The B. lactis bulgaricus is one of a widely distributed group of lactic acid-producing organisms which do not proliferate in laboratory media. Metchnikoff and others believe these bacilli modify the intestinal flora, thus limiting auto-intoxication and its train of arteriosclerotic changes which lead to premature senility. While the theory is not proven, the administration of sour-milk products is often beneficial, thus taking the place of protein food and improving nutrition.

Cultures of these bacteria are used to sour milk; they may be given as a remedy, and they may be Used in treating sinuses.

The Streptococcus lacticus is also used to sour milk, as it grows readily at room temperature, whereas the B. bulgaricus does not. In making Kefir and Koumiss, lactic acid-producing organisms are associated with an alcohol-producing yeast, which latter renders the proteins of milk more digestible, but adds an alcohol content.

To produce ferment-action in the intestinal tract, the B. bulgaricus is commonly given in tablet form.

Pure cultures in aqueous suspension are Applied to the nasal cavities and sinuses in putrefactive and suppurative conditions.

For data upon the products offered in trade, see "New and Nonofficial Remedies."