Changes in the rectal FUNGAL microbiome associated with oral itraconazole administration in healthy cats

The microbiome serves many important functions at various sites within the body. Drugs, particularly antimicrobials, can interfere with normal functions causing dysbiosis and predisposing to disease. Fungi are an important part of the body's microbiome. Therefore, it is possible that anti fungal drugs, which are commonly used in cats to treat infections such as dermatophytosis, negatively impact the fungal microbiome. Furthermore, changes in the fungal microbiome cause reciprocal shifts in bacterial populations, so anti fungal drugs may also alter the bacterial microbiomes of cats. This study examined changes in the fungal and bacterial populations of healthy feline gut (rectal swab) before, during, and through to 6 months after administration of a standard 5-week course of itraconazole. Samples were analyzed for microbial genetic composition using high-throughput sequencing methods. Identifying if and how the feline microbiome changes in response to itraconazole has several important implications for feline gut health. We documented disruption in gut microbial populations. Thus, it is possible that this dysbiosis could contribute to the adverse gastrointestinal effects of this drug and therapies directed at improving microbiome health (e.g., prebiotics, probiotics) could be helpful in decreasing these signs. Identifying changes in the gut microbiome caused by itraconazole also improves our understanding of how anti fungal therapy could influence risk for future diseases associated with dysbiosis (e.g., inflammatory bowel disease, metabolic disease).