Journal Article

Effects of feeding infant formula rich in sn-2 palmitate for 6 months on fecal saponified fatty acids, calcium and stool characteristics: a cluster-randomized controlled trial

Zhao, Ai, Ye, Wenhui, Wu, Wei, Luo, Sha, He, Tingchao, Liu, Biao, Hao, Yanjie, Shen, Qianqian, Zhang, Yumei, Jiang, Hua

2025

Overview

Background Human milk palmitic acid (PA) is mainly esterified at the sn-2 position of triacylglycerols, while infant formula contains palmitate predominantly in the sn-1/3 positions. Current evidence on long-term health effects of increasing sn-2 palmitate in formula remains insufficient. This study investigated the effects of high sn-2 PA formula (> 40%) on fecal saponified fatty acid, calcium, magnesium and stool characteristics in healthy full-term infants. Methods In this cluster-randomized controlled trial, healthy infants < 14 d were assigned to breastfeeding (BF group, n  = 66), high sn-2 palmitate formula (sn-2 group, n  = 66, 46.3% sn-2 PA) or low sn-2 palmitate formula (control group, n  = 67, 10.3% sn-2 PA). Infant demographics, feeding status, stool characteristics, physical exams, and stool samples were collected at 6, 16, and 24 weeks. Per-protocol analysis was used. Results The sn-2 group exhibited a significant time-dependent decline in fecal saponified PA and calcium over time ( P h for Trend < 0.001). The BF group declined faster than the sn-2 group ( P adjusted for Group*Time < 0.001). Fecal saponified PA proportion in sn-2 group was significantly lower than controls at all timepoints. At week 24, fecal calcium was lower in the sn-2 group vs. control (0.9 vs. 1.3 mg/g, P  = 0.010). No significant difference was found in stool frequency, consistency or size between sn-2 and control groups at any point. Conclusion Infant formula enriched with > 40% sn-2 palmitate reduces fecal fatty acid and calcium excretion, supports efficient lipid and calcium absorption, shows a fecal magnesium pattern similar to breastfed infants, but does not alter stool characteristics relative to the control formula. Trial registration The trial is registered at Chinese Clinical Trial Registry: ChiCTR1800014479; 30/Jan./2018.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Antibiotics / Babies / Baby foods / Breast Feeding / Breast milk / Breastfeeding & lactation / Calcium / Calcium - analysis / Calcium - metabolism / Calcium absorption / Calcium, Dietary / Clinical Nutrition / Clinical trials / Cluster randomized controlled trial / Fatty acids / Fatty Acids - analysis / Fecal saponified fatty acid / Feces / Feces - chemistry / Female / Formula / Health Promotion and Disease Prevention / Hospitals / Humans / Infant / Infant Formula - chemistry / Infant formulas / Infant Nutritional Physiological Phenomena / Infant, Newborn / Infants / Intervention / Lipids / Magnesium / Male / Medicine / Medicine & Public Health / Milk, Human - chemistry / Nutrition / Oils & fats / Palmitates - administration & dosage / Palmitic Acid / Pediatric research / Physiological aspects / Saturated fatty acids / Sn-2 palmitate / Testing / Triglycerides