Two fermented dairy foods can look similar nutritionally while doing very different things for your body. Skyr, a thick Icelandic-style cultured dairy food, stands out for protein, while kefir, a fermented milk drink, offers a wider variety of beneficial microorganisms. That distinction may become increasingly important as maintaining muscle and supporting gut health become bigger priorities with age.
Skyr contains about 11 grams of protein per 100 grams compared with roughly 3.5 grams in kefir, making it the stronger choice when protein is the priority. Kefir has a different advantage. Its fermentation involves a mixture of lactic acid bacteria, acetic acid bacteria and yeasts, giving it a more diverse microbial profile. Fermentation can also reduce kefir's lactose content, potentially making it easier for some people to tolerate.
You don't necessarily have to choose between them. Consider incorporating traditionally fermented dairy foods according to what your body needs, whether that's additional high-quality protein or greater microbial diversity. Whichever you choose, read the ingredient list carefully and look for minimally processed varieties without unnecessary sweeteners or artificial flavorings, and choose products containing live cultures if probiotics are your goal.
SOURCE:
Health, September 3, 2026