More Pronounced Reduction of Gut Bacteria in Crohn’s Disease than Ulcerative Colitis may have just Reflected Intimate Connection Rather than Difference of these two Diseases-A Different View on Findings Published in Gut

I read with great interest a paper published recently in Gut [1], as its fi nding that patients with Crohn's disease (CD) have more pronounced reduction and dysbiosis in gut bacteria than ulcerative colitis (UC) is just as what I have predicted during the last fi fteen years [2,3]. However, in contrast to the notion of the authors of the Gut paper that the more pronounced reduction in gut bacteria in CD suggests CD and UC are two different diseases, my prediction came from the perception of the profound intimate connections between UC and CD. As we know, countries and places have a high incidence of UC usually also have high rate of CD.