Selection strategy of second-line biologic therapies in adult patients with ulcerative colitis following prior biologic treatment failure: Systematic review and meta-analysis.

BACKGROUND: Optimizing second-line biologic therapies for adult ulcerative colitis (UC) post first-line failure is essential. OBJECTIVE: Compare second-line biologic therapy efficacy in adult UC patients with prior treatment failure. METHODS: A comprehensive search of electronic databases up to May 2023 was conducted to assess second-line biologic therapy efficacy using a random effects model. Parameters analyzed included clinical remission rate, clinical response rate, mucosal healing rate, annual discontinuation rate, and colectomy rates. RESULTS: Forty-three research papers were analyzed. Clinical remission rates for second-line biologics were ranked at 6-14 weeks: Infliximab (30%) was followed by Vedolizumab (29%), Ustekinumab (27%), and Adalimumab (19%). At 52-54 weeks, the order shifted, with Vedolizumab (35%) followed by Infliximab (32%), Ustekinumab (31%), and Adalimumab (26%). The mucosal healing rate was 21%, ranked as: Infliximab (31%), Vedolizumab (21%), Adalimumab (21%), and Ustekinumab (14%). The annual discontinuation rate stood at 20%, with Adalimumab (25%), Vedolizumab (18%), Infliximab (17%), and Ustekinumab (16%). Discontinuation rates due to primary failure (PF), secondary failure (SF), and adverse events (AE) were 6%, 12%, and 3%, respectively. The annual colectomy rate was 9%, with Adalimumab (15%) followed by Vedolizumab (10%), Ustekinumab (9%), and Infliximab (5%), and colectomy rates of 10% due to PF, 12% due to SF, and 4% due to AE. CONCLUSION: For UC patients with first-line treatment failure, it is recommended to prioritize infliximab or vedolizumab as second-line biologic therapies, while avoiding adalimumab as the primary choice. Further clinical trials are necessary to assess ustekinumab efficacy accurately.

Targeting Desulfovibrio vulgaris flagellin-induced NAIP/NLRC4 inflammasome activation in macrophages attenuates ulcerative colitis.

INTRODUCTION: The perturbations of gut microbiota could interact with excessively activated immune responses and play key roles in the etiopathogenesis of ulcerative colitis (UC). Desulfovibrio, the most predominant sulfate reducing bacteria (SRB) resided in the human gut, was observed to overgrow in patients with UC. The interactions between specific gut microbiota and drugs and their impacts on UC treatment have not been demonstrated well. OBJECTIVES: This study aimed to elucidate whether Desulfovibrio vulgaris (D. vulgaris, DSV) and its flagellin could activate nucleotide-binding oligomerization domain-like receptors (NLR) family of apoptosis inhibitory proteins (NAIP) / NLR family caspase activation and recruitment domain-containing protein 4 (NLRC4) inflammasome and promote colitis, and further evaluate the efficacy of eugeniin targeting the interaction interface of D. vulgaris flagellin (DVF) and NAIP to attenuate UC. METHODS: The abundance of DSV and the occurrence of macrophage pyroptosis in human UC tissues were investigated. Colitis in mice was established by dextran sulfate sodium (DSS) and gavaged with DSV or its purified flagellin. NAIP/NLRC4 inflammasome activation and macrophage pyroptosis were evaluated in vivo and in vitro. The effects of eugeniin on blocking the interaction of DVF and NAIP/NLRC4 and relieving colitis were also assessed. RESULTS: The abundance of DSV increased in the feces of patients with UC and was found to be associated with disease activity. DSV and its flagellin facilitated DSS-induced colitis in mice. Mechanistically, RNA sequencing showed that gene expression associated with inflammasome complex and pyroptosis was upregulated after DVF treatment in macrophages. DVF was further demonstrated to induce significant macrophage pyroptosis in vitro, depending on NAIP/NLRC4 inflammasome activation. Furthermore, eugeniin was screened as an inhibitor of the interface between DVF and NAIP and successfully alleviated the proinflammatory effect of DVF in colitis. CONCLUSION: Targeting DVF-induced NAIP/NLRC4 inflammasome activation and macrophage pyroptosis ameliorates UC. This finding is of great significance for exploring the gut microbiota-host interactions in UC development and providing new insights for precise treatment.

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

Crohn's disease (CD) is an inflammatory bowel disease (IBD) with complex clinical manifestations such as chronic diarrhea, weight loss and hematochezia. Despite the increasing incidence worldwide, cure of CD remains extremely difficult. The rapid development of high-throughput sequencing technology with integrated-omics analyses in recent years has provided a new means for exploring the pathogenesis, mining the biomarkers and designing targeted personalized therapeutics of CD. Host genomics and epigenomics unveil heredity-related mechanisms of susceptible individuals, while microbiome and metabolomics map host-microbe interactions in CD patients. Proteomics shows great potential in searching for promising biomarkers. Nonetheless, single omics technology cannot holistically connect the mechanisms with heterogeneity of pathological behavior in CD. The rise of multi-omics analysis integrates genetic/epigenetic profiles with protein/microbial metabolite functionality, providing new hope for comprehensive and in-depth exploration of CD. Herein, we emphasized the different omics features and applications of CD and discussed the current research and limitations of multi-omics in CD. This review will update and deepen our understanding of CD from integration of broad omics spectra and will provide new evidence for targeted individualized therapeutics.

Lactobacillus rhamnosus GG supernatant promotes intestinal mucin production through regulating 5-HT4R and gut microbiota.

Lactobacillus rhamnosus GG (LGG) is a well-known probiotic widely used in foods and drugs. It has been reported that LGG can improve bowel dysfunction in gastrointestinal motility disorders, such as constipation; however, the specific mechanisms remain unclear. The colonic mucus layer is mainly composed of mucin secreted by goblet cells, which plays important roles in lubricating colonic contents and maintaining normal defecation function. It has been reported that increased mucin production is beneficial for relieving constipation symptoms. In this study, we aimed to investigate the role of LGG in regulating intestinal mucin production and the associated mechanisms. Six-week-old C57BL/6J mice were randomized into 3 groups, and were treated with De-Man Rogosa and Sharpe broth (MRS group), tegaserod maleate (tegaserod group) and LGG supernatant (LGGs group) by gavage, respectively. After treatments, defecation parameters, intestinal mucin-2 (MUC2) and serotonin 4 receptor (5-HT4R), goblet cells, and microbiota composition of the mice in each group were assessed. In comparison with the MRS group, higher fecal water content and increased fecal pellet number were found in the tegaserod group and LGGs group. Moreover, LGGs increased the number of goblet cells and upregulated the expression of 5-HT4R and MUC2 in the mouse colon. In addition, Alcian Blue Periodic acid Schiff staining showed that activated 5-HT4R enhanced intestinal MUC2 secretion. Further exploration of the mechanism discovered that LGGs upregulated intestinal S100A10, which was found to be involved in regulating 5-HT4R expression. Furthermore, gut microbiota analysis showed the higher abundance of Alistipes, Allobaculum, Desulfovibrio, and Clostridium XlVa in the LGGs group, which have been reported to be involved in regulating gut motility and the intestinal barrier, and alleviating bowel dysfunction. Interestingly, gut dysbiosis was present in the tegaserod group. It is noteworthy that the fecal microbiota transplanted from LGGs-treated mice significantly improved the gut dysmotility in a constipation mouse model. Our results suggested that LGGs could upregulate 5-HT4R to promote MUC2 production, as well as modulate the gut microbiota, thus improving the defecation function in mice. This finding might provide evidence for the application of diet supplementary LGG in relieving gastrointestinal motility disorders.

Gut microbial metabolome in inflammatory bowel disease: From association to therapeutic perspectives.

Inflammatory bowel disease (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), is a set of clinically chronic, relapsing gastrointestinal inflammatory disease and lacks of an absolute cure. Although the precise etiology is unknown, developments in high-throughput microbial genomic sequencing significantly illuminate the changes in the intestinal microbial structure and functions in patients with IBD. The application of microbial metabolomics suggests that the microbiota can influence IBD pathogenesis by producing metabolites, which are implicated as crucial mediators of host-microbial crosstalk. This review aims to elaborate the current knowledge of perturbations of the microbiome-metabolome interface in IBD with description of altered composition and metabolite profiles of gut microbiota. We emphasized and elaborated recent findings of several potentially protective metabolite classes in IBD, including fatty acids, amino acids and derivatives and bile acids. This article will facilitate a deeper understanding of the new therapeutic approach for IBD by applying metabolome-based adjunctive treatment.