In this study the intestinal microbiome and metabolic profiles of patients with inflammatory bowel disease will be determined upon probiotic intervention.

Inclusion Criteria:

• Signed informed consent
• Diagnosis of inflammatory bowel disease according to actual guidelines (Porto Criteria)
• General good health
• Ability to understand and follow study procedures and understand informed consent
• Age 5 -18 years
• No probiotic therapy 4 weeks before entering into the study.

Exclusion Criteria:

• Participation in other clinical studies interfering with study procedures.
• Inability or contraindications to undergo the investigated intervention
• Severe or acute flare of disease (for UC PUCAI score ≥35, for CD wPCDAI >40)
• Treatment escalation within last 4 weeks for uncontrolled disease.
• Antibiotic or probiotic therapy within the last 4 weeks.

Individual participant data that underlie the results reported, after deidentification

Immediately following publication, ending 36 months following article publication

Investigators whose proposed use of the data has been approved by an independent review committe identified for this purpose