Workers who take a daily dose of beneficial bacteria, also known as probiotics, are much less likely to fall sick, than their colleagues who don't. Probiotics are present in yoghurt and other fermented foods. They've been shown to have a number of positive health effects, helping, for example, to prevent gastrointestinal illness and to boost the immune system function. Researchers from the Tetra Pak Occupational Health and Safety AB, USA, conducted the following study to determine if one probiotic, Lactobacillus reuteri, might help prevent sickness due to respiratory or gastrointestinal infections. They randomly assigned 262 employees of a company to take a drink containing L. reuteri or a placebo drink every day for 80 days. A total of 181 workers completed the study. Twenty-three of the 87 workers on placebo took sick leave during the course of the study, compared to 10 of the workers taking the probiotic, or 11%. Among the subset of workers on the night shift, none of the 26 taking the probiotic called in sick, compared to 9 of their 27 colleagues. Shift workers are known to be more prone to develop stomach ailments, colds and other types of short-term illnesses leading to sick leave. While the mechanism by which the probiotic might help prevent illnesses isn't clear, it's likely that it helped to strengthen immune function. Shift-workers are known to be at risk for having a weaker immune defence as compared to those working daytime shifts only. Consequently it can be argued that shift-workers would benefit relatively more by the immune stimulating effect of L. reuteri. However, further studies are needed to investigate this issue.
Environmental Health,
November 2005