Impaired Butyrate Induced Regulation of T Cell Surface Expression of CTLA-4 in Patients with Ulcerative Colitis

Evaluating the anti-inflammatory and antioxidant efficacy of complementary and alternative medicines (CAM) used for management of inflammatory bowel disease: a comprehensive review

Inflammatory bowel disease (IBD) is a chronic autoimmune condition whose pathogenesis has not been fully elucidated, and current treatments are not definitive and often carry several side effects. The Complementary and Alternative Medicine (CAM) offers a new approach to conventional medicine. However, their clinical application and mechanisms remain limited.Objective: The aim of this review is to evaluate the anti-inflammatory, impact on microbiota and antioxidant efficacy of currently available CAM for IBD.Methods: The literature collection was obtained from Google Scholar, MEDLINE, PubMed and Web of Science (WOS). Studies in both human and animal models, published in English language between 2018 and 2024, were selected. Sixty-seven studies were included in the current review after inclusion and exclusion screening processes.Results: Mostly, studies showed significant anti-inflammatory, gut microbiota restoring, antioxidant effects of polyphenols, polysaccharides, emodin, short-chain fatty acids (SCFA; including butyrate, propionate and acetate), and probiotics although some contrasting results were noted. Current evidence shows that polyphenols exhibit the most consistent result in alleviating IBD pathophysiology, primarily due to their significant SCFA-elevating effect.Discussion: Future studies may focus on human studies, narrowing down on individual factors which may change natural product's metabolism. Further research studies are also essential to obtain therapeutic recommendations.

Holothuria leucospilota polysaccharides (HLP) ameliorate colitis rats via regulation of the metabolic profiling and TLR4/NLRP3 signaling pathways

Recently, the development of natural polysaccharides for ameliorating immunity and gut metabolism has attracted extensive attention. This study used Holothuria leucospilota polysaccharides (HLP) to explore the improvement mechanism in ulcerative colitis rats on perspectives of immunity and metabolism. The results showed that HLP increased goblet cells’ number and the content of tight junction proteins (zona occludens 1 and occludin) and improved intestinal barrier permeability. The levels of immune cytokines (IL‐4, IL‐6, IL‐10, IL‐18, TNF‐α, and IL‐1β) and the activity of oxidative stress‐related enzymes (superoxide dismutase, catalase, malondialdehyde, and glutathione peroxidase) were regulated. HLP regulated the related genes and proteins expression of immune cytokines, MAPK, and NLRP3 inflammasome. Furthermore, HLP treatment increased the concentration of short‐chain fatty acids (SCFAs) and regulated serum metabolic disorders by regulating amino acid metabolism, SCFA metabolism, and energy metabolism. These results provide a new perspective for developing HLP as a promising functional food for preventing and mitigating colitis.

Fatty acids and lipid mediators in inflammatory bowel disease: from mechanism to treatment

Inflammatory Bowel Disease (IBD) is a chronic, relapsing inflammatory disorder of the gastrointestinal tract. Though the pathogenesis of IBD remains unclear, diet is increasingly recognized as a pivotal factor influencing its onset and progression. Fatty acids, essential components of dietary lipids, play diverse roles in IBD, ranging from anti-inflammatory and immune-regulatory functions to gut-microbiota modulation and barrier maintenance. Short-chain fatty acids (SCFAs), products of indigestible dietary fiber fermentation by gut microbiota, have strong anti-inflammatory properties and are seen as key protective factors against IBD. Among long-chain fatty acids, saturated fatty acids, trans fatty acids, and ω-6 polyunsaturated fatty acids exhibit pro-inflammatory effects, while oleic acid and ω-3 polyunsaturated fatty acids display anti-inflammatory actions. Lipid mediators derived from polyunsaturated fatty acids serve as bioactive molecules, influencing immune cell functions and offering both pro-inflammatory and anti-inflammatory benefits. Recent research has also highlighted the potential of medium- and very long-chain fatty acids in modulating inflammation, mucosal barriers, and gut microbiota in IBD. Given these insights, dietary intervention and supplementation with short-chain fatty acids are emerging as potential therapeutic strategies for IBD. This review elucidates the impact of various fatty acids and lipid mediators on IBD and delves into potential therapeutic avenues stemming from these compounds.

Identification of hub genes and immune infiltration in ulcerative colitis using bioinformatics

Ulcerative colitis (UC) is a chronic inflammatory disease of the intestine, whose pathogenesis is not fully understood. Given that immune infiltration plays a key role in UC progression, our study aimed to assess the level of immune cells in UC intestinal mucosal tissues and identify potential immune-related genes. The GSE65114 UC dataset was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between healthy and UC tissues were identified using the "limma" package in R, while their Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were determined with the clusterProfiler package. Protein-protein interaction network analysis and visualization were performed with STRING and Cytoscape. Immune cell infiltration was calculated with CIBERSORT. The relationship between hub genes and immune-infiltrated cells in UC was determined by Pearson correlation. A total of 206 DEGs were identified, of which 174 were upregulated and 32 downregulated. GO and KEGG functional classification indicated DEG enrichment in immune response pathways, including Toll-like receptor signaling, IL-17 signaling, and immune system process and chemokine signaling. 13 hub genes were identified. Infiltration matrix analysis of immune cells showed abundant plasma cells, memory B cells, resting CD4 memory T cells, γδ T cells, M0 and M1 macrophages, and neutrophils in UC intestinal tissues. Correlation analysis revealed 13 hub genes associated with immune-infiltrated cells in UC. 13 hub genes associated with immune-infiltrated cells in UC were identified; they included CXCL13, CXCL10, CXCL9, CXCL8, CCL19, CTLA4, CCR1, CD69, CD163, IL7R, PECAM1, TLR8 and TLR2. These genes could potentially serve as markers for the diagnosis and treatment of UC.

Regulation of CD4+ and CD8+ T Cell Biology by Short-Chain Fatty Acids and Its Relevance for Autoimmune Pathology

The gut microbiota encodes a broad range of enzymes capable of synthetizing various metabolites, some of which are still uncharacterized. One well-known class of microbiota-derived metabolites are the short-chain fatty acids (SCFAs) such as acetate, propionate, butyrate and valerate. SCFAs have long been considered a mere waste product of bacterial metabolism. Novel results have challenged this long-held dogma, revealing a central role for microbe-derived SCFAs in gut microbiota-host interaction. SCFAs are bacterial signaling molecules that act directly on host T lymphocytes by reprogramming their metabolic activity and epigenetic status. They have an essential biological role in promoting differentiation of (intestinal) regulatory T cells and in production of the anti-inflammatory cytokine interleukin-10 (IL-10). These small molecules can also reach the circulation and modulate immune cell function in remote tissues. In experimental models of autoimmune and inflammatory diseases, such as inflammatory bowel disease, multiple sclerosis or diabetes, a strong therapeutic potential of SCFAs through the modulation of effector T cell function was observed. In this review, we discuss current research activities toward understanding a relevance of microbial SCFA for treating autoimmune and inflammatory pathologies from in vitro to human studies.