Kombucha is fine given its not loaded with residual sugar, longer ferments are preferred.
I think your case is less severe given you don’t have chronic digestive disorders, allergies, etc. That’s a good thing.
I would recommend you temporarily cut out sugars, gluten, desserts, and the obvious stuff.
Try fermenting veggies (e.g sauerkraut,Curtido, etc.) or take a good pro-biotic (e.g. Prescript assist, Probiotic-3, etc.).
I would also give an anti-fungal like Nystatin a try. The reason being is it doesn’t harm your beneficial flora like Garlic (allicin), Caprylic acid, etc. will.
Protecting ones gut microbiome is of most importance, I wish somebody told me this before I began this journey.