Proof of principle for linaclotide to improve gut symptoms in cystic fibrosis

A Randomised, Placebo-controlled Crossover Study Defining the Mode of Action of Linaclotide in Healthy Volunteers Using MRI

Early Phase 1 Interventional University of Nottingham · NCT07569419

This will test whether linaclotide can increase intestinal fluid and ease constipation and abdominal symptoms in adults with cystic fibrosis.

Quick facts

PhaseEarly Phase 1
Study typeInterventional
Enrollment26 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorUniversity of Nottingham Academic / other
Locations1 site (Nottingham)
Trial IDNCT07569419 on ClinicalTrials.gov

What this trial studies

This early-phase interventional study gives adults with cystic fibrosis a linaclotide capsule (290 micrograms) and a matched lactose placebo on separate visits under controlled conditions. Participants consume a standardized rice pudding/blue dye meal and undergo MRI scans to track intestinal fluid distribution and transit. Stool frequency and appearance are recorded alongside imaging to link symptoms with physiological effects. The study is conducted at a single centre (Sir Peter Mansfield Imaging Centre, University of Nottingham).

Who should consider this trial

Good fit: Adults aged 18–60 with cystic fibrosis who can fast overnight, tolerate MRI scanning, and are not taking excluded medications are ideal candidates.

Not a fit: People who are pregnant, lactating, have MRI contraindications, pre-existing GI disorders that affect bowel function, or who cannot comply with study conditions are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, linaclotide could reduce constipation and abdominal discomfort in people with cystic fibrosis by restoring intestinal fluid balance.

How similar studies have performed: Linaclotide is effective for chronic constipation and IBS-C in non-CF populations, but its use specifically in cystic fibrosis is largely untested and represents a novel application.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Participant is willing and able to give informed consent for participation in the study

Not currently taking any medications (except for selective serotonin reuptake inhibitors, low dose tricyclic antidepressants, antihistamines, and oral contraceptive pill).

Aged between 18-60 years.

Ability to conform to the study protocol, including overnight fasting, dietary and lifestyle restriction, administering linaclotide and placebo intervention, MRI scanning, consuming the rice pudding/blue dye meal, and rating stool frequency and appearance.

Exclusion Criteria:

Contraindication to MRI scanning (i.e. metallic implants, pacemakers, history of metallic foreign body in eye(s) and penetrating eye injury, unable to lie flat and relatively still for less than 5 minutes.)

Pregnancy, lactating, or planning pregnancy during the investigation declared by candidate.

History declared by the candidate of pre-existing gastrointestinal disorder that may affect bowel function.

Reported history of previous resection of the oesophagus, stomach, or intestine (excluding appendix).

Intestinal stoma.

Any medical condition that may potentially compromise participation in the study e.g., known food intolerance to rice pudding, known contraindication to the oral administration of linaclotide or placebo.

Has a body mass index (BMI) value less than 18.5 or greater than 35.

Will not agree to follow dietary and lifestyle restrictions required.

Unable to stop drugs known to alter GI motility including mebeverine, opiates, monoamine oxidase inhibitors, phenothiazines, benzodiazepines, calcium channel antagonists for the duration of the study.

Participants who are currently (or in the past 3 months) taking antibiotics or probiotics as these may impact GI function.

Participation in night shift work the week prior to the study day. Night work is defined as working between midnight and 6.00 AM.

Anyone who in the opinion of the investigator is unlikely to be able to comply with the protocol e.g., cognitive dysfunction, chaotic lifestyle related to substance abuse.

Having taken part in a research study in the last 3 months involving invasive procedures or an inconvenience allowance

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Where this trial is running

Nottingham

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Cystic Fibrosislinaclotidecystic fibrosisgastrointestinalMRI
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.