This invention provides a method for introducing substances into cells comprising contacting a composition comprising orally administered beta-glucan with said cells. This invention also provides a method for introducing substances into a subject comprising administering to the subject an effective amount of the above compositions. The substance, which could be delivered orally includes but is not limited to peptides, proteins, RNAs, DNAs, chemotherapeutic agents, biologically active agents, plasmids, and other small molecules and compounds. Finally, this invention provides a composition comprising orally administered beta-glucan capable of enhancing efficacy of IgM and different uses of the said composition.