In this sense, a large body of evidence has demonstrated that leptin supplementation reduced the infections of some pathogens; such as bacteria (Listeria monocytogenes, Klebsiella pneumonia, Escherichia coli, Mycobacterium tuberculosis, etc....) [61,62,63,64] virus, fungus and parasite infections as well as their pathogenicity by increasing the phagocytic activity of macrophages. This evidence concerns the gene LEP and parasitic infectious disease.