Objective: To evaluate the digestive characteristics of boiled， brined， tea-leaf and rotten eggs in the elderly in vitro and their effects on intestinal flora. Method: Three elderly in vitro digestion models [oral (E1)， oral and gastric (E2)， oral and gastrointestinal (E3)] were constructed， and healthy adult model (C) was used as a control for exploration. The results demonstrated that the protein content of the four types of egg products ranged from 11.84% to 13.40%， the fat content varied from 7.79% to 16.15%， and the moisture content fluctuated between 68.50% and 76.11%. Among the samples， rotten eggs exhibited the lowest protein content (approximately 11.84%)， while their fat content was the highest (approximately 16.15%). The in vitro digestion simulation results indicated that the protein digestion rate of rotten eggs was the lowest in elderly individuals (approximately 47%)， while the protein digestion rates of the other three types of egg products were comparable (approximately 70%). Furthermore， the study established that E2 model did not result in a decline in protein digestibility， while E3 model exerted a substantial impact on the digestion of egg protein， reducing it by approximately 12% to 21%. Subsequent analysis revealed that the relative content of functional amino acids in the stinky egg group was higher than in the other three groups， demonstrating strong biological activity. The study also found that four types of egg products caused changes in the gut microbiota structure of elderly people. A total of 56 genera were identified in the sample group， among which the relative abundance of Bifidobacterium genus was the highest. The relative abundance of Bifidobacterium in the brined egg group， rotten egg group， boiled egg group and tea-leaf egg group were 51.44%， 47.75%， 47.56% and 44.05%， respectively， and the B/E values of the four egg products were 1.27， 1.12， 1.09 and 0.92， respectively， indicating that brined egg and rotten egg had better ability to improve the structure of intestinal flora. A significant variation in the impact of four distinct categories of egg products on the composition of various short-chain fatty acids within the intestinal tract was observed. Notably， the stinky egg group exhibited the most pronounced effect on the release of propionic acid and butyric acid， with concentrations of 1.12 mmol/L and 0.38 mmol/L， respectively.