Qi-Fu-Yin Attenuates Frailty by Regulating Gut Microbiota and Neuroendocrine Hormones in 5xFamilial Alzheimer's Disease Transgenic Mice.

Abstract

Frailty is a common and debilitating feature of Alzheimer's disease (AD), yet effective therapeutic strategies targeting both cognitive decline and physical frailty remain limited. Qi-Fu-Yin (QFY), a traditional Chinese herbal formulation, has been used to treat aging-related disorders, but its effects on frailty in AD and the underlying mechanisms are unclear. This study aimed to evaluate whether QFY alleviates frailty in 5xFamilial Alzheimer's Disease (FAD) transgenic mice and to explore the potential involvement of gut microbiota and neuroendocrine hormones. Mice were treated with QFY at low (2.8 g/kg), medium (5.6 g/kg), or high (11.2 g/kg) doses, or with donepezil as a positive control, for 194 days. Frailty-related behaviors were assessed using CatWalk gait analysis, grip strength, rotarod, nest-building, and aging scoring. Plasma hormone levels were measured, and fecal gut microbiota composition and function were analyzed by 16S rRNA sequencing and metagenomic analysis. QFY treatment significantly improved gait parameters, grip strength, motor coordination, nesting ability, and reduced aging scores in 5xFAD mice, with effects comparable to or superior to those of donepezil. QFY also restored aberrant levels of estradiol, testosterone, and corticosterone, and reshaped gut microbiota composition, particularly by increasing the abundance of Adlercreutzia, which negatively correlated with senescence and testosterone levels. Functional metagenomics revealed that QFY partially restored disease-associated microbial pathways, including those involved in carbohydrate metabolism and virulence. These findings suggest that QFY alleviates frailty in 5xFAD mice, with effects associated with concurrent modulation of gut microbiota and neuroendocrine function, though causal relationships require further validation. These findings support further investigation of QFY as a potential intervention for AD-associated frailty.