By David Liu, PHD

Monday Sept 3, 2012 (foodconsumer.org) -- Breast milk with higher levels of protective immunoglobulin (Ig) A (IgA) is the best measure against rotavirus-induced diarrhea in infants.  A new study in Journal of Pediatric Gastroenterology and Nutrition suggests that taking probiotics boosts the immunoprotective effect of breast milk against the viral infection in infants.

Y. Kadooka of Milk Science Research Institute, Megmilk Snow Brand Co Ltd in Kawagoe, Saitama, Japan and colleagues conducted the study and found probiotics-fed dams that were immunized with rotavirus secreted breast milk that significantly lowered incidence of rotavirus-induced diarrhea among their pups, compared with their counterparts immunized with rotavirus alone. 

For the study, a diet supplemented with Lactobacillus gasseri SBT2055 (LG2055) or a placebo was given to female BALD/C mouse dams, four weeks prior to mating and

 throughout the experiment.  The animals were immunized orally with simian rotavirus SA-11 and then five days after birth, mouse pups were infected with rotavirus and incidence of diarrhea was determined four days later.

Mouse dams immunized with rotavirus but also supplemented with the probiotics secreted breast milk that reduced incidence of rotavirus-induced diarrhea in their pups, compared with dams immunized only with rotavirus.

Mouse dams immunized with rotavirus and supplemented with probiotics were also found to produce a significantly higher level of rotavirus-specific IgA in breast milk obtained from the pups' stomach.

Additionally, the probiotics stimulated the production of total IgA in splenocyte cultures from Toll-like receptor (TLR)-4-knockout mice.

The researchers concluded probiotics -fed dams reduced rotavirus infection in their pups and increased rotavirus-specific IgA levels in breast milk of stomach origin.