Six weeks of consuming a glass of the blueberry drink were associated with significant increases in Bifidobacterium spp., while no changes were observed in other bacterial species, including Bacteroides and Clostridium coccoides.
“The wild blueberry drink may also be interesting as a basis for the formulation of a ‘functional’ drink that could combine the positive prebiotic activity observed of the wild blueberry components with the probiotic activity of live Biﬁdobacterium and/or Lactobacillus strains,” report researchers from the Università degli Studi di Milano in Italy.
Consumer interest in blueberries and the compounds they contain has increased in recent years, following results from studies reporting a wide range of health benefits, most notably for brain health and reducing the risk of Alzheimer’s.
The beneficial effects of the blueberries are thought to be linked to their flavonoid content - in particular anthocyanins and flavanols.
The new study indicates that the benefits of the berries may also extend to gut health. Stefano Vendrame and his Milan-based co-authors report that the bifidobacteria-boosting effects of blueberries may be linked to the polyphenol or fiber content, or the vitamin K in the berries.
The researchers recruited 20 healthy men with an average age of 46 and an average BMI of 25 kg/m2, and randomly assigned them to one of two groups. One group consumed a daily 250 ml drink of juice containing 25 grams of wild blueberry powder, while the second group consumed a placebo drink daily.
After six weeks, both groups underwent another six of ‘washout’ before being crossed over to the other group.
Results showed that the populations of Bifidobacterium spp. and Lactobacillus spp. in the berry group, while Lactobacillus spp. only increased in the placebo, “probably related to the presence of simple sugars”, said the researchers.
On the other hand, no changes for Bacteroides spp., Prevotella spp., Enterococcus spp., and Clostridium coccoides were reported by the researchers.
“The results of this study suggest that regular consumption of a wild blueberry drink is able to favorably modulate the composition of the intestinal microbiota, increasing in particular bacterial strains from the genus Biﬁdobacterium, which is among the most health promoting bacterial groups,” wrote the researchers.
“Considering the discovery-based nature of this investigation, further experiments on a larger population group investigating speciﬁc species of biﬁdobacteria are strongly recommended,” they concluded.
Source: Journal of Agricultural and Food Chemistry
Published online ahead of print, Articles ASAP, doi: 10.1021/jf2028686
“Six-Week Consumption of a Wild Blueberry Powder Drink Increases Bifidobacteria in the Human Gut”
Authors: S. Vendrame, S. Guglielmetti, P. Riso, S. Arioli, D. Klimis-Zacas, M. Porrini