While I did not have leaky gut, I did have a significant candida infection for a long time.
Using a zapper and natural probiotics helped tremendously. Also, a 1 day Water Fast followed by flushing with Epsom Salts is helpful.
For natural probiotics, kefir is the best followed by yogurt (should contain live and active cultures of at least 5 or 6 microbes). You do not need to eat a lot or either. A tablespoon or two several times a day is better than a lot at once.