Both milk kefir and buttermilk are probiotic-rich drinks full of gut-healthy bacteria. The main difference between kefir and buttermilk is in the number of beneficial bacteria each has to offer. Depending on the variety that you use, milk kefir grains may contain up to 60 strains of beneficial bacteria and yeasts.Click to see full answer. People also ask, what is healthier kefir or buttermilk?An 8-ounce serving of kefir provides 162 calories, while an 8-ounce serving of buttermilk provides 150 calories. The difference of 12 calories between kefir and buttermilk is unlikely to be significant, even if you are dieting, as the amount is less than 1 percent of the daily suggested intake of 2,000 calories.Furthermore, can you substitute kefir for buttermilk? You can use plain kefir to replace buttermilk cup for cup. Therefore, if your recipe calls for 1 cup of buttermilk, simply substitute 1 cup (237 ml) of kefir. Though kefir contains a wider range of beneficial bacteria and other microbes than buttermilk, heating it will kill many of the microbes ( 7 , 8 ). Herein, whats the difference between buttermilk and kefir? Kefir (kuh-FEAR, not KEE-fur) is fermented from whole milk using special kefir grains (more about them in a minute). Buttermilk, more formally called cultured buttermilk, is made by fermenting skim milk with lactic acid bacteria, Streptococcus lactis.Is buttermilk a good probiotic?Buttermilk is a good source of probiotics, thanks to the live cultures added to ferment the milk sugars. It’s made by fermenting milk with yeasts and bacteria referred to as kefir ‘grains.