A craft beer made with ingredients from kefir — a fermented milk drink that resembles yogurt— may sound a little gross. But drinking it could bring health benefits, a new study done in rats suggests.
Moreover, the researchers in Brazil found that the "kefir beer" seemed to reduce inflammation and stomach ulcers that had been induced in the rats for the study.
Although the concept of kefir beer is interesting, it is too early to determine whether these health benefits would apply to humans, considering the study was done in an animal model, said Dr. Arun Swaminath, director of the inflammatory bowel disease program at Lenox Hill Hospital in New York City, who was not involved in the study. "It is a very preliminary study," Swaminath told Live Science.
To make the kefir beer, the researchers added kefir grains — white or yellowish gelatinous clumps that contain bacteria and yeast — to a barley malt. The bacteria and yeast fermented the malt. For a control group, they also brewed another, regular kind of beer, where, instead of adding kefir grains, they added yeast to ferment the malt.
In one experiment in the study, the researchers induced inflammation in the hind paws of 48 rats by giving them a compound called carrageenan, which is sometimes used a food additive, but is known to promote inflammation. [7 Ways Alcohol Affects Your Health]
The researchers then divided the rats into six groups, with eight rats each, and gave them one of the following: kefir beer, kefir, regular beer, water, ethanol or an anti-inflammatory drug.
They found the kefir, kefir beer and regular beer all reduced the inflammation. However, when the researchers compared the effects of the two beers, they found that the kefir beer reduced the inflammation by about 48 percent, whereas the regular beer reduced it by 28 percent.
In a separate experiment, in which the researchers induced inflammation in the rats with a different pro-inflammatory compound called histamine, the inflammation was reduced by 76 percent in those rats that were given kefir beer. Conversely, in the rats that were given regular beer, the inflammation was only reduced by about 4 percent.
In another group of 48 rats, the researchers induced stomach ulcers with alcohol, and then made the rats fast for a day. This time, they found that treating the rats with kefir, kefir beer or regular beer all resulted in significant reduction of ulcers. However, the effects of the kefir beer and kefir alone were both greater than those of regular beer, the researchers said.
Moreover, when the researchers added some kefiran, a type of molecule made by kefir grains, to the regular beer, and gave the drink to the animals, the ulcers "virtually disappeared," the researchers wrote in the study, published in the upcoming March issue of the Journal of Functional Foods.
The beneficial effects of the kefir beer may have something to do with the combination of individual health benefits associated with its respective main components, according to the study. For example, previous research has suggested that nutrients called polyphenols, which are found in beer, may have anti-inflammatory qualities.
Studies in animals have suggested that kefir may have anti-inflammatory, antimicrobial and wound-healing properties, the researchers said.
The new research was funded by the Foundation for Research Support of the State of Minas Gerais in Brazil.