The objective of this study is to determine an efficacy of the combination of L. rhamnosus 19070-2 (FloraActiveTM) and L. reuteri DSM 122460 (FloraActiveTM) in decreasing cry/fuss in infants aged 4 through 12 weeks with IC. The active group of infants will receive lactobacilli with vitamin D3 while the control group will receive vitamin D3 2 times daily as oil suspension for 28 days. Duration of infant fuss/cry will be measured at baseline and at the end of intervention to define a difference between the groups

There is accumulating interest in role of lactobacilli in decreasing cry and fuss in infant colic, the condition that affects around 1 of 4-5 infants. The interest for dietary supplementation has been evoked by a line of earlier studies, indicating that infants with colic had an increased number of gas-forming E.coli in the intestines and potential interference between lactobacilli and E.coli. Systematic review of evidence, based on the 6 randomized controlled dietary studies, conducted in Italy, Poland, Australia, Canada, and Finland, has concluded of the decrease of the mean time cry of infant by -55 minutes a day after the 3 weeks dietary course with lactobacilli . In the mentioned studies most commonly used lactobacilli were L. reuteri, however, the effect of combination of L. reuteri with other lactobacilli remains unknown.

Inclusion Criteria:

1. Informed consent form signed by both parents.
2. Gender: males and females;
3. Age: 4 -12 weeks;
4. Infant colic, defined as cry/fussing lasting > 3 h, occurring > 3 d for 7 days;
5. Gestational age 37-42 weeks;
6. Birth weight 2,500-4,200 g;
7. Stated availability throughout the study period;
8. Sated availability of mobile phone or phone with answering machine.

Exclusion Criteria:

1. Any formula feeding in any amount;
2. Failure to thrive (weight gain less than 100 grams per week as averaged from the birth weight to the weight at entry);
3. Current maternal smoking;
4. Known moderate or severe disease of any systems (neural, skeletal, muscular, cutaneous, gastrointestinal, respiratory, genital, urinary, immune);
5. Present intake of antibiotics by infant or mother;
6. Present intake of prebiotics or probiotics by infant or mother;
7. Difficulty of parents to comprehend study requirements as judged by the physician;
8. Suspected parental alcohol or drug addiction as judged by the physician.