The effect of treadmill exercise on memory function and gut microbiota composition in old rats

Area of Science:

• Neuroscience
• Gerontology
• Microbiology

Background:

• Aging is linked to cognitive decline, particularly in memory function.
• Changes in gut microbiota composition are also characteristic of the aging process.
• Inflammation and reduced neurotrophic factors are implicated in age-related memory impairment.

Purpose of the Study:

• To investigate the effects of treadmill exercise on age-related memory decline.
• To examine exercise's impact on inflammatory markers and neurotrophic factors in the hippocampus.
• To assess how exercise influences gut microbiota diversity and composition in aging mice.

Main Methods:

• Mice were divided into control, control+exercise, old, and old+exercise groups.
• Treadmill exercise was administered for 8 weeks.
• Memory was assessed using step-through and Morris water maze tests.
• Hippocampal inflammation (TNF-α, IL-6) and neurotrophic factors (BDNF, TrkB) were measured.
• Gut microbiota diversity and composition were analyzed via metagenomic sequencing.

Main Results:

• Old mice exhibited impaired short-term and spatial learning memory.
• Aging mice showed increased pro-inflammatory cytokines (TNF-α, IL-6) and decreased neurotrophic factors (BDNF, TrkB).
• Significant reductions in gut microbiota diversity and beneficial bacteria were observed in old mice.
• Treadmill exercise improved memory, reduced inflammation, and increased neurotrophic factor expression in old mice.
• Exercise also enhanced gut microbiota diversity and the abundance of beneficial bacteria.

Conclusions:

• Treadmill exercise effectively mitigates age-related memory decline.
• Exercise reduces systemic inflammation and enhances neurotrophic support in the aging brain.
• Exercise positively modulates the gut microbiota, increasing diversity and beneficial bacteria, which may contribute to cognitive improvements.