High-Fat/High-Sugar Diet and High-Temperature/High-Humidity Exposure Aggravates Ulcerative Colitis in an Experimental...

Area of Science:

• Gastroenterology
• Immunology
• Metabolism

Background:

• Ulcerative colitis (UC), an inflammatory bowel disease (IBD), is linked to high calorie/lipid intake and summer temperatures.
• Dietary and environmental factors may influence UC progression.

Purpose of the Study:

• To investigate the impact of high-fat/high-sugar diets and high-temperature/high-humidity exposure on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in a mouse model.
• To assess the exacerbation of UC symptoms and underlying mechanisms.

Main Methods:

• Mice were modeled for UC using 2.0% dextran sulfate sodium (DSS).
• Combined exposure to a high-fat/high-sugar diet and high temperature/humidity was applied.
• Evaluated body weight, disease activity index (DAI), histopathology, serum lipids, diamine oxidase (DAO), D-Lactate (D-LA), inflammatory cytokines (IL-6, IL-17A, IL-1β), and tight junction proteins (ZO-1).

Main Results:

• High-fat/high-sugar diet and hot/humid conditions worsened DSS-induced UC, causing more severe colon damage.
• Increased pro-inflammatory cytokine expression (IL-6, IL-17A, IL-1β) and compromised intestinal barrier (reduced ZO-1, elevated DAO/D-LA) were observed.
• Metabolic disturbances in glucose and lipid profiles were exacerbated, unlike in DSS-only treated mice.

Conclusions:

• Dietary and environmental factors significantly exacerbate UC progression and gut barrier dysfunction.
• This study provides novel insights into the combined effects of diet and climate on UC pathogenesis.
• Findings highlight the importance of lifestyle and environmental considerations in managing UC.