The regulatory role of the n-6/n-3 ratio in intestinal barrier function and glucose and lipid metabolism disorders

Abstract

An unbalanced intake of n-6 and n-3 polyunsaturated fatty acids (PUFAs) can damage the gut barrier and disturb metabolism. This study used a high-fat diet mouse model of diabetes to examine the effects of different n-6/n-3 ratios (20:1, 10:1, and 4:1). Mice were fed the test diets for 12 weeks. When the ratio was reduced to 4:1, villus height and tight-junction protein levels increased by about 50%. Plasma lipopolysaccharide (LPS) dropped by 42%, and the HOMA-IR index decreased by 32%. The gut microbiota also changed, showing more Bifidobacterium and Bacteroides in the 4:1 group. These results indicate that a lower n-6/n-3 ratio supports the intestinal barrier, lowers endotoxin levels, and improves insulin sensitivity. The study suggests that keeping an n-6/n-3 ratio near 4:1 may help control inflammation and reduce metabolic problems linked to diabetes.