ACV can actually act an anti-fungal, but it’s reported to have a number of other health benefits. This only applies to unpasteurised ACV that still contains mother of vinegar, a web-like substance made up of acetic acid bacteria that will continue to grow in the bottle. I haven’t seen any research on it, but perhaps the bacteria essentially act as a special kind of probiotic that helps maintain acidity in the bowels.
You can take 1 tbsp in a glass of warm water, but you might want to test yourself first with a 1 tsp dose to see if you get a strong reaction to it. Some people use it in cooking too.