Artikel
Consumption of a fermented dairy product containing the probiotic Lactobacillus casei CNCM I-1518 improves clinical outcome of common infections and quality of life in adults under stress (firemen students) in a randomized controlled trial
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Veröffentlicht: | 24. Oktober 2011 |
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Objective: The risk of infections and their severity may be increased in people under physical and psychological stress. Subjects undergoing physically stressful heavy exercise represent a population with such a known higher susceptibility to common infections [1], [2], [3], [4], [5].
The aim of this study was to assess the effect of a fermented dairy drink containing the probiotic strain Lactobacillus casei CNCM I-1518, on the resistance to common infectious diseases (CID), respiratory and gastro-intestinal, in physically and mentally stressed healthy adults.
Material/Methods: A multicenter, randomised, double-blind, controlled trial was conducted in 239 healthy volunteers undertaking Firemen training, a model combining multi-stressor conditions such as intensive exercise, sleep deprivation, and psychological pressure. Volunteers were randomized for the consumption of 200g of either a fermented dairy product (N=118) or the control (non-fermented) dairy product (N=121) daily during seven weeks. The incidence, duration, severity, and type of common infectious diseases experienced were recorded. Quality of Life (QoL) during the study was assessed through the SF-36 questionnaire.
Results: The consumption of the fermented product significantly reduced the average duration per episode of CID (3.00 vs. 4.00 days in control group, p=0.046). This was accompanied with an increase of Lactobacillus casei species in stools throughout the fermented product consumption (from 2.8x106 at baseline to 6.6x108 equivalent CFU/g faeces, 4 weeks after consumption had started, p<0.001).
Furthermore, the consumption of the fermented product had a beneficial effect on QoL, improving social functioning for all volunteers (p=0.005) and bodily pain for volunteers experiencing CIDs (p=0.013) in both the ITT population and PP population.
The cumulative number of CIDs (primary outcome) was not different between groups nor was the CID severity, fever, pathogens occurrence, medication, immune blood parameters. The study products were ingested in accordance with the study protocol and compliance was good (97.9% in control group and 97.6% in product group). There were no serious adverse events and clinical safety was excellent.
Conclusion: In healthy adults under heavy physical training and psychological stress conditions, the regular consumption of a fermented dairy product containing the probiotic strain L. casei CNCM I-1518 was associated with a decreased duration of CIDs in comparison with the control group, and with an improvement in some dimensions of Quality of Life. Thus, the inclusion of such a fermented dairy product in the diet of comparable populations such as athletes undergoing intensive training periods may be of interest to improve their resistance to common infections.
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