Dr. Kellogg's Lectures on Practical Health Topics, Vol. 1

Excerpt from Dr. Kellogg's Lectures on Practical Health Topics

The germs that are ordinarily found in the human intestine may be divided into two classes; namely, fermentation germs and putrefaction germs. Fermentation germs feed upon carbohydrates; that is, starch, sugar and dextrin; while putrefaction germs feed upon protein  such substances as the white of eggs, the lean of meat, and the curd of milk. Roughly speaking, we may say that fermentation germs feed upon vegetable and putrefaction germs upon animal substances.