significantly increased (66.6 ± 27.7 ng/mL, < 0.05) compared to C, with positive SCFA correlations, except acetate. Acetate was stable in WE, increasing in PS and C. Significant propionate differences occurred between WE and PS (14.8 ± 5.6 μmol/L, = 0.010). WE exhibited notable changes in the relative abundance of the and genera. Strong positive SCFA correlations were observed with and , while , and showed negative correlations. In conclusion, whole egg supplementation improves growth factors that may be related to bone formation and growth; it may also promote benefits to gut microbiota but may not affect SCFAs.