MicroRNAs in inflammatory bowel disease: What do we know and what can we expect?

Table 1 Roles of microRNAs in patients with inflammatory bowel disease

What is already known about miRNAs in IBD?	What can we expect from miRNAs in IBD?	Ref.
Regulate cellular processes and homeostasis	Discover new functions in the pathophysiology of IBD	[8-11]
Differentially expressed between patients with IBD and healthy controls	Can be used as diagnostic markers for IBD	[5,6,16-19]
Differentially expressed between UC and CD	Can be used to differentiate UC from CD	[6]
Differentially expressed with respect to disease activity	Can be used as biomarkers of inflammatory activity	[16,17,19,32]
Regulated in response to drug exposure	Can be used as markers of drug responses	[20]
Regulate the expression of inflammatory cytokines	Potential therapeutic targets in IBD	[21,22,23]
Act on the intestinal barrier	Potential therapeutic targets in IBD	[25,26]
Modulate the intestinal microbiota	Potential therapeutic targets in IBD	[27-29]

CD: Crohn’s disease; IBD: Inflammatory bowel disease; miRNA: microRNA; UC: Ulcerative colitis.

Table 2 Barriers to the use of microRNAs in clinical practice

High exam cost

Better definition of miRNAs as diagnostic markers in IBD (differentiation between UC and CD and diagnosis of disease activity)

Few validation studies of miRNAs as blood, fecal, and endoscopic biomarkers

Better definition of the differences between the expression of fecal, blood, and tissue miRNAs

Lack of evidence validating miRNAs as a tool for evaluating mucosal healing

Lack of evidence validating miRNAs as a tool for evaluating histological remission

Lack of evidence validating miRNAs predictors of clinical and endoscopic responses

Lack of evidence validating miRNAs in treatment monitoring

Lack of evidence validating miRNAs as predictors of severe disease

Insufficient data on the role of miRNAs in modulating the inflammatory response

Insufficient data on the effects of miRNAs on the intestinal barrier, intestinal microbiota, and the response to probiotics

CD: Crohn’s disease; IBD: Inflammatory bowel disease; miRNA: microRNA; UC: Ulcerative colitis.