Here is a guide from Dr Myhill that is worth a read for every one of us. Some of the information may seem obvious, but it provides a useful breakdown of all the basics.
drmyhill.co.uk/wiki/The_general_approach_to_maintaining_and_restoring_good_health
Considering that we all jump to and from theories and/ or treatments in hope that our problems will be resolved. The very best thing we can do is take on a lifestyle that will cover every base, even if it brings small improvements.