Wild blueberry drink and gut bacteria in 15 men
What it found
Drinking a wild blueberry powder drink for six weeks raised levels of bifidobacteria in the guts of healthy men.
Another type of gut bacteria rose after both the blueberry drink and a sugar-matched placebo.
What they found
Studies in people
Bifidobacteria increased with blueberry
Compared to total gut bacteria, bifidobacteria more than doubled after six weeks of the wild blueberry drink in these 15 men. This rise did not happen during the placebo period. The authors suggest the fiber and plant compounds in the blueberries may have fed these bacteria specifically.
Lactobacillus rose with both drinks
A group of bacteria called Lactobacillus acidophilus rose about six-fold after both the blueberry drink and the placebo drink in these men. Both drinks contained sugars like fructose and glucose, which the authors think may explain why this bacteria grew regardless of blueberries.
Other bacteria stayed the same
Four other groups of gut bacteria measured in the stool samples showed no meaningful changes after either the blueberry drink or the placebo drink in these men.
Other findings
What was in the drink
Each daily serving of the wild blueberry drink provided 375 mg of anthocyanins, 77.5 mg of chlorogenic acid, 17.1 g of sugar and 4.5 g of fiber. The placebo drink was made from water, sugars, citric acid, flavoring and food coloring to look similar but without the blueberry compounds.
What the authors conclude
- They conclude that drinking a wild blueberry beverage every day can shift the mix of gut bacteria in a way they consider favorable, especially by raising bifidobacteria.
- They recommend larger studies to confirm these results and to look at specific species of bifidobacteria.
- They suggest wild blueberry drinks could be used as a base for beverages that combine plant compounds with live beneficial bacteria.
How it was done
Wild blueberries contain plant compounds and fiber that gut bacteria can break down. The authors wanted to see if drinking them regularly could change the mix of bacteria living in the human gut, since this had only been tested in lab dishes and animals before.
Fifteen healthy men, average age about 46, drank either a daily wild blueberry powder drink or a placebo drink for six weeks, then switched to the other drink after a six-week break. Each serving of the blueberry drink contained 25 g of wild blueberry powder mixed in water, providing 375 mg of anthocyanins and 4.5 g of fiber. The researchers collected stool samples at the start and end of each period to measure different types of gut bacteria.
What it can’t tell you
- Only 15 men took part, so the results might not apply to women, children or larger groups.
- The study measured changes in gut bacteria but did not track whether those changes led to any health effects.
- Because everyone received both drinks, scientists cannot rule out that something else happening over those months influenced the results.
Who paid
- Authors work at
- Università degli Studi di Milano, Italy
The paper
- Title
- Six-week consumption of a wild blueberry powder drink increases bifidobacteria in the human gut
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Vendrame S, Guglielmetti S, Riso P, Arioli S, Klimis-Zacas D, Porrini M (2011). Six-week consumption of a wild blueberry powder drink increases bifidobacteria in the human gut. Journal of agricultural and food chemistry. doi:10.1021/jf2028686Free full textPubMed 22060186DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error