Microbiota profiling in aging-associated inflammation and liver degeneration

Area of Science:

• Gerontology and Aging Research
• Gastroenterology
• Immunology

Background:

• Global population aging correlates with increased age-associated diseases and impairments.
• Aging is linked to altered bacterial endotoxin levels, contributing to inflammaging and liver degeneration.
• Mechanisms of gut microbiota-liver interaction in aging-associated inflammation remain unclear.

Purpose of the Study:

• To investigate age-related changes in intestinal microbiota composition.
• To determine if these alterations correlate with intestinal barrier function markers.
• To assess the association with inflammation and liver degeneration.

Main Methods:

• Analysis of intestinal microbiota, barrier function markers, and antimicrobial peptides in mice of varying ages (2-30 months).
• Assessment of liver damage, inflammation, lipopolysaccharide binding protein (Lbp), and toll-like receptors (Tlr) 1-9.
• Utilized C57BL/6 mice fed standard chow.

Main Results:

• No significant changes in gut microbial diversity or richness with age.
• Reduced nitric oxide in the small intestine of older mice; antimicrobial peptide expression remained unchanged.
• Older mice exhibited increased liver inflammation, fibrosis, higher plasma endotoxin, and elevated hepatic Lbp and Tlr expression (Tlr1, Tlr2, Tlr4, Tlr6, Tlr9).

Conclusions:

• Age-related alterations in small intestinal barrier function markers were observed.
• These changes are associated with the induction of specific Toll-like Receptors (Tlrs) and the onset of hepatic inflammation in aging mice.
• Gut barrier dysfunction and liver inflammation increase with age.