The present invention relates to composition derivable from a bifidobacteria, methods and uses thereof, for use in modulating the immune system in a subject by affecting viral action and/or viral effects in said subject. Furthermore, said composition may also be used in reducing the risk of development and exacerbation of chronic respiratory diseases such as asthma and COPD in a subject；preferably by modulating the immune system in the subject by affecting viral action and/or viral effects in said subject.
