Brief Disruption of Circadian Rhythms Alters Intestinal Barrier Integrity and Modulates DSS-Induced Colitis Severity...

Area of Science:

• Physiology
• Chronobiology
• Gastroenterology

Background:

• Circadian rhythms optimize organismal fitness and anticipate environmental changes.
• Disruptions in intestinal circadian rhythms are linked to metabolic disorders and gastrointestinal inflammation.

Purpose of the Study:

• To characterize intrinsic intestinal rhythms.
• To assess disruptions caused by continuous darkness or light exposure on gut integrity and function.

Main Methods:

• C57BL/6 mice were exposed to standard light-dark cycles or continuous light/darkness for 48 hours.
• Evaluations included intestinal morphology, mucus production, nitric oxide levels, and permeability (FITC-dextran uptake, IgG-coated bacteria).
• Impact on DSS-induced colitis was assessed.

Main Results:

• Continuous light altered small intestine epithelium and lamina propria, reduced colonic nitric oxide, and shifted mucin profiles.
• Increased intestinal permeability was observed under continuous light.
• Short-term light-dark cycle disruption differentially affected DSS-induced colitis severity.

Conclusions:

• Circadian rhythms are critical for maintaining gut histoarchitecture and function.
• Short-term disruptions in light-dark cycles compromise intestinal barrier integrity.
• Altered circadian rhythms can significantly impact inflammatory outcomes in the gut.