British Journal of Nutrition

Full Papers

Nutritional Immunology

Reducing the risk of infection in the elderly by dietary intake of yoghurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1

Seiya Makinoa1 c1, Shuji Ikegamia1, Akinori Kumea1, Hiroshi Horiuchia2, Hajime Sasakia1 and Naoki Oriia1

a1 Food Science Institute, Meiji Dairies Corporation, 540 Naruda, Odawara, Kanagawa 250-0862, Japan

a2 Research and Development Centre, Meiji Dairies Corporation, 540 Naruda, Odawara, Kanagawa 250-0862, Japan

Abstract

Immune senescence potentially leads to an increased risk of infections. It is desirable to augment the immune system and protect against infections by daily consumption of immunostimulatory food. The present study evaluated whether the intake of yoghurt fermented with Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) OLL1073R-1 has an effect on resistance to the common cold. We conducted two independent studies, in which fifty-seven (median age 74·5 years) and eighty-five healthy elderly individuals (median age 67·7 years) were participants. In each study, the subjects were divided into two groups based on age and sex and instructed to eat 90 g yoghurt or drink 100 ml milk once per d over an 8- or 12-week period. A meta-analysis of the results of these two independent studies showed the risk of catching the common cold was about 2·6 times lower (OR 0·39; P = 0·019) in the yoghurt group than in the milk group and the increase of natural killer cell activity was significantly higher in the yoghurt group than in the milk group (P = 0·028). In addition, the quality of life score for the ‘eye/nose/throat’ system after intake was significantly higher in the yoghurt group than in the milk group and the improvement of the score was correlated with the promotion of natural killer cell activity. In conclusion, consumption of yoghurt fermented with L. bulgaricus OLL1073R-1 augmented natural killer cell activity and reduced the risk of catching the common cold in elderly individuals.

(Received November 19 2009)

(Revised March 11 2010)

(Accepted April 01 2010)

(Online publication May 21 2010)

Correspondence:

c1 Corresponding author: Seiya Makino, fax +81 465 37 3619, email seiya_makino@meiji-milk.com

Footnotes

Abbreviations: Con A, concanavalin A; cpm, counts per min; QOL, quality of life