Monocyte function in healthy middle-aged people receiving fermented milk containing Lactobacillus casei.
BACKGROUND
Lactic acid bacteria have been suggested as a dietary strategy to enhance immune system activity.


OBJECTIVE
The aim of the current work was to test the effects of a Lactobacillus casei fermented milk consumption on monocyte activity of middle-aged volunteers.


METHODS
Forty-five healthy volunteers, 24 women and 21 men (aged: 51 - 58 years), were randomized in two groups to receive three cups per day of a fermented milk containing L. casei DN114001 (108 - 1010/g) (n = 23), or placebo (n = 22), during 8 weeks. White blood cell count and the oxidative burst capacity of monocytes and granulocytes were examined with a FACScalibur. Measurements were performed at baseline and after the nutritional intervention, at day fifty-six.


RESULTS
After the trial, no changes in immune cell proportions were detected in both groups, as well as in monocyte activity after the placebo consumption (p = 0.625). However, volunteers included in the probiotic-treated group increased (p = 0.029) their oxidative burst capacity of monocytes, and this increment inversely and significantly correlated with the intensity registered at baseline (r = -0.653, p = 0.004).


CONCLUSIONS
Results showed that daily intake of fermented milk containing Lactobacillus casei was able to module the oxidative burst capacity of monocyte subset in healthy middle-aged people, particularly in subjects with lower initial levels. Thus, this nutritional strategy could be considered to maintain immune competence in ageing.
Parra
D
D
Department of Physiology and Nutrition, University of Navarra (Edif. Investigación), C/ Irunlarrea, s/n, 31008 Pamplona, Spain.
De Morentin
B Martinez
BM
Cobo
J M
JM
Mateos
A
A
Martinez
J A
JA
D000375:Aging / Q000276:immunology*; D043302:Cultured Milk Products / Q000276:immunology*; D004311:Double-Blind Method; D005260:Female; D005285:Fermentation; D005434:Flow Cytometry; D006801:Humans; D007780:Lacticaseibacillus casei; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000502:physiology*; D010919:Placebos; D019936:Probiotics; D016897:Respiratory Burst / Q000187:drug effects*
D010919:Placebos