RT Journal Article SR Electronic T1 Unsolved mysteries of intestinal M cells JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 735 OP 739 DO 10.1136/gut.47.5.735 VO 47 IS 5 A1 C NICOLETTI YR 2000 UL http://gut.bmj.com/content/47/5/735.abstract AB