Phenotypic Characteristics of Superlean Individuals Including Gut Microbiome

January 19, 2026 updated by: John R. Speakman, Shenzhen Institutes of Advanced Technology ,Chinese Academy of Sciences

Study on the Phenotype and Gut Microbiome Composition of Healthy Superlean Individuals (BMI < 18.5)

The goal of this observational study is to build on our previous work to further characterise the phenotype of superlean individuals (BMI < 18.5) when compared to normal BMI people (BMI 21.5 to 25). This will include characterising the body composition, food intake behaviour, circulating hormone levels, genetics and characteristics of the gut microbiota. The investigators expect to recruit up to 200 healthy superlean and control volunteers respectively,

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The focus of this work is to characterise the phenotype and genotype of individuals who have low BMI ( < 18.5) but are otherwise healthy and do not have eating disorders. The investigators term this group 'superlean' individuals. The study is observational and the investigators aim to establish a healthy superlean cohort,and use the combined metagenomic and metabolomic multi-omics analysis techniques, combined with imaging and physiological measurements, to focus on the correlation between gut microbiota characteristics and metabolism in superlean population. The investigators expect to recruit up to 200 healthy superlean and control volunteers (BMI 21.5 to 25) respectively, to explore the microbiota characteristics and differences between control and healthy superlean populations by measuring the basic physical indicators and metabolic parameters. This will include analyzing the postprandial hormonal changes, appetite differences, and changes in the gut microbiome and serum metabolome in the two groups of volunteers, establishing the relationship between the gut microbiota and the metabolite and metabolic phenotypes of the body, and exploring the gut microbiota.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
104

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • China
      • Shenzhen, China
        • Shenzhen Institute of Advanced Technology,

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

25 years to 40 years (Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Participants are healthy, with no metabolic disorder, 25 - 40 years old

Description

Inclusion Criteria:

  • Control group (21.5≤ BMI<25), Superlean group (BMI≤18.5)
  • Age between 25-40 years old

Exclusion Criteria:

  • Having metabolic diseases or eating disorders
  • Recent weight loss due to various disease causes
  • Being treated for weight loss
  • Having an infectious disease
  • Pregnant and lactating women
  • People with blood sickness, pathological hypo- or hypertension
  • People suffering from claustrophobia
  • No metal implants in the body
  • Use of antibiotics, probiotics, oral laxatives, etc. within 8 weeks

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Control
21.5≤BMI<25, age between 25-40 years old, 200subjects.
Other: Observation without intervention
Observation of food intake, body composition, microbiota, genetics, metabolic rate, metabolomics.
Superlean
BMI≤18.5, age between 25-40 years old, 200 subjects.
Other: Observation without intervention
Observation of food intake, body composition, microbiota, genetics, metabolic rate, metabolomics.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Weight
Time Frame: Through study completion, an average of 2 years, will be measured on arrival.
Volunteers will be asked to fast for 10 hours and measured fasting weight.
Through study completion, an average of 2 years, will be measured on arrival.
Height
Time Frame: Through study completion, an average of 2 years, will be measured on arrival.
Height will be measured by seca 217 stable stadiometer.
Through study completion, an average of 2 years, will be measured on arrival.
Waist circumferences
Time Frame: Through study completion, an average of 2 years, will be measured on arrival.
Waist circumferences will be measured using a whole body laser scanner.
Through study completion, an average of 2 years, will be measured on arrival.
Hip circumferences
Time Frame: Through study completion, an average of 2 years, will be measured on arrival.
Hip circumferences will be measured using a whole body laser scanner.
Through study completion, an average of 2 years, will be measured on arrival.
Bone mineral density
Time Frame: Through study completion, an average of 2 years, will be measured on arrival.
Bone mineral density will be measured by Dual Energy X-ray Absorptiometry (Horizon Wi).
Through study completion, an average of 2 years, will be measured on arrival.
Fat mass
Time Frame: Through study completion, an average of 2 years, will be measured on arrival.
Fat mass will be measured by Magnetic Resonance Imaging (Shanghai united imaging, uMR 790 ).
Through study completion, an average of 2 years, will be measured on arrival.
Fat free mass
Time Frame: Through study completion, an average of 2 years, will be measured on arrival.
Fat free mass will be measured by Bioimpedance Analysis (Tanita, MC-980).
Through study completion, an average of 2 years, will be measured on arrival.
Blood pressure
Time Frame: Through study completion, an average of 2 years, will be measured on arrival.
Systolic and diastolic blood pressure will be measured using an Omron sphygmomanometer.
Through study completion, an average of 2 years, will be measured on arrival.
Glucose
Time Frame: Through study completion, an average of 2 years, will be recorded for a consecutive of 7 days.
Fasting and post-prandial glucose after a standard meal will be recorded by the continuous glucose monitoring system.
Through study completion, an average of 2 years, will be recorded for a consecutive of 7 days.
Body temperature
Time Frame: Through study completion, an average of 2 years, will be measured before and after feeding.
Body temperature will be measured before and after feeding using a thermal imaging camera.
Through study completion, an average of 2 years, will be measured before and after feeding.
Resting energy expenditure
Time Frame: Through study completion, an average of 2 years, will be measured on arrival.
The measurement of resting energy expenditure will be performed using indirect calorimetry.
Through study completion, an average of 2 years, will be measured on arrival.
Physical activity
Time Frame: Through study completion, an average of 2 years, will be recorded for a consecutive of 7 days.
Physical activity of the participants will be recorded using GT3X monitor for a consecutive of 7 days.
Through study completion, an average of 2 years, will be recorded for a consecutive of 7 days.
Body shape
Time Frame: Through study completion, an average of 2 years, will be measured on arrival.
Body shape will be measured using a whole body laser scanner.
Through study completion, an average of 2 years, will be measured on arrival.
Energy intake
Time Frame: Through study completion, an average of 2 years, will be measured on arrival.
Response on standard feeding table, the food consumption will be recorded continuously by balances underneath each food dish. The total energy intake will be calculated in KJ (kilojoule).
Through study completion, an average of 2 years, will be measured on arrival.
Circulating hormones
Time Frame: Through study completion, an average of 2 years, will be measured after standard intervention meal.
Levels of circulating hormones (including leptin, insulin, ghrelin etc) will be measured when fasted and after a standard intervention meal. Levels of circulating hormones in the serum will be measured by ELISA (Bio Tek, Synergy4) in mmol/L.
Through study completion, an average of 2 years, will be measured after standard intervention meal.
Microbiome
Time Frame: Through study completion, an average of 2 years, will be measured after samples collected.
Abundance of gut microbiome will be from Metagenomic profiling of feces by Illumina.
Through study completion, an average of 2 years, will be measured after samples collected.
Metabolites
Time Frame: Through study completion, an average of 2 years, will be measured after samples collected.
Abundance of metabolites will be from metabolomic profiling of serum and feces by LC-MS (liquid chromatography-mass spectrometry).
Through study completion, an average of 2 years, will be measured after samples collected.
Genetics
Time Frame: Through study completion, an average of 2 years, will be measured after samples collected.
Polymorphic variation will be assessed in a panel of SNPs (single nucleotide polymorphism) previously linked to body composition and physical activity using a Mass array sequencer.
Through study completion, an average of 2 years, will be measured after samples collected.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Shenzhen Institutes of Advanced Technology ,Chinese Academy of Sciences

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 1, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 17, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 27, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 7, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 21, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 19, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • SIAT-IRB-221115-H0628

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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