Probiotic Strain Improves Immune Health in Elderly

KANTVIK, FinlandConsumption of DuPont Nutrition & Health's probiotic strain Bifidobacterium lactis Bi-07 improves the function of specialized innate immune cells, the phagocytes, in elderly subjects, according to a new study published in the Journal of Nutritional Science.

DuPont Nutrition & Health and the University of Reading studied the effect of probiotic Bifidobacterium lactis Bi-07 on immune function in healthy elderly subjects. The elderly commonly have reduced immune function and this physiological effect may thus contribute to better health.

Upon completion of a screening process, 40 healthy elderly volunteers were randomly divided into four groups. In a double-blinded, placebo-controlled, randomized cross-over study, 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).

Daily portions were based on dose-response clinical studies showing that an 8-gram portion of GOS increases the number of bifidobacteria in the intestine, and that 109 colony-forming units of B. lactis induce changes in elderly microflora. Volunteers were randomized to four groups that consumed the study products in random order in four periods. 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.

Blood, saliva and fecal samples were taken from the study subjects 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.

Primary statistical analysis revealed carry-over effects, which had the potential to bias results, and thus the statistical analysis was conducted for parallel groups using results from samples obtained on day 0 (before the first supplementation) and on day 21 (after the first supplementation period). It was found that subjects in the Bi-07 group had higher phagocytic activity of monocytes (p<0.001) and granulocytes (p=0.02) than subjects in the placebo group. Changes in other markers of immune function or microbiota composition were not detected in any supplementation groups.

Alterations in the gut microbiota and immune functions of elderly adults are associated with higher susceptibility to infections and metabolic disorders," said Markus Lehtinen, Ph.D., senior scientist, DuPont Nutrition & Health. Phagocytosis, by which immune cells eat bacteria or infected cells, is one of the mechanisms that help to resist infections. Results of this study show that the probiotic Bi-07 may provide health benefits to elderly individuals by increasing the activity of phagocytic cells."

The investigators found that the 28-day wash-out period for GOS and Bi-07 was not sufficient in this elderly population, although previously it has been found useful for adult populations. This finding indicates that results on probiotic and prebiotic interventions may not be extrapolated from one population to another that differs in microbiota and immune function.

Researchers concluded that Bi-07 consumption improved innate phagocytic activity of monocytes and granulocytes in healthy elderly. This could be beneficial to elderly who suffer from decreased phagocytic activity and higher susceptibility to infections. Supplementation with GOS or with the synbiotic combination of GOS and Bi-07 did not have an impact on any of the parameters that were measured.

In 2013, DuPont launched HOWARU® Protect probiotics to help maintain natural immune defenses in children, adults and sports enthusiasts. HOWARU Protect Kids supports respiratory health in children by shortening the duration of cold/flu symptoms from 6.5 to 3.5 days, resulting in a strong reduction in antibiotic use and a reduced number of sick days.