1 a Gastroenterology Department , Hospital da Senhora da Oliveira , Guimarães , Portugal.
2 b Gastroenterology Department, Hospital da Senhora da Oliveira, Guimarães, Portugal, Life and Health Sciences Research Institute , University of Minho, Braga/Guimarães, Portugal, ICVS/3B's, PT Government Associate Laboratory , Braga/Guimarães , Portugal.