You can reduce the acidity in your body by consuming some apple cider vinegar.
Also try eating a bit more slowly which helps reduce the acid build up in your body and stomach.
To reduce the acidity in your body you should also avoid foods that are more acidic and avoid drinking too much soda.
Some good foods you can eat when you need to reduce the acidity in your body are foods such fruits and vegetables and drink lots of water.
Doing those things can reduce the acidity in your body overtime.
Also consider sleeping on an incline especially if you have acid Reflux disease.
Apple Cider Vinegar is pretty acidic so it would increase the acidity in your body instead of reducing the acidity in your body.
Still your body has ways of keeping the acidity in your body at correct levels so even though the Apple Cider Vinegar may increase acidity in your body it won't increase it by much.
Also some people have reported that Apple Cider Vinegar does become Alkaline so it may reduce acidity in your body but there's no guarantee.
Eating leafy green vegetables and drinking some Alkaline based water can help reduce the acidity in your body.