V. Fanos, R. Pintus, M. C. Pintus, M. Mussap, and M. A. Marcialis, “Seven secrets of COVID-19: fever, ACE2 receptors, gut-lung axis, metabolomics, microbiomics, probiotics, diet”, J Pediatr Neonat Individual Med, vol. 10, no. 1, p. e100145, Jan. 2021.