Preventive Effect of Cow’s Milk Fermented with Lactobacillus paracasei CBA L74 on Common Infectious Diseases in Children: A Multicenter Randomized Controlled Trial

This was a multicenter randomized controlled trial in healthy children aged 12 to 48 months attending day care or preschool in urban Italy. Seventy-three children were randomized to the active product and 73 to control, with 66 and 60 completers, respectively.

Children in the active arm received 7 g/day of cow's skim milk fermented with Lactobacillus paracasei CBA L74 by mouth once daily for 3 months, diluted in up to 150 mL of cow's milk or water. The product was a fermented milk preparation containing inactivated bacteria rather than live organisms.

The fermented milk reduced common infectious diseases and was well tolerated, with no adverse events recorded. In intention-to-treat analysis, common infectious disease occurred in 60% of the active group versus 83% of controls (p < 0.01; ARD -23%, 95% CI -37% to -9%), and in per-protocol analysis 18% versus 40% (p < 0.01; ARD -22%, 95% CI -37% to -6%). Upper respiratory tract infection and acute gastroenteritis were also lower in the active group, and fewer children used at least one medication course (45% vs 65%); one child in the control group required hospitalization. The intervention was also associated with significant changes in α-defensin, β-defensin, LL-37, and sIgA at 3 months.

The trial had a relatively small sample size, and follow-up lasted only 3 months during a single winter season. Generalizability is limited to healthy children from urban Italian daycare or preschool settings, and some baseline characteristics were not reported separately by arm.