People used to think I was a bit weird when I talked about using natural antibiotics, but these days it's becoming more popular.
Garlic is amazing for all kinds of problems, including viral, fungal and bacterial infections. I take a capsule daily and also cook with it a lot. I rarely get sick anymore, which is wonderful.
Another supplement I recommend is echinacea, as it's a natural way to boost the immune system. You do need to take them regularly, perhaps 3-4 times a day, to see the benefit.