I can't find a flavored Liberty brand container right now to see if it is sweetened with sugar but I suspect it is--I'll get back to you on that.
But the unflavored kind lists no sugar in the ingredients:organic partly skinned milk,bacterial cultures - but 6grams/175ml in the Nutrition Facts bar.
Another brand, Elwest, lists a hosts of ingredients:skim milk, cream, water modified corn starch, gelatin,guar gum, pectin, potasium sorbate (a mold inhibitor it says-blek), bacterial culture.--11grms sugar/250grms(1cup) on the bar. I don't like this kind at all.
Both are said to be made from original Russian recipes.
I hope that helps you.
All I know is that I feel much better after drinking it and will often have many cups a day--the drawback is the price however -one 454gram (a little under 2 cups) of Liberty Kefir is $2.99 Canadian--but like I said it is often all I can drink or I'll have some if I feel some problems starting.
You can get the bacterial culture in a health food store, I believe, and grow your own.
When I put my foot in my mouth I hope someone will tell me before I wiggle my toes.