Intestinal microbial remodeling and metabolite regulation may be related to the improvement of social avoidance in depressed mice by Modified Xiaoyaosan.

Dementia is a progressive neurodegenerative condition that is characterized by motor and cognitive impairments, limiting functionality, independence and quality of life (). Global estimates indicate that over 57 million individuals were living with dementia in 2025, reflecting the substantial and growing public health burden associated with aging populations (). Evidence from recent epidemiological reviews highlights that dementia incidence varies significantly across regions, with declines observed in parts of Europe and the United States but increases reported in countries such as Japan, Taiwan, and Republic of Korea, underscoring the heterogeneity of global trends (). Low- and middle-income countries are expected to experience the most rapid growth in dementia cases over the coming decades, largely due to demographic expansion and under-diagnosis in earlier years (). Dementia is primarily characterized by progressive cognitive decline that interferes with independence in everyday activities. Core cognitive impairments typically include memory deterioration, especially episodic memory, executive dysfunction, language disturbances, and visuospatial deficits (). memory impairment remains the most prevalent early symptom, reflecting degeneration in medial temporal lobe structures, while deficits in planning, attention, and problem-solving emerge as frontal networks become affected (). Furthermore, visuospatial dysfunction such as difficulty navigating familiar environments or recognizing objects, have been identified as a common early sign, particularly in Alzheimer’s disease and dementia with Lewy bodies (). Beyond cognitive decline, motor symptoms are increasingly recognized as integral to the clinical presentation of several dementia syndromes. Bradykinesia, impaired gait and dual-task performance, and balance disturbances often appear as the disease progresses, reflecting broader neurodegenerative involvement leading to functional impairment (; ). Understanding these cognitive and motor impairments is essential for identifying the functional challenges faced by individuals with dementia. These challenges directly inform the selection and design of therapeutic interventions aimed at preserving independence and improving overall quality of life.