The main objective is to investigate whether the continuous, once a day, 12-weeks use of Yakult product containing Lactobacillus casei Shirota could affect immunological parameters in HIV-infected patients on suppressive antiretroviral treatment with poor CD4+ T cell recovery. A total of 48 volunteers will be followed for 12 week after initiation of daily use of Lactobcillus casei Shirota or placebo, randomized in a 1:1 ratio.