The study aims to explore whether prophylactic dietary supplementation with prebiotic inulin-type fructans is able to influence the intestinal microbiota and the frequency of infectious disease episodes in kindergarten children during a winter period.

Inclusion Criteria:

• Subject is healthy at the time of pre-examination
• Subject is aged 3-6 years at the time of pre-examination
• Subject attends a kindergarten at the time of pre-examination

Exclusion Criteria:

• congenital disease or malformation influencing the gastrointestinal System
• children with congenital or acquired immunodeficiency
• children with food intolerance, food allergy or metabolic disorder requiring special diet
• children who regularly (more than 3 times per week) consumed products or food supplements containing prebiotics or probiotics
• children who consumed antibiotics or laxatives within 14 days
• children who had any infectious disease within 14 days at the time of pre-examination