Written by Angeline A. De Leon, Staff Writer. A twelve week daily consumption of dairy yogurt containing L. paracasei, B. lactis, and heat-treated L. plantarum enhanced the immune system functioning in 200 participating nondiabetic older adults.
Dairy yogurt contains a wide array of nutritional components associated with healthy immune function, including protein, vitamin B6, zinc, and probiotics 1. Probiotics, especially, are critical in terms of activating immune system response 2, and studies show that different probiotic strains influence immune function in unique ways 3. Lactobacillus paracasei ssp. paracasei (L. paracasei) and Bifidobacterium animalis ssp. Lactis (B. Lactis), for example, demonstrate the ability to enhance immune function by boosting systemic response to immune challenge 4. Another strain, heat-treated Lactobacillus plantarum (L. plantarum), is noted for its reduction of expressed inflammatory markers 5 and its ability to protect against viral infections through modulation of immune responses 6. Given the marked decline in immune function associated with aging, research investigators in Korea (2017) examined whether consumption of dairy yogurt containing these specific strains, L. paracasei, B. lactis, and heat-treated L. plantarum, could be used to enhance the immunity of older adults, based on biomarkers of immune function.
A 12-week, randomized, placebo-controlled study was conducted on 200 nondiabetic older adults (aged 60 years and above) who were divided into two groups: half of participants were assigned to consume 120 mL of dairy yogurt containing L. paracasei, B. lactis, and heat-treated L. plantarum once per day, while the other half (placebo) were assigned to consume milk by the same volume daily. Using blood samples provided by participants, measurements of immune system function were obtained based on natural killer cell activity (NK, immune system’s frontline defense against tumors and viral infections), interleukin-12 (IL-12, involved in coordinating adaptive immune responses), and immunoglobulin G1 levels (IgG1, the main antibody found in human blood).
At 12 weeks, compared to baseline, IL-12 and IgG1 serum levels were found to be significantly raised in the yogurt group (p < 0.05 trend). In comparison to placebo, supplementation with yogurt also produced greater increases in concentrations of IFN-γ (the signaling protein activated by IL-12) (p = 0.041) and IgG1 (p = 0.022). Concerning NK activity, in relation to placebo, the yogurt group demonstrated significantly greater increases in serum NK cell activity at every cell ratio that was measured in the study (activity of NK cells was measured based on five different effector-to-target cell ratios, p < 0.05 trend).
General findings indicate that daily supplementation of dairy yogurt containing probiotic strains of L. paracasei, B. lactis, and heat-treated L. plantarum is associated with immune-enhancing action that may be particularly beneficial for aging individuals with compromised immunity. Consumption of probiotic-rich yogurt was not only successful in ramping up the activity of NK cells, which are key to innate immune response 7, but also the production of cytokines associated with critical anti-tumor properties (IFN-γ, 8. Dairy yogurt containing these particular probiotic strains appears promising in its ability to stimulate and enhance immune system function and, therefore, should be further studied.
Source: Lee A, Lee YJ, Yoo HJ, et al. Consumption of dairy yogurt containing Lactobacillus paracasei ssp. paracasei, Bifidobacterium animalis ssp. lactis and heat-treated Lactobacillus plantarum improves immune function including natural killer cell activity. Nutrients. 2017; 9(6): 558. DOI: 10.3390/nu9060558.
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Posted July 17, 2017.
Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program.
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