CVIDNCT07844668
Microbiome, Dietary and Quality of Life Analysis of People Living With CVID Treated With or Without Immunoglobulins.
A study testing Diet in people with CVID and SPAD, run by Universitair Ziekenhuis Brussel at 2 sites in Belgium.
Trial summary
Our research group focusses on finding evidence-based diet strategies to overcome immune dysregulation either due to immune checkpoint inhibitors (ICI) or common variable immunodeficiency (CVID) (Figure 1). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- CVID, SPAD, Antibody Deficiency
- What is being tested?
- Diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 70 participants
- Where
- 2 sitesBelgium
- Study dates
- 15 Aug 2026to Sep 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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
- CVID diagnosis according to ESID criteria
- 18y or older
Who cannot join
- start of therapeutic doses of antibiotics < 30 days prior to inclusion
- start of an immunomodulator < 30 days prior to inclusion Patient excluded for the above reasons will be able to step in the study at a later timepoint (30 days after start of antibiotics of immunomodulators)
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium2 sites
Universitair ziekenhuis Brussel
Brussels, Brussels Capital, 1090
Universitair Ziekenhuis Brussel
Ninove, Belgie, 9400
About this study
Our research group focusses on finding evidence-based diet strategies to overcome immune dysregulation either due to immune checkpoint inhibitors (ICI) or common variable immunodeficiency (CVID) (Figure 1). CVID is an inborn error of immunity, which is defined, among other factors, by a low level of immunoglobulins, resulting in an increased risk of infections, auto-immune/inflammatory diseases, and cancer.
The gut microbiome (GM) plays a crucial role in maintaining immune homeostasis and modulating the host's innate and adaptive immune responses. Modulation of the GM can be achieved by dietary interventions that have been demonstrated to change the composition of the GM within 2 weeks (Oliver et al., 2021). The intake of more than 30 different plant products (vegetables, fruits, seeds and grains) on a weekly basis is associated with a more diverse microbiome in healthy adults (McDonald et al., 2018). Although direct proof of a link between diet and functioning of the immune system is lacking, it is striking that in a retrospective study, melanoma patients treated with immune checkpoint inhibitors (ICI) had a better overall survival when they consumed enough fibers without taking probiotics (Spencer et al., 2021). Currently, we have included 54 of 60 foreseen patients receiving ICI in an interventional study (FORX-01 (NCT05832606)) at our centre, providing them weekly with 30 different plants to be integrated in their diet (funded by Delhaize and FWO). The aim is to measure if the interventional group develops less immune-related adverse events (= side effects of ICI) by changing their GM.
Similarly, we hypothesize that introducing a fiber-rich diet in patients with CVID will result in a more diverse GM leading to a decrease in autoimmune disorders and infections and as such lead to an improvement of quality of life. To challenge this hypothesis, we plan to organize a similar diet trial, called KNIVES. To prepare this study, we will first perform an observational study to describe the microbiome of people with CVID (DELICIOUS) followed at UZ Brussel.
- Conditions
- CVID, SPAD, Antibody Deficiency
- Being tested
- Diet
- Keywords
- CVID, fiber-rich diet, spad, auto-immune
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DietOther
Participants receive individualized dietary counseling to increase their dietary fiber intake and follow a high-fiber diet according to the study protocol throughout the intervention period.
| Study group | Role | What they receive |
|---|---|---|
| CVID participants of Observational cohort | Other | Participants assigned to this arm will follow a high-fiber dietary intervention according to the study protocol. Clinical outcomes, gastrointestinal symptoms, dietary intake, and biological samples will be collected throughout the study to assess the effects of the intervention. Receives: Other: Diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Primary outcomes
To describe the gut microbiome of people living with CVID followed at UZ Brussel.
To perform microbiome analysis through metagenomics (depending on availability, pricing, and emerging literature).
To analyze one faecal sample of each participant at inclusion and additionally during infectious or autoinflammatory events.
To assess microbiome diversity and composition, including:
Alpha-diversity. Beta-diversity. Firmicutes/Bacteroidetes ratio (as a proximal marker for dysbiosis).
Abundance of specific short-chain fatty acid-producing genera, including:
Prevotella. Lactobacillaceae. Bifidobacteriaceae. Lachnospiraceae.
Measured: 1 year
Secondary outcomes (1)
Secondary outcome
- Dietary pattern assessment: Collection and analysis of 3-day food diaries at baseline according to Nubel, with focus on fiber intake.
- CVID characteristics assessment: Classification of patients based on infectious complications, dysimmune complications, and IgA deficiency status.
- Fatigue Severity Scale (Krupp et al., 1989).
- CVID_QoL questionnaire (Quinti et al., 2016).
- EQ-5D questionnaire.
- IBS Symptom Severity Scale.
- Rome PI-IBS Questionnaire.
- Rome IV Diagnostic Questionnaire for Adult Functional Gastrointestinal Disorders (R4DQ).
- Gastrointestinal Symptom Rating Scale (GSRS).
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Sep 2026
- Study start15 Aug 2026
- Primary completionAug 2028 (estimated)
- Study completionSep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for CVIDStudies of the same condition, open and under way.
- More trials run by Universitair Ziekenhuis BrusselThe sponsor's other registered studies.
- 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
- Supportive care
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 70 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Universitair Ziekenhuis Brussel
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07844668
- Sponsor's protocol ID
- DELICIOUS
- Status last verified
- Jul 2026
- First submitted
- 21 Sep 2026
- Last updated
- 28 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 28 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Microbiome, Dietary and Quality of Life Analysis of People Living With CVID Treated With or Without Immunoglobulins.
- ClinicalTrials.gov ID
- NCT07844668
- Acronym / sponsor ID
- DELICIOUS
- Conditions
- CVID, SPAD, Antibody Deficiency
- Keywords
- CVID, fiber-rich diet, spad, auto-immune
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 70 participants (estimated)
- Lead sponsor
- Universitair Ziekenhuis BrusselUniversity, hospital or other
- Study start
- 15 Aug 2026 (actual)
- Primary completion
- Aug 2028 (estimated)
- Study completion
- Sep 2028 (estimated)
- First posted
- 28 Sep 2026 (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.
Our research group focusses on finding evidence-based diet strategies to overcome immune dysregulation either due to immune checkpoint inhibitors (ICI) or common variable immunodeficiency (CVID) (Figure 1). CVID is an inborn error of immunity, which is defined, among other factors, by a low level of immunoglobulins, resulting in an increased risk of infections, auto-immune/inflammatory diseases, and cancer.
The gut microbiome (GM) plays a crucial role in maintaining immune homeostasis and modulating the host's innate and adaptive immune responses. Modulation of the GM can be achieved by dietary interventions that have been demonstrated to change the composition of the GM within 2 weeks (Oliver et al., 2021). The intake of more than 30 different plant products (vegetables, fruits, seeds and grains) on a weekly basis is associated with a more diverse microbiome in healthy adults (McDonald et al., 2018). Although direct proof of a link between diet and functioning of the immune system is lacking, it is striking that in a retrospective study, melanoma patients treated with immune checkpoint inhibitors (ICI) had a better overall survival when they consumed enough fibers without taking probiotics (Spencer et al., 2021). Currently, we have included 54 of 60 foreseen patients receiving ICI in an interventional study (FORX-01 (NCT05832606)) at our centre, providing them weekly with 30 different plants to be integrated in their diet (funded by Delhaize and FWO). The aim is to measure if the interventional group develops less immune-related adverse events (= side effects of ICI) by changing their GM.
Similarly, we hypothesize that introducing a fiber-rich diet in patients with CVID will result in a more diverse GM leading to a decrease in autoimmune disorders and infections and as such lead to an improvement of quality of life. To challenge this hypothesis, we plan to organize a similar diet trial, called KNIVES. To prepare this study, we will first perform an observational study to describe the microbiome of people with CVID (DELICIOUS) followed at UZ Brussel.
Study design
- Primary purpose
- Supportive care
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| CVID participants of Observational cohort | Other | Other: DietParticipants assigned to this arm will follow a high-fiber dietary intervention according to the study protocol. Clinical outcomes, gastrointestinal symptoms, dietary intake, and biological samples will be collected throughout the study to assess the effects of the intervention. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- CVID diagnosis according to ESID criteria
- 18y or older
Key exclusion criteria (2 listed)
- start of therapeutic doses of antibiotics < 30 days prior to inclusion
- start of an immunomodulator < 30 days prior to inclusion Patient excluded for the above reasons will be able to step in the study at a later timepoint (30 days after start of antibiotics of immunomodulators)
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 |
|---|---|---|
| DietParticipants receive individualized dietary counseling to increase their dietary fiber intake and follow a high-fiber diet according to the study protocol throughout the intervention period. | Other | CVID participants of Observational cohort |
Primary outcome
Primary outcomes
Time frame: 1 year
To describe the gut microbiome of people living with CVID followed at UZ Brussel. To perform microbiome analysis through metagenomics (depending on availability, pricing, and emerging literature). To analyze one faecal sample of each participant at inclusion and additionally during infectious or autoinflammatory events. To assess microbiome diversity and composition, including: Alpha-diversity. Beta-diversity. Firmicutes/Bacteroidetes ratio (as a proximal marker for dysbiosis). Abundance of specific short-chain fatty acid-producing genera, including: Prevotella. Lactobacillaceae. Bifidobacteriaceae. Lachnospiraceae.
1 secondary outcome
Secondary outcome
Time frame: 1 year
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Sep 2026.
- Individual participant dataSharing planned: No
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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.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Diet in people with CVID and SPAD, run by Universitair Ziekenhuis Brussel at 2 sites in Belgium.
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 2 inclusion and 2 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: enrolling by invitation, as of the sponsor's last update on 28 Sep 2026. 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 Belgium. 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. 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?
This study is still under way. Results are not available in the source record yet.
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?
Primary outcomes (time frame: 1 year). 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 28 Sep 2026.