The trusted source for
healthcare information and
By Donald Brown, MD
Managing Director, Natural Product Research Consultants, Seattle, WA
Dr. Brown reports he is a retained consultant for Nature’s Way and Linnea. This article originally appeared in the September 2014 issue of Integrative Medicine Alert.
SOURCE: West NP, et al. Probiotic supplementation for respiratory and gastrointestinal illness symptoms in healthy physical active adults. Clin Nutr 2014;33:581-587.
This 150-day, randomized, double-blind, placebo controlled trial (RCT) with 465 healthy adult volunteers (mean age 37 years old) was designed to examine the effects of probiotics on the incidence of upper respiratory tract infections (URTI). Participants were assigned to one of three groups:
Bifidobacterium animalis subsp. lactis Bl-04
(2 x 109 cfu/day);
Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp. lactis Bi-07
(5 x 109 cfu of each strain per day); or
Each preparation was delivered in a powder to be mixed into a cold beverage. At the end of the study, participants taking the Bl-04 had an approximately 27% reduction in risk of URTI compared to the placebo group (P = 0.022). There was no significant difference in the number of URTIs between the NCFM/Bi-07 group and the placebo group (P = 0.15). Both probiotic supplement regimens were associated with a delay in time to a URTI of approximately 0.8 months compared to placebo.
The results of this trial continue to support the use of probiotics for the prevention of URTIs. They add to the positive findings of a 2011 Cochrane Review meta-analysis of 10 RCTs which concluded that probiotics were superior to placebo in reducing the incidence of acute URTIs in adults and children as well as reducing antibiotic use.1 It’s interesting to note that a similar trial with preschool age children (included in the meta-analysis above) found that the combination of L. acidophilus NCFM and Bi-07 was effective in reducing the incidence of URTIs.2 It is hard to speculate why the combination was not as effective with adults.