Changes in gut mycobiome in Polish melanoma patients

Recent research has suggested that the microorganisms inhabiting our gut, collectively known as the gut microbiota, may play a critical role in the development and progression of melanoma. Most research has concentrated on bacteria, while gut fungi are usually neglected. Meanwhile, gut fungi can strongly affect the human body - positively or negatively, depending on the particular species.Here we aim to investigate the association between gut mycobiota and melanoma and characterize changes in gut mycobiota during anti-PD-1 therapy. We analyzed 163 stool samples from melanoma patients treated with ICI therapy and 134 stool samples from healthy donors. We found out that the gut mycobiota of melanoma patients is distinct from the gut mycobiota of healthy participants. Melanoma samples were characterized by an increased amount of Candida albicans, Candida dubliniensis, Neurospora crassa, and a slight increase of Thermothielavoides terrestris. At the same time, Saccharomyces cerevisiae and Debaryomyces hansenii were decreased in melanoma samples. We also detected several fungal species whose abundance varied during anti-PD-1 therapy.To our knowledge, this is the first study entirely concentrated on the fungal part of the intestinal microbiota of melanoma patients and the first tracking its changes during anti-PD-1 therapy. The findings from this study may provide important insights into the complex interplay between the gut microbiome and cancer, paving the way for the development of novel strategies for the prevention and treatment of melanoma.