Fungal ITS1 amplicon sequencing of IgA- and IgG-based sorting of healthy human fecal microbiota.

Antibodies mediate natural and vaccine-induced immunity against viral and bacterial pathogens, but their importance to antifungal immunity and the control of fungal infections of intestinal origin remains undefined. Healthy human fecal samples were incubated with matched serum samples from the same individual to allow systemic antibodies in the blood to allow for systemic antibody binding to intestinal microbes that are also already bound to the luminally secreted antibodies present in the feces. Feces were then stained with anti-human IgA and IgG secondary antibodies for sorting of antibody bound (IgG+IgA+, IgG+IgA-) and unbound (IgG-IgA-) fungal and bacterial fractions on FACSAria III (BD) with a 100-micrometer flow cell.