Natural odor levels in spinal fluid after inhalation

Abundance of a Natural Odour in Human Cerebrospinal Fluid After Olfactory Exposure - the OLFO-Brain Study

This study will test whether inhaling a natural odor leads to detectable levels of that odor in the spinal fluid and blood of lean and obese adults undergoing a lumbar puncture.

Quick facts

• Phase: EARLY_PHASE1
• Study type: Interventional
• Enrollment: 32 (estimated)
• Ages: 18 Years to 60 Years
• Sex: All
• Sponsor: University Hospital, Basel, Switzerland (other)
• Locations: 2 sites (Basel and 1 other locations)
• Trial ID: NCT06370845 on ClinicalTrials.gov

What this trial studies

This is a randomized, placebo-controlled early-phase interventional trial in adults aged 18–60 with lean (BMI 18–25) or obese (BMI ≥30, non-diabetic) categories. Participants scheduled for a routine lumbar puncture will inhale either a natural odor or a placebo via an inhaler and provide blood samples; cerebrospinal fluid will be collected as part of their standard-of-care lumbar puncture. The trial measures the abundance of the inhaled odor compound in cerebrospinal fluid and blood to determine whether the odor reaches central compartments. Common exclusions include pregnancy, severe chronic disease, prior nasal or sinus surgery, acute upper respiratory infection, or allergy to the odor.

Who should consider this trial

Good fit: Ideal candidates are adults 18–60 who are already scheduled for a routine lumbar puncture and meet either lean (BMI 18–25) criteria or obese (BMI ≥30) without diabetes, and who can give informed consent.

Not a fit: People who are pregnant, breastfeeding, have severe chronic illnesses, recent nasal/sinus surgery, active upper respiratory infections, a known allergy to the odor, or who are not undergoing a lumbar puncture are unlikely to benefit from participating.

Why it matters

Potential benefit: If successful, the trial could show that inhaled natural odors can be detected in spinal fluid and blood, which might open new directions for diagnostics or mechanistic research though direct clinical benefit is uncertain.

How similar studies have performed: This specific measurement in human cerebrospinal fluid after inhalation is largely novel, though related research has detected inhaled or volatile compounds in blood and peripheral tissues.

Eligibility criteria

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

Where this trial is running

Basel and 1 other locations

• University Hospital Basel — Basel, Switzerland (NOT_YET_RECRUITING)
• University Hospital of Basel — Basel, Switzerland (RECRUITING)

Study contacts

• Principal investigator: Katharina Timper, Prof. Dr. med. — University Hospital Basel, Department of Endocrinology, Diabetology and Metabolism
• Study coordinator: Katharina Timper, Prof. Dr. med.

Conditions: Overweight and Obesity, natural odour Inhalation, RCT, Placebo Controlled, Cerebrospinal Fluid