Feces of influenza-infected mice on the high fiber diet, contained almost 140-fold greater concentration of butyrate than controls, which was accompanied with accumulation of alternatively activated macrophages in the lungs, enhanced hematopoiesis of pulmonary anti-inflammatory macrophage precursors (Ly6c– monocytes) in the bone marrow, decreased pulmonary concentration of myeloperoxidase, improvement of symptomatic and survival rates [39]. Here, MPO is linked to influenza.