Compared with placebo, daily consumption of the probiotic supplement was associated with a 45% decrease in URTI, report researchers from the University of Bordeaux, Biofortis-Mérieux NutriSciences, Paris 7 University and Lesaffre Human Care.
Levels of secretory IgA (sIgA) were also significantly increased following 10 days of Bacillus subtilis CU1 consumption at a dose of two billion spores per day.
“Production of secretory IgA (SIgA) at the mucosal surfaces decreases with age and can lead to an increased risk of infection,” explained the researchers in Immunity & Ageing. “SIgA, the predominant immunoglobulin class in human external secretions, is a key element in the maintenance of gut microbiota homeostasis and in the protection of gastrointestinal and respiratory tracts against pathogens.”
Commenting on the study’s findings, Elodie Ruffin, Probiotics Marketing Manager at Lesaffre Human Care, said: “These results provide evidence that consumption of B. subtilis CU1 may be a safe and effective prevention strategy to stimulate immune responses and provide long-term support to people at risk of sIgA deficiency such as the elderly, people suffering from chronic stress/sleep deprivation, professional athletes, etc.”
Bacillus subtilis CU1 is a spore forming bacteria positioned for support immune health, particularly in people with weakened natural defenses like the elderly. The organism is registered with the French National Collection of Microorganism Cultures as CNCM I-2745.
Led by Lesaffre’s Marie Lefevre, the researchers recruited 100 healthy volunteers between 60 and 74 years old and with a history of winter infections to participate in their randomized, double-blind, placebo-controlled study.
Performed during the winter months, the trial involved consuming B. subtilis CU1 or placebo for 10 days, and then the participants were followed for a further 18 days without intervention.
Results showed that there were no significant differences between the groups with respect to the mean number of days of reported common infectious disease symptoms. However, in a random sub-group of 44 participants, B. subtilis CU1 decreased the frequency of URTIs by 45% compared with placebo, while a significant increase in sIgA concentrations were also recorded.
“Increased SIgA levels of 87 % and 45 % in feces and saliva respectively are most probably of physiological significance in ameliorating the health status of seniors receiving B. subtilis CU1,” the researchers wrote.
The researchers also noted that there were no side effects reported during the study.
“Our study provides evidence that B. subtilis CU1 supplementation during the winter period may be a safe effective way to stimulate immune responses in elderly subjects,” they concluded.
Source: Immunity & Ageing
2015 12:24, doi: 10.1186/s12979-015-0051-y
“Probiotic strain Bacillus subtilis CU1 stimulates immune system of elderly during common infectious disease period: a randomized, double-blind placebo-controlled study”
Authors: M. Lefevre, et al.