Study supports probiotic yogurt’s immune boosting effects

By Stephen Daniells

- Last updated on GMT

© iStock
© iStock
Yogurt containing two probiotic strains plus heat-treated bacteria may boost the activity of immune cells called natural killer (NK) cells in people over 60, says a new study.

Twelve weeks of consuming yogurt containing a combination of Lactobacillus paracasei​ ssp. paracasei​ (L. paracasei​), Bifidobacterium animalis​ ssp. lactis​ (B. lactis​) and heat-treated Lactobacillus plantarum​ (L. plantarum​) also led to significant increases in levels of immunoglobulin (Ig) G1 (a type of antibody), compared to placebo.

“The results suggest that daily consumption of dairy yogurt containing ​L. paracasei, B. lactis and heat-treated ​L. plantarum could improve immune function by enhancing NK cell activity,”​ wrote scientists from Yonsei University and Purmil Co., Ltd. in Nutrients​.

Study details

The Korea-based scientists recruited 200 non-diabetic elderly people to participate in their randomized, open-label, placebo-controlled study. The volunteers were randomly assigned to consume placebo or a yogurt with 1.2 billion CFUs per day of L. paracasei​ (L. casei​ 431, Chr Hansen), 1.2 billion CFUs per day of B. lactis​ (BB-12, Chr Hansen) and 0.0175% heat-treated L. plantarum​ (Biogenics Korea Co) for 12 weeks.

Results showed that, compared to baseline values, significant increases in NK cell activity were observed, as were levels of interleukin (IL)-12 (a “communicator” molecule in the immune system) and IgG1.

Compared to placebo, NK cell activity, and levels of IgG1 and interferon (IFN)-gamma were increased.  

Immune-enhancement

“NK cells provide a substantial defense against viral infection, and low NK cell activity was shown to be associated with the development of infections in healthy elderly subjects,” ​wrote the researchers. “In a murine experiment, NK cells were shown to be a major source of IFN-gamme, a potent immune-stimulatory cytokine also known for its antiviral, immunoregulatory, and anti-tumor properties.

“IFN-gamma also has an effect on NK cell regulation; therefore, the increase in serum IFN-gamma concentration accompanying the increase in NK cell activity measured in the test group in this study could have contributed to the immune-enhancing action of supplementation with dairy yogurt containing ​L. paracasei, B. lactis and heat-treated ​L. plantarum.”

Source: Nutrients
2017, 9(6), 558; doi:10.3390/nu9060558
“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”
Authors: A. Lee et al.

Related topics: R&D, Functional Dairy, Yogurt and Desserts

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