Elderly people have increased susceptibility to infections and cancer that are associated with decline in cellular immune function. It has been suggested that probiotic supplementation could offer a means to reverse some age-related changes in intestinal microflora composition and to help maintain the aging immune systems that are associated with age-related morbidities. A study published in the journal Nutrients analyzes four clinical trials that suggest daily consumption of Bifidobacterium animalis ssp. lactis HN019 (supplied by DuPont) may enhance cellular immune activity in healthy elderly adults.
The researchers conducted a systematic review of Medline and Embase for controlled trials that reported polymorphonuclear (PMN) cell phagocytic capacity or natural killer (NK) cell tumoricidal activity following B. lactis HN019 consumption in the elderly. They performed a random effects meta-analysis with standardized mean difference (SMD) and 95% confidence interval between probiotic and control groups for each outcome. A total of four clinical trials were included in the analysis.
The pooled data showed that short-term (3–6 weeks) consumption of B. lactis HN019 resulted in significantly enhanced PMN phagocytic capacity and NK cell tumoricidal activity in the healthy elderly population. It should be noted that the limitations of the research were the small number of included studies, short-term follow-up, and assessment of a single probiotic strain. “As the health of the elderly was not assessed in the original studies, the correlation between B. lactis HN019 mediated PMN and NK cell activity improvement and resistance to infection and diseases remains to be confirmed in future trials,” wrote the authors.