LAUSR

Purpose of review Although the mucosal barrier serves as a primary interface between the environment and host, little is understood about the repair of acute, superficial lesions or deeper, persistent lesions that if not healed, can be the site of increased permeability to luminal antigens, inflammation and/or neoplasia development. Recent findings Recent studies have focused on focal adhesion kinase, which regulates controlled matrix adhesion during restitution after superficial injury. Actin polymerization regulates cell migration and the importance of actin-related proteins was also highlighted. Work on SARS-CoV-2 infection lent important new insights on gastroduodenal mucosal injury in patients with Covid-19 infection and work done with organoids and intestine-on-a-chip contributed new understanding about how coronaviruses infect gastrointestinal tissues and its resulting barrier dysfunction. A novel risk stratification paradigm was proposed to assist with decision making about repeat endoscopy for patients with gastric or duodenal ulcers and new therapeutic options were studied for ulcer disease. Lastly, work to support the mechanism of metaplasia development after deep injury and parietal cell loss was provided using novel transgenic mouse models. Summary Recent studies highlight novel molecular targets to promote mucosal healing after injury of the gastroduodenal mucosa.