Kinetic Study Of Supplementation With The Enzyme Diamine Oxidase In Patients With Histamine Intolerance

NCT07006558 | Completed

• 1 other identifier: HCB/2023/0345
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

The present study was conducted to assess the safety and tolerability of five ascending doses of plant-based DAO enzyme supplement in subjects with symptoms of histamine intolerance.

Conditions

Histamine Intolerance

Keywords

diamine oxidase; histamine intolerance; safety; tolerability; pea sprout; diamine oxidase supplementation

Outcome Measures

Primary Outcomes (3)

• Number of participants with treatment-related adverse events (AEs)

  Number of participants with treatment-related adverse events (AEs) experienced during the supplementation, assessed through a questionnaire.

  At "day 14", "day 28", "day 42", "day 56" and "day 70".

• Type of adverse effects (AEs)

  Symptoms of adverse effects (AEs) experienced during the supplementation, assessed through a questionnaire including the different body systems: gastrointestinal, CNS, respiratory, dermatological).

  At "day 14", "day 28", "day 42", "day 56" and "day 70".

• DAO enzymatic activity in serum using a radioextraction immunoassay

  DAO enzymatic activity in serum (mU/mL) using a radioextraction immunoassay (REA-3H, Laboratorio Echevarne, Barcelona, Spain).

  At "baseline or day 1", "day 14", "day 28", "day 42", "day 56" and "day 70".

Secondary Outcomes (38)

• Dietary habits

  At "baseline or day 1", "day 14", "day 28", "day 42", "day 56" and "day 70".

• Histamine in 24h urine

  At "baseline or day 1", "day 14", "day 28", "day 42", "day 56" and "day 70".

• Hemogram

  At "baseline or day 1", "day 14", "day 28", "day 42", "day 56" and "day 70".

• Glycemia

  At "baseline or day 1", "day 14", "day 28", "day 42", "day 56" and "day 70".

• HbA1c

  At "baseline or day 1", "day 14", "day 28", "day 42", "day 56" and "day 70".

Study Arms (5)

Phase 1 (4.2 mg adiDAO®Veg)

EXPERIMENTAL

Patients receive the standard dose of 4.2 mg of adiDAO®Veg three times a day for a period of 2 weeks.

Dietary Supplement: Diamino Oxidase

Phase 2 (8.4 mg adiDAO®Veg)

EXPERIMENTAL

If, after phase 1, the measured DAO enzyme activity levels remain unnormalized, supplementation is continued for a further 2 weeks doubling the dose to 8.4 mg of adiDAO®Veg three times a day.

Dietary Supplement: Diamino Oxidase

Phase 3 (16.8 mg adiDAO®Veg)

EXPERIMENTAL

If, after phase 2, the measured DAO enzyme activity levels remain unnormalized, supplementation is continued for a further 2 weeks doubling the dose to 16.8 mg of adiDAO®Veg three times a day.

Dietary Supplement: Diamino Oxidase

Phase 4 (33.6 mg adiDAO®Veg)

EXPERIMENTAL

If, after phase 3, the measured DAO enzyme activity levels remain unnormalized, supplementation is continued for a further 2 weeks doubling the dose to 33.6 mg of adiDAO®Veg three times a day.

Dietary Supplement: Diamino Oxidase

Phase 5 (67.2 mg adiDAO®Veg)

EXPERIMENTAL

If, after phase 4, the measured DAO enzyme activity levels remain unnormalized, supplementation is continued for a further 2 weeks doubling the dose to 67.2 mg of adiDAO®Veg three times a day.

Dietary Supplement: Diamino Oxidase

Interventions

Diamino Oxidase DIETARY_SUPPLEMENT

The investigational product is a dehydrated power of DAO enzyme from green pea (Pisum sativum L.) sprouts (adiDAO®Veg, DR Healthcare, S.L.U., Barcelona, Spain), with an enzymatic activity \> 298 mU/g (\> 14,500 kHDU/g).

Phase 1 (4.2 mg adiDAO®Veg); Phase 2 (8.4 mg adiDAO®Veg); Phase 3 (16.8 mg adiDAO®Veg); Phase 4 (33.6 mg adiDAO®Veg); Phase 5 (67.2 mg adiDAO®Veg)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Recent history of 2 or more symptoms associated to histamine intolerance.
• Altered activity of plasmatic DAO enzyme and/or at least one genetic variants linked to DAO deficiency (rs10156191, rs1049742, rs1049793, rs2052129).
• Not having started a dietary intervention (low histamine diet or DAO supplementation) before the start of this study.

You may not qualify if:

• Treatment with low-histamine diet and/or dietary DAO enzyme supplementation prior to the study.
• Pharmacological treatment with antibiotics or probiotic supplements within the last month prior to enrollment.
• Breast-feeding or pregnant women.
• Inability to provide informed consent.

Sponsors & Collaborators

• AB Biotek: lead
• Hospital Clinic of Barcelona: collaborator

Study Sites (1)

Hospital Clinic de Barcelona

Barcelona, Barcelona, 08036, Spain

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: After signing the informed consent, participants start taking the standard dose of 4.2 mg of adiDAO®Veg three times a day for a period of 2 weeks (phase 1). If the measured DAO enzyme activity levels remain unnormalized, supplementation is continued for a further 2 weeks doubling the dose (8.4 mg) (phase 2), and repeating the process of doubling doses (16.8 mg) (phase 3), 33.6 mg (phase 4), and 67.2 mg (phase 5).

Study Record Dates

• First Submitted: May 19, 2025
• First Posted: June 5, 2025
• Study Start: June 23, 2023
• Primary Completion: August 5, 2024
• Study Completion: August 5, 2024
• Last Updated: June 18, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will share

Locations

ES (1)