Treatment of Histamine Intolerance Using Probiotic Intervention

Treatment of Histamine Intolerance Using Probiotic Intervention - a Randomized Controlled Trial in Adults With Clinical Signs of Histamine Intolerance

The goal of this clinical trial is to learn if a probiotic product can lower symptoms in adults with histamine intolerance. Histamine intolerance can cause stomach and bowel problems as well as symptoms such as flushing, itching, headaches, and dizziness. The study will also learn how safe and well tolerated the probiotic is.

The main questions this study aims to answer are:

Does the probiotic lower digestive symptoms linked to histamine intolerance?

Does it lower other common symptoms, such as flushing, itching, headaches, or dizziness?

Researchers will compare the probiotic to a placebo. A placebo is a look-alike powder that contains no active bacteria. This will help determine whether the probiotic works better than no treatment.

Participants will:

Take either the probiotic or the placebo once a day for four weeks

Visit the study center for screening and two study visits

Answer symptom questionnaires

Provide blood samples and urine samples

The study is for adults with symptoms of histamine intolerance. Participation is voluntary, and participants can stop taking part at any time.

Study Overview

• Status: Completed
• Conditions: Histamin Intolerance
• Intervention / Treatment: Dietary supplement: Probio Histamed®, a multi-species probiotic preparation containing Bifid. breve, Bifid. lactis, Bifid. infantis, Bifid. longum, Lact. gasseri, and Lact. rhamnosus (5 x 10⁹ CFU per day); Other: Placebo Control

• Study Type: Interventional
• Enrollment (Actual): 54
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Germany
  • Stuttgart, Germany, 70599
    • Zentrum für klinische Ernährung Stuttgart

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Signed consent form
• Symptoms of histamine intolerance (based on medical history)
• DAO < 10 U/mL
• Age 18-70 years
• Willingness to refrain from changing eating habits and physical activity during the study
• Sufficient understanding of the German language and sufficient mental state to understand information and instructions related to the study

Exclusion Criteria:

• Lactose intolerance
• Fructose malabsorption
• Helicobacter pylori infection
• Celiac disease
• Chronic inflammatory bowel disease
• Food allergy with gastrointestinal manifestation
• Mastocytosis
• Use of antihistamines
• Other gastrointestinal diseases or use of gastrointestinal medications, as determined by the investigator
• (Planned) change in current medication, as determined by the investigator
• Pregnancy and breastfeeding
• Inability to take the investigational drug orally
• Intolerance to the investigational drug
• Admission to a clinic or similar facility due to official or court order
• Participation in another clinical trial (currently or within the last 30 days prior to study start)
• A health condition or regular medication use that, in the opinion of the investigator, does not allow participation in the study or the evaluation of study parameters or the consumption of the investigational drug (individual decision)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intervention; Participants receive Probio Histamed® (Lactopia GmbH), a multi-species probiotic preparation containing Bifidobacterium breve, Bifidobacterium lactis, Bifidobacterium infantis, Bifidobacterium longum, Lactobacillus gasseri, and Lactobacillus rhamnosus (total dose 5 × 10⁹ CFU per day). The product is administered as a powder (2 g per day) dissolved in a cold or warm beverage and taken once daily before a meal for four weeks.	Dietary supplement: Probio Histamed®, a multi-species probiotic preparation containing Bifid. breve, Bifid. lactis, Bifid. infantis, Bifid. longum, Lact. gasseri, and Lact. rhamnosus (5 x 10⁹ CFU per day); Multi-species probiotic preparation containing Bifidobacterium breve, Bifidobacterium lactis, Bifidobacterium infantis, Bifidobacterium longum, Lactobacillus gasseri, and Lactobacillus rhamnosus (total dose 5 × 10⁹ CFU per day). The product is administered as a powder (2 g per day) dissolved in a cold or warm beverage and taken once daily before a meal for four weeks.
Placebo Comparator: Control; Participants receive a placebo powder containing maltodextrin, identical in appearance and administration to the probiotic product. The placebo is administered as 2 g per day dissolved in a cold or warm beverage and taken once daily before a meal for four weeks.	Other: Placebo Control; maltodextrin

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Irritable bowel severity scoring system (IBS-SSS)	Chang of total score of IBS-SSS, a score ranging from 0 to 500. High values mean high gastrointestinal symptoms.	From baseline to the end of the study (4 weeks)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Facial flushing	Facial flushing is measured on a visual analogue scale ranging from 0 to 100 with higher values meaning more pronounced symptoms.	From baseline to the end of the study (4 weeks)
Itching	Itching is measured on a visual analogue scale ranging from 0 to 100 with higher values meaning more pronounced symptoms.	From baseline to the end of the study (4 weeks)
Headache	Headache is measured on a visual analogue scale ranging from 0 to 100 with higher values meaning more pronounced symptoms.	From baseline to the end of the study (4 weeks)
Dizziness	Dizziness is measured on a visual analogue scale ranging from 0 to 100 with higher values meaning more pronounced symptoms.	From baseline to the end of the study (4 weeks)

Other Outcome Measures

Outcome Measure	Time Frame
Concentration of Diaminooxidase in capillary blood	From baseline to the end of the study (4 weeks)
Concentration of Methylhistamine in urine	From baseline to the end of the study (4 weeks)

Collaborators and Investigators

• Sponsor: University of Hohenheim
• Collaborators: Lactopia GmbH, An der Römerbrücke 16, 66121 Saarbrücken, Germany

Study record dates

Study Major Dates

• Study Start (Actual): May 2, 2024
• Primary Completion (Actual): July 25, 2025
• Study Completion (Actual): July 25, 2025

Study Registration Dates

• First Submitted: January 23, 2026
• First Submitted That Met QC Criteria: February 2, 2026
• First Posted (Actual): February 9, 2026

Study Record Updates

• Last Update Posted (Actual): February 9, 2026
• Last Update Submitted That Met QC Criteria: February 2, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Probiotics; microbiome; gut health; Digestive symptoms
• Other Study ID Numbers: ZKES-HistaProbi-2023

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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