The study indicates that daily consumption of acetic acid (what gives kumbucha that tart tang) was shown to improve depressive symptoms and weight loss. The sample cohort is small, but it’s a good sign that it might have a powerful effect! More study needed for sure.
https://equinoxkombucha.com/blog/health/the-science-behind-the-organic-acids-in-kombucha/
I made kombucha in a brewery with two cultures from different local people and one from white labs. I drank a lot of it. I would imagine either I went over a too much of a good thing threshold, or the benefits are suspect to begin with. I was and still am highly depressed