The present invention pertains to a novel micro-organism of the genus Bifidobacterium longum, in particular to its genomic and plasmid sequence and to a method of producing polypeptides of said Bifidobacterium, respectively. The invention also relates to methods of detecting these nucleic acids or polypeptides, respectively. A data carrier is provided comprising nucleotide sequences and/or polypeptide sequences of NCC2705. In addition, the present invention pertains to the Bifidobacterium longum strain NCC2705 and also to food and pharmaceutical compositions containing said Bifidobacterium oractive components thereof for the prevention and/or treatment of diarrhoea brought about by rotaviruses and pathogenic bacteria.