Intestinal Permeability Biomarker Zonulin is Elevated in Healthy Aging

Area of Science:

• Gerontology
• Gastroenterology
• Immunology

Background:

• Increased intestinal permeability, termed 'leaky gut', is hypothesized to contribute to age-related inflammation and gut dysbiosis.
• Limited data exist on the direct relationship between leaky gut markers, inflammation, and physical frailty in aging individuals.

Purpose of the Study:

• To investigate the hypothesis that an aging-associated leaky gut is linked to age-related inflammation and physical frailty.

Main Methods:

• A comparative study involving young (18-30 years) and older (≥70 years) healthy adults.
• Serum analysis of inflammatory markers (TNF-α, IL-6), a leaky gut marker (zonulin), and an inflammation-triggering protein (HMGB1).
• Correlation analysis between serum zonulin/HMGB1 levels and physical function metrics (muscle strength, daily steps).

Main Results:

• Older adults exhibited significantly higher serum concentrations of zonulin (22% increase) and HMGB1 (16% increase) compared to younger adults.
• Serum zonulin positively correlated with systemic inflammatory markers TNF-α and IL-6.
• Both zonulin and HMGB1 showed significant negative correlations with skeletal muscle strength and habitual physical activity levels.

Conclusions:

• Elevated serum zonulin is associated with both systemic inflammation and key indicators of physical frailty in older adults.
• These findings suggest that a leaky gut may play a critical role in the pathogenesis of age-related inflammation and physical decline.