This website claims that apple cider vinegar is a strong bactericide and is useful in alleviating food-poisoning illness by killing any and all ingested food-borne bacteria which release abhorrent toxins.
Does this claim have scientific merit? If so, does any type of vinegar work, and how much should be taken and at which time intervals?
I would be highly skeptical of this claim. The mechanism that this is supposed to work by is as some sort of antibacterial agent. Although, the mild acid in vinegar really is nothing compared to the acids that are already in your stomach. The main reason that vinegar is associated as a food poisoning remedy could be because vinegar is often used as a method of preserving food for longer periods (i.e. pickling).
Or as is mentioned at the Washington State University site
ORGANIC ACIDS: As you recall, all microbes require an #optimum pH or acidity in their environment to grow. If there is too much acid or base, a microbe will not grow. As the by-products of many microbial fermentations include the production of chemicals like ACETIC ACID (vinegar), LACTIC ACID, and PROPIONIC ACID it is not too surprising to find that humans, and other life, can actually use these substances as nutrients. However, when they are added to foods in sufficient quantities to lower the pH below that which will support the growth of most food-spoilage microbes, they can serve as natural food preservatives. Again, our ancestors recognized that "SPOILED" foods such as milk and certain vegetables, retained their nutrition upon becoming acidic and remained eatable (preserved) for long periods. Thus was born choice food items like yogurt, sauerkraut, pickles, cheese and buttermilk. Artificial acids, like benzoic acid, inhibit the growth of some molds, thus it is added to breads and other bakery products that require long shelf live. In many foods, like the sauerkraut you made in lab, salt is combined with acids to preserve food.
This site from the University of Maryland Medical Center states
Apple cider vinegar is a traditional remedy that, although it has not been studied scientifically, may have some antimicrobial properties. Mix 2 tsp. in one cup warm water and drink several times a day.
BOTTOM LINE: No studies back it up, but there appears to be no harm in doing it as long as you dilute the vinegar.
Keep in mind, if someone has ingested a non-food poison, Poison Control Centers specifically state
Do not give salt, vinegar, citrus juice or induce vomiting unless instructed to do so by the Poison Control Center.
Vinegar is a potent antimicrobial agent. It can kill many of the most bacteria most commonly associated with food poisoning, including Salmonella, E. Coli, and Staphyloccus (Chang and Fang 2007; Rhee et al, 2003; Entani et al 1998; Wang et al 2011)
Most studies only address the direct effect of vinegar on pathogenic organisms, but do not address the effects of vinegar taken after infection.
