LAUSR

There has been increased interest in the use of dietary ingredients, including prebiotics such as human-milk oligosaccharides (HMOs), as therapeutic strategies for food allergy. Understanding the mechanisms underlying the beneficial effects of HMOs is important to realizing their therapeutic potential. Here we demonstrate that the HMO, 6'-sialyllactose (6'SL) inhibited chemokine (IL-8 and CCL20) release from T-84 and HT-29 cells stimulated with antigen-antibody complex, TNFα or PGE2 ; an effect that was PPARγ dependent and associated with decreased activity of the transcription factors AP-1 and NFκB. In contrast, 2'-fucosyllactose (2'FL) selectively inhibited CCL20 release in response to antigen antibody complex in a PPARγ independent manner. This study reinforces the concept that structurally different oligosaccharides have distinct biological activities and identifies, for the first time, that the HMOs, 6'SL, and 2'FL, modulate human epithelial cell responses related to allergic disease. These findings encourage further investigation of the therapeutic potential of specific HMOs in food allergy. PRACTICAL APPLICATION This study provides evidence for direct effects of HMOs in addition to their prebiotic role and demonstrates, for the first time, modulation of Ag-IgE complex activation of human epithelial cells that may have important implications for food-allergy. The study also reinforces the concept that structurally different oligosaccharides have distinct biological activities. In determining the composition of infant formula, addition of oligosaccharides with specific structures may provide direct modulation of immune responses and potentially attenuate symptoms or development of food allergy.