Differential effects of egg consumption on fecal lipid metabolism: Insights from C57BL/6J mice under chow diet and high-fat diet

Given the relatively stronger association between egg consumption and cardiovascular diseases risk based on Western diets, this study utilized C57BL/6J mice fed with different egg-containing diets to compare differences in lipid metabolism. Results showed that egg consumption had no significant impact on plasma total cholesterol under chow diet but significantly increased liver cholesterol levels. The levels of blood lipid biomarkers of egg-containing chow diet groups were overall lower than those of high-fat groups. Conversely, egg consumption resulted in a significant increase in plasma total cholesterol and accelerated weight gain and fat accumulation under high-fat diet. Western Blot and RT-qPCR results suggested that the excretion of bile acids increased in mice after egg consumption. The upregulation of cholesterol synthesis under egg-containing high-fat diets might be responsible for the disrupted cholesterol homeostasis, representing a crucial distinction between the two egg-containing diets. Lipidomics results revealed the changes in abundance of bile acids, phytosterols, Vitamin D3 and phospholipids, and other fecal metabolites following egg consumption. Possible reasons for these changes included alterations in nutrients intake, bioaccessibility and endogenous metabolism. This study emphasized the importance of considering dietary patterns when assessing the effects of egg consumption on cardiovascular diseases risk.