Gut Microbiota Profiles and Microbial-Based Therapies in Post-operative Crohn's Disease: A Systematic Review

Letter: Gut microbiota-An overlooked therapeutic target in the prevention of post-operative recurrence of Crohn's disease

This article is linked to Bak et al paper. To view this article, visit https://doi.org/10.1111/apt.18240.

Preventing Recurrence of Crohn's Disease Post-Ileocaecal Surgery in Paediatric Patients: A Therapy Guide Based on Systematic Review of the Evidence

BACKGROUND AND AIMS

Ileocaecal resection (ICR) is frequent in paediatric patients with Crohn's disease (pCD). Despite rates of reoperation being low, the risk of clinical or endoscopic post-operative recurrence (POR) is high; effective medical strategies to prevent POR are thus needed. The aim of this systematic review (SR) was to identify and evaluate the published literature on post-operative medical prevention of POR in pCD to draft a possible therapy guide for pCD patients undergoing ICR.

METHODS

We performed an SR according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards and registered it in the PROSPERO database (ID: CRD42024533855). The population, intervention, control, outcome (PICO) model was focussed on post-surgical medical prevention of POR in pCD with clearly expressed definition of recurrence (endoscopically using a standardized scoring system (e.g. Rutgeerts score) or by laboratory markers, for example, faecal calprotectin (F-CPT), C-reactive protein (CRP) or by histological findings or by clinical activity indexes [e.g. weighted paediatric Crohn's disease activity index - (w)PCDAI]. From inception until 29 February 2024, the following databases were searched: PubMed/MEDLINE, Scopus/Embase, Web of Sciences, Evidence-Based Medicine Reviews (including Cochrane), Cochrane Central Registrar of controlled Trials (CENTRAL), ClinicalTrials.gov and EudraCT. Retrieved articles were evaluated for eligibility and finally selected publications for risk of bias using ROBINS-I tool.

RESULTS

Out of 811 publications identified by the search, only 5 fulfilled inclusion criteria of the SR. None of the studies fully answered our PICO question. The studies were overall of poor quality and the heterogeneity of the data did not allow us to perform meta-analysis, detailed statistical analysis or formal synthesis of data. Adverse events of post-operative medication were not described in any of the included studies. Existing guidelines of European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN), North American Society for Paediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN), European Crohn's and Colitis Organisation (ECCO) and American Gastroenterological Association (AGA) were reviewed and paediatric therapy guide for pCD undergoing ICR was drafted with respect to recent SRs and meta-analyses in adult population and including scarce paediatric data identified by our SR. As pCD patients undergoing ICR are a high-risk population, they should not be left untreated post-operatively. Anti-tumour necrosis factor (anti-TNF) drugs should be considered as first-line therapy in the majority of patients. Non-anti-TNF biologics should be considered in case of anti-TNF failure. Regular endoscopic monitoring starting at 6 months after the surgery and supported by regular F-CPT evaluation should be used to identify early endoscopic recurrence and to escalate the treatment.

CONCLUSION

Our SR revealed that there is wide variability in treatment strategies in children, and high-quality data are generally lacking. At the moment, paediatric prophylaxis of POR should be guided by available adult evidence with respect to the high-risk nature of pCD. Extensive research in pCD should be encouraged.

Post-operative Crohn's Disease Recurrence and Infectious Complications: A Transcriptomic Analysis

BACKGROUND

Crohn's disease (CD) is a chronic inflammatory condition affecting the gastrointestinal tract, characterized by complications such as strictures, fistulas, and neoplasia. Despite medical advancements, a significant number of patients with Crohn's disease require surgery, and many experience post-operative complications and recurrence. Previous studies have analyzed gene expression to study recurrence and post-operative complications independently. This study aims to identify overlapping differentially expressed genes and pathways for recurrence and post-operative complications.

METHODS

A dataset including 45 patients with Crohn's disease, including gene expression from ileum and colon tissue, endoscopic recurrence, and intra-abdominal septic complications was analyzed. Gene set enrichment analysis was used to identify gene pathways associated with the outcomes. Finally, a multi-variable logistic regression model was created to assess whether gene pathways were independently associated with both outcomes.

RESULTS

In ileum tissue, several inflammatory pathways, including interferon alpha and gamma response were upregulated in patients with endoscopic recurrence and intra-abdominal septic complications. In addition, there was upregulation of the epithelial mesenchymal transition pathway. In colon tissue, metabolic processes, such as myogenesis and oxidative phosphorylation were downregulated in both outcomes. In a multivariate model, downregulation of myogenesis in colon tissue was significantly associated with both endoscopic recurrence and intra-abdominal septic complications.

CONCLUSION

These findings shed light on the underlying biology of these outcomes and suggest potential biomarkers or therapeutic targets to reduce their occurrence. Further validation and multi-institutional studies are warranted to confirm these results and improve post-operative outcomes for patients with Crohn's disease.

Efficacy and safety of probiotics in IBD: An overview of systematic reviews and updated meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Probiotics show promise in inflammatory bowel disease (IBD), yet knowledge gaps persist. We performed an overview of systematic reviews and an updated metanalysis of randomized controlled trials (RCT) assessing the effect of probiotics on Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

MEDLINE, Web of Science, and the Cochrane Central Register of Controlled Trials were searched up to September 2023. Primary outcomes were clinical remission and recurrence; secondary outcomes included endoscopic response and remission, and adverse events. We calculated odds ratios (OR) using a random-effects model in R. The quality of systematic reviews was assessed using the AMSTAR-2; the trials' risk of bias was evaluated using the Cochrane Collaboration tool. Evidence certainty was rated using the GRADE framework.

RESULTS

Out of 2613 results, 67 studies (22 systematic reviews and 45 RCTs) met the eligibility criteria. In the updated meta-analysis, the OR for clinical remission in UC and CD was 2.00 (95% CI 1.28-3.11) and 1.61 (95% CI 0.21-12.50), respectively. The subgroup analysis suggested that combining 5-ASA and probiotics may be beneficial for inducing remission in mild-to-moderate UC (OR 2.35, 95% CI 1.29-4.28). Probiotics decreased the odds of recurrence in relapsing pouchitis (OR 0.03, 95% CI 0.00-0.25) and trended toward reducing clinical recurrence in inactive UC (OR 0.65, 95% CI 0.42-1.01). No protective effect against recurrence was identified for CD. Multi-strain formulations appear superior in achieving remission and preventing recurrence in UC. The use of probiotics was not associated with better endoscopic outcomes. Adverse events were similar to control. However, the overall certainty of evidence was low.

CONCLUSION

Probiotics, particularly multi-strain formulations, appear efficacious for the induction of clinical remission and the prevention of relapse in UC patients as well as for relapsing pouchitis. Notwithstanding, no significant effect was identified for CD. The favorable safety profile of probiotics was also highlighted.

Mucosal microbiome of surgically treated terminal ileal Crohn's disease

Crohn's disease (CD) is associated with changes in the microbiome. The role of these changes and their precise association with disease course and activity remain ambiguous. In this prospective single-center study, the mucosal microbiome of surgical CD and non-CD patients was compared at the time of surgery. Microbial analyses were individually performed for ileal and colonic tissue samples obtained during surgery using 16S-rRNA-gene amplicon sequencing. Three groups out of the 46 included patients were formed: 1) a study group of CD of patients who received ileocecal resection due to CD involvement (CD study, n=10); 2) a control group of non-CD of patients who received intestinal resection due to indications other than CD (non-CD control, n=27); and 3) a second control group of CD who underwent resection of the intestine not affected by CD (CD non-affected control, n=9). Species richness and Shannon diversity were not different between all formed groups and regions analyzed (p>0.05). Several significant taxonomic differences were seen at the phylum-, order-, and genus-levels between the formed groups, such as a decrease of Firmicutes (phylum-level) and an increase of Bacteroides and Escherichia/Shigella/Pseudescherichia (genus-level) in CD study - colon vs. the non-CD control - colon (p ≤ 0.05). The CD non-affected control presented the largest amount of differentially abundant taxa in comparison to the other groups. These results underline that CD is accompanied by changes in affected and non-affected intestinal regions compared to non-CD controls. This study contributes the mucosal microbiome of a well-defined subset of surgical CD patients without confounding aspects of the fecal microbiome or regional microbial differences to the existing literature.

The Role of Oral Probiotics in Alleviating Inflammation, Symptom Relief, and Postoperative Recurrence and Their Side Effects in Adults With Crohn's Disease: A Systematic Review

Crohn's disease (CD) is a lifelong problem for patients, despite having multiple pharmacological options and surgeries for treatment. In order to achieve best results, probiotics are being used even though their efficacy is still debatable. This systematic review analyzes the safety and efficacy of several probiotics in CD. PubMed, the Cochrane Library, and ScienceDirect are the databases searched for randomized controlled trials (RCTs), animal studies, in vitro studies, and reviews. After quality appraisal and cross checking the literature, this systematic review is carried out grounded on Preferred Reporting Items for Systematic Review and Meta-Analysis 2020 (PRISMA 2020) guidelines. A study of 16 papers in total which include nearly 2023 subjects showed that only very few probiotics are efficient in furnishing remission in CD complaints. Kefir, an inexpensive fermented milk product, significantly reduced the inflammation and drastically bettered the quality of life and hence can be considered as an asset for CD patients. Lactobacillus thermophilus, Bifidobacterium longum, Enterococcus faecalis, and Bacillus licheniformis can control diarrhea in patients of 22-54-year age group and improve cognitive reactivity in sad mood with short-term consumption. VSL#3 (VSL Pharmaceuticals, Gaithersburg, Maryland, United States) has good efficacy in precluding recurrence and easing side effects after ileocecal resection in adults. Animal models and lab studies have proved that Lactobacillus plantarum CBT LP3, Saccharomyces cerevisiae CNCM I-3856 (yeast), few strains of Lactobacillus plantarum, Bifidobacterium animalis spp., Lactobacillus acidophilus LA1, Lactobacillus paracasei 101/37, and especially Bifidobacterium breve Bbr8 are significant enough to ameliorate the disease condition. In conclusion, probiotics are safe in CD with very few modifiable side effects. Some probiotics are proven to be significant in animal and lab studies; hence, these should be studied in human RCTs, to check their efficiency in human beings. There are limited observational and interventional studies in this regard. Large population-sizes trials are highly demanded in the areas of prognosticated positive results that are mentioned in this systematic review.

Integration and implementation of precision medicine in the multifaceted inflammatory bowel disease

Inflammatory bowel disease (IBD) is a complex disease with variability in genetic, environmental, and lifestyle factors affecting disease presentation and course. Precision medicine has the potential to play a crucial role in managing IBD by tailoring treatment plans based on the heterogeneity of clinical and temporal variability of patients. Precision medicine is a population-based approach to managing IBD by integrating environmental, genomic, epigenomic, transcriptomic, proteomic, and metabolomic factors. It is a recent and rapidly developing medicine. The widespread adoption of precision medicine worldwide has the potential to result in the early detection of diseases, optimal utilization of healthcare resources, enhanced patient outcomes, and, ultimately, improved quality of life for individuals with IBD. Though precision medicine is promising in terms of better quality of patient care, inadequacies exist in the ongoing research. There is discordance in study conduct, and data collection, utilization, interpretation, and analysis. This review aims to describe the current literature on precision medicine, its multiomics approach, and future directions for its application in IBD.

Definition of a microbial signature as a predictor of endoscopic post-surgical recurrence in patients with Crohn's disease

Background and aims: Although there are several effective drugs for the treatment of Crohn's disease (CD), almost 70% of patients will require surgical resection during their lifetime. This procedure is not always curative, as endoscopic recurrence occurs in 65%-90% of patients in the first year after surgery. The aetiology of the recurrence is unknown; however, several studies have shown how the resident microbiota is modified after surgery. The aim of this study was to evaluate samples from patients with Crohn's disease before and after an intestinal resection to determine whether there were differences in the abundance of different microbial markers, which may predict endoscopic recurrence at baseline. Methods: In this observational study, a stool sample was obtained from 25 patients with Crohn's disease before undergoing surgery, recruited at three Catalan hospitals. From each sample, DNA was purified and the relative abundance of nine microbial markers was quantified using qPCR. Results: An algorithm composed of four microbial markers (E. coli, F. prausnitzii phylogroup I, Bacteroidetes, and Eubacteria) showed a sensitivity and specificity of 90.91% and 85.71%, respectively, and a positive and negative predictive value of 83.33% and 92.31%, respectively. Conclusion: A microbial signature to determine patients who will have post-surgical recurrence was identified. This tool might be very useful in daily clinical practice, allowing the scheduling of personalized therapy and enabling preventive treatment only in patients who really require it.

Adlay (Coix lacryma-jobi L.) Polyphenol Improves Hepatic Glucose and Lipid Homeostasis through Regulating Intestinal Flora via AMPK Pathway

SCOPE

Non-alcoholic fatty liver disease (NAFLD) is a type of metabolic syndrome characterized of abnormal lipid deposition in the liver. Adlay polyphenol (AP), an effective component extracted from Coix lacryma-jobi L., has been reported that it can be used as a dietary supplement to prevent NAFLD. In this study, the mechanism and action of AP on lipid metabolism and regulation of intestinal flora are investigated.

METHODS AND RESULTS

AP significantly decreases the lipid accumulation in free fatty acid-treated HepG2 cells. Western blot results indicate that AP improves lipid metabolism via activating the p-AMPK/p-ACC pathway. In vivo experiments show AP treatment significantly decreases the body weight, liver weight, hepatic triglyceride, and total cholesterol contents, as well as the serum glucose levels in high fat diet-fed mice, which may affect lipid accumulation by activating AMPK pathway and changing intestinal bacterial communities and intestinal microbiome metabolism.

CONCLUSION

AP can be used as a food supplement for improving lipid metabolic dysfunction and reducing the incidence of metabolic diseases.

Endoscopic Recurrence or Anastomotic Wound Healing Phenomenon after Ileocolic Resection for Crohn's Disease: The Challenges of Accurate Endoscopic Scoring

BACKGROUND AND AIMS

Adequate endoscopic scoring in Crohn's disease (CD) is crucial, as dictates the need for initiating postoperative medical therapy and is utilized as outcome parameter in clinical trials. We aimed to observe anastomotic wound healing in relation to endoscopic scoring of both inverted and everted stapled lines in side-to-side anastomoses.

METHODS

Two prospective patient cohorts were included: ileocolic resection (ICR) for CD, and right-sided colon resection for colorectal cancer (CRC). Videos taken during colonoscopy six months postoperatively were evaluated. The SES-CD and modified Rutgeerts score were determined. Primary outcome was the presence of ulcerations in CD patients on both the inverted and everted stapled lines. Secondary outcomes were the presence of anastomotic ulcerations in CRC patients and the number of cases having ulcerations exclusively at the inverted stapled line.

RESULTS

Of the 82 patients included in the CD cohort, ulcerations were present in 63/82 (76·8%) at the inverted- versus 1/71 (1·4%) at the everted stapled line. Likewise in the CRC cohort, ulcerations were present in 4/6 (67·7%) at the inverted versus 0/6 (0%) at the everted stapled line. 27% of the 63 patients in the CD cohort had ulcerations exclusively on the inverted stapled line.

CONCLUSION

Inverted stapled lines heal with ulcerations, whereas the everted stapled line heal without any ulcerations, both in CD and non-CD patients. The abnormalities at the inverted stapled line might interfere with endoscopic scoring of recurrence, with potentially an impact on patients' quality of life and on health-care costs if postoperative treatment is initiated incorrectly.

Comprehensive Phenotyping in Inflammatory Bowel Disease: Search for Biomarker Algorithms in the Transkingdom Interactions Context

Inflammatory bowel disease (IBD) is the most common form of intestinal inflammation associated with a dysregulated immune system response to the commensal microbiota in a genetically susceptible host. IBD includes ulcerative colitis (UC) and Crohn's disease (CD), both of which are remarkably heterogeneous in their clinical presentation and response to treatment. This translates into a notable diagnostic challenge, especially in underdeveloped countries where IBD is on the rise and access to diagnosis or treatment is not always accessible for chronic diseases. The present work characterized, for the first time in our region, epigenetic biomarkers and gut microbial profiles associated with UC and CD patients in the Buenos Aires Metropolitan area and revealed differences between non-IBD controls and IBD patients. General metabolic functions associated with the gut microbiota, as well as core microorganisms within groups, were also analyzed. Additionally, the gut microbiota analysis was integrated with relevant clinical, biochemical and epigenetic markers considered in the follow-up of patients with IBD, with the aim of generating more powerful diagnostic tools to discriminate phenotypes. Overall, our study provides new insights into data analysis algorithms to promote comprehensive phenotyping tools using quantitative and qualitative analysis in a transkingdom interactions network context.