Nutrition Notes

N-Acetylglucosamine and Immunometabolism

N-Acetylglucosamine (NAG) is a monosaccharide classified as an amino sugar that supports many aspects of human health. NAG is a critical component of many health-supportive molecules, including hyaluronic acid, glycoproteins, proteoglycans, and glycosaminoglycans (GAGs). It is also important to gastrointestinal (GI) function and immune health. 

Certain agents in the gut microbiome release NAG and other similar compounds into the intestinal lumen. NAG is therefore also referred to as a mucus-derived sugar and may support mucosal health in the GI lining. 

NAG has been shown in studies to support GI function in the presence of harmful bacteria. A laboratory study showed that NAG reduced biofilm formation in the presence of pathogenic Escherichia coli (E. coli). 

Inflammatory bowel disease (IBD) involves complex pathways related to inflammation, immune, and gut health. Recent studies suggest that NAG may play a health-supportive role in IBD. Fibrosis of parts of the bowel is believed to be related to the loss of GAGs in the intestinal wall. NAG may help restore the formation of protective structures in the gut. It may also help to increase the elasticity of tissues surrounding vessels. 

NAG and its derivatives have also been shown to support many aspects of immune health. O-linked NAG (O-NAG) is required for the intracellular mechanisms involved in T-cell activation. Certain proteins linked to O-NAG have been shown to play an important role in T-cell receptor signal transmission

O-NAG also helps regulate CD4+ T-cell differentiation. Studies have observed that the dysregulation of O-NAG linkage resulted in CD4+ T-cell dysfunction. Certain genetic abnormalities related to the metabolism of NAG and its derivatives have been observed in autoimmune conditions. Hypomethylation of the X-linked gene for the O-NAG transferase enzyme has been observed in some populations of individuals with systemic lupus erythematosus (SLE). 

Differentiated T cells and other immune-related cells may have varying metabolic needs. Inflammation associated with autoimmunity has been associated with disruptions in the metabolic pathways of T cells. Certain metabolic changes in synthesis pathways related to T cells have been associated with abnormal increases in O-NAG linking. Chronic activation of the phosphatidylinositol-3-kinase protein kinase B mammalian target of rapamycin (PI3K-AKT-mTOR) pathway has been shown to increase the amount of inflammatory Th17 cells in cases of SLE. 

Abnormally increased levels of O-NAG linking have also been associated with metabolites related to gut dysbiosis. They have also been observed in the presence of elevated blood glucose and free fatty acid levels. This is believed to potentially relate to downstream inflammatory states. 

Research is still emerging related to the potential of NAG to support many aspects of human health. Current research indicates it may support GI function and gut mucosal health. In addition, NAG may support a healthy immune response. 

By Colleen Ambrose, ND, MAT