Fluorescence Spectroscopy for Gut Permeability Assessment

NCT ID: NCT03434639

Last Updated: 2020-02-12

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

UNKNOWN

Total Enrollment

50 participants

Study Classification

OBSERVATIONAL

Study Start Date

2019-03-29

Study Completion Date

2021-09-30

Brief Summary

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This research aims to develop portable devices - known as fluorescence spectrometers - to monitor the leakage of fluorescent dyes out of the gut into the blood stream. These devices will measure the leakiness (permeability) of the gut in a non-invasive manner and will provide an early warning that patients are at risk of infections caused by the unwanted flow of bacteria from the intestine to the rest of the body.

Detailed Description

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"Leaky gut" - or, increased permeability of the intestine - involves the leakage of certain intestinal constituents (e.g. endotoxins or even bacteria) from the gut into the rest of the body. This condition is associated with many widespread diseases including coeliac disease, inflammatory bowel disease, HIV, liver cirrhosis, sepsis and environmental enteric dysfunction (EED). It has a considerable impact on quality of life and, in extreme cases (e.g. sepsis), it can even lead to death. Furthermore, in the developing world (as part of EED), it severely hampers the mental and physical development of young children. Thus, new devices that can help us to learn more about leaky gut and more accurately monitor its effects are urgently needed.

In this project, patients will drink a small dose of a fluorescent dye. Then, by shining light on the patients' skin and recording the color and brightness of the light (fluorescence) that comes back, it will be possible to measure the amount of dye that has leaked into the blood (indicating the likelihood that bacteria are escaping from the gut and causing infections). We refer to this as a "Spectroscopic gut permeability test." We will also ask patients to take a traditional permeability test (known as a PEG permeability test) so that we can validate our new sensor. Overall, this research will deliver vital information that will improve our understanding of leaky gut and help guide the development of treatments for the many diseases in which it occurs.

Conditions

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Development and Validation of Gut Permeability Sensor Permeability; Increased Celiac Disease Inflammatory Bowel Diseases Liver Diseases HIV/AIDS

Study Design

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Observational Model Type

CASE_CONTROL

Study Time Perspective

CROSS_SECTIONAL

Study Groups

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1 - Ophthalmology patients

Ophthalmology patients who are receiving an intravenous dose of either fluorescein or indocyanine green (ICG) as part of their routine ophthalmic care (e.g. as part of a fluorescence angiography examination) will be recruited to the first stage of this study. These patients will take part in preliminary studies aimed at determining whether it is possible to detect fluorescein and ICG in the blood using transcutaneous fluorescence measurements.

Spectroscopic gut permeability test

Intervention Type DIAGNOSTIC_TEST

The spectroscopic gut permeability test first involves patients receiving an oral dose of one or more fluorescent dyes. A wearable sensor will then be attached to the patients' skin and this will be used to monitor the leakage of the fluorescent dyes from the intestine into the blood stream in a non-invasive manner. In this way, a measure of the permeability of the intestine will be obtained.

Note that patients in Group 1 (ophthalmology patients) will not receive oral doses of contrast agents. Instead, the wearable sensor will simply be used to detect the presence of fluorescent dyes that were administered intravenously as part of planned ophthalmic procedures.

Complete details of the spectroscopic gut permeability test can be found in the attached protocol.

2a - Healthy subjects

Healthy subjects with no known issues of increased gut permeability. These subjects will act as negative controls in all gut permeability studies.

Spectroscopic gut permeability test

Intervention Type DIAGNOSTIC_TEST

The spectroscopic gut permeability test first involves patients receiving an oral dose of one or more fluorescent dyes. A wearable sensor will then be attached to the patients' skin and this will be used to monitor the leakage of the fluorescent dyes from the intestine into the blood stream in a non-invasive manner. In this way, a measure of the permeability of the intestine will be obtained.

Note that patients in Group 1 (ophthalmology patients) will not receive oral doses of contrast agents. Instead, the wearable sensor will simply be used to detect the presence of fluorescent dyes that were administered intravenously as part of planned ophthalmic procedures.

Complete details of the spectroscopic gut permeability test can be found in the attached protocol.

2b - Healthy subjects (gastric emptying)

A subset of healthy volunteers will be recruited to take part in experiments to help in understanding the impact of gastric emptying rate as a confounding factor in measurements of gut permeability.

Spectroscopic gut permeability test

Intervention Type DIAGNOSTIC_TEST

The spectroscopic gut permeability test first involves patients receiving an oral dose of one or more fluorescent dyes. A wearable sensor will then be attached to the patients' skin and this will be used to monitor the leakage of the fluorescent dyes from the intestine into the blood stream in a non-invasive manner. In this way, a measure of the permeability of the intestine will be obtained.

Note that patients in Group 1 (ophthalmology patients) will not receive oral doses of contrast agents. Instead, the wearable sensor will simply be used to detect the presence of fluorescent dyes that were administered intravenously as part of planned ophthalmic procedures.

Complete details of the spectroscopic gut permeability test can be found in the attached protocol.

3 - Increased permeability

Gastro-intestinal (GI) and non-GI patients who are expected to exhibit increased gut permeability (e.g. patients with celiac disease, inflammatory bowel disease (IBD), liver disease, HIV or another condition in which increased intestinal permeability is common). The more extreme cases in this group will act as positive controls.

Spectroscopic gut permeability test

Intervention Type DIAGNOSTIC_TEST

The spectroscopic gut permeability test first involves patients receiving an oral dose of one or more fluorescent dyes. A wearable sensor will then be attached to the patients' skin and this will be used to monitor the leakage of the fluorescent dyes from the intestine into the blood stream in a non-invasive manner. In this way, a measure of the permeability of the intestine will be obtained.

Note that patients in Group 1 (ophthalmology patients) will not receive oral doses of contrast agents. Instead, the wearable sensor will simply be used to detect the presence of fluorescent dyes that were administered intravenously as part of planned ophthalmic procedures.

Complete details of the spectroscopic gut permeability test can be found in the attached protocol.

Interventions

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Spectroscopic gut permeability test

The spectroscopic gut permeability test first involves patients receiving an oral dose of one or more fluorescent dyes. A wearable sensor will then be attached to the patients' skin and this will be used to monitor the leakage of the fluorescent dyes from the intestine into the blood stream in a non-invasive manner. In this way, a measure of the permeability of the intestine will be obtained.

Note that patients in Group 1 (ophthalmology patients) will not receive oral doses of contrast agents. Instead, the wearable sensor will simply be used to detect the presence of fluorescent dyes that were administered intravenously as part of planned ophthalmic procedures.

Complete details of the spectroscopic gut permeability test can be found in the attached protocol.

Intervention Type DIAGNOSTIC_TEST

Eligibility Criteria

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Inclusion Criteria

* Ability to give informed consent
* Aged 18 years or above
* No evidence of prior adverse reactions to fluorescein, ICG, dextran or PEG
* No evidence of prior adverse reactions to iodine (for ICG experiments only)
* For healthy volunteers: healthy with no active GI/liver disease (or other condition in which increased gut permeability is expected, e.g. HIV) and no antibiotics taken within the previous four weeks.
* For cases: exhibiting symptoms of GI, liver or other diseases (e.g. HIV) in which increased intestinal permeability is expected.
* For ophthalmology patients recruited in Stage 1: healthy (i.e. as described above for healthy volunteers) and prescribed to have an ophthalmic angiography with an intravenous injection of either fluorescein or ICG.

Exclusion Criteria

* Unable to give informed consent
* Aged \<18 years
* Previous adverse reaction to fluorescein, ICG, dextran or PEG
* Known allergy to iodine (for ICG experiments only)
* Pregnancy (in Stage 1 this will be at the discretion of the patient's ophthalmologist)
* Breastfeeding (in Stage 1 this will be at the discretion of the ophthalmologist)
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Imperial College London

OTHER

Sponsor Role lead

Responsible Party

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Alexander Thompson

Dr Alex Thompson (Imperial College Research Fellow)

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Alex J Thompson, PhD

Role: PRINCIPAL_INVESTIGATOR

Imperial College London

Locations

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IMPERIAL COLLEGE Healthcare Trust

London, , United Kingdom

Site Status RECRUITING

Countries

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United Kingdom

Central Contacts

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Alex J Thompson, PhD

Role: CONTACT

+442033125035

Ruth Nicholson

Role: CONTACT

+442075941862

Facility Contacts

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Alexander J Thompson, PhD

Role: primary

References

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Gan J, Chen Q, Monfort Sanchez E, Mandal N, Xu J, Wang Z, Agarwal A, Oluwatunmise E, Ramkumar P, Salam A, Chekmeneva E, Gomez-Romero M, Maslen L, Balarajah S, Perry R, Yong KK, Hoare J, Powell N, Alexander J, Avery J, Ashrafian H, Darzi A, Thompson AJ. Non-invasive fluorescence sensing reveals changes in intestinal barrier function and gastric emptying rate in a first-in-human study of Crohn's disease. Therap Adv Gastroenterol. 2025 Aug 13;18:17562848251361634. doi: 10.1177/17562848251361634. eCollection 2025.

Reference Type DERIVED
PMID: 40821739 (View on PubMed)

Provided Documents

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Document Type: Informed Consent Form: ICF for ophthalmology patients

View Document

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Document Type: Informed Consent Form: ICF for GI, liver and HIV patients

View Document

Document Type: Informed Consent Form: ICF for healthy volunteers (Group 2a)

View Document

Document Type: Informed Consent Form: ICF for healthy volunteers (Group 2b)

View Document

Other Identifiers

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18SM4374

Identifier Type: -

Identifier Source: org_study_id

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