Molecular targets and the use of biologics in the management of small bowel fibrosis in inflammatory bowel disease

Integrating inflammatory biomarker analysis and artificial-intelligence-enabled image-based profiling to identify drug targets for intestinal fibrosis

Intestinal fibrosis, often caused by inflammatory bowel disease, can lead to intestinal stenosis and obstruction, but there are no approved treatments. Drug discovery has been hindered by the lack of screenable cellular phenotypes. To address this, we used a scalable image-based morphology assay called Cell Painting, augmented with machine learning algorithms, to identify small molecules that could reverse the activated fibrotic phenotype of intestinal myofibroblasts. We then conducted a high-throughput small molecule chemogenomics screen of approximately 5,000 compounds with known targets or mechanisms, which have achieved clinical stage or approval by the FDA. By integrating morphological analyses and AI using pathologically relevant cells and disease-relevant stimuli, we identified several compounds and target classes that are potentially able to treat intestinal fibrosis. This phenotypic screening platform offers significant improvements over conventional methods for identifying a wide range of drug targets.

Integrating new and emerging therapies into inflammatory bowel disease clinical practice

PURPOSE OF REVIEW

The purpose of this review is to highlight new and emerging therapies in inflammatory bowel disease (IBD) and provide insight on how these therapies can be integrated into clinical practice.

RECENT FINDINGS

The article covers clinical and real-world data for Janus kinase inhibitors, anti-interleukin antibodies, sphingosine-1-phosphate receptor modulators, and anti-integrin therapies. It also explores the potential role of antifibrotic agents, microbiota-based innovations, and for personalized medicine in IBD.

SUMMARY

The treatment of IBD has evolved significantly in the last two decades, with a host of new treatment options available and arising for patients. With these advancements, positioning these drugs in a treatment algorithm to create a more personalized approach to improve efficacy and prognosis is critical.

Intestinal strictures in Crohn's disease: a 2021 update

Intestinal strictures remain one of the most intractable and common complications of Crohn's disease (CD). Approximately 70% of CD patients will develop fibrotic strictures after 10 years of CD diagnosis. Since specific antifibrotic therapies are unavailable, endoscopic balloon dilation and surgery remain the mainstay treatments despite a high recurrence rate. Besides, there are no reliable methods for accurately evaluating intestinal fibrosis. This is largely due to the fact that the mechanisms of initiation and propagation of intestinal fibrosis are poorly understood. There is growing evidence implying that the pathogenesis of stricturing CD involves the intricate interplay of factors including aberrant immune and nonimmune responses, host-microbiome dysbiosis, and genetic susceptibility. Currently, the progress on intestinal strictures has been fueled by the advent of novel techniques, such as single-cell sequencing, multi-omics, and artificial intelligence. Here, we perform a timely and comprehensive review of the substantial advances in intestinal strictures in 2021, aiming to provide prompt information regarding fibrosis and set the stage for the improvement of diagnosis, treatment, and prognosis of intestinal strictures.

Constrictive and Hypertrophic Strictures in Ileal Crohn's Disease

BACKGROUND & AIMS

Strictures in Crohn's disease (CD) are classically attributed to fibromuscular hypertrophy of the intestinal wall. We have identified and characterized CD-related ileal strictures that result instead from mural constriction (ie, reduced external circumference).

METHODS

Twenty-four strictures and internal controls from 17 adults with obstructive CD were analyzed by cross-sectional morphometry.

RESULTS

The stricture-to-control circumference ratios (CRs) ranged from 0.53 to 1.7. Six strictures with CR ≥1.0, designated hypertrophic, had concentrically thickened walls, mean 3-fold increases in cross-sectional area and stainable fibromucular tissue, and high transmural inflammation scores. In contrast, 18 strictures with CR <1.0, designated constrictive, had thin, pliant walls, cross-sectional areas and stainable fibromuscular tissue comparable with control values, and low transmural inflammation scores. Eight mildly constrictive strictures also showed mild fibromuscular mural expansion that fell short of statistical significance. Twelve of 18 constrictive strictures (67%) occurred multiply (2-4 strictures per specimen) in contrast with hypertrophic strictures, all of which occurred singly (P = .01). Constriction correlated quantitatively with circumferential serosal fat wrapping (P = .003) and was associated with myenteric lymphocytic plexitis (P = .02). Disease duration was shortest among subjects with constrictive strictures and correlated with increasing circumference (CR ≤0.8, 6.3 ± 6.2 years; CR >0.8, 8.7 ± 6.4 years; and CR ≥1.00, 13.7 ± 5.0 years, respectively; P = .03).

CONCLUSIONS

Constrictive ileal strictures in CD differ pathologically and clinically from hypertrophic strictures, featuring little or no fibromuscular mural expansion, frequent multiplicity, and earlier onset. Mesenteric fat wrapping and myenteric plexitis may contribute to their pathogenesis. Pathologic manifestations of constriction and hypertrophy can coexist, suggesting that stricture heterogeneity may be shaped in part by the dynamics of constrictive and hypertrophic processes.

Probiotics and gut health

BACKGROUND

Gut microbiota is a complex ecosystem of bacteria, viruses, archea, protozoa and yeasts in our intestine. It has several functions maintaining human body equilibrium. Microbial " dysbiosis " can be responsible for several gastrointestinal diseases.

METHODS

to build a narrative review we performed a Pubmed, Medline, EMBASE search for English language papers, reviews, meta-analyses, case series, and randomized controlled trials (RCTs) by keywords and their associations: gut microbiota, dysbiosis, gastrointestinal diseases, probiotics.

RESULTS

gut microbiota is altered in several gastrointestinal diseases with very different pathophysiology. They range from multi-factorial diseases such as irritable bowel syndrome (IBS), non-alcoholic fatty liver disease (NAFLD) and gastric and colorectal cancers, immunemediated such as celiac disease, inflammatory bowel diseases (IBD), antibioticrelated such as Clostridium Difficile infection (CDI). Microbial dysbiosis re-modulation by probiotics is feasible and safe in some of them.

CONCLUSIONS

gut microbial dysbiosis is statistically associated with several gastro-intestinal diseases, affecting their pathophysiology. Its reverse by probiotics has some promising evidences of efficacy.