MICROBES IN THE HUMAN BODY 37 



breaks down the peptones, producing indol, phenol, mercaptan 

 and sulphuretted hydrogen. It is precisely these bodies, 

 putrefaction products, which enter the blood and produce the 

 chronic poisoning which induces premature old age.^ Among 

 the bacteria of the intestine, B. ladis aerogenes, B. perfringens, 

 B. sporogenes, Staphylococcus pyogenes and Proteus produce 

 indol. B. colt produces both indol and phenol, and there is ex- 

 perimental proof that indol, phenol, and their sulpho-compounds 

 can produce auto-intoxications of the body. With indol and 

 potassium phenyl-sulphate, aortic atheroma has been produced 

 in rabbits in about 60 per cent, of those tried, whereas 

 spontaneous atheroma does not occur in more 'than 6 to 10 

 per cent. Monkeys treated with paracresol presented arterial 

 lesions in the brain and kidney. By combining the phenols 

 with sulphur, the body manufactures " sulpho-compounds " 

 which are less injurious than the pure phenols, but which are 

 still chronic poisons (Metchnikofif). 



Intestinal Putrefaction. — The study of the putrefactive 

 bacteria being in its infancy and beset with great difficulties 

 besides, it is not surprising that certain authorities maintain that 

 intestinal putrefaction is harmless to man. 



It is true, they say, that our instinct leads us to reject putre- 

 fying food and that common sense has always connected 

 putrefaction with disease. Yet we see the Indo-Chinese, the 

 Malays, Polynesians, and the Greenlanders regaling them- 

 selves with decayed fish, meat, or eggs ! Meat which has gone 

 bad frequently determines diseases resembling acute pbisoning ; 

 but it is not because it is putrefying ; it is because it contains 

 pathogenic bacteria of the family of B. typhosus, or bacilli like 

 the B. of botulismus, which produces a violent toxin. Extracts 

 of putrefied meat have been injected into different animals with- 

 out result. Further, how many people exist in perfect health in 

 spite of the putrefaction going on normally in their intestine ! 

 It recalls the dictum of Malvoz : " Tout ce qui pue ne tue 



' The intestinal flora of the dog does not differ from thai of man. 

 Little rabbits eight days old have not a rich flora. The flora of parrots, 

 young and old, is also scanty (five species in the ileum). The flora of the 

 alligator is much less rich than that of man. 



