OBJECTIVE To investigate the ameliorative effect of Guifu Dihuang Wan (GFDHW) on intestinal lipid absorption dysfunction in aging mice and its potential mechanisms. METHODS Twenty-six SPF male C57BL/6J mice aged 11 months were raised to 21 months and divided into an aging model group (Model group) and a GFDHW group (1.17 g·kg^-1). The GFDHW group received medication via feed administration for 3 months, with free access to water during the administration period, while the Model group was fed normal feed and had free access to water. Weekly changes in body weight were recorded for each group of mice, and specimens were collected at 24 months of age. Nine SPF male C57BL/6J mice aged 8 months were used as the youth control group (Con group) and were acclimatized for 1 week before specimen collection. Prior to specimen collection, all groups of mice were fasted for 24 hours, and 0.2 mL of olive oil was administered by gavage to each group of mice at the end of the fasting period, followed by gavage of 0.2 mL of semi-solid nutrient solution 30 minutes before specimen collection. Small intestine propulsion tests were conducted to assess the small intestine motility of each group of mice. Biochemical reagent kits were used to measure the serum levels of triglycerides (TG), total cholesterol (TC), and low-density lipoprotein (LDL) in each group of mice. Transmission electron microscopy was used to observe changes in the number of lipid droplets in intestinal epithelial cells of each group. The calcium cobalt method was used for alkaline phosphatase staining to detect intestinal alkaline phosphatase (IAP) activity in each group of intestines. Hematoxylin-eosin (HE) staining was used to observe the morphology of intestinal epithelia in each group. Immunohistochemical staining was performed to detect the expression of Olfm4, Lgr5, PCNA, Notch1, Hes1 and Villin in the small intestines of each group of mice. Western blot analysis was conducted to determine the expression levels of lipid absorption-related molecular proteins in the small intestines of each group of mice. RESULTS Compared with the Con group mice, the Model group mice exhibited faster weight loss, decreased small intestine motility, increased serum TG, TC, and LDL levels, and increased number of lipid droplets in intestinal epithelial cells. The GFDHW group mice showed improved small intestine motility and decreased serum TG, TC, and LDL levels. HE staining revealed disordered arrangement and fracture of small intestinal villi, shortened villus length, decreased crypt depth, and reduced crypt numbers in Model group mice, whereas the GFDHW group mice exhibited orderly and continuous arrangement of small intestinal villi, increased villus length, higher crypt depth, and increased crypt numbers. The immunohistochemical results showed that compared to the Con group mice, the expression of Olfm4, PCNA, Notch1, Hes1, and Villin proteins in the small intestine of the Model group mice decreased, while the levels of these proteins increased in the GFDHW treated group mice. Western blot analysis revealed that compared to the Con group mice, the expression of CD36, FATP4, SR-BI, ACAT2, FABP1 and MTTP proteins in the small intestine of the Model group mice decreased, whereas the levels of these proteins increased in the GFDHW treated group mice. CONCLUSION GFDHW improves lipid absorption function in aging mice by upregulating Notch1 expression, promoting differentiation of intestinal stem cells into absorptive cells, and increasing the expression levels of related molecular proteins in the lipid absorption pathway.