Efficacy of Bifidobacterium animalis ssp. lactis HN019 on Cellular Immune Function in Healthy Elderly: A Systematic Review and Meta-Analysis

BackgroundElderly have increased susceptibility to infections that is associated with decline in cellular immune function. Limited clinical data suggests that probiotic bacteria could have potential for improving polymorphonuclear (PMN) cell phagocytic activity or natural killer (NK) cell tumoricidal activity in the elderly. One of the probiotics having clinical documentation in this area is Bifidobacterium animalis ssp. lactis HN019 (HN019). ObjectiveTo determine the efficacy of HN019 supplementation on PMN cell phagocytic activity or NK cell tumoricidal activity in healthy elderly. MethodsWe searched MEDLINE and EMBASE databases, in addition to Directory of Open Access Journals, Google Scholar, and the reference lists of included papers and relevant meta-analyses in June 2016 for randomized/non-randomized controlled studies reporting PMN cell phagocytosis activity or NK cell tumoricidal activity following HN019 consumption in healthy elderly. A random effects meta-analysis was conducted and the pooled s...