Garlic definately helps, but I would recommend to cook it into food. The gas comes because garlic (and onions) are hard to digest even though they kill the candida. - so yes, it helps and yes, it gives gas. Maybe try flax seed, flax seeds oil or coconut oil - easier to digest and kill the Candida.
What I am doing right now is first detoxing my stomche with flax seed pulver from the health store and then I will start killing the candida again and building up my stomach with min, vitamins, acidophilus and so forth - that kills the candida in a way, that this creates an alkaline environment in which the candida cannot overgrow.