Some Infections May Be Endogenous

This paper advances a previous hypothesis “Human body may produces bacteria”, and proposes that some infections may be endogenous. It has been demonstrated that the Christensenellaceae, a family in the phylum Firmicutes, is heritable suggesting that human genetic material and gut bacterial material are related and human cells may generate some gut microbes It has also been shown that the fetus is exposed to bacteria prior to birth -without any evidence that they are contaminants or acquired from the environment -suggesting a possible endogenous origin of bacteria in breast milk, meconium, placenta , umbilical cord blood and amniotic fluid. Malassezia yeasts are not contagious, not culturable from the environment, cannot colonize human skin by inoculation without occlusion and neonate skin is free of Malassezia but is colonized in the first month of life suggesting that they may be endogenous. Human stem cells seem to be the most likely candidates to produce microbes: This is because they differentiate to epithelial cells and cancer cells and contain the essentials to transform to microorganisms. Future experimental studies are necessary to validate this hypothesis which may offer a new paradigm to combat opportunistic infections of possible endogenous origin.