ANEtjRlNE (tHlAMlNE) 



in ruminants (see page 79). Refected rats excrete more vitamin B 

 than non-refective rats on the same vitamin B-deficient diet. 



Refection has also been observed in the pigeon,^ whilst the rabbit 

 may derive some, and possibly most, of its vitamin B supply from 

 the consumption of its faeces. Rabbits excrete two types of faeces, 

 one normal, voided during the day-time, the other, softer and pro- 

 duced during the night. The latter are normally swallowed by the 

 rabbit directly from the anus.® They swarm with bacteria, and are 

 presumably rich in the vitamin B complex. 



Role of the Intestinal Flora 



The presence in rat faeces of components of the vitamin B complex 

 was demonstrated by Light et al.,^^ who found that the animals lost 

 weight when sulphaguanidine was added to the diet, and that growth 

 was restored either by giving the vitamin B complex or faeces from 

 normal rats. They concluded that the sulphonamide inhibited the 

 bacterial synthesis of essential factors belonging to the complex. 



The aneurine content of human faeces was shown to be independent 

 of the aneurine intake by L. Wildemann,^^ who ascribed this to syn- 

 thesis of the vitamin by bacteria in the intestine. He put forward 

 these results rather to prove that faecal excretion, in contrast to 

 urinary excretion, is not a measure of the nutritional status of an 

 individual. His conclusions have since been confirmed by Alexander 

 et al}^ 



The possible significance of the independence of faecal excretion 

 and diet was not appreciated until the publication in 1943 of a paper 

 by V. A. Najjar and L. E. Holt ^^ who, in an attempt to establish the 

 aneurine requirements of man with greater accuracy than had hitherto 

 been possible, maintained nine young male volunteers for several 

 months on a diet supplying only o-i to 0-2 mg. per day. Five showed 

 the anticipated signs of aneurine deficiency, but four showed no 

 signs at all, even after the complete exclusion of aneurine from the 

 diet for a further seven weeks. Free aneurine was found to be present 

 in the faeces, and on giving one of these four anomalous subjects 

 sulphasuxidine the faecal aneurine fell to zero, rising again to the 

 original value when the administration of the sulphonamide was 

 stopped. 



This appeared to indicate that aneurine formed by the flora of 

 the intestine could, under certain conditions, be absorbed in sufficient 

 quantities to prevent the development of aneurine deficiency. That 

 it was probably absorbed from the large intestine was demonstrated 

 by giving a retention enema containing aneurine ; a pronounced rise 

 in the urinary excretion of aneurine followed. 



76 



