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NCT Number: NCT06370845

ABUNDANCE of A NATURAL ODOUR in HUMAN CEREBROSPINAL FLUID AFTER OLFACTORY EXPOSURE - the OLFO-Brain Study

The goal of this clinical trial is to investigate the abundance of a natural odour in human cerebrospinal fluid in obese and lean participants after inhalation thereof. Participants will undergo blood sample collection and inhalation of either a natural odour or placebo through an inhaler in addition to a liquor puncture prescribed in standard of care context.

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Key information

Conditions

Overweight and Obesity Body Weight Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

University Hospital Basel, Basel, Switzerland

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Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

Obese Participants:

  • Age 18-60 years
  • Written informed consent
  • Scheduled for routine liquor puncture
  • BMI ≥ 30 kg/m2
  • No proven diagnose of diabetes

Inclusion criteria

Lean Participants:

  • Age 18-60 years
  • Written informed consent
  • Scheduled for routine liquor puncture
  • BMI 18-25 kg/m2

Exclusion criteria

  • Known allergy to the natural odour
  • Acute upper respiratory tract infection, acute or chronic sinusitis
  • Present or past surgical intervention of the nasal cavity, the paranasal sinus, the pituitary or the frontal brain
  • Pregnancy/lactation
  • Any kind of severe chronic disease (e.g. severe heart failure, active cancer disease, severe renal impairment with an estimated glomerular filtration rate <30 ml/min/m2)
  • Inability to understand the study procedure and to sign the study consent

Treatment and study plan

Inhalation - Natural Odour

Combination Product

Inhalation of 50 uL of a natural odour via nasal septum mini-inhaler.

Inhalation - Placebo

Combination Product

Inhalation of 50 uL of Placebo via nasal septum mini-inhaler.

Primary outcomes

  1. Detection of a natural odour in human CSF

    Time frame: 1 time assessment at baseline

    Detection of a natural odour in human CSF within 30 min following end of an 15 min olfactory stimulation thereof compared to placebo. The presence of the Verum (natural odour) will be assessed via Gas Chromatography-Mass Spectrometry. This will be analyzed using a binary logistic regression model to determine the odds ratio of detecting a natural odour in the CSF post-stimulation. The model will account for variables such as age, sex, and BMI category (obese vs. lean). The significance level will be set at p < 0.05.

Secondary outcomes

  1. Abundance of a natural odour in human CSF of obese versus lean participants

    Time frame: 1 time assessment at baseline

    Detection of a natural odour in human CSF of obese versus lean participants within 30 min following end of an 15 min olfactory stimulation with a natural odour. Titration of the natural odour will be done via Gas Chromatography-Mass Spectrometry.

  2. Change in abundance of a natural odour in blood before and after olfactory stimulation in relation to abundance in human CSF.

    Time frame: 2 times assessment at baseline (immediately before olfactory stimulation and within 30 min following end of olfactory stimulation)

    Change in abundance of a natural odour in blood before and after end (max 30 min) of an olfactory stimulation for 15 min in relation to abundance in human CSF. Titration of the natural odour in CSF and blood samples will be done via Gas Chromatography-Mass Spectrometry.

  3. Change in abundance of a natural odour in blood before and after olfactory stimulation in obese as compared to lean participants.

    Time frame: 2 times assessment at baseline (immediately before olfactory stimulation and within 30 min following end of olfactory stimulation)

    Change in abundance of a natural odour in blood before and after end (max 30 min) of an olfactory stimulation for 15 min in obese as compared to lean participants. Titration of a natural odour in blood samples will be done via Gas Chromatography-Mass Spectrometry.

Study contacts

Contact information is provided by the study sponsor or research team.

Isabel M Hofer

CONTACT

[email protected]

0041 61 328 68 14

Katharina Timper, Prof. Dr. med.

CONTACT

[email protected]

0041 61 328 57 42

Sponsors and collaborators

Lead sponsor

University Hospital, Basel, Switzerland

Other

Registry information

Acronym: OLFO-Brain

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Apr 17, 2024
Registry last updated
May 4, 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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