Author contribution
All authors have made substantial contributions to conception and design of the study. M.M. and L.T. designed the study. E.S. and C.F. performed the clinical interventions. E.C., M.D., and I.S. analyzed the microbiological samples; E.C. performed the statistical analysis. M.M., E.S., E.C., M.E.G., R.F., L.T., G.G., and S.M. have been involved in data analysis and interpretation. A.S. and E.C. drafted the manuscript, and all the authors were involved in revising it critically and have given final approval of the version to be published.