From Guanidine, Cider Vinegar and Health, by Dr. Royal Lee, about Dr. D.C. Jarvis's book, Folk Medicine.
Apple Cider Vinegar has been shown to help allergies, burns, shingles, migraine headaches, hypertension, as well as other conditions.
"The control of the flora of the bowel may also be part of the mechanism of apple cider vinegar. Guanidine is an organic alkaline base which we have reported as
being one of the products of unfavorable bacterial activity in the colon.
Sour milk, yogurt and acidophilus yeast (also) have long been known to be beneficial in correcting the local environment; they favor the friendly bacteria and block the growth of toxin producing organisms. The common syndrome of constipation, calcium deficiency symptoms, and a drift to arthritis is obviously a situation calling for acidophilus yeast..."