Multi-omics in Crohn's disease: New insights from inside

Role and mechanism of gut microbiota-host interactions in the pathogenesis of Crohn's disease

BACKGROUND

Crohn's disease (CD) is a chronic, nonspecific inflammatory bowel disease with a poor prognosis. Despite its increasing incidence, curing CD remains challenging due to its complex etiology and unclear pathogenesis.

METHODS

A comprehensive PubMed and Web of Science search was conducted using the keywords Crohn's disease, gut microbiota, dysbiosis, pathogenesis and treatment, focusing on studies published between 2014 and 2024.

RESULTS

Recent studies have demonstrated a close relationship between gut microbiota dysbiosis and the development of CD. Although many dysbioses associated with CD have not yet been proven to be causal or consequential, it has been observed that the gut microbiota in CD patients exhibits reduced diversity, a decrease in beneficial bacteria, and an increase in pathogenic bacteria. These changes may lead to decreased intestinal barrier function, abnormal immune responses, and enhanced inflammatory reactions, which are related to the disease's activity, phenotype, drug treatment efficacy, and postoperative therapeutic outcomes. Therefore, further exploration of the microbiota-host interactions and the pathogenesis of CD, the identification of biomarkers, and the development of targeted strategies for modulating the gut microbiota could offer new avenues for the prevention and treatment of CD.

CONCLUSIONS

This review highlights the pivotal role of gut microbiota dysbiosis in driving CD pathogenesis and its progression, while underscoring its potential as a therapeutic target through dietary modulation, microbial interventions, and integrative strategies to improve clinical management and prognostic outcomes.

Microbiome characterization of patients with Crohn disease and the use of fecal microbiota transplantation: A review

Inflammatory bowel disease is a chronic inflammatory condition predominantly affecting the intestines, encompassing both ulcerative colitis and Crohn disease (CD). As one of the most common gastrointestinal disorders, CD's pathogenesis is closely linked with the intestinal microbiota. Recently, fecal microbiota transplantation (FMT) has gained attention as a potential treatment for CD, with the effective reestablishment of intestinal microecology considered a crucial mechanism of FMT therapy. This article synthesizes the findings of population-based cohort studies to enhance our understanding of gut microbial characteristics in patients with CD. It delves into the roles of "beneficial" and "pathogenic" bacteria in CD's development. This article systematically reviews and compares data on clinical response rates, remission rates, adverse events, and shifts in bacterial microbiota. Among these studies, gut microbiome analysis was conducted in only 7, and a single study examined the metabolome. Overall, FMT has demonstrated a partial restoration of typical CD-associated microbiological alterations, leading to increased α-diversity in responders and a moderate shift in patient microbiota toward the donor profile. Several factors, including donor selection, delivery route, microbial state (fresh or frozen), and recipient condition, are identified as pivotal in influencing FMT's effectiveness. Future prospective clinical studies with larger patient cohorts and improved methodologies are imperative. In addition, standardization of FMT procedures, coupled with advanced genomic techniques such as macroproteomics and culture genomics, is necessary. These advancements will further clarify the bacterial microbiota alterations that significantly contribute to FMT's therapeutic effects in CD treatment, as well as elucidate the underlying mechanisms of action.

Fecal microbiota and metabolites in the pathogenesis and precision medicine for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract, and its pathogenesis is believed to be associated with an imbalance between commensal organisms and the intestinal immune system. This imbalance is significantly influenced by the intestinal microbiota and metabolites and plays a critical role in maintaining intestinal mucosal homeostasis. However, disturbances in the intestinal microbiota cause dysregulated immune responses and consequently induce intestinal inflammation. Recent studies have illustrated the roles of the intestinal microbiota in the pathogenesis of IBD and underscored the potential of precision diagnosis and therapy. This work summarises recent progress in this field and particularly focuses on the application of the intestinal microbiota and metabolites in the precision diagnosis, prognosis assessment, treatment effectiveness evaluation, and therapeutic management of IBD.

Interaction between diet and genetics in patients with inflammatory bowel disease

In this editorial, we comment on the article by Marangoni et al, published in the recent issue of the World Journal of Gastroenterology 2023; 29: 5618-5629, about "Diet as an epigenetic factor in inflammatory bowel disease". The authors emphasized the role of diet, especially the interaction with genetics, in promoting the inflammatory process in inflammatory bowel disease (IBD) patients, focusing on DNA methylation, histone modifications, and the influence of microRNAs. In this editorial, we explore the interaction between genetics, gut microbiota, and diet, in an only way. Furthermore, we provided dietary recommendations for patients with IBD. The Western diet, characterized by a low fiber content and deficiency the micronutrients, impacts short-chain fatty acids production and may be related to the pathogenesis of IBD. On the other hand, the consumption of the Mediterranean diet and dietary fibers are associated with reduced risk of IBD flares, particularly in Crohn's disease (CD) patients. According to the dietary guidance from the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD), the regular consumption of fruits and vegetables while reducing the consumption of saturated, trans, dairy fat, additives, processed foods rich in maltodextrins, and artificial sweeteners containing sucralose or saccharine is recommended to CD patients. For patients with ulcerative colitis, the IOIBD recommends the increased intake of natural sources of omega-3 fatty acids and follows the same restrictive recommendations aimed at CD patients, with the possible inclusion of red meats. In conclusion, IBD is a complex and heterogeneous disease, and future studies are needed to elucidate the influence of epigenetics on diet and microbiota in IBD patients.

Apoptosis Inhibitor 5: A Multifaceted Regulator of Cell Fate

Apoptosis, or programmed cell death, is a fundamental process that maintains tissue homeostasis, eliminates damaged or infected cells, and plays a crucial role in various biological phenomena. The deregulation of apoptosis is involved in many human diseases, including cancer. One of the emerging players in the intricate regulatory network of apoptosis is apoptosis inhibitor 5 (API5), also called AAC-11 (anti-apoptosis clone 11) or FIF (fibroblast growth factor-2 interacting factor). While it may not have yet the same level of notoriety as some other cancer-associated proteins, API5 has garnered increasing attention in the cancer field in recent years, as elevated API5 levels are often associated with aggressive tumor behavior, resistance to therapy, and poor patient prognosis. This review aims to shed light on the multifaceted functions and regulatory mechanisms of API5 in cell fate decisions as well as its interest as therapeutic target in cancer.

From multi-omics approaches to personalized medicine in myocardial infarction

Myocardial infarction (MI) is a prevalent cardiovascular disease characterized by myocardial necrosis resulting from coronary artery ischemia and hypoxia, which can lead to severe complications such as arrhythmia, cardiac rupture, heart failure, and sudden death. Despite being a research hotspot, the etiological mechanism of MI remains unclear. The emergence and widespread use of omics technologies, including genomics, transcriptomics, proteomics, metabolomics, and other omics, have provided new opportunities for exploring the molecular mechanism of MI and identifying a large number of disease biomarkers. However, a single-omics approach has limitations in understanding the complex biological pathways of diseases. The multi-omics approach can reveal the interaction network among molecules at various levels and overcome the limitations of the single-omics approaches. This review focuses on the omics studies of MI, including genomics, epigenomics, transcriptomics, proteomics, metabolomics, and other omics. The exploration extended into the domain of multi-omics integrative analysis, accompanied by a compilation of diverse online resources, databases, and tools conducive to these investigations. Additionally, we discussed the role and prospects of multi-omics approaches in personalized medicine, highlighting the potential for improving diagnosis, treatment, and prognosis of MI.