Microplastics, Gut Dysbiosis, and Inflammatory Pathways in Ulcerative Colitis.

Area of Science:

• Environmental Science
• Microbiology
• Gastroenterology

Background:

• Microplastics (MPs) are ubiquitous pollutants entering the human body via inhalation and diet.
• MPs accumulate in the gut, disrupting microecological homeostasis and contributing to digestive diseases.
• Ulcerative colitis (UC) is linked to gut microbiota dysbiosis, a key pathogenic mechanism.

Purpose of the Study:

• To comprehensively review MPs' characteristics and interactions with gut microbiota and metabolites.
• To elucidate mechanisms of MP-induced UC initiation and progression, focusing on barrier dysfunction and immune dysregulation.
• To connect the regulatory axis of MPs-gut microbiota-metabolites-intestinal barrier-immune inflammation for UC.

Main Methods:

• Literature review of existing research on microplastics, gut microbiota, and ulcerative colitis.
• Analysis of mechanistic pathways involving MPs, microbial metabolites (e.g., SCFAs), and host immune responses (e.g., TLR4-NF-κB).
• Integration of findings to establish a comprehensive pathological chain of MP-induced UC.

Main Results:

• MPs disrupt short-chain fatty acid (SCFA)-producing microbial networks.
• MPs activate epithelial inflammatory pathways, notably TLR4-NF-κB signaling, exacerbating mucosal inflammation.
• This review provides the first integrated analysis of the MP-gut microbiota-metabolites-intestinal barrier-immune inflammation axis in UC.

Conclusions:

• MPs play a significant role in the etiology and progression of ulcerative colitis.
• Understanding the MP-gut axis offers a novel theoretical framework for UC pathogenesis.
• Future research should explore intervention strategies targeting this axis for UC prevention and treatment.