Branched chain fatty acids positional distribution in human milk fat and common human food fats and uptake in human intestinal cells

Abstract Branched chain fatty acids (BCFA) are components of common food fats but little is known about their positional distribution on triacylglycerols (TAG). Human milk fat, mature milk of cows and goats, and several fish oil products available in China were evaluated for BCFA content in the sn-2 position. Compared to the sn-1/sn-3 (α) positions, BCFA are enriched in sn-2 (β) position of human milk (68% of BCFA), but randomly distributed among the sn-2 and sn-1/sn-3 positions of cow and goat milk. Fish oil TAG sn-2 BCFA were consistently depleted compared to the sn-1/sn-3 positions (5.2–11.9% of BCFA). Human intestinal epithelial cells were incubated with human milk sn-2 MAG, or fatty acids liberated from human milk sn-2 MAG. Cells incorporated more BCFA as sn-2 MAG than as FFA. The stereochemical positioning of BCFA in human milk fat may be unique compared to other BCFA sources, and mediate selective absorption of BCFA.