The aim of the study is to estimate the effect of a probiotic dairy drink on occurrence and duration of AAD and gastrointestinal symptoms during Helicobacter pylori (Hp) eradication therapy and during 4 weeks thereafter and calculating the sample size for a confirmatory study.

Helicobacter p. positive subjects aged ≥18 years with an indication for Helicobacter pylori (Hp) eradication recommended by a gastroenterologist should be included in the study. Subjects should be willing to consume 2 servings of the study product per day for 6 weeks, and to undergo an Hp eradication therapy for 14 days starting with the consumption period.

Inclusion Criteria:

• Individuals, both genders, aged ≥ 18 y
• Helicobacter p. infected individuals, to which eradication therapy has been recommended by gastroenterologists
• Willingness to undergo the Helicobacter p. eradication therapy
• Willingness to abstain from food and supplements containing probiotics, prebiotics and fermented products except the study product
• Written informed consent

Exclusion Criteria:

• Subjects currently enrolled in another interventional trial

• subjects having finished another interventional trial within the last 4 weeks before inclusion

• incapacity to comply with the study protocol

• allergy or hypersensitivity to any component of the test product (allergy against milk protein)

• allergy or hypersensitivity to any component of the eradication therapy (e.g. penicillin allergy)

• acute GIT infections

• chronic inflammatory bowel diseases (IBD)

• irritable bowel syndrome (IBS)

• any episode of diarrhea according to WHO criteria during the last 4 weeks before inclusion

• history of lactose intolerance

• severe chronic disease (cancer, malabsorption, malnutrition, severe chronic inflammatory diseases (except chronic gastritis), renal, hepatic or cardiac diseases, artificial cardiac valve, COPD, respiratory insufficiency)

• history of active or persistent hepatitis B and C

• known congenital, acquired or iatrogenic immunodeficiency (e.g. HIV, chemotherapy, immunosuppression)

• systemic treatment with antibiotics during the last 4 weeks before inclusion

• systemic treatment likely influencing absorption, metabolism and excretion of food ingredients (metoclopramide, laxatives, body weight management and/or medication etc.)

• systemic treatment likely interfering or influencing effectiveness of the eradication drugs used e.g. ergotamine, statins, clopidogrel

• regular medical treatment including OTC, which may have impact on the study aims (e.g. probiotics, antibiotic drugs, laxatives etc.)

• severe neurological, cognitive or psychiatric diseases

• surgery or intervention requiring general anaesthesia within 2 months before the study

• vegan

• eating disorders (e.g. anorexia, bulimia)

• present alcohol and drug abuse

• pregnancy or lactation

• legal incapacity

• blood parameters:

  • Hb < 12 g/dL
  • liver transaminases (ALT, AST) > 2-fold increased
  • serum creatinine out of the normal range

• subjects who are scheduled to undergo hospitalization during the study period