A Proof-of-Concept Study to Evaluate the Efficacy of NOBO, a Novel Postbiotic, in Controlling Axillary Odor in Healthy Adults

A Randomized, Double-Blind, Placebo-Controlled, Split-Axilla, Proof-of-Concept Study to Evaluate the Efficacy of NOBO, a Novel Postbiotic, in Controlling Axillary Odor in Healthy Adults

The goal of this clinical trial is to evaluate the performance of NOBO, a yeast-based fermentation product (postbiotic) designed to control axillary odor, in controlling axillary odor in healthy male and female adults age 18 - 70 with confirmed self-perception of body odor. The main question it aims to answer is:

Does NOBO decrease self-perceived odor of the intervention axilla compared to the placebo axilla at any time point? Researchers will compare the intervention axilla to the placebo axilla to see if there is a difference in self-perceived odor and microbiome.

Participants will:

• be given a NOBO deodorant spray and a placebo deodorant spray (each assigned to one axilla)
• self assess body odor
• sample axilla with cotton round for 3rd party odor assessment
• sample axilla with a swab for skin microbiome analysis via qPCR
• self assess skin irritation

Study Overview

• Status: Completed
• Conditions: Body Odor
• Intervention / Treatment: Other: Placebo Aqueous Deodorant; Other: NOBO Aqueous Deodorant

Detailed Description

The study aims to evaluate the performance of NOBO, a yeast-based fermentation product (postbiotic) designed to control axillary odor, in controlling axillary odor and potentially impacting the skin microbiome. This study serves the purpose of validating the postbiotic's efficacy and de-risking future external clinical studies.

For this study, a total of 5-7 subjects will be recruited based on the recruitment requirements. The target population for this study is healthy male and female adults age 18 - 70 with no existing skin conditions (e.g., eczema, psoriasis, contact dermatitis) and no known allergies to skin treatment products or cosmetics, toiletries, and/or topical drugs, with confirmed self-perception of body odor.

On Day -7 to Day 0, each subject goes through a wash-in period with controlled washing with only unscented soap. For the first 4 days of the wash-in period, no antiperspirant is allowed. For the last 3 days of the wash-in period, no underarm product is allowed.

Participants are randomly assigned a treatment axilla: either left or right. One axilla (intervention axilla) will receive NOBO for the full duration of the intervention period. The other axilla (control axilla) will receive a placebo for the full duration of the study.

On Day 1 (AM), before showering the subject first performs the baseline microbiome sampling of both axilla. The subject then showers with unscented soap and performs the baseline self assessment of axillary odor. The subject then applies the deodorants to each axilla and self assesses odor immediately after the first application. On Day 1 (PM), ~12 hours after Day 1 AM application, the subject self assesses odor and applies the deodorants to each axilla again. On Day 2 (AM), the subject self assesses odor and applies the deodorant to each axilla. On Day 2 (PM), the subject self assesses odor and applies the deodorant to each axilla. On Days 3-12, the subject applies the deodorants to each axilla twice daily (AM & PM) and self-assesses odor only once a day (PM). On Day 2 AM, Day 6 AM, and Day 12 AM, the subject samples the axilla for third party odor assessment. On Day 1 AM, Day 3 AM, Day 6 AM, Day 9 AM, and Day 12 AM, the subject performs microbiome sampling on each axilla. On Day 1 PM, Day 3 PM, Day 6 PM, Day 9 PM, and Day 12 PM, the subject self-assesses skin irritation on each axilla.

Observing a decrease in self perceived odor of the intervention (NOBO) axilla compared to the placebo axilla at any time point is the primary success criterion of this study.

• Study Type: Interventional
• Enrollment (Actual): 5
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New York
    • Brooklyn, New York, United States, 11205
      • Kingdom

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age: The subject is an adult between 18 and 70 y.o.
• Skin health: The subject has no active skin conditions or lesions in the axillary region and no existing skin conditions (e.g., eczema, psoriasis, contact dermatitis).
• Skin allergies: The subject has no known allergies to skin treatment products or cosmetics, toiletries, and/or topical drugs.

Exclusion Criteria:

• Subject is pregnant, nursing, or planning to become pregnant in the next 6 months.
• Subject is an insulin-dependent diabetic.
• Subject has been diagnosed or treated for cancer in the past 5 years.
• Subject is currently using or has not used in the past two weeks any systemic antibiotics.
• Subject is currently using or used within the last month any topical medications, over-the-counter (OTC) or prescription products on the underarms.
• Subject is currently taking or plans to take during the study any anti-inflammatory for a chronic condition (except 81 mg-Aspirin per day), immunosuppressant, antihistamine, or sedative medications (i.e. containing antihistamines like Tylenol PM, Nyquil, etc.).
• Subject is currently participating in another underarm clinical trial. Subjects may participate in other studies as long as the same test sites are not used or are testing similar products.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: NOBO aqueous deodorant; The NOBO aqueous deodorant is composed of ≤7.2% yeast fermentation product (INCI: Yeast) and ≤ 40% ethanol in water. A dose is 0.48 mL per axilla for female subjects (3 actuations) or 0.64 mL per axilla for male subjects (4 actuations), delivered twice a day.	Other: NOBO Aqueous Deodorant; The active ingredient in the NOBO aqueous deodorant is a yeast-based fermentation product (postbiotic) of the Starmerella genus.
Placebo Comparator: Placebo aqueous deodorant; The placebo deodorant is composed of ≤ 40% ethanol in water. The placebo deodorant contains the same concentration of ethanol as the NOBO aqueous deodorant. A dose is 0.48 mL per axilla for female subjects (3 actuations) or 0.64 mL per axilla for male subjects (4 actuations), delivered twice a day.	Other: Placebo Aqueous Deodorant; The placebo deodorant is composed of ≤ 40% ethanol in water.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Axillary odor self assessment (on 0-5 odor scale)	A 0 on the odor scale corresponds to "no axillary odor"; a 5 corresponds to "very strong axillary odor"	At baseline (before application), immediately after first application, Day 1 PM, Day 2 AM, and Day 2 PM; then once a day (PM) for Days 3-12

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Axillary odor self assessment (comparative)	Comparative assessment is simply a measurement of which axilla (left or right) smells worse.	At baseline (before application), immediately after first application, Day 1 PM, Day 2 AM, and Day 2 PM; then once a day (PM) for Days 3-12
Axillary odor third party assessment (on 0-5 scale)	A 0 on the odor scale corresponds to "no axillary odor"; a 5 corresponds to "very strong axillary odor." The third party odor assessor smells cotton rounds which the subject has rubbed on the axillae.	At Day 2 AM, Day 6 AM, and Day 12 AM
Axillary odor third party assessment (comparative)	Comparative assessment is simply a measurement of which axilla (left or right) smells worse.	At Day 2 AM, Day 6 AM, and Day 12 AM
Skin irritation (pain & redness) self assessment (0-4 Draize scale; 0-10 pain scale)	A 0 on the Draize scale corresponds to no redness/edema; a 4 on the Draize scale corresponds to severe redness/edema. On the 0-10 pain scale, 0 = No pain at all, 5 = Moderate pain, 10 =Severe or unbearable pain.	At baseline (before application), Day 3 PM, Day 6 PM, Day 9 PM, Day 12 PM
Axillary skin microbiome assessment via swab (qPCR to assess change in Staphylococcus genus)	Axillary skin swabs are sequenced via qPCR to assess change in the Staphylococcus genus, a key resident of the axillary microbiome.	At baseline (Day 1 AM), Day 3 AM, Day 6 AM, Day 9 AM, and Day 12 AM

Collaborators and Investigators

• Sponsor: Kingdom
• Investigators: Principal Investigator: Aylesse Sordillo, PhD, Principal Scientist at Kingdom

Study record dates

Study Major Dates

• Study Start (Actual): April 16, 2026
• Primary Completion (Actual): May 4, 2026
• Study Completion (Actual): May 4, 2026

Study Registration Dates

• First Submitted: April 17, 2026
• First Submitted That Met QC Criteria: April 17, 2026
• First Posted (Actual): April 23, 2026

Study Record Updates

• Last Update Posted (Actual): May 11, 2026
• Last Update Submitted That Met QC Criteria: May 6, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Body Odor; Deodorant
• Additional Relevant MeSH Terms: Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Body Odor
• Other Study ID Numbers: NOBO105A03

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: No IPD will be shared.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No