A new study found that the consumption of the probiotic Bifidobacterium lactis Bi-07 (by DuPont Nutrition & Health) improves the function of specialized innate immune cells, the phagocytes, in elderly subjects (Journal of Nutritional Science (2014) http://dx.doi.org/10.1017/jns.2013.31). The study was a collaboration between DuPont Nutrition & Health and the University of Reading.
The double blind, placebo-controlled, randomized cross-over study included 40 healthy elderly volunteers who were divided into four groups. Volunteers received maltodextrin as a placebo (8 g/d), prebiotic galacto-oligosaccharides (GOS) (8 g/d), probiotic (Bi-07; 109 colony-forming units/d) and synbiotic GOS + Bi-07 (8 g GOS/d and 109 colony-forming units Bi-07/d). Supplements were provided for 21 days, with a 28-day wash-out period that has been effective in previous studies with B. lactis and GOS. Participants consumed the study products in a random order in four periods.
Blood, saliva and fecal samples were taken from the participants in order to analyze markers of immune function and microbiota composition. The phagocytic activity was analyzed using fluorescent bacteria that were incubated in blood samples containing phagocytes. The number of bacteria in the phagocytes was detected by using flow cytometry. Analysis revealed carry-over effects, which had the potential to bias the results, so the statistical analysis was conducted for parallel groups using results from samples obtained on day zero (before the first supplementation) and on day 21 (after the first supplementation period). The subjects in the Bi-07 group had higher phagocytic activity of monocytes and granulocytes than subjects in the placebo group. Changes in other markers of immune function or microbiota composition were not detected in any supplementation groups.
The researchers concluded that the consumption of Bi-07 improved innate phagocytic activity of monocytes and granulocytes in the healthy elderly participants. This is beneficial to elderly who suffer from decreased phagocytic activity and prone to infections. Supplementation with GOS or with the synbiotic combination of GOS and Bi-07 did not have an affect on the measured parameters.