Abstract
The role of the Fungal Microbiome in the human body has been gradually revealed. Its presence in the gut, although scarce in comparison to bacteria, is now associated with several physiologic functions such as immune responses and interactions with other systems and diseases such as systemic infections and cancer. It is known that fungi may have an impact on the disease progression in certain cancers such as in colon and pancreas and also be influenced by these conditions and the treatments involved (e.g. chemotherapy). Moreover, it is shown that the presence of certain fungal species such as Candida albicans tend to increase in the gut as an effect of therapeutic agents, causing spreading of the he fungi into the bloodstream. Breast cancer, known as the most common cancer in women, is a condition in which the gut mycobiome might be affected by this disease and the therapies applied. The aim of these project is to discover the function of the gut mycobiome and the effects caused by breast cancer and the diverse therapies involved on this group of microorganisms.
For this study 44 breast cancer patients were selected obtaining faecal samples at timepoints 0 and 12 months. DNA was isolated from the samples and amplified through PCR. The PCR product was sequenced using Illumina Miseq and the resulting data analyzed. We examined changes in the number of fungal reads according to time point and several clinical parameters by using Principal Component Analysis (PCA) and Projection to Latent Structures Discriminant Analysis (PLS-DA). In addition, the alpha-diversity (richness in species in an ecosystem) and the mycobiome composition at different taxonomical levels were also assessed.
Although major changes were not found in the composition of the mycobiome or the alpha diversity due to diverse limitations, our results demonstrated that radiotherapy might have an impact in the abundance of several fungal communities in the gut.