Normally, hydrochloric acid and the relatively brief duration of gastric digestion, prevent any conspicuous degree of activity of microorganisms in the stomach. Moreover, the stomach normally becomes nearly sterile in its resting periods. Thus stomach contents, whether after a meal or consisting of the jejune juices, contain fewer bacteria by far than the mouth or intestine, under ordinary conditions. Hpyerchlorhy-dria, unless complicated with ischochymia, or unless occurring as an occasional, transitory condition, is incompatible with any marked degree of saprophytosis, either consisting of fermentation of carbohydrates, rancidity of fats or putrefaction of proteins and other nitrogenous foods, providing that such changes are not already in progress when they are ingested.

Any condition that tends either to depress hydrochloric acidity, directly to interfere with digestion, or to cause stagnation in the stomach, tends to cause gastric saprophytosis. Sometimes one, sometimes all of these factors are operative, and there is not always a direct correspondence of potential cause and actual effect. Usually, gastric saprophytosis is limited mainly to fermentation 18 of carbohydrates. Notable rancidity of fats and putrefaction of proteins and other nitrogenous foods usually occur together and only when there is marked failure of hydrochloric acid as well as protracted stagnation - hence mainly in cancer or when, for some reason, intestinal bacteria have invaded the stomach, as after gastroenterostomy or during intestinal obstruction more or less absolute.

In all forms of gastric saprophytosis, there is an indication to limit the food stuffs attacked by saprophytes, even to the degree of keeping the stomach entirely free from food for a few days but there is an obvious nutritional contraindication to reducing any or all kinds of organic foods for any considerable period. Thus, in the ordinary form, consisting in fermentation of carbohydrates, it is well to limit the starches and sugars to some degree, fats can almost always be eliminated from the diet for any length of time, and meats and eggs whose proteins are most prone to putrefaction, may be dispensed with for some time.

The real indications, however, are to restore gastric motility and secretion, if possible; to administer foods recently sterilized by heat rather than raw foods and to avoid foods, however well sterilized, in which saprophytic changes have already begun; to use actual antiseptics, in addition to the hydrochloric acid implied in the first indication since certain antiseptics are relatively efficient, in spite of the scepticism bred by test tube experiments; to keep the mouth and throat as nearly aseptic as possible - and conservative or destructive and constructive dentistry must not be forgotten in this connexion - to keep the stomach also relatively aseptic by lavage or at least the use of hot water before meals; and to diminish intestinal saprophytosis by appropriate means.

In mild cases, it suffices to avoid gross dietetic errors and to maintain hydrochloric acidity. In others, more severe but mainly limited to carbodydrate fermentation, a meat, egg or milk diet may be pursued for a few days. Again, the best diet is of cereals with small quantities of meat, milk and eggs and fruit juices. So long as nothing is done to restore gastric function, it is too apt to follow that the more the diet is reduced, the more it has to be. It is a general principle that certain strains of bacteria become increased in virulence by constant use of the same pabulum. Thus a radical change in diet is usually indicated.

Milk is especially apt to cause trouble hence, particularly in infants, temporary change to some substitute food as already mentioned under dietetics of infancy, or even to another kind of milk, as goat's milk, is often indicated. In adults, milk may usually be suspended altogether.

In the more serious and often cancerous conditions, attended with rancidity and putrefaction, a diet consisting mainly of cereals and of soft, well masticated or chopped green vegetables, such as peas, green beans etc., and fruit, in moderate quantities, even with considerable amounts of sugar to supply energy, often works well.