The intestinal microflora plays an important not only in establishing immune tolerance but also in the development of inflammatory bowel disease and obesity. While studies of the microbiome have mostly focused on commensal bacteria, several species of fungi are also major constituents of the mammalian gastrointestinal system, with highest fungal concentrations in the colon. It is estimated that fungi are detectable in all gastrointestinal segments of about 70% of healthy adults, with Candida spp. being predominant. Candida albicans is a commensal fungus of the human gastro-intestinal tract, capable of causing life-threatening opportunistic fungal infections. C. albicans is considered opportunistic pathogen or a “pathobiont”, a resident microbe with pathogenic potential yet harmless under normal conditions. Gut-colonizing Candida can cause candidaemia, but mucosal damage and neutropenia are required for Candida dissemination from the colon. An increase in fungal load and Candida species was observed in patients suffering from Crohn’s disease. The C-type lectin Dectin-1, which recognizes cell wall b1,3- glucan, is the major receptor involved in antifungal immune responses. While essential during antifungal immune responses during systemic C. albicans infections in mice, lack of Dectin-1 does not affect gastrointestinal colonization by C. albicans. Dectin-1 knockout mice are more sensitive to chemically-induced colitis, presumably due to diminished immune surveillance of endogenous fungal species. The contribution of fungi to the development of IBD is further illustrated by human polymorphisms in Dectin-1 associated with ulcerative colitis and its signaling molecule CARD9. The latter has been associated with both UC and Crohn’s disease. Serum antibodies against yeast cell wall components are predictive for Crohn’s disease and ulcerative colitis. Influenza A virus is an enveloped virus containing eight negative-sense RNA gene segments. It is the causative agent of seasonal epidemics of respiratory illness as well as occasional pandemics, the most recent of which occurred in 2009. IAV is pleomorphic, producing virions of spherical and filamentous morphology. Strains that produce predominantly spherical or ovoid virions have typically been passaged many times within laboratory substrates, while filament-producing strains occur in primary or low passage isolates. Filaments are of variable length and can be up to 30 mm long. Herein, we NVP-BKM120 define filaments as any virion 300 nm in length or longer. Studies performed using reverse genetics systems have identified the M1 matrix protein as the major genetic determinant of virion morphology, however portions of the viral nucleoprotein as well as the cytoplasmic tails of the M2 ion channel, hemagglutinin and neuraminidase proteins have been shown to affect virion morphology as well. Early observations showed that the filamentous morphology is gradually lost upon continued passage in embryonated chicken eggs in favor of a more spherical morphology.