Dietary fructooligosaccharides up‐regulate immunoglobulin A response and polymeric immunoglobulin receptor expression in intestines of infant mice

SUMMARY We examined whether or not dietary fructooligosaccharides (FOS) in infancy can have a beneficial effect on the mucosal immune system. Newborn BALB/c mice, accompanied by their dams until 21 days of age, were fed either a control diet based on casein [FOS(–) diet group] or a FOS(–) diet supplemented with 5% (w/w) FOS [FOS(+) diet group]. Total IgA levels in tissue extracts from the intestines of mice in the FOS(+) diet group at 38 days of age were about twofold higher (P