BackgroundAirways of lung cancer patients are often colonized by fungi. Some of these colonizing fungi, under particular conditions, produce cancerogenic mycotoxins. Given the recent interest in the infective origin of lung cancer, with this preliminary study we aim to give our small contribution to this field of research by analysing the fungal microbiome of the exhaled breath condensate of lung cancer patients from Puglia, a region of Italy.MethodsWe enrolled 43 lung cancer patients and 21 healthy subjects that underwent exhaled breath condensate and bronchial brushing collection. The fungal incidence and nature of sample collected were analysed by using a selected media for Aspergillus species.ResultsFor the first time we were able to analyse the fungal microbioma of the exhaled breath condensate. 27.9% of lung cancer patients showed a presence of Aspergillus niger, or A. ochraceus or Penicillium ssp. while none of the healthy subjects did so.ConclusionThe results confirmed the high percentage of fungal colonization of the airways of lung cancer patients from Puglia, suggesting the need to conduct further analyses in this field in order to evaluate the exact pathogenetic role of these fungi in lung cancer as well as to propose efficient, empirical therapy.