Poster Topical Area: Maternal, Perinatal and Pediatric Nutrition
Location: Hall D
Poster Board Number: 337
Objectives: To determine if postnatal diet influences hepatic bile acid synthesis as measured by changes in fecal bile acid (BA) output and composition in infants receiving breast milk, dairy-based or soy-based infant formula.
Methods: Infants were recruited based upon their postnatal diet of breast milk or infant formula prior to enrollment at age 3 months. In the BM group, all infants were exclusively breastfed until 12 months of age. Formula-fed infants consumed either dairy-based milk formula (MF) or soy based formula (SF) until 12 months of age. Solid food could be introduced to infants in all diet groups by 4 months of age. Infant fecal samples were collected at 3 (BM: n=16; MF: n=9; SF: n=15), 6 (BM: n=17; MF: n=20; SF: n=17) and 12 (BM: n=15; MF: n=14; SF: n=15) months of age and primary (CA, CDCA) and secondary (DCA, LCA, UDCA) bile acids (BAs) were quantified by liquid chromatography mass spectrometry. The effect of diet, time and the interaction thereof on cholic acid (CA) and its derivative, deoxycholic acid (DCA), chenodeoxycholic acid (CDCA) and its derivatives, lithocholic acid (LCA) and ursodeoxycholic acid (UDCA), and total BAs were determined by Two-way ANOVA followed by Student-Newman Keuls post hoc analysis.
Results: When compared to the BM group at 3 months, total BAs were 2-fold lower in the MF group. In the SF group, total BAs were increased by 2- to 4-fold relative to the BM and MF groups, respectively (P<0.05). At 6 months, total BAs remained higher in the SF group relative to the BM and MF group (P<0.05), with no statistical differences in total BAs between the MF and BM groups. At 12 months, total BAs between the BM, MF and SF groups were similar, yet we observed a significant shift in the composition of the bile acid pool toward CDCA and its derivatives, in both MF and SF groups relative to the BM group (P<0.05).
Conclusions: Soy formula feeding increases fecal output of total bile acids relative to breast fed and dairy milk formula fed infants at 3 and 6 months of age, suggesting increased hepatic bile acid synthesis in the SF group. At 12 months, differences in total BAs normalize, yet there is a distinct shift toward bacterial-derived BAs in both formula groups suggesting altered microbial function relative to breastfed infants.
Funding Source: USDA-ARS Project 6026-51000-010-05S
Arkansas Children's Nutrition Center
Little Rock, Arkansas