Apple cider vinegar is a well-loved cure-all for numerous conditions. Over the course of centuries, vinegar has been credited for healing rashes, and helping ease digestive complaints and acne. Little evidence exists to prove these claims one way or the other. However, some research does suggest apple cider vinegar has an effect on bacteria. That being said, do not substitute vinegar for antibiotics or use it medicinally in any other way without consulting your doctor.
According to Medscape General Medicine, apple cider vinegar has been shown in laboratory research to reduce the amount of bacteria on food. It is believed the acidity in vinegar helps to create an environment where bacteria just won't grow. This explains vinegar's long-time use as a preservative. However, little research has been done to show vinegar's effect on bacteria outside of food preservation, let alone its effect on bacterial infections in the body.
According to alternative health expert Earl Mindell, M.D. and author of "Dr. Earl Mindell's Amazing Apple Cider Vinegar," apple cider vinegar can prevent urinary tract infections. Mindell asserts that drinking vinegar creates a slightly more acidic environment in the urinary tract and creates slightly more acidic urine, both of which help to discourage bacterial growth. Unfortunately, this may only work as an infection preventative, not a cure. If you believe you have an infection, you should see a doctor for antibiotics.
Apple cider vinegar is also thought to aid in the prevention of sinus infections. According to "The Vinegar Institute," adding 1/4 cup of vinegar to a vaporizer along with water can flush out the sinuses. Again, this shouldn't be used as a substitute for antibiotics or medical care. Rather, it may be a way of preventing further infections.
Apple cider vinegar has been used as a method of treating wounds for centuries. According to Medscape General Medicine, vinegar was used to clean out wounds and prevent infections all the way back to 400 BC. According to a study from the University of North Carolina School of Medicine referenced in Medscape General Medicine, vinegar can prevent bacteria from growing. Though this is a promising result, modern-day wound treatment methods are much more effective than vinegar. So, while applying diluted apple cider vinegar to a wound may stave off infection, it's not substitute for antibiotics, nor will it cure an existing bacterial infection.