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Completed

NCT Number: NCT05804929

Phenotypic Characteristics of Superlean Individuals Including Gut Microbiome

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,

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Key information

Conditions

Thinness Behavior Body Weight Feeding Behavior Food Preferences Health Behavior Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

25 year–40 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Shenzhen Institute of Advanced Technology,

Shenzhen, China

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Observation without intervention

Other

Observation of food intake, body composition, microbiota, genetics, metabolic rate, metabolomics.

Primary outcomes

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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).

  6. 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 ).

  7. 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).

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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).

  15. 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.

  16. 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.

  17. 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).

  18. 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.

Sponsors and collaborators

Lead sponsor

Shenzhen Institutes of Advanced Technology ,Chinese Academy of Sciences

Other

Registry information

Official study title

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

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
Apr 7, 2023
Registry last updated
Jan 21, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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