The two best supplements for me with this problem are digestive enzymes (I recommend one called pro-gest) and hydro-chloric acid (HCL) (I take a product called zypan). If you lack stomach acid your body isn’t breaking down the foods correctly. Additionally, if you lack enzymes the same thing will happen.
Bitters cause you produce your own enzymes naturally but I have never tried them.
Able900 doesn’t think enzymes are safe for an anti-candida protocol but I have taken throughout my treatment and feel that they have been quite important for my recovery. Some people like the garden of life probiotics a lot and these contain enzymes.
Also, if you are not chewing your food 30+ times per each bite this can be apart of the problem as well. Enzymes are produced when you chew food and this is very important to digestive health (digestion starts in the mouth).