Monday, August 15, 2016
Benefits of sphingolipids in infant gut health and immunity
Sphingolipids (SL) such as sphingomyelin (SM), glycosphingolipids, and gangliosides are the major polar lipids found in the milk fat globule membrane (MFGM). Digestion of SM in the intestine produces metabolites that may affect mucosal growth and immune maturation. An article published in The Journal of Pediatrics focused on the role of sphingolipids in infant gut health and immunity.
An infant fed with breast milk ingests about 150 mg of SM per day. The ingested SM is hydrolyzed by the enzymes nucleotide phosphodiesterase pyrophosphatase 7 (NPP7) and neutral ceramidase (NC) at the brush border of the intestinal epithelium and in the gut lumen. The enzyme NPP7 plays a central role in SM digestion. In a study conducted on preterm and term infants, significant levels of the enzymes NPP7 and NC were found in meconium, indicating that these infants can digest SM from the breast milk.
Digestion of SM generates bioactive metabolites such as ceramide, sphingosine and sphingosine-1-phosphate (S1P). Ceramide plays an important role in numerous signalling functions related to regulation of cell growth, induction of apoptosis and inflammation. Sphingosine is associated with cellular processes and certain signalling pathways. Sphingosine-1-phosphate plays an important role in the regulation of the gut immune system.
Gangliosides exhibit a protective role by interacting with bacterial toxins and influencing the gut bacterial flora in premature infants by increasing bifidobacteria and decreasing E. coli. It also plays a role in immune maturation by influencing T cell differentiation and IgA production. Gangliosides exert a protective role against lipopolysaccharide-induced bowel inflammation and necrosis.
Digestion of milk SL to bioactive metabolites is important for the intestine to adapt to external challenges. Although additional research in neonates is required to provide a definite confirmation of the positive effects of SL on mucosal growth and immune maturation, studies conducted thus far provide well-founded hypotheses for the beneficial effects of SL.
News source - Nilsson A. Role of Sphingolipids in Infant Gut Health and Immunity. The Journal of Pediatrics. 2016 Jun 30; 173:S53–9.