Preliminary technological and potential probiotic characterisation of bifidobacteria isolated from breast milk for use in dairy products

Six isolates of Bifidobacterium animalis subsp. lactis were obtained out of 16 samples of breast milk and were present in levels ranging from 1.4 to 2.8 log cfu mL−1. Isolates were stable in frozen storage (−20 °C and −70 °C, 6 months) and to refrigerated storage (5 °C, 4 weeks) in lactic acid-acidified milk (pH 4.5). Isolates were also able to grow in skim milk with yeast extract and they were stable to spray-drying in 20% (w/v) skim milk. Spray-dried cultures maintained a high number of viable cells when stored at 5 °C for 6 months and were stable to rehydration in water up to 50 °C. The oral administration of B. animalis subsp. lactis INL1 to mice increased the number of IgA+ cells in the small and large intestine. B. animalis subsp. lactis INL1 showed technological and probiotic potential for its incorporation to dairy products, whether fermented or not.