The preliminary experimental and clinical study of the relationship between the pigment gallstone and intestinal mucosal barrier

Moderate and severe depression increase the incidence of cholelithiasis: Results from Mendelian randomization study and the NHANES 2017-March 2020

BACKGROUND

Depression may be a contributing factor to cholelithiasis. However, the exact correlation between cholelithiasis and depression severity remains unclear.

METHODS

First, a two-sample Mendelian randomization (MR) analysis was performed to validate previous research findings, utilizing separate datasets for major depressive disorder (MDD) and cholelithiasis. The MDD dataset (135,458 cases, 344,901 controls) came from a published GWAS, and cholelithiasis data (19,023 cases, 195,144 controls) were sourced from FinnGen. The primary analytical approach for the MR study was the inverse variance weighting (IVW) method. Second, an observational study based on the National Health and Nutrition Examination Survey (NHANES) was conducted to explore the relationship between the severity of depression and cholelithiasis. 7071 participants were included in the observational study in total. Depression severity (no, mild, moderate, severe) was measured by Patient Health Questionnaire-9 (PHQ-9). Weighted multivariable-adjusted logistic regression was employed to assess the association between depression severity and cholelithiasis.

RESULTS

In the MR study, the IVW analysis revealed that MDD may increase the risk of cholelithiasis (OR 1.25, 95% CI 1.07-1.45, P = 0.004). The observational study showed that moderate (OR 1.06, 95% CI 1.00-1.11, p = 0.037) and severe (OR 1.07, 95% CI 1.00-1.15, p = 0.044) depression rises the incidence of cholelithiasis. However, no significant association was found between mild depression and cholelithiasis (p = 0.275).

CONCLUSIONS

Moderate and severe depression might rise the incidence of cholelithiasis, while mild depression may not. Further validation through prospective studies is necessary.

Role of Secretory Mucins in the Occurrence and Development of Cholelithiasis

Cholelithiasis is a common biliary tract disease. However, the exact mechanism underlying gallstone formation remains unclear. Mucin plays a vital role in the nuclear formation and growth of cholesterol and pigment stones. Excessive mucin secretion can result in cholestasis and decreased gallbladder activity, further facilitating stone formation and growth. Moreover, gallstones may result in inflammation and the secretion of inflammatory factors, which can further increase mucin expression and secretion to promote the growth of gallstones. This review systematically summarises and analyses the role of mucins in gallstone occurrence and development and its related mechanisms to explore new ideas for interventions in stone formation or recurrence.

Hepatolithiasis: Epidemiology, presentation, classification and management of a complex disease

The term hepatolithiasis describes the presence of biliary stones within the intrahepatic bile ducts, above the hilar confluence of the hepatic ducts. The disease is more prevalent in Asia, mainly owing to socioeconomic and dietary factors, as well as the prevalence of biliary parasites. In the last century, owing to migration, its global incidence has increased. The main pathophysiological mechanisms involve cholangitis, bile infection and biliary strictures, creating a self-sustaining cycle that perpetuates the disease, frequently characterised by recurrent episodes of bacterial infection referred to as syndrome of "recurrent pyogenic cholangitis". Furthermore, long-standing hepatolithiasis is a known risk factor for development of intrahepatic cholangiocarcinoma. Various classifications have aimed at providing useful insight of clinically relevant aspects and guidance for treatment. The management of symptomatic patients and those with complications can be complex, and relies upon a multidisciplinary team of hepatologists, endoscopists, interventional radiologists and hepatobiliary surgeons, with the main goal being to offer relief from the clinical presentations and prevent the development of more serious complications. This comprehensive review provides insight on various aspects of hepatolithiasis, with a focus on epidemiology, new evidence on pathophysiology, most important clinical aspects, different classification systems and contemporary management.

Infection with a human-derived enteroinvasive Escherichia coli strain altered intestinal barrier function in guinea pigs

BACKGROUND/AIMS

The aim was to characterize a bacterium causing intestinal mucosal barrier damage and to identify the possible invasion mechanism.

MATERIALS AND METHODS

The intestinal permeability and tight junction protein levels were detected in guinea pigs infected with Escherichia coli D-09 via immunofluorescence analysis and western blotting. In order to explain this invasion mechanism at the gene level, whole genome sequencing analysis was performed on this bacterium.

RESULTS

The results showed an increased intestinal permeability and upregulated expression of the leaky protein claudin-2 in both the colon and liver of the infected animals. In addition, the draft genome of E. coli D-09 comprised 42 scaffolds (size, > 645 bp) with a total size of 4,679,567 bp. A total of 4379 protein coding genes were identified, which contained 45 antibiotic resistance and 86 virulence-related genes and covered 88.0% of the whole genome.

CONCLUSIONS

This study verified that the human-derived enteroinvasive E. coli strain could destroy intestinal barrier function in guinea pigs. Additionally, our data first characterized the genome features of E. coli O124:K72 D-09, which may provide new insights into the possible invasion mechanism.

Analysis of the relationship between bile duct and duodenal microbiota reveals that potential dysbacteriosis is the main cause of primary common bile duct stones

Bacteria play an important role in the formation of primary Common Bile Duct (CBD) stones. However, the composition and function of the microbiota of bile duct in patients with primary CBD stones remained to be explored. We utilized the 16S rRNA gene high-throughput sequencing technology to analyze the microbial diversity and community composition of biliary and duodenal microbiota in 15 patients with primary CBD stones and 4 patients without biliary tract diseases. Alpha diversity analysis showed that the microbiota richness was similar in bile and intestinal fluid; Beta diversity analysis showed that there were differences in the composition between biliary microbiota and the duodenal microbiota, but the abundance of the main groups showed similarities. The composition of the biliary microbiota from gallstone patients was more complex, as was the duodenal microbiota. Proteobacteria and Firmicutes were the dominant bacteria at phylum level, accounting for at least 75% of the total reads in each subgroup. Pseudomonas and Escherichia-Shigella were the major genus among subgroups, but Escherichia-Shigella had increased abundance in duodenal microbiota with primary choledocholithiasis, which may play an important role in stone formation. It is noteworthy that Clostridiumsensu_stricto, Lachnospiraceae _UCG-008, Butyrivibrio and Roseburia which could produce short chain fatty acids (SCFAs), were significantly decreased in biliary microbiota with primary CBD stones (p < 0.05). Our study provided new insights into the compositional of normal biliary microbiota. The micro-ecology of biliary and duodenal in patients with stones is complex and closely related, and there is a potential for dysbacteriosis. The decrease in abundance of certain major acid-producing bacteria affects the health of the biliary tract and thus leads to the formation of stones.

Changes and Correlations of the Intestinal Flora and Liver Metabolite Profiles in Mice With Gallstones

There is increasing appreciation for the roles of the gut-liver axis in liver and gall diseases. Specific gut microbes are associated with susceptibility to gallstone diseases, while the relationship between intestinal flora and liver metabolism in the formation of gallstones remains unclear. In this study, an experimental group of model mice was given a lithogenic diet, and a control group was given a normal diet. Both groups were fed for 8 weeks. Integrating 16S rRNA gene sequencing and non-targeted metabolomics to explore the impact of the lithogenic diet on intestinal flora and liver metabolism, Spearman correlation analysis reveals the network of relationships between the intestine and liver. Our findings showed that the gut microbiome and liver metabolome compositions of the test group were significantly changed compared with those of the normal group. Through our research, biomarkers of gallstones were identified at the phylum (5), class (5), order (5), family (7), and genus levels. We predicted the function of the differential flora. We analyzed the liver metabolism of mice with gallstones paired with their flora, and the results showed that there were 138 different metabolites between the two groups. The metabolic pathways enriched by these differential metabolites are highly consistent with the functions of the disordered flora. We focused on an analysis of the relationship between deoxycholic acid, asymmetric dimethylarginine, glucosamine, tauroursodeoxycholic acid, and the disordered flora. This provides a basis for the establishment of the intestine-liver axis in gallstone disease. This research provides a theoretical basis for the research and development of probiotics and prebiotics.

Mode of renal replacement therapy determines endotoxemia and neutrophil dysfunction in chronic kidney disease

Bacterial infection and sepsis are common complications of chronic kidney disease (CKD). A vicious cycle of increased gut permeability, endotoxemia, inadequate activation of the innate immune system and resulting innate immune dysfunction is hypothesized. We assessed endotoxemia, neutrophil function and its relation to oxidative stress, inflammation and gut permeability in patients with CKD grade 3–5 without renal replacement therapy (CKD group, n = 57), patients with CKD stage 5 undergoing haemodialysis (HD, n = 32) or peritoneal dialysis (PD, n = 28) and patients after kidney transplantation (KT, n = 67) in a cross-sectional observational study. In HD patients, endotoxin serum levels were elevated and neutrophil phagocytic capacity was decreased compared to all other groups. Patients on HD had a significantly higher mortality, due to infections during follow up, compared to PD (p = 0.022). Oxidative stress, neutrophil energy charge, systemic inflammation and gut permeability could not completely explain these differences. Our findings suggest that dialysis modality and not renal function per se determine the development of neutrophil dysfunction and endotoxemia in CKD-patients. HD patients are particularly prone to neutrophil dysfunction and endotoxemia whereas neutrophil function seems to improve after KT. Multi-target approaches are therefore warranted to improve neutrophil function and potentially reduce the rate of infections with patients undergoing haemodialysis.

Impaired cholecystokinin-induced gallbladder emptying incriminated in spontaneous "black" pigment gallstone formation in germfree Swiss Webster mice

"Black" pigment gallstones form in sterile gallbladder bile in the presence of excess bilirubin conjugates ("hyperbilirubinbilia") from ineffective erythropoiesis, hemolysis, or induced enterohepatic cycling (EHC) of unconjugated bilirubin. Impaired gallbladder motility is a less well-studied risk factor. We evaluated the spontaneous occurrence of gallstones in adult germfree (GF) and conventionally housed specific pathogen-free (SPF) Swiss Webster (SW) mice. GF SW mice were more likely to have gallstones than SPF SW mice, with 75% and 23% prevalence, respectively. In GF SW mice, gallstones were observed predominately in heavier, older females. Gallbladders of GF SW mice were markedly enlarged, contained sterile black gallstones composed of calcium bilirubinate and <1% cholesterol, and had low-grade inflammation, edema, and epithelial hyperplasia. Hemograms were normal, but serum cholesterol was elevated in GF compared with SPF SW mice, and serum glucose levels were positively related to increasing age. Aged GF and SPF SW mice had deficits in gallbladder smooth muscle activity. In response to cholecystokinin (CCK), gallbladders of fasted GF SW mice showed impaired emptying (females: 29%; males: 1% emptying), whereas SPF SW females and males emptied 89% and 53% of volume, respectively. Bilirubin secretion rates of GF SW mice were not greater than SPF SW mice, repudiating an induced EHC. Gallstones likely developed in GF SW mice because of gallbladder hypomotility, enabled by features of GF physiology, including decreased intestinal CCK concentration and delayed intestinal transit, as well as an apparent genetic predisposition of the SW stock. GF SW mice may provide a valuable model to study gallbladder stasis as a cause of black pigment gallstones.

Plasma lipopolysaccharide is closely associated with glycemic control and abdominal obesity: evidence from bariatric surgery

OBJECTIVE

It is of vital importance to elucidate the triggering factors of obesity and type 2 diabetes to improve patient care. Bariatric surgery has been shown to prevent and even cure diabetes, but the mechanism is unknown. Elevated levels of lipopolysaccharide (LPS) predict incident diabetes, but the sources of LPS are not clarified. The objective of the current study was to evaluate the potential impact of plasma LPS on abdominal obesity and glycemic control in subjects undergoing bariatric surgery.

RESEARCH DESIGN AND METHODS

This was a prospective observational study involving a consecutive sample of 49 obese subjects undergoing bariatric surgery and 17 controls. Main assessments were plasma LPS, HbA1c, adipose tissue volumes (computed tomography), and quantified bacterial DNA in adipose tissue compartments.

RESULTS

Plasma levels of LPS were elevated in obese individuals compared with controls (P < 0.001) and were reduced after bariatric surgery (P = 0.010). LPS levels were closely correlated with HbA1c (r = 0.56; P = 0.001) and intra-abdominal fat volumes (r = 0.61; P < 0.001), but only moderately correlated with subcutaneous fat volumes (r = 0.33; P = 0.038). Moreover, there was a decreasing gradient (twofold) in bacterial DNA levels going from mesenteric via omental to subcutaneous adipose tissue compartments (P = 0.041). Finally, reduced LPS levels after bariatric surgery were directly correlated with a reduction in HbA1c (r = 0.85; P < 0.001).

CONCLUSIONS

Our findings support a hypothesis of translocated gut bacteria as a potential trigger of obesity and diabetes, and suggest that the antidiabetic effects of bariatric surgery might be mechanistically linked to, and even the result of, a reduction in plasma levels of LPS.

Changes in intestinal permeability in patients with cholecystolithiasis

AIM: To investigate whether intestinal permeability changes in patients with cholecystolithiasis.

METHODS: Twenty-four patients with cholecystolithiasis and 20 healthy adults were included in the study. Intestinal permeability was assessed using the urine lactulose/mannitol (L/M) ratio measured by high pressure liquid chromatography.

RESULTS: Intestinal permeability was significantly higher in terms of the L/M ratio in the cholecystolithiasis group than in the control group (0.035 ± 0.026 vs 0.020 ± 0.005, P = 0.015). The percentage of subjects who had a L/M ratio exceeding the upper limit of normal (0.022) was significantly higher in the cholecystolithiasis group than in the control group (66.7% vs 15%, P = 0.001).

CONCLUSION: Intestinal permeability changes in patients with cholecystolithiasis.

New pathophysiological concepts underlying pathogenesis of pigment gallstones

Pigment gallstones, which are much less frequent than cholesterol stones, are classified descriptively as "black" or "brown". They are composed mostly of calcium hydrogen bilirubinate, Ca(HUCB)(2), which is polymerized and oxidized in "black" stones but remains unpolymerized in "brown" stones. Black stones form in sterile gallbladder bile but brown stones form secondary to stasis and anaerobic bacterial infection in any part of the biliary tree, including the gallbladder. Other calcium salts coprecipitate in both stone types; crystalline calcium phosphate and/or carbonate in the case of "black" stones and amorphous calcium salts of long chain saturated fatty acids ("soaps") in the case of "brown" stones. Cholesterol is present in variable proportions in "brown" more than "black" stones and in the latter, the bile sterol may be totally absent. The "scaffolding" of both stone types is a mixed mucin glycoprotein matrix secreted by epithelial cells lining the biliary tree. The critical pathophysiological prerequisite for "black" stone formation is "hyperbilirubinbilia" (biliary hypersecretion of bilirubin conjugates). It is due principally to hemolysis, ineffective erythropoiesis, or pathologic enterohepatic cycling of unconjugated bilirubin. Endogenous biliary β-glucuronidase hydrolysis of bilirubin conjugates in gallbladder bile provides HUCB(-) molecules that precipitate as insoluble salts with ionized Ca. Putatively, reactive oxygen species secreted by an inflamed gallbladder mucosa are responsible for transforming the initial soft yellow precipitates into hard black [Ca(HUCB)(2)](n) polymers. Despite "brown" gallstones being soft and amenable to mechanical removal, chronic anaerobic infection of the biliary tree is often markedly resistant to eradication.

Over-starvation aggravates intestinal injury and promotes bacterial and endotoxin translocation under high-altitude hypoxic environment

AIM: To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.

METHODS: Sprague-Dawley rats were exposed to hypobaric hypoxia at a simulated altitude of 7000 m for 72 h. Lanthanum nitrate was used as a tracer to detect intestinal injury. Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Serum levels of diamino oxidase (DAO), malondialdehyde (MDA), glutamine (Gln), superoxide dismutase (SOD) and endotoxin were measured in intestinal mucosa. Bacterial translocation was detected in blood culture and intestinal homogenates. In addition, rats were given Gln intragastrically to observe its protective effect on intestinal injury.

RESULTS: Apoptotic epithelial cells, exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells. Lanthanum particles were found in the intercellular space and intracellular compartment. Bacterial translocation to mesenteric lymph nodes (MLN) and spleen was evident. The serum endotoxin, DAO and MDA levels were significantly higher while the serum SOD, DAO and Gln levels were lower in intestine (P < 0.05). The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group (0.47 ± 0.83 vs 2.38 ± 1.45, P < 0.05). The bacterial translocation was found in each organ, especially in MLN and spleen but not in peripheral blood. The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln.

CONCLUSION: High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation, which can be treated with Gln.