The role of the gut microbiome in the development of inflammatory bowel disease (IBD) – Literature Review

Abstract

Introduction: Inflammatory bowel diseases (IBD), which include Crohn's disease (CD) and ulcerative colitis (UC), are chronic diseases characterized by recurrent inflammation and progressive destruction of the intestinal mucosa. Their etiology is multifactorial, involving genetic predisposition, dysregulated immune response, and alterations in the intestinal microbiota. In recent decades, advances in metagenomic techniques have allowed a better understanding of the role of the gut microbiome in maintaining homeostasis and modulating immunity, highlighting its relevance in the pathogenesis of IBD. Objective: To critically analyze the scientific evidence published between 2010 and 2024 regarding the relationship between the intestinal microbiome and the development of inflammatory bowel diseases, with emphasis on pathophysiological mechanisms and therapeutic strategies for microbial modulation. Methods: This is a narrative literature review, conducted through searches in the PubMed, SciELO, Virtual Health Library (VHL), and Google Scholar databases. Original articles, systematic reviews, and meta-analyses available in full text, in Portuguese and English, addressing the interaction between intestinal microbiota, immunity, and chronic intestinal inflammation were selected. Studies without full text, editorials, and abstracts from scientific events were excluded. Results and Discussion: Studies indicate that IBD results from the interaction between genetic, immunological, and environmental factors that modulate the intestinal microbiota. Dysbiosis, characterized by a reduction in beneficial species such as Faecalibacterium prausnitzii and an increase in pro-inflammatory microorganisms such as Escherichia coli, compromises immunological tolerance and contributes to persistent inflammation. Mutations in genes such as NOD2 and ATG16L1 aggravate susceptibility by altering epithelial function and microbial recognition. Therapeutic strategies aimed at restoring eubiosis have shown promising results. Conclusion: The gut microbiome plays a central role in the pathophysiology of IBD, participating in both the initiation and maintenance of inflammation. Understanding the mechanisms that integrate the microbiota, genetics, and immune system opens new perspectives for personalized therapies and preventive interventions. Restoring eubiosis represents one of the main challenges and, simultaneously, one of the most promising therapeutic approaches in the management of inflammatory bowel diseases.