Inflammatory Bowel Disease

The term inflammatory bowel disease (IBD) addresses a series of serious conditions affecting the gut. The most common ones are represented by Crohn’s disease and ulcerative colitis which are characterised by chronic inflammation in the intestine.1 In both diseases, symptoms include bloody stools, abdominal pain, diarrhoea and weight loss. 

In ulcerative colitis, the inner lining of the large intestine is continuously inflamed and the development of ulcers is commonly observed.2 In contrast to ulcerative colitis, Crohn’s disease affects the entire digestive tract (from mouth to anus) although common cases locate in the small intestine and the proximal part of the colon (in all layers of the bowel walls).3 In contrast to ulcerative colitis, patients with Crohn’s disease present inflamed areas of the intestine within healthy parts of the intestine.  Both Crohn’s disease and ulcerative colitis recur repeatedly which represents a burden to patients who undergo to a long period of treatment consisting in dietetic and steroid therapies.4 

The causes triggering both conditions are yet to be elucidated. However, they have been suggested to be multifactorial including a genetic predisposition and an abnormal reaction of the immune system to the commensal gut bacteria. In the latter case, some characteristic shifts from the composition of the commensal gut microbiota have been observed. For instance, Bacteroides and Firmicutes are decreased as well as Faecalibacterium prausnitzii and there is an increase in Gammaproteobacteria abundance. The microbial function also shifts presenting a lower butyrate production and amino acids biosynthesis and a high oxidative stress.5

IBD has a considerable impact on the quality of life of subjects. Besides experiencing a drop in their energy levels, individuals can experience abscesses or blockages in the gut. The modulation of gut’s inflammation is a key factor for the handling of both Crohn’s disease and ulcerative colitis. In case the conditions are not improved by medication, surgery is commonly performed in order to remove the affected gut segment.  



1. Baumgart (2012) Crohn’s Disease and Ulcerative Colitis—From Epidemiology and Immunobiology to a Rational Diagnostic and Therapeutic Approach. Springer, New York, 2012, ISBN 1461409977.

2. Adams and Bornemann. (2013) American Family Physician 87(10):699-705.

3. Baumgart and Sandborn. (2012) Lancet 380:1590-1605.

4. Drossman et al. (Eds.). (2016). Rome IV: Functional Gastrointestinal Disorders: Disorders of Gut-brain Interaction. Rome Foundation.

5. Kostic et al. (2014) Gastroenterology 46(6):1489–1499.