Respiratory and gastrointestinal infections remain a particularly urgent problem in children attending groups of children. Thus, in children attending kindergartens, the risk of developing respiratory and gastrointestinal infections is 1.5 to 3.0 times higher than that of "domestic" children. It is believed that the use of probiotics can improve the immune properties of the macro-organism, especially resistance to infectious diseases of the gastrointestinal tract.

In a multicenter, prospective, randomized, double-blind, placebo-controlled study in Israel, 201 healthy children aged 4 to 10 months were randomized to receive infant formulas fortified with Lactobacillus reuteri (group 1, 68 children), the same mixture, but enriched with B Bifidobacterium lactis BB-12 (group 2, 73 children), or just a milk formula (placebo) - group 3, 60 children. In the 12 weeks following study participation, children receiving probiotics reported significantly fewer episodes of fever (0.11 vs 0.27 vs 0 , 41, respectively, p = 0.001; BB-12 and L. reuteri vs placebo) and the duration of the fever was shorter (0.17 vs 0.86 vs 0.83, respectively, p = 0.001; L. reuteri vs BB-12 and placebo). In the placebo group, a significantly higher number of episodes of diarrhea was observed (0.02 vs 0.13 vs 0.31, respectively, p = 0.001 ; L. reuteri vs BB-12 and placebo) and the duration of diarrhea was significantly higher in the placebo group (0.15 vs 0.37 vs 0.59, respectively, p = 0.001; L. reuteri vs BB-12 and placebo) (average per child ). Relatively fewer clinic visits (0.23 vs 0.52 vs 0.55, were recorded in the group of patients receiving lactobacilli, compared to the group BB-12 and control p = 0.002), a significantly lower number of days absent from the children's center (0.14 vs 0.41 vs 0, 43, p = 0.015) and a significantly lower frequency of antibiotic appointments (0.06 vs 0.21 vs 0.19, p = 0.037). The frequency of respiratory infections (0.17 vs 0.25 vs 0.24) and the number of days of illness (0.38 vs 0.68 vs 0.6) did not differ significantly between the groups, however, there was a tendency for a lower incidence and duration in the group receiving L.reuteri .

Thus, the simple use of a mixture of milk enriched with lactobacilli can considerably reduce the incidence of gastrointestinal infections in children.