Rhodotorula spp. in the gut – foe or friend?

Rhodotorula spp. belong to the basidiomyceteous fungi. They are widespread in the environment. Transmission to humans occur mainly through air and food. Intestinal colonization is rather common, but an overgrowth is normally suppressed, since their optimal growth temperature is exceeded in the body. A massive presence in the gut indicates a disturbance of the balance of the microbial flora due to different causes. One particular reason will be the treatment with azoles because this will create an advantage for these azole resistant fungi. First of all, the finding of increased numbers of Rhodotorula in stool specimen is not alarming. In contrast, the colonized human will profit from such a situation since these fungi produce a lot of useful nutrients such as proteins, lipids, folate, and carotinoids. Furthermore, a probiotic effect due to regulation of multiplication of pathogenic bacteria and by neutralizing or destroying their toxins can be anticipated. On the other hand, their massive presence may increase the risk of fungemia and ensuing organ infections especially when the host defense system is hampered. Indeed, Rhodotorula spp. range among the emerging fungal pathogens in the compromised host. However, it can be doubted whether all these opportunistic infections reported originate primarily from the gut.