Gastrointestinal Digestion of Starch

Previous papers have dealt with the identification, partial separation, substrate requirements, and properties of the intestinal carbohydrases involved in terminal starch digestion ( 14).The question of the bacterial origin of these enzymes was previously examined.Intestinal extracts prepared in the usual manner and filtered through bacteriological filters were shown to contain enzymatic activity (1).Enzymatic activities of intest,inal extracts prepared from hogs fed a normal rat,ion were compared with those from hogs fed an antibiotic mixture sufficient to elicit a growth response, and no differences were noted (1).In the present experiments, intestinal extracts from germ-free and normally reared rats have been studied.The results indicate that intestinal carbohydrases are present in rats reared in t.he germ-free state in levels comparable to those present in non-germ-free animals.Since enzymatic act,ivities of extracts prepared from single animals vary and the number of animals examined was limited, the question of a bacterial contribution to enzymatic activity is unsettled.