Urinary and oral microbiota from participants in a pilot case-control study of breast cancer in Polish women

Anna Marciniak ^1* Marzena Skrzypczak-Zielinska ² Oliwia Zakerska-Banaszak ² Elżbieta Nowakowska ³ Anna Kozaczka ⁴ Brunon Zemła ⁵ Andrzej Szpak ⁶ Dariusz Godlewski ¹ Jadwiga Charzewska ⁷ Dorothy Pathak ⁸

• ¹ Center of Cancer Prevention and Epidemiology OPEN, Poznan, Poland
• ² Institute of Human Genetics, Polish Academy of Sciences, Poznań, Greater Poland, Poland
• ³ Affidea International Cancer Center Poznan, Poland, Poznan, Poland
• ⁴ Department of Nephrology, Transplantation and Internal Medicine, Medical University of Silesia, Katowice, Poland, Katowice, Poland
• ⁵ Department of Nuclear Medicine and Oncological Endocrinology , Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Poland
• ⁶ Institute of Rural Medicine Witold Chodźki (IMW), Lublin, Lublin, Poland
• ⁷ Department of Nutrition and Nutritional Value of Food, National Institute of Public Health NIH-National Research Institute, Warsaw, Poland
• ⁸ Department of Epidemiology and Biostatistics, College of Human Medicine, Michigan State University, East Lansing, Michigan, United States

Introduction: The human microbiota can be a critical component in the development and progression of various diseases, including cancer. This study aims to investigate the composition of the urinary and oral microbiota in Polish breast cancer (BC) patients relative to healthy controls (HC) and to predict relevant metabolic pathways of microbiota in studied groups. Methods: Urine and oral samples from 48 participants, 24 BC and 24 HC randomly selected from 417 BC cases and 514 HC, were analyzed using next-generation sequencing of bacterial 16S rRNA gene (V1-V9) and fungal ITS regions, and bioinformatics tools to identify and compare microbial communities and to predict relevant pathways of microbiota in studied groups. Results: BC cases urine microbiota contained an increased abundance of Corynebacterium (5.2-fold, but not significant), Gammaproteobacteria including unknown genus and Pseudomonas (1.7 and 1.8-fold), and decreased abundance of Family XI (0.3-fold) and Bifidobacteriaceae (0.4-fold) compared to HC. Oral BC microbiota contains higher levels of bacterial families: P5D1-392, Leptotrichiaceae, and Pasteurellaceae (3.3, 3.3 and 1.9-fold), whereas Cellulosimicrobium, Pseudomonas and Pantoea genera were significantly less abundant (0.4, 0.3 and 0.3-fold). At the species level, the most differentiating between BC and HC was uncultured Pseudomonas sp. (1.8-fold) in urine and Pantoea agglomerans (0.2-fold) in oral microbiota. Fungal composition did not show any significant differences between groups. Functional analysis based on PICRUSt2 predicted, i.a. enhanced hydrogen production and benzoyl-CoA degradation in, and reduced CMP-diacetamido-8-epilegionaminic acid biosynthesis in BC cases. Discussion: The study underscores the potential importance of the microbiota in BC pathogenesis. Further research is needed to elucidate the mechanisms underlying microbiota-tumor interactions and to explore the clinical applications.