Unveiling the impact of dietary components on tropomyosin-induced anaphylaxis: Analysis from the perspective of intestinal barrier

There exists a strong correlation between diets and the increased incidence of food allergy. However, the precise mechanism underlying the impact of dietary fat, sucrose, or inulin on tropomyosin (TM)-induced anaphylaxis remains unclear. Therefore, the murine model of TM-induced food allergy fed with a high-fat, high-sucrose, highdietary-fiber, or control diet was used to explore the mechanism. The high-sucrose diet was found to result in glucose and lipid metabolism disorders, as well as heightened allergic reactions characterized by decreased specific IgG2a levels and increased levels of specific IgE, specific IgG1, IL-4, peritoneal albumin, histamine, and mast cell degranulation. The aggravating impact of a high-fat diet on allergic reactions was weaker than that of a high-sucrose diet. It was attributed to the destruction of the intestinal mucus layer, the decreased expression of zona occludens 1 and occludin, and the increased release of IL-25 and IL-33. Meanwhile, a high sucrose intake led to dysbiosis of intestinal microbiota, and increased the abundance of Roseburia and norank_f_Oscillospiraceae, contributing to a further impairment of intestinal barrier function. Additionally, inulin intake significantly reduced the level of specific IgG1 and peritoneal albumin due to its protective effect on the intestinal barrier. To sum up, a better understanding of the relationship between diet and immune responses will be crucial for developing effective strategies for managing TM-induced food allergy.