Analysis of the fungal, archaeal and bacteriophage diversity in the human distal gut
The composition and role of bacteria in the human gut has been studied intensely and is a burgeoning field of scientific research. However, there is a relative lack of research on other microorganisms which compose our gut flora such as bacteriophage, archaea and fungi. The aim of our study was to begin to fill this gap. The archaeal, fungal and bacteriophage diversity in the gut was analyzed using a PCR-DGGE fingerprinting method on fecal samples from 3 healthy donors. These samples were inoculated into chemostats and the microbes were grown in continuous culture to model the interactions of our flora in vitro. Norepinephrine was also added to the chemostats to test the microbial community’s reaction to stress. Here we report that, relative to bacteria, fungal and archaeal diversity in the gut is low. The archaeal populations seemed stable over time varied depending on the individual. Fungal populations were more variable over time and changes in the community structure were observed after the addition of norepinephrine. DNA sequence analysis confirmed the presence of fungal species that are not yet cultured, yet are residents of the gut. Species of Podophage can also be detected as residents of the gut based on sequence analysis. It is clear that there is a core set of archaeal and fungal species living as residents in the gut. Bacteriophage are also present but their ecological role and effect on the microbial community in the gut is unknown.