MMP1 and Abnormal intestine morphology: Although we did not directly investigate a link between enteropathy and MMPs in this study, this finding suggests a mechanism by which M. avium, through induction of MMP-1 (Biancheri et al., 2013, Giuffrida et al., 2014, Steck et al., 2012), could at least be partially responsible for some of the morphological changes seen in enteropathy.