The gastrointestinal tract of humans is colonized by hundreds of microbial species, - bacteria, archaebacterial, fungi, protozoa and viruses -, collectively named the gut microbiome. The intestinal commensal bacteria have an important role in metabolic processes and contribute to colonization resistance against intestinal pathogens. Fungi are usually considered to be a minor component of the global microbiome. However, the mycobiome (fungal component of the entire microbiome) has been in fact little studied particularly with regards to its relationships with the other components of the microbiome. Fungi could be important players of the microbiome because some fungal species are able to proliferate in response to diet or during dysbiosis due to antibiotic treatment or gut inflammation. The aim of this project is to investigate the effect of specific antibiotics (primarily anti-Gram negative bacteria antibiotic) on the gut mycobiome. More specifically, we will examine the impact of cefotaxime and ceftriaxone, 2 antibiotics with same antimicrobial spectra but different rates of biliary elimination, on the changes in fungal communities.

Bacteria analysis of fecal samples by 16S sequencing has provided a wealth of information for the distribution of bacterial species in both health and disease conditions. When looking at bacterial com