This study is a randomized, placebo-controlled, single-masked (blinded), post-marketing clinical study of a drug Lactobacillus Reuteri NCIMB 30351 drops in functional disorders of gastrointestinal tract and skin symptoms of food allergies in children between the ages of one and four months inclusive.

The aim of the study is to assess clinical effects of probiotics Lactobacillus Reuteri NCIMB 30351 drops on the symptoms of infantile colic, constipation, diarrhea, gastroesophageal reflux, atopic dermatitis/eczema in full-term newborns during the first months of life, laboratory parameters of microbiome will also be assessed.

A prospective study comparing two treatment groups:

Group 1 (treatment group) - 60 infants. Group 2 (control group) - 30 infants, placebo. The study drug will be taken in 1 time per day within 25 days. Allowed symptomatic therapy includes defoamers (simethicone-based preparations), carminative preparations (dill water (fennel)), etc.

Inclusion Criteria:

1. Parents / guardians speak Russian, understand the essence of study, are informed about the purpose of the study, understand their rights and signed informed consent form (ICF).
2. Vaginal delivery.
3. Full-term newborn.
4. Age at the time of the signing of informed consent form 1-4 months 28 days.
5. Breast- and formula-fed infants.
6. Colic , constipation , diarrhea, regurgitation (single symptom or combination of several symptoms).
7. Infant does not have other deviations in health, which would require the appointment of a specialized diet
8. Parents / guardians can and ready to regularly fill out the proposed diary form.

Exclusion Criteria:

1. Born by Cesarean section.
2. Premature newborn.
3. Congenital abnormalities or other clinical manifestations that may interfere with the study.
4. Lactase food supplements.
5. Other probiotic drugs, antibiotics, enteric antiseptics, antifungal and antiprotozoal drugs.