Enteral enriched nutrition to prevent cognitive dysfunction after surgery; a study in rats

Area of Science:

• Neuroscience
• Gerontology
• Nutritional Science

Background:

• Postoperative cognitive dysfunction (POCD) is linked to inflammation, especially in elderly patients.
• Enteral enriched nutrition has demonstrated anti-inflammatory properties.
• This study investigates enteral enriched nutrition's potential therapeutic role in a rat model of POCD.

Purpose of the Study:

• To explore the therapeutic potential of enteral enriched nutrition in a rat model of POCD.
• To examine the mechanism of action in young rats.
• To evaluate responses in elderly patients using old rats.

Main Methods:

• Wistar rats (3 and 23 months old) received enriched nutrition pre-surgery.
• Inflammatory response assessed via systemic markers and brain microglia activity.
• Gut-brain axis investigated in old rats through microbiome analysis.
• Cognitive function tested days 9-14 post-surgery; brains collected on day 16.

Main Results:

• In young rats, enriched nutrition improved long-term memory and reduced inflammation (IL-1β, VEGF), but did not affect microglia or neurogenesis.
• In old rats, short-term memory improved, but long-term memory was impaired; systemic inflammation and gut microbiome were unaffected.
• Microglia activity appeared increased in old rats.

Conclusions:

• Preoperative enteral enriched nutrition reduced systemic inflammation and improved cognition in young rats.
• Old rats exhibited mixed cognitive outcomes with no systemic anti-inflammatory effect.
• The anti-inflammatory effects were not linked to reduced microglia activity or a significant gut-brain axis role.
• Findings suggest caution when extrapolating the benefits of enriched nutrition from younger to older populations.