Abstract: The present invention relates to novel mannose-specific adhesins, and variants thereof, as well as nucleic acid sequences encoding these. The invention also relates to host cells expressing nucleic acids encoding the mannose-specific adhesins or variants thereof, as well as to pharmaceutical or nutraceutical compositions comprising the mannose-specific adhesins and/or host cells expressing the adhesins, and their use in treating or preventing bacterial infection. Further, screening methods suitable for identifying bacteria strains with probiotic properties are provided.