On the utilization of salep mannan

Some experiments on the utilization of salep mannan were reported in 1911. 1 It was found that this anhydride of mannose was not hydrolyzed by the enzymes of saliva, pancreatic and intestinal juice, nor by malt diastase, but disappeared almost completely from the human alimentary tract when eaten, the coefficient of digestibility in three out of four experiments being 100 per cent. and 94 per cent. in the fourth. Studies of the effect of fecal bacteria indicated that some of them could produce appreciable amounts of sugar from this polysaccharide, and stimulated further research as to its precise fate in the animal organism. Investigations were interrupted in 1914, when the war cut off the supply of salep, and what has been accomplished along several lines is now reported as it is doubtful when these studies can be resumed.

Four more determinations of the coefficient of digestibility were made, two on healthy young women and two on diabetics. The young women, consuming identical and uniform diets, free from cellulose, throughout a fore, mid, and after period, took in the mid period of three days 75 grams of salep mannan, equivalent to 61 grams of glucose. The coefficient of digestibility was 97 per cent. in one case and 95 in the other. A diabetic man given in one day 45 grams of salep mannan, with no other food but broth, coffee and whiskey, had a coefficient of 98 per cent. A diabetic boy fifteen years old, took in three days 33, 65 and 70 grams of mannan respectively, and the coefficient of digestibility was 96 per cent. This was the largest amount administered to any subject. There was in no case any discomfort from gas formation, or other evidence of fermentation.