-The type of kefir you use will determine the fuel type of this frozen kefir. If you use single-fermented low-fat kefir (regular low-fat storebought kefir), it's a THM E (low fat). If you use double-fermented low-fat kefir, it's a THM FP (low carb and low fat). If you use double-fermented full-fat kefir, it's a THM S (low carb).
-Some kefir is actually lactose free, so keep that in mind if you have allergies. I used Green Valley Organics brand of low-fat kefir. It was super thick and creamy - and lactose free. (If you have a lactose allergy it would be a good idea to run this past your doctor first, though.)
-Feel free to substitute your favorite fruit or berry for the strawberries! I think peaches or cherries would be great in this with double-fermented low-fat kefir for a THM E option.
-I do not recommend replacing the xylitol with a less concentrated sweetener. The sugar alcohols are important in this recipe. Erythritol may work in its place, but I haven't tested it to see if it has the same properties as xylitol in ice cream. I much prefer the taste (or lack thereof) of xylitol. Feel free to experiment replacing the xylitol and stevia with your favorite low-glycemic sweetener, such as Swerve, Pyure, or THM Gentle Sweet (to taste). The more volume of sugar alcohols you have, the better.
-I don't recommend omitting the vegetable glycerin either. It helps keep the ice cream from sticking to the ice cream maker and vastly improves the creamy texture of the ice cream. We buy this brand from Amazon.