The role of dietary fatty acids on the gut mycobiome of Muc2-/- mice and the implications of maternal dietary fat intake on the breast milk mycobiome

Knowledge about the mycobiome and the factors that drive fungal composition in various niches of the body is poorly understood. Though only a small component of the entire microbiome, many relationships between fungi, the host, other microbes, and environmental exposures such as diet have been described. The aims of this project were to 1) utilize next generation sequencing techniques to explore the diversity and community composition of fungi in the gut of Muc2-/- mice and in human breast milk, and 2) to determine the effect of dietary fats on the fungal community in these two environments. In mice, changes in the stool and colon tissue mycobiome were examined after 9 weeks on diets differing only in fatty acids. In human breast milk, the fungal community was analyzed at two time points over the early breastfeeding period, and relationships between the intake of maternal dietary fat and other dietary compounds with the mycobiome were explored. In mice, we observed fungal compositional changes in Muc2-/- mice compared with Muc2+/- mice, suggesting a link between enteric disease progression and gut fungi. The stool mycobiome is not as heavily influenced by dietary fats as are fungi associated with colonic epithelial tissue; however, changes in the large rarely occurring community was observed in both. I suggest a mucosal-associated mycobiome has the physiological potential to persist in the gut and fatty acid exposure could be influential in fungal shifts and inflammatory disease progression. In breast milk, we observed high fungal richness and a community composition that is relatively stable over time. Maternal diet was not a major driver of the overall milk mycobiome composition, though correlations between individual taxa and dietary components and fats were observed. Overall, we show dietary fats are not strong predictors of the overall fungal composition in either niche. However, fats do influence shifts in alpha diversity and relative abundance of specific taxa. While more studies are needed to determine the effect of these shifts, the results of this study can provide insight into predicting the presence of fungi that could impact host enteric disease susceptibility and aspects of infant immune development.Science, Irving K. Barber Faculty of (Okanagan)Biology, Department of (Okanagan)Graduat