Diet - exclude sugar/wheat/gluten/yeast products completely and see if you notice a change in a few weeks. You may notice worsening of symptoms and increased food cravings initially, as die off/detox can take place. Stick it out, it is worth it.

Even this alone can help a whole lot in a person's condition, particularly with mercury/candida/gluten intolerance at work. So often mercury creates the other conditions, which burdens the gut/liver and immunity further.

Supplements can also be of help. Namely antioxidants like vitamin C, E, selenium (selenium apparently works better when taken away from vitamin C, 2 hours apart). Minerals like magnesium, zinc and getting enough iodine (which mercury blocks/depletes). B complex maybe helpful also and essential fatty acids in fish oil (molecularly distilled mercury free one), extra virgin olive oil, butter, etc.

These are just some examples that maybe of extra aid to the diet.

Make sure you get enough protein in eggs and meats, because that is also helpful in those with mercury toxicity, including butter. I also found consuming more raw fruits/vegetables was helpful to me with detoxing! However, fruit can pose a problem if one has a serious enough candida problem (as though healthy, they are still high in natural sugars - fructose, which can still feed a bad yeast problem). I cannot have them these days, but I could have them once. But I could not have sugar/gluten/wheat/yeast and once I excluded those, I had alot of improvement after a few weeks of sticking to it.

That's what I'd personally recommend, at least as a start to what you may add and do later on.