Asthma BronchialeNCT07053956
Impact of Chewing Gum on FeNO Levels in Patients With Bronchial Asthma
A study testing Chewing Gum in people with Asthma Bronchiale and FeNO, run by RWTH Aachen University at 2 sites in Germany.
Trial summary
The aim of the study is to investigate the influence of chewing gum consumption on FeNO levels in asthma patients in order to avoid systematic errors in treatment decisions. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Asthma Bronchiale, FeNO, Chewing Gum
- What is being tested?
- Chewing Gum
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 30 participants
- Where
- 2 sitesGermany
- Study dates
- 1 Aug 2025to 23 Dec 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- have known bronchial asthma with a FeNO level ≥25 ppb at regular medical checkups
- are of legal age
- are mentally and physically capable of understanding the significance and scope of the study and obeying the instructions of study personnel
- are legally competent and have signed the informed consent form.
Who cannot join
- Current or past medically relevant illness or treatment that could impact the evaluability of the study.
- FeNO levels < 25 ppb
- Medical contraindications to conducting FeNO measurements
- Expected unwillingness to actively participate in study-related measures.
- Known allergies or intolerances to the contents of chewing gum
- Smoking, alcohol consumption, mouthwash use, chewing gum/candy/lettuce/spinach/kale/beetroot/radish/sausage consumption, or exercise on the day of the study.
Trial locations and contacts
2 sites in 1 country.
Germany2 sites
University Hospital Aachen
Aachen, Aachen, 52074
Department of Pneumology and Intensive Care Medicine, RWTH Aachen University Hospital
Aachen, North Rhine-Westphalia, 52074
About this study
The aim of the study is to investigate the influence of chewing gum consumption on FeNO levels in asthma patients in order to avoid systematic errors in treatment decisions.
Read the detailed description
FeNO measurement is a non-invasive, available measure both for the diagnostic workup of patients with suspected bronchial asthma and for therapy management after a confirmed diagnosis. In patients with bronchial asthma, FeNO is a biomarker of airway inflammation. The recommended lower FeNO limits of the American Thoracic Society (ATS) are < 25 ppb in adults. A significantly elevated FeNO level (≥ 50 ppb), especially in the presence of increased blood eosinophil counts (≥ 300/µl), indicates an increased risk of exacerbation. Furthermore, patients with elevated FeNO levels are generally (inhalative cortison treatment; ICS) responsive. Conversely, elevated FeNO levels (especially FeNO levels > 50 ppb) during ICS therapy, despite clinical stability, argue against a reduction in the ICS dose.
Elevated FeNO levels during ICS therapy can occur due to poor treatment adherence. However, persistently elevated FeNO levels despite ICS therapy can also indicate inflammation in the airways that does not respond to further increases in the ICS dose. In summary, measuring airway inflammation using FeNO is an important component in the diagnosis and management of asthma.
It is already known that acute tobacco smoke exposure lowers FeNO levels in patients with asthma. Furthermore, FeNO levels are strongly influenced by factors such as infections, stress, or exposure to pollutants. Food containing nitrates (salad, sausage) can increase FeNO levels. Our patients are informed about these known factors so that they can avoid exposure prior to their medical consultation and examination. Conversely, it is suspected that chewing gum, which influences the oral flora, may lower FeNO levels, which would lead to false-negative FeNO levels and thus potentially prevent better diagnosis and treatment of asthma. However, to the best of our knowledge no study has yet examined the influence of chewing gum on FeNO levels.
Hence, the aim of the study is to investigate the influence of chewing gum consumption on FeNO levels in asthma patients in order to avoid systematic errors in treatment decisions.
Patients admitted to our outpatient clinic for bronchial asthma undergo regular FeNO measurements. If the value is ≥ 25 ppb (elevated), the patients are randomized into two groups after obtaining their consent. In the control group, a FeNO measurement is performed again after 15 minutes. In the second group, the FeNO measurement is measured again after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum. The following data are then collected and documented from the patients: age, gender, height, weight, smoking status, current medication, other illnesses, whole body lung function test, and laboratory tests (eosinophils, IgE). Participation in the study will not change the course of the patient's stay in our clinic.
- Conditions
- Asthma Bronchiale, FeNO, Chewing Gum
- Being tested
- Chewing Gum
- Keywords
- Asthma bronchiale, FeNO, Chewing Gum
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Chewing GumOther
Patients admitted to our outpatient clinic for bronchial asthma undergo regular FeNO measurements. If the value is ≥ 25 ppb (elevated), the patients are randomized into two groups after obtaining their consent. In the control group, a FeNO measurement is performed again after 15 minutes. In the second group, the FeNO measurement is measured again after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum. The following data are then collected and documented from the patients: age, gender, height, weight, smoking status, current medication, other illnesses, whole body lung function test, and laboratory tests (eosinophils, IgE). Participation in the study will not change the course of the patient's stay in our clinic.
| Study group | Role | What they receive |
|---|---|---|
| Chewing gum arm | Active comparator | Patients admitted to our outpatient clinic for bronchial asthma undergo regular FeNO measurements. If the value is ≥ 25 ppb (elevated), the patients are randomized into two groups after obtaining their consent. In the control group, a FeNO measurement is performed again after 15 minutes. In the second group, the FeNO measurement is measured again after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum. The following data are then collected and documented from the patients: age, gender, height, weight, smoking status, current medication, other illnesses, whole body lung function test, and laboratory tests (eosinophils, IgE). Participation in the study will not change the course of the patient's stay in our clinic. Receives: Other: Chewing Gum |
| Control arm | Sham comparator | Patients admitted to our outpatient clinic for bronchial asthma undergo regular FeNO measurements. If the value is ≥ 25 ppb (elevated), the patients are randomized into two groups after obtaining their consent. In the control group, a FeNO measurement is performed again after 15 minutes. In the second group, the FeNO measurement is measured again after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum. The following data are then collected and documented from the patients: age, gender, height, weight, smoking status, current medication, other illnesses, whole body lung function test, and laboratory tests (eosinophils, IgE). Participation in the study will not change the course of the patient's stay in our clinic. Receives: Other: Chewing Gum |
What is being measured
The primary outcome is the main question the study is designed to answer.
FeNO measurement after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum
FeNO measurement is measured again after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum
Measured: 15 Minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jul 2025
- Study start1 Aug 2025
- Primary completion17 Dec 2025
- Study completion23 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Asthma BronchialeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Factorial
- Model description
- Single-center interventional randomized case-controlled study
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- RWTH Aachen University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jens Spießhöfer, RWTH Aachen University
- Investigators
- Dr. Maria Aetou Aetou, Principal investigator, RWTH Aachen University HospitalProfessor Michael Dreher Dreher, Study director, RWTH Aachen University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07053956
- Sponsor's protocol ID
- 24-515
- Status last verified
- Dec 2025
- First submitted
- 27 Jun 2025
- Last updated
- 30 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Upon reasonable request study protocol and SAP and data will be shared in pseudonomyzed form
Study at a glance
From the registry record, last updated by the sponsor on 30 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Chewing Gum on FeNO Levels in Patients With Bronchial Asthma
- ClinicalTrials.gov ID
- NCT07053956
- Acronym / sponsor ID
- 24-515
- Conditions
- Asthma Bronchiale, FeNO, Chewing Gum
- Keywords
- Asthma bronchiale, FeNO, Chewing Gum
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- RWTH Aachen UniversityUniversity, hospital or other
- Study start
- 1 Aug 2025 (actual)
- Primary completion
- 17 Dec 2025 (actual)
- Study completion
- 23 Dec 2025 (actual)
- First posted
- 8 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim of the study is to investigate the influence of chewing gum consumption on FeNO levels in asthma patients in order to avoid systematic errors in treatment decisions.
Detailed description
FeNO measurement is a non-invasive, available measure both for the diagnostic workup of patients with suspected bronchial asthma and for therapy management after a confirmed diagnosis. In patients with bronchial asthma, FeNO is a biomarker of airway inflammation. The recommended lower FeNO limits of the American Thoracic Society (ATS) are < 25 ppb in adults. A significantly elevated FeNO level (≥ 50 ppb), especially in the presence of increased blood eosinophil counts (≥ 300/µl), indicates an increased risk of exacerbation. Furthermore, patients with elevated FeNO levels are generally (inhalative cortison treatment; ICS) responsive. Conversely, elevated FeNO levels (especially FeNO levels > 50 ppb) during ICS therapy, despite clinical stability, argue against a reduction in the ICS dose.
Elevated FeNO levels during ICS therapy can occur due to poor treatment adherence. However, persistently elevated FeNO levels despite ICS therapy can also indicate inflammation in the airways that does not respond to further increases in the ICS dose. In summary, measuring airway inflammation using FeNO is an important component in the diagnosis and management of asthma.
It is already known that acute tobacco smoke exposure lowers FeNO levels in patients with asthma. Furthermore, FeNO levels are strongly influenced by factors such as infections, stress, or exposure to pollutants. Food containing nitrates (salad, sausage) can increase FeNO levels. Our patients are informed about these known factors so that they can avoid exposure prior to their medical consultation and examination. Conversely, it is suspected that chewing gum, which influences the oral flora, may lower FeNO levels, which would lead to false-negative FeNO levels and thus potentially prevent better diagnosis and treatment of asthma. However, to the best of our knowledge no study has yet examined the influence of chewing gum on FeNO levels.
Hence, the aim of the study is to investigate the influence of chewing gum consumption on FeNO levels in asthma patients in order to avoid systematic errors in treatment decisions.
Patients admitted to our outpatient clinic for bronchial asthma undergo regular FeNO measurements. If the value is ≥ 25 ppb (elevated), the patients are randomized into two groups after obtaining their consent. In the control group, a FeNO measurement is performed again after 15 minutes. In the second group, the FeNO measurement is measured again after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum. The following data are then collected and documented from the patients: age, gender, height, weight, smoking status, current medication, other illnesses, whole body lung function test, and laboratory tests (eosinophils, IgE). Participation in the study will not change the course of the patient's stay in our clinic.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Single-center interventional randomized case-controlled study
| Arm | Type | Receives |
|---|---|---|
| Chewing gum arm | Active comparator | Other: Chewing GumPatients admitted to our outpatient clinic for bronchial asthma undergo regular FeNO measurements. If the value is ≥ 25 ppb (elevated), the patients are randomized into two groups after obtaining their consent. In the control group, a FeNO measurement is performed again after 15 minutes. In the second group, the FeNO measurement is measured again after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum. The following data are then collected and documented from the patients: age, gender, height, weight, smoking status, current medication, other illnesses, whole body lung function test, and laboratory tests (eosinophils, IgE). Participation in the study will not change the course of the patient's stay in our clinic. |
| Control arm | Sham comparator | Other: Chewing GumPatients admitted to our outpatient clinic for bronchial asthma undergo regular FeNO measurements. If the value is ≥ 25 ppb (elevated), the patients are randomized into two groups after obtaining their consent. In the control group, a FeNO measurement is performed again after 15 minutes. In the second group, the FeNO measurement is measured again after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum. The following data are then collected and documented from the patients: age, gender, height, weight, smoking status, current medication, other illnesses, whole body lung function test, and laboratory tests (eosinophils, IgE). Participation in the study will not change the course of the patient's stay in our clinic. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- have known bronchial asthma with a FeNO level ≥25 ppb at regular medical checkups
- are of legal age
- are mentally and physically capable of understanding the significance and scope of the study and obeying the instructions of study personnel
- are legally competent and have signed the informed consent form.
Key exclusion criteria (6 listed)
- Current or past medically relevant illness or treatment that could impact the evaluability of the study.
- FeNO levels < 25 ppb
- Medical contraindications to conducting FeNO measurements
- Expected unwillingness to actively participate in study-related measures.
- Known allergies or intolerances to the contents of chewing gum
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Chewing GumPatients admitted to our outpatient clinic for bronchial asthma undergo regular FeNO measurements. If the value is ≥ 25 ppb (elevated), the patients are randomized into two groups after obtaining their consent. In the control group, a FeNO measurement is performed again after 15 minutes. In the second group, the FeNO measurement is measured again after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum. The following data are then collected and documented from the patients: age, gender, height, weight, smoking status, current medication, other illnesses, whole body lung function test, and laboratory tests (eosinophils, IgE). Participation in the study will not change the course of the patient's stay in our clinic. | Other | Chewing gum arm, Control arm |
Primary outcome
FeNO measurement after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum
Time frame: 15 Minutes
FeNO measurement is measured again after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Dec 2025.
- Individual participant dataSharing planned: Yes. Upon reasonable request study protocol and SAP and data will be shared in pseudonomyzed form
Related trials for Asthma Bronchiale
Not yet recruiting
Virtual Breathing Intervention for Enhancing Asthma-related Quality of Life - A Randomized Controlled Trial
Asthma Bronchiale
Active, not recruiting
Digital Implementation of the German S3 Clinical Practice Guideline for Multimorbidity
Asthma Bronchiale, Breast Neoplasms
RecruitingObservational study
Fixed Triple Inhaled Combination in Asthmatic Patients in a Real-life Setting (STRENGTH)
Asthma, Asthma Patients
Active, not recruiting
Expand Pulmonary Rehabilitation to Other Chronic Respiratory Diseases Than COPD
Idiopathic Pulmonary Fibrosis (IPF), Sarcoidosis
Not yet recruitingObservational study
Bronchodilator Response in COPD and Asthma: Correlation Between Spirometry, IOS Indices, and Dyspnea Relief
Asthma Bronchiale, COPD
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Dr. Maria Aetou Aetou principal investigator
RWTH Aachen University Hospital
Professor Michael Dreher Dreher study director
RWTH Aachen University Hospital
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Chewing Gum in people with Asthma Bronchiale and FeNO, run by RWTH Aachen University at 2 sites in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 30 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
FeNO measurement after 15 minutes of consuming sugar-free, antioxidant-containing chewing gum (time frame: 15 Minutes). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Dec 2025.