70 EXPERIMENT STATION RECORD. 



cium in the feces consists of calcium phosphate which was not resorbed. The 

 effect of phosphorus on masnesium was of the same character as that on cal- 

 cium but was less marked. 



Metabolic minimum in man, R. Tigerstedt (^kand. Arch. Physiol., 23 

 {1910). Xo. .i-//, pp. 302-30Jf). — In connection with a brief summary and dis- 

 cussion of recent data, the author concludes that 1 calorie per hour per kilo- 

 gram of body weight is to be regarded as the minimum value for energy in an 

 adult man. 



The influence of dietary alternations on the types of intestinal flora, C. A. 

 Herter and A. I. Kendall (Jour. Biol. Chcm.. 7 (1910). No. 3. pp. 203-236, /)?s. 

 3). — The experiments which are reported were carried on with kittens and 

 monkeys, and the results obtained, according to the authors, show that an 

 abrupt change in dietary from a dominantly protein diet (meat and eggs) to 

 a milk and sugar diet is followed by an alternation of physiological conditions 

 with respect to the nature of the intestinal flora, the putrefactive products in 

 the feces and urine, and in certain clinical conditions. 



" The chief characteristic of the bacterial change is the gradual but rapid 

 substitution of an acidophilic nonproteolyzing type of flora for a strongly pro- 

 teolyzing type. The chief feature of the putrefactive conditions in the intestine 

 is the reduction of the indol, skatol, phenol and bound hydrogen sulphid and a 

 diminution in the indican and aromatic oxyacids of the urine. Clinically the 

 most striking feature of the change in diet is (in' monkeys) an improvement in 

 spirits and activity which may safely be construed as showing a markedly 

 improved sense of bodily and psychical well being. 



" It seems fair to ascribe these very definite changes of melioration in part 

 to a somewhat reduced intake in protein material, since in the change from a 

 meat or egg diet to a milk and sugar diet, there has generally been some dimi- 

 nution in protein. It is well known that, other conditions remaining unchanged, 

 a diminution in protein intake is followed by diminished intestinal putrefaction. 

 It is our opinion, however, that the mere reduction in protein in our experiments 

 is not adequate to explain the changes noted. Xor is it likely that the change 

 in the chemical nature of the proteins ingested, as from the [irotein of beef or 

 eggs to the protein of milk, is a prominent influence in effecting this change. 

 It seems much more probable that changes in the flora observed by us are due 

 mainly to the influence of the carbohydrates and that the diminished intestinal 

 putrefaction is due to the combined influence of a diminution in protein and 

 the addition of carbohydrate materials to the diet. 



" One of the most interesting features of our studies is the extensive bac- 

 terial degeneration which follows the change from one diet to another. It is 

 possible that in conditions of disease of the intestinal tract where undesirable 

 bacteria abound both on a protein diet and on a diet rich in carbohydrates, 

 frequent alternations in the chemical nature of the diet ai"e beneficial by inter- 

 fering with the establishment of any one type of bacteria in the intestine. 



"The physiological alternations in thq flora which we may claim to have 

 established by our studies have been noted by us only in normal animals. We 

 have as yet made no effort to study the effects of diet on animals in which the 

 digestive tract is the seat of inflammation. It is our intention to determine 

 what influence, if any, is exerted by pathological processes on the laws of bac- 

 terial alternations which we have noted in health. 



" We are unable to state whether the processes which we have studied in 

 animals hold sway in man but consider it likely that analogous conditions will 

 be found to e.xist." 



For earlier work see a previous note (E. S. II., 22, p. 373). 



