Is kombucha in the no zone for no sugar/no flour?

I have been following a protocol to include avoiding sugar and flour and intermittent fasting (8 hour window) for 3 weeks and have already lost 4 pounds! I love the fasting by the way – who knew?!
I also enjoy a kombucha that has low sugar and carbs. wondering if anyone has an opinion on kombucha in general or does it depend on the sugar and carbs?