Effect of sphincter of Oddi dysfunction on the abundance of biliary microbiota (biliary microecology) in patients with common bile duct stones

Effect of duodenal papilla morphology on biliary cannulation and complications in patients with common bile duct stones

BACKGROUND

The endoscopic appearance of the major duodenal papilla influences biliary cannulation and complications. This study aimed to investigate the role of major duodenal papillae in the endoscopic treatment of common bile duct (CBD) stones.

METHODS

This retrospective study was conducted at Bishan Hospital of Chongqing Medical University between January 2018 and August 2022. Patients with native papillae who underwent endoscopic treatment for CBD stones were recruited and divided into four groups according to Haraldsson's classification of papillae (types I-IV). Univariate and multivariate logistic regression analyses were used to identify risk factors for difficult cannulation and post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP).

RESULTS

A total of 596 patients with CBD stones were enrolled. The proportion of patients with type I papilla was the highest (n = 231, 38.8%), followed by type III papilla (n = 175, 29.4%), type IV papilla (n = 101, 16.9%) and type II papilla (n = 89, 14.9%). Difficult cannulation occurred in 188 of 596 patients (31.5%), with most cases occurring in those with type III papilla (71/175, 40.6%, P = 0.020). Multivariate logistic analysis revealed that age [odds ratio (OR) = 1.034, 95% confidence interval (CI): 1.021-1.047, P < 0.001], type III papilla (OR = 2.255, 95% CI: 1.439-3.535, P < 0.001), gallbladder in situ (OR = 2.486, 95% CI: 1.346-4.590, P = 0.004), and CBD diameter < 10 mm (OR = 1.600, 95% CI: 1.049-2.441, P = 0.029) were risk factors for difficult cannulation. The total incidence of PEP was 10.9%. Compared with the other types of papillae, the rate of PEP was the highest in those with type I papilla (15.2%, P = 0.030). Multivariate analysis demonstrated that PEP was associated with difficult cannulation (OR = 1.811, 95% CI: 1.044-3.143, P = 0.035) and white blood cells (WBCs) < 10 × 109/L (OR = 2.199, 95% CI: 1.051-4.600, P = 0.036).

CONCLUSIONS

The endoscopic appearance of the major papilla is an important factor that influences both biliary cannulation and outcomes. Type III papilla is more frequently difficult to cannulate in the endoscopic treatment of CBD stones.

Intermittent fasting regulates gut microbiota and serum metabolome profiles in middle-aged mice fed high-fat diet

BACKGROUND

Intermittent fasting (IF) has received wide attention as an effective diet strategy. Existing studies showed that IF is a promising approach for weight control, improving insulin sensitivity and reducing type 2 diabetes mellitus (T2DM) prevalence.

METHODS

Twenty-eight 8-month-old male C57BL/6J mice were randomly divided into a normal control group (NC), a high-fat diet group (HFD) and an HFD + IF group. Body weight (BW) and food intake were monitored weekly. After 20 weeks, the intraperitoneal glucose tolerance test (IPGTT), oral glucose tolerance test (OGTT), and intraperitoneal insulin tolerance test (IPITT) were performed weekly in sequence. Fresh faeces were collected to examine changes in gut microbiota, and serum untargeted metabolite profiling was conducted on serum samples.

RESULTS

IF significantly reduced weight gain, fat mass and liver weight, improved glucose tolerance and insulin sensitivity in middle-aged mice fed with high-fat diet. 16 S rRNA gene sequencing revealed that IF significantly reduced the Firmicutes/Bacteroidetes (F/B) ratio by increased Muribaculaceae, Bacteroides, Parabacteroides, and decreased Bilophila, Colidextribacter, Oscillibacter. The serum untargeted metabolomics revealed that IF could modulate differential metabolites and metabolic pathways associated with glycolipid metabolism. Spearman's correlation analysis indicated that key differential microbiota were strongly correlated with glucose metabolism-related indicators and serum metabolites such as stearic acid, obeticholic acid, and N-acetylglycine.

CONCLUSIONS

IF improves glucose metabolism, regulates gut microbiota, and alters serum metabolites in middle-aged mice fed a high-fat diet. This provides a new pathway for trials testing diabetes prevention in middle-aged and elderly patients.

The close association of Muribaculum and PA (10:0/a-17:0) with the occurrence of pancreatic ductal adenocarcinoma and immunotherapy

Background

Progress in immunotherapy for pancreatic ductal adenocarcinoma (PDAC) has been slow, yet the relationship between microorganisms and metabolites is crucial to PDAC development. This study compares the biliary microbiota and metabolomic profiles of PDAC patients with those of benign pancreatic disease patients to investigate PDAC pathogenesis and its relationship with immunotherapy.

Methods

A total of 27 patients were recruited, including 15 diagnosed with PDAC and 12 with benign pancreaticobiliary conditions, all of whom underwent surgical treatment. Intraoperative bile samples were collected and analyzed using 16S rRNA sequencing in conjunction with liquid chromatography-mass spectrometry (LC-MS). Multivariate statistical methods and correlation analyzes were employed to assess differences in microbial composition, structure, and function between malignant and benign pancreatic diseases. Additionally, a retrospective analysis was conducted on PDAC patients post-surgery regarding immunotherapy and its correlation with metabolic components.

Results

PDAC patients exhibited a significantly higher abundance of bile microbiota compared to controls, with notable differences in microbiota structure between the two groups (P < 0.05). At the genus level, Muribaculum was markedly enriched in the bile of PDAC patients and was strongly correlated with phosphatidic acid (PA) (10:0/a-17:0). Both of these components, along with the tumor marker CA199, formulated a predictor of PDAC. Furthermore, PA (10:0/a-17:0) demonstrated a strong correlation with PDAC immunotherapy outcomes (Rho: 0.758; P=0.011).

Conclusion

These findings suggest that the biliary microbiota and associated metabolites play a crucial role in the development of PDAC and may serve as potential predictive biomarkers and therapeutic targets for disease management.

The assessment of postoperative cholangitis in malignant biliary obstruction: a real-world study of nasobiliary drainage after endoscopic placement of self-expandable metal stent

Objectives

Endoscopic retrograde cholangiopancreatography(ERCP) with endoscopic metallic biliary endoprosthesis(EMBE) serves as a crucial palliative treatment for advanced malignant biliary obstruction(MBO). While endoscopic nasobiliary drainage(ENBD) effectively reduces post-ERCP cholangitis (PEC) incidence, its impact on PEC in MBO patients is unclear. This study evaluates ENBD's effects on PEC in patients undergoing EMBE and identifies risk factors.

Methods

This retrospective cohort study at the First Hospital of Jilin University involved MBO patients who underwent EMBE from September 2011 to September 2022. Propensity score matching (PSM) was applied to minimize selection bias. Primary and secondary outcomes included the incidence and recovery rate/time of PEC, biliary drainage success, and hospitalization duration. Univariate, multivariate, and Lasso regression analyses identified independent risk factors.

Results

In this study of 1,008 patients, 730 were analyzed after PSM(365 each in the EMBE+ENBD and EMBE groups). No significant differences were observed in PEC incidence(10.7% vs 11.2%, p=0.9057) or recovery rates(48.7% vs 31.7%, p=0.1855). However, PEC recovery time was shorter in the EMBE+ENBD group(4.0 days [3.0, 6.0] vs 5.0 days [4.0, 7.5], p=0.0240), as was hospitalization duration(6.0 days [4.0, 8.0] vs 7.0 days [5.0, 10.0], p=0.0146), and a higher success rate of biliary drainage(54.0% vs 43.3%, p=0.0049). Tumor location(HR 1.10, 95% CI 1.00-1.20) and preoperative total bilirubin(HR 2.13, 95% CI 1.66-2.73) were identified as independent risk factors.

Conclusion

In this large-scale PSM study, ENBD did not reduce PEC incidence but expedited recovery and shortened hospital stays. Patients with hilar MBO of Bismuth III-IV or high preoperative bilirubin were more prone to PEC.

Sphincter of Oddi Dysfunction Induces Gallstone by Inhibiting the Expression of ABCB11 via PKC-α

The abnormal increase of Oddi sphincter pressure and total bile duct pressure may play an important role in the formation of cholesterol stones, but the specific molecular mechanism is still unclear. This study aims to investigate it through in vitro and in vivo experiments. A mouse model of Oddi sphincter dysfunction was constructed by stone-inducing diet. We compared the two groups with PKC-α inhibitor GÖ6976 and PKC-α agonist thymeleatoxin. Oddi sphincter pressure and total bile duct pressure were measured. Biochemical analysis of total cholesterol, bile acid and bilirubin was then conducted. The histopathologic changes of bile duct were observed by HE staining and the ultrastructure of liver cells and surrounding tissues was observed by transmission electron microscopy. Through the above experiments, we found that the change of PKC-α expression may affect the formation process of gallstones. The relationship between PKC-α and ABCB11 was further verified by in vitro and in vivo experiments. Our results suggest that ABCB11 and PKC-α are co-expressed in the tubule membrane of hepatocytes and interact with each other in hepatocytes. The high cholesterol diet further enhances the activation of PKC-α and thus reduces the expression of ABCB11. The formation of cholesterol stones is associated with the down-regulation of ABCB11 expression in the tubule membrane of hepatocytes due to kinase signaling. This is the first study to demonstrate that sphincter of Oddi dysfunction induces gallstones through PKC-α inhibition of ABCB11 expression.

Understanding bacterial infiltration of the pancreas through a deformable pancreatic duct

Tiny amount of bacteria are found in the pancreas in pancreatitis and cancer, which seemed involved in inflammation and carcinogenesis. However, bacterial infiltration from the duodenum is inhibited by the physical defense mechanisms such as bile flow and the sphincter of Oddi. To understand how the bacteria possibly infiltrate the pancreas through a deformable pancreatic duct, influenced by the periodic contractions of the sphincter of Oddi, a mathematical model of bacterial infiltration is developed that considered large deformation, fluid flow, and bacterial transport in a deformable pancreatic duct. In addition, the sphincter's contraction wave is modeled by including its propagation from the pancreas toward the duodenum. Simulated structure of the deformed duct with the relaxed sphincter and simulated bile distribution agreed reasonably well with the literature, validating the model. Bacterial infiltration from the duodenum in a deformable pancreatic duct, following the sphincter's contraction, is counteracted by a gradual peristalsis-like deformation of the pancreatic duct, due to an antegrade contraction wave propagation from the pancreas to the duodenum, Parametric sensitivity analysis demonstrated that bacterial infiltration is increased with lower bile and pancreatic juice flow rate, greater contraction amplitude and frequency, thinner wall thickness, and retrograde contraction wave propagation. Since contraction waves following retrograde propagation are increased in patients with common bile duct stones and pancreatitis, they may possibly be factors for continuum inflammation of pancreas. (224 words).