Human Milk Oligosaccharides Influence Intestinal Epithelial Cell Maturation In Vitro.

Objectives: Human milk oligosaccharides (HMOs) are reported to promote epithelial cell differentiation in vitro. The aim of the present study was to assess induction of epithelial cell differentiation by individual and combined administration of 3 HMOs.

Methods: An in vitro epithelial model of the crypt-villus axis consisting of preconfluent HT-29, preconfluent Caco-2Bbe, and postconfluent Caco-2Bbe cells was used. Cultures were randomized to 17 treatments for 72 hours of incubation: low- and high-dose HMOs (3'sialyllactose [3'SL] at 0.2 and 1.0 g/L, 6'siallylactose [6'SL] at 0.4 and 1.0 g/L, and 2'fucosyllactose at 0.2 and 2.0 g/L), HMO combinations at both low and high doses, and controls (culture medium, 4 g/L pooled HMO, and lipopolysaccharide).

Results: High doses of individual HMOs (P < 0.05), combined HMOs (P < 0.05), and pooled HMO decreased (P < 0.001) proliferation in preconfluent HT-29 cultures. Pooled means of individual low and high treatments with 3'SL and 6'SL, combinations of 2 or 3 high-dose HMOs, and total HMO significantly reduced (P < 0.05) proliferation in preconfluent Caco-2Bbe cells. HMOs increased differentiation in preconfluent HT-29 and Caco-2Bbe cells. 3'SL and 6'SL increased alkaline phosphatase activity but did not affect disaccharidase activity in postconfluent Caco-2Bbe cells. Apoptosis and necrosis were both decreased (P < 0.001) in postconfluent Caco-2Bbe cells treated with pooled HMO.

Conclusions: HMO treatments inhibited proliferation with some associated enhancement of epithelial differentiation. Effects of HMOs were additive but no specific combinations of HMOs were especially potent. These results suggest that commercially viable individual HMOs and specific combinations may promote intestinal epithelial cell maturation.