Consumption of OLL1073R-1 yogurt improves psychological quality of life in women healthcare workers: secondary analysis of a randomized controlled trial.

BACKGROUND: We conducted a randomized controlled trial to investigate the effects of consumption of yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 in women healthcare workers. In a previous study we used these data to investigate hypothesized preventive effects against flu, however any effects on improving mental quality of life were not analyzed at that time. In the present study, we focus on that aspect. METHODS: The participants (961 women; mainly nurses, aged 20-71 years) were randomly allocated to either the yogurt group (n = 479) or the control group (n = 482). Participants in the yogurt group drank 112 mL of OLL1073R-1 yogurt for 16 weeks, while those in the control group did not consume any yogurt. All participants were prohibited from consuming other yogurt or fermented dairy products during the study period. The participants answered the Pittsburgh Sleep Quality Index (PSQI), Short Form-8 Health Survey (SF-8), and Gastrointestinal Symptom Rating Scale (GSRS) questionnaires at baseline and after 16 weeks. RESULTS: The PSQI score showed significant improvement after the intake of yogurt (p < 0.01). SF-8 results showed significant intervention effects in the General Health and Vitality scores (p = 0.02 and p = 0.01, respectively). In other subscales of SF-8, we did not observe significant effects of the yogurt. In the GSRS, daily intake of yogurt exerted a preventive effect on constipation (p = 0.03). CONCLUSIONS: Consumption of yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 enhances subjective psychological quality of life by improving quality of sleep and gastrointestinal condition among women healthcare workers.

The effects of OLL1073R-1 yogurt intake on influenza incidence and immunological markers among women healthcare workers: a randomized controlled trial.

Probiotics have been expected to enhance human immune function. The aim of this study was to evaluate the effects of dietary intake of yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 (OLL1073R-1) on the prevention of influenza during winter and on the activation of immunological markers among women healthcare workers. 961 women aged 20-71 years were randomly assigned to either the yogurt group (n = 479) or the control group (n = 482). Participants in the yogurt group consumed a 112 mL yogurt drink fermented with OLL1073R-1 every day for 16 weeks, whereas those in the control group consumed no yogurt during this period. All participants were instructed not to consume any other kinds of yogurt or fermented dairy products throughout this trial. The cumulative incidence rate of influenza was measured, and immunological markers were examined at the baseline and after 16 weeks. No significant difference in the incidence rate of influenza was found between the two groups (cumulative incidence rates of flu: yogurt 7.5% and control 7.7%). Natural killer (NK) cell activity did not show a significant intervention effect (p = 0.11), whereas the intervention effect on serum interferon gamma (IFN-γ) production was significant (p = 0.03). Other immunological markers did not show significant intervention effects. Consumption of OLL1073R-1 yogurt did not show a significant preventive effect against influenza or a significant enhancement in NK cell activity. However, intake of this yogurt showed an increase in IFN-γ production.