[Sidenote: Solubility and distribution of bacterial waste-products]
Under ordinary conditions the bacteria themselves do not penetrate the intestinal walls, and their evil influence would be confined to mechanical disturbance of gas in the digestive organs, and to the destruction of a portion of the nutritive material of food, were it not for the fact that these harmful and poisonous waste-products I have mentioned, are soluble, and hence pass through the intestinal walls with the digested food material, into the blood, and are thus distributed throughout the body.
It has been observed in the presence of intestinal congestion, where the food lies in the intestines for an abnormally long period, that the amount of these harmful nitrogenous decomposition products excreted by the kidneys, is considerably increased, proving that these products have circulated throughout the body.
[Sidenote: Causes of hardening of the arteries]
Arterio-sclerosis, or the hardening of the walls of the arteries, which has for many years been recognized by scientists as one of the principal causes of old age, comes from two causes:
(1) The over-consumption of starchy foods, especially of the cereal group; and (2) by the continued presence, in the blood, of small quantities of poisonous material which gradually destroys the protoplasm of the arterial walls, and causes them to be replaced by a degenerate form of tissue.
For example, alcohol and the poison of syphilis are prolific causes of the hardening of the arteries. If the diet were balanced so as to avoid excesses of starch and these toxic substances, the hardening of the arteries would not take place.
[Sidenote: Overeating an ultimate cause of old age]
The poisons produced in the intestines by bacterial decomposition, superinduced largely by overeating, are absorbed into the blood, and undoubtedly their action is similar to the other poisons herein mentioned. Thus they become a most potent factor in the cause of old age and premature death, being practically universal among all civilized tribes.
Numerous other disorders or dis-eases can be traced to this same general cause, and the subject of the poisonous products of fermentation and decomposition in the intestines will therefore be constantly referred to throughout this work.