 M cells within the Peyer's patches physically transport the insoluble whole glucan particles into the gut-associated lymphoid tissue.An assay to detect the presence of (1,3)-β-D-glucan in blood is marketed as a means of identifying invasive or disseminated fungal infections.This test should be interpreted within the broader clinical context, however, as a positive test does not render a diagnosis, and a negative test does not rule out infection.