Hypothesis: Use of Bifidobacterium animalis subsp. lactis can effectively prevent common infections (gastrointestinal and respiratory) in healthy children who attend day care centre

This study is a prospective, randomized, double blind, placebo- controlled parallel study in healthy children attending day care centers.

The study will investigate the effect of supplementation with the probiotic strain Bifidobacterium animalis subsp. lactis on the incidence and duration of gastrointestinal and respiratory infections and absence from day care due to infections.

The test product is a sachet containing 1 gram of powder. The test product will contain minimum 1 billion CFU (colony forming units) of probiotic per serving. The placebo product is an identical product except for the absence of probiotics.

The study includes 3 months (90 days) of intervention period. The study product will be consumed daily in the evening together with a meal.

The consumption of the study products will be taken under the surveillance of the parents.

During the entire intervention period the subjects are not allowed to consume any probiotic products other than the study products supplied to them by the study personnel.

Data on infections will be recorded in a diary, filled in and administered by the parents and diary recorded by referring physician (on-call log).

All infections are to be diagnosed by the local physician. The incidence of infections will be analyzed based on the information recorded in the diaries (parent's & physician's).

Inclusion Criteria:

• Healthy children attending day care at kindergartens located in the Zagreb's city centre
• Age from 1 year to 7 years
• Attendance at daycare centers: > 3 days per week
• Signed informed consent by the parents

Exclusion Criteria:

• Immunodeficiency
• Receiving probiotic and /or prebiotic products prior to enrolment (2 weeks prior to study start)
• Neoplasms
• Severe chronic disorders