A Pilot Study: Micro and NanoPlastics in Association With Crohn's Disease

Integrated Multi-phase Investigation of Role of Micro and NanoPlastics in Association With Crohn's Disease: Targeting Microbiome, Immunity, and Barrier Dysfunction: A Pilot Study

Micro and nanoplastics (MNPs) are environmental contaminants found in food and water. Recent evidence suggests these particles may be linked to intestinal inflammation and changes in gut bacteria, which are key features of Crohn's Disease (CD). This study aims to investigate if patients with Crohn's Disease have a reduced ability to clear these plastic particles and how this affects their immune system and intestinal health.

Study Overview

• Status: Not yet recruiting
• Conditions: Crohn's Disease (CD)

Detailed Description

Micro and nanoplastics may influence Crohn's Disease activity and gut health by impairing microplastic-degrading capacity of the gut microbiome due to the decreased plastic-degrading genes (PDGs) encoding enzymes (e.g., esterases, cutinases, PETases, laccases). Persistent Microplastics (MPs) drive worsening dysbiosis, which in turn amplifies immune activation, evidenced by increase in pro-inflammatory cytokines and disrupts intestinal barrier integrity. The resulting barrier leakage facilitates further MPs translocation, perpetuating disease exacerbation. This study is looking at the effects of micro- and nanoplastics (MNPs) on the gut microbiome, immune function, and intestinal barrier function.

Patients with Crohn's disease (CD) and healthy controls will be recruited during routine clinic visit or on the day of their scheduled colonoscopy following written informed consent.

In this study, demographic data (age, sex, smoking and alcohol status), as well as past medical and surgical history and current medications will be collected. A questionnaire focused on plastic-packaged foods in daily lives will also be administered.

All recruited subjects will have biopsies taken at their scheduled colonoscopy within 4 weeks of recruitment. Stool and blood will be collected cross-sectionally at recruitment.The fecal calprotectin tests and the Harvey-Bradshaw Index (HBI) will be used to assess the severity.

The flow cytometry to quantify cell populations; multiplex ELISA to determine levels of pro- and anti-inflammatory cytokines and a phagocytosis assay will be used for the scientific outcome measurements of the samples collected.

• Study Type: Observational
• Enrollment (Estimated): 90

Contacts and Locations

• Study Contact: Name: Joyce Wing Yan Mak; Phone Number: +85226373260; Email: wingyanmak@cuhk.edu.hk

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong
    • Prince of Wales Hospital
    • Contact: Joyce Wing Yan Mak; Phone Number: +85226373260; Email: wingyanmak@cuhk.edu.hk
    • Principal Investigator: Joyce Wing Yan Mak

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

Potential subjects will be identified at the Department of Medicine and Therapeutics of the Prince of Wales Hospital, or by personal referral from staff.

Description

Inclusion Criteria:

Cases:

• Age 18-80 years
• Confirmed diagnosis of Crohn's disease (for cases)
• Ability to provide informed consent.

Control:

• Age 18-80 years old
• No history of major large bowel resection
• Ability to provide informed consent.

Exclusion Criteria:

Cases:

• Antibiotic/probiotic use within 4 weeks
• History of gastrointestinal malignancy
• Presence of stoma
• Currently Pregnant
• Advanced terminal medical illness, e.g. terminal malignancies; end staged renal failure and liver failure

Control:

• Currently Pregnant
• Advanced terminal medical illness, e.g. terminal malignancies; end staged renal failure and liver failure
• Inability in giving consent

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
CD group; Crohn's disease patients with the score of Harvey-Bradshaw Index ≥ 5
Control group; Age- and sex-matched healthy individuals

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Micro- and nanoparticle abundance between subjects with Crohn's Disease and controls	Blood sample and intestinal biopsy specimens will be collected to perform micro and nanoplastics quantification.	Cross-sectional when the blood sample and the intestinal biopsy are collected.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plastic-degrading gene [PDG] abundance between subjects with Crohn's Disease and controls.	Blood and stool samples, as well as intestinal biopsy specimens will be collected to perform fecal DNA extraction, metagenomic sequencing and Plastic-Degrading Genes (PDG) analysis.	Cross-sectional when the stool, blood sample and the intestinal biopsy are collected.

Collaborators and Investigators

• Sponsor: Mak Wing Yan
• Investigators: Principal Investigator: Joyce Wing Yan Mak, Chinese University of Hong Kong

Study record dates

Study Major Dates

• Study Start (Estimated): June 15, 2026
• Primary Completion (Estimated): June 30, 2031
• Study Completion (Estimated): December 31, 2031

Study Registration Dates

• First Submitted: June 2, 2026
• First Submitted That Met QC Criteria: June 2, 2026
• First Posted (Actual): June 5, 2026

Study Record Updates

• Last Update Posted (Actual): June 5, 2026
• Last Update Submitted That Met QC Criteria: June 2, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Intestinal Diseases; Digestive System Diseases; Gastrointestinal Diseases; Gastroenteritis; Inflammatory Bowel Diseases; Crohn Disease
• Other Study ID Numbers: PLASTIC-CD