Primary biliary cholangitis (PBC) is a cholestatic liver disease characterized by immune-mediated injury to small bile ducts. Although PBC is an autoimmune disease, the effectiveness of conventional immunosuppressive therapy is disappointing. Nearly 40% of PBC patients do not respond to the first-line drug UDCA. Without appropriate intervention, PBC patients eventually progress to liver cirrhosis and even death. There is an urgent need to develop new therapies. The gut–liver axis emphasizes the interconnection between the gut and the liver, and evidence is increasing that gut microbiota and bile acids play an important role in the pathogenesis of cholestatic diseases. Dysbiosis of gut microbiota, imbalance of bile acids, and immune-mediated bile duct injury constitute the triad of pathophysiology in PBC. Autoimmune cholangitis has the potential to be improved through immune system modulation. Considering the failure of conventional immunotherapies and the involvement of gut microbiota and bile acids in the pathogenesis, targeting immune factors associated with them, such as bile acid receptors, microbial-derived molecules, and related specific immune cells, may offer breakthroughs. Understanding the gut microbiota–bile acid network and related immune dysfunctions in PBC provides a new perspective on therapeutic strategies. Therefore, we summarize the latest advances in research of gut microbiota and bile acids in PBC and, for the first time, explore the possibility of related immune factors as novel immunotherapy targets. This article discusses potential therapeutic approaches focusing on regulating gut microbiota, maintaining bile acid homeostasis, their interactions, and related immune factors.

Bile acid diarrhea (BAD) is a multifaceted intestinal disorder involving intricate molecular mechanisms, including farnesoid X receptor (FXR), fibroblast growth factor receptor 4 (FGFR4), and Takeda G protein–coupled receptor 5 (TGR5). Current diagnostic methods encompass bile acid sequestrants (BAS), 48-h fecal bile acid tests, serum 7α-hydroxy-4-cholesten-3-one (C4), fibroblast growth factor 19 (FGF19) testing, and ⁷⁵Selenium HomotauroCholic acid test (⁷⁵SeHCAT). Treatment primarily involves BAS and FXR agonists. However, due to the limited sensitivity and specificity of current diagnostic methods, as well as suboptimal treatment efficacy and the presence of side effects, there is an urgent need to establish new diagnostic and treatment methods. While prior literature has summarized various diagnostic and treatment methods and the pathogenesis of BAD, no previous work has linked the two. This review offers a molecular perspective on the clinical diagnosis and treatment of BAD, with a focus on FXR, FGFR4, and TGR5, emphasizing the potential for identifying additional molecular mechanisms as treatment targets and bridging the gap between diagnostic and treatment methods and molecular mechanisms for a novel approach to the clinical management of BAD.

Primary biliary cholangitis (PBC) is a cholestatic liver disease characterized by immune-mediated injury to small bile ducts. Although PBC is an autoimmune disease, the results of traditional immunosuppressive therapy are disappointing. Nearly 40% of PBC patients do not respond to the first-line drug UDCA. Without appropriate intervention, PBC patients would eventually progress to liver cirrhosis and even death. There is an urgent need to develop new therapies. The gut-liver axis emphasizes the interconnection between the gut and the liver, and there is increasing evidence that gut microbiota and bile acids play an important role in cholestatic diseases. Dysbiosis of gut microbiota, imbalance of bile acids, and immune-mediated bile duct injury constitute the triad of pathophysiology in PBC. Understanding the gut microbiota-bile acid network and corresponding immune functions in PBC provides a new perspective for its treatment strategies. Therefore, we summarize the latest advancements in research of gut microbiota and bile acids in PBC and, for the first time, explore the potential of immune factors related to them as novel immunotherapy targets. This article discusses potential therapeutic approaches focusing on regulating gut microbiota, maintaining bile acid homeostasis, their interactions, and related immune factors.

Although nanomedicine has enabled significant advances in drug delivery, the clinical translation of conventional synthetic nanocarriers is limited by immune clearance, non-specific biodistribution, and gastrointestinal instability. This poses major challenges for therapy targeting the intestines. Cell membrane-coated nanotechnology (CMCT) and membrane vesicle-based systems have emerged as biomimetic platforms integrating synthetic nanomaterials with naturally derived biological interfaces. These biohybrid systems inherit biological functions originating from cells, including immune evasion, prolonged circulation, lesion homing, and microenvironment-responsive interactions, through the direct transfer of intact membrane components. This review summarizes recent advances in CMCT and membrane vesicle-based strategies for intestinal drug delivery. It covers fabrication methodologies, programmable manufacturing approaches, and functional regulation enabled by diverse membrane sources and hybrid engineering designs. Applications in inflammatory bowel disease, colorectal cancer, and intestinal infections are highlighted, emphasizing key therapeutic mechanisms, such as targeting inflammation, neutralizing toxins, modulating the immune system, and regulating the microbiome. We also discuss the major challenges of translation, such as preserving membrane and coating integrity, ensuring oral stability, achieving batch reproducibility, and ensuring biosafety. Overall, this review establishes a conceptual and engineering framework to guide the transition of membrane-based nanocarriers from passive biomimicry to adaptive, clinically translatable intestinal delivery systems.

Locally advanced rectal cancer (LARC) presents a significant burden on lower gastrointestinal diseases, with current treatment strategies primarily involving neoadjuvant chemoradiotherapy (nCRT) followed by radical surgery. However, patient responses to nCRT exhibit significant variability, highlighting the need for personalized therapeutic approaches. Emerging evidence suggests that the gut microbiota plays a critical role in influencing both treatment outcomes and toxicity in LARC patients. Intestinal dysbiosis has been linked to LARC progression and may affect the efficacy and adverse effects of nCRT. This narrative review critically evaluates the current literature on the relationship between gut microbiota and nCRT in LARC. Certain microbial taxa, such as Alistipes spp., Akkermansia muciniphila , and Faecalibacterium prausnitzii , have been associated with enhanced therapeutic responses, while others, such as Fusobacterium nucleatum and Enterotoxigenic Bacteroides fragilis , may contribute to treatment resistance and exacerbate adverse effects. We also discuss novel mechanisms by which specific gut microbiota and their metabolites modulate nCRT response distinct from conventional immune regulation, alongside emerging strategies for microbiota modulation, including dietary interventions, probiotics, prebiotics, and fecal microbiota transplantation. Despite challenges in standardizing microbiota analysis and fully understanding the precise mechanisms, microbiota-targeted interventions offer a promising avenue for personalized treatment in LARC, with the potential to improve patient outcomes and quality of life.

Objectives American College of Gastroenterology (ACG) and Chinese expert consensus recommended different algorithmic approaches for the diagnosis of gastro-oesophageal reflux disease (GERD) are not yet defined. We compared the two recommended diagnostic processes using a Chinese population-based health economics analysis. Methods Our analysis considered a hypothetical cohort of patients with typical reflux symptoms. We constructed a decision tree model to compare the two recommended diagnostic processes described in ACG clinical guidelines (stratified endoscopy strategy) and Chinese expert consensus (endoscopy-first strategy). The first strategy begins with hazard stratification based on alarm symptoms. Patients with alarm symptoms directly undergo endoscopic examination, while patients without alarm symptoms receive proton pump inhibitors as diagnostic treatment. In the second strategy, all patients with reflux symptoms complete an endoscopic examination. Sensitivity analysis was performed to evaluate a range of cost and probability estimates on costs and health outcomes over a 1-year time horizon from the healthcare system perspective. Results The total expected costs were US$122.51 for the stratified endoscopy strategy and US$150.12 for the endoscopy-first strategy. The incremental cost-effectiveness ratio (ICER) comparing the endoscopy-first strategy with the stratified endoscopy strategy was US$440.39 per additional correct case of GERD. The rates of detecting upper gastrointestinal carcinoma of the two strategies were 0.0088 and 0.0120, and the ICER was US$8561.34. Conclusions The use of endoscopy for all patients with reflux symptoms was more effective but with an increased cost compared with the strategy recommended in international guidelines.