The ability of several strains of LAB to enhance both innate and
adaptive immunity has been demonstrated in mice [10,11] and in
human trials [12e14]. It has been found that the presence of
immunomodulatory properties and the pattern of immunomodulation
depend on various factors, including the LAB involved [15],
the individual LAB strain [16], the use of viable or killed LAB [10],
and the dose at which LAB is used [10]. The immunomodulatory
effects could be due to the produced cytokines that further regulate
innate and adaptive immune responses, and evidence exists on
immune responses directed either to the Th1 or Th2 type [17].
Due to their interdependency on adjacent lymphoid cells, the
epithelial cells in the gastrointestinal tract (GIT) are active participants
in the mucosal immune system. Cytokines, such as