A
protein obtainable from a non pathgenic microorgansim, said
protein having mucosa binding promoting activity and a molecular weight of 20-40 kD is disclosed. Application of such a
protein or
a peptide derived therefrom in a method of screening non pathogenic microorganisms for a
microorganism capable of specifically binding mucosa, said method comprising detection in a manner known per se of the presence of a particular protein on or in a
microorganism or in a culture of microorganisms, said particular protein being the already defined protein. Kits suitable for such a
screening method are also disclosed. Use of a component selected from the group of components comprising a protein or
peptide as defined; an
expression vector comprising
nucleic acid encoding such protein or
peptide; a recombinant
microorganism or a part of said microorganism expressing such protein or
peptide, said part expressing mucosa binding promoting activity; a non
pathogenic microorganism capable of expressing such protein or peptide or a part of said microorganism, said part expressing mucosa binding promoting activity as pharmaceutically
active component in a pharmaceutical composition for prophylaxis and / or treatment of
disease or illness associated with a mucosa colonizing
pathogenic microorganism. Use of such components as
food additive and compositions comprising such components are described.