In vitro analysis of gallstone formation in the presence of bacteria

Physicochemical Characterization of Gallstone Surfaces to Predict Their Interaction with Salmonella Typhi

Salmonella Typhi can adhere to and build biofilms on the surface of gallstones causing abnormal gallbladder mucosa, which could lead to carcinogenesis. The surface physicochemical properties of microbial cells and materials have been shown to play a crucial role in adhesion. Therefore, the purpose of this study was to investigate, for the first time, the surface properties of nine gallstones and to evaluate the influence of these parameters on the theoretical adhesion of S. Typhi to gallstone surfaces. The physicochemical properties were determined by SEM-EDX and contact angle measurements (CAM) while the predictive adhesion of S. Typhi on gallstones was estimated using the XDLVO approach. SEM-EDX analysis revealed that cholesterol is the principal component on the surface of all gallstones, with carbon and oxygen as the main elements. Aluminum was detected as a trace element in only three gallstones: GS2, GS4, and GS5. S. Typhi CIP5535 has a hydrophilic character (ΔGiwi = 33.54 mJ m-2), as well as strong electron donor (γ- = 55,80 mJ m-2) and weak electron acceptor properties (γ+  = 1,95 mJ m-2). Regarding gallstones, it was found that they have a hydrophobic character (ΔGiwi between -29,9 mJ m-2 and -75,2 mJ m-2), while their electron donor/acceptor characters change according to each gallstone. Predictive adhesion showed that all gallstones could be colonized by S. TyphiΔ G XDLVO Total < 0 except GS1, GS5, and GS6Δ G XDLVO Total > 0 . Understanding the interfacial phenomena implicated in the process of bacterial adhesion makes it possible to limit or even inhibit the adhesion of S. Typhi on gallstone surfaces.

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.

The role of bacteria in gallstone formation

Gallstones are a prevalent biliary system disorder that is particularly common in women. They can lead to various complications, such as biliary colic, infection, cholecystitis, and even gallbladder cancer. However, the etiology of gallstones remains incompletely understood. The significant role of bacteria in gallstone formation has been demonstrated in recent studies. Certain bacteria not only influence bile composition and the gallbladder environment but also actively participate in stone formation by producing enzymes such as β-glucuronidase and mucus. Therefore, this review aimed to analyze the mechanisms involving the types and quantities of bacteria involved in gallstone formation, providing valuable references for understanding the etiology and clinical treatment of gallstones.

Insight into the mechanism of gallstone disease by proteomic and metaproteomic characterization of human bile

Introduction

Cholesterol gallstone disease is a prevalent condition that has a significant economic impact. However, the role of the bile microbiome in its development and the host's responses to it remain poorly understood.

Methods

In this study, we conducted a comprehensive analysis of microbial and human bile proteins in 40 individuals with either gallstone disease or gallbladder polyps. We employed a combined proteomic and metaproteomic approach, as well as meta-taxonomic analysis, functional pathway enrichment, and Western blot analyses.

Results

Our metaproteomic analysis, utilizing the lowest common ancestor algorithm, identified 158 microbial taxa in the bile samples. We discovered microbial taxa that may contribute to gallstone formation, including β-glucuronidase-producing bacteria such as Streptococcus, Staphylococcus, and Clostridium, as well as those involved in biofilm formation like Helicobacter, Cyanobacteria, Pseudomonas, Escherichia coli, and Clostridium. Furthermore, we identified 2,749 human proteins and 87 microbial proteins with a protein false discovery rate (FDR) of 1% and at least 2 distinct peptides. Among these proteins, we found microbial proteins crucial to biofilm formation, such as QDR3, ompA, ndk, pstS, nanA, pfIB, and dnaK. Notably, QDR3 showed a gradual upregulation from chronic to acute cholesterol gallstone disease when compared to polyp samples. Additionally, we discovered other microbial proteins that enhance bacterial virulence and gallstone formation by counteracting host oxidative stress, including sodB, katG, rbr, htrA, and ahpC. We also identified microbial proteins like lepA, rtxA, pckA, tuf, and tpiA that are linked to bacterial virulence and potential gallstone formation, with lepA being upregulated in gallstone bile compared to polyp bile. Furthermore, our analysis of the host proteome in gallstone bile revealed enhanced inflammatory molecular profiles, including innate immune molecules against microbial infections. Gallstone bile exhibited overrepresented pathways related to blood coagulation, folate metabolism, and the IL-17 pathway. However, we observed suppressed metabolic activities, particularly catabolic metabolism and transport activities, in gallstone bile compared to polyp bile. Notably, acute cholelithiasis bile demonstrated significantly impaired metabolic activities compared to chronic cholelithiasis bile.

Conclusion

Our study provides a comprehensive metaproteomic analysis of bile samples related to gallstone disease, offering new insights into the microbiome-host interaction and gallstone formation mechanism.

Evaluation of gallstone classification and their diagnosis through serum parameters as emerging tools in treatment: a narrative review

The treatment of gallstones is a matter of real concern as they may cause gallbladder cancer if not properly attended to. Evaluating the classification of gallstones can give major clues in their treatment as it will decide their aetiology, chemical composition, and pathogenesis. Also, serum parameters have emerged as an efficient tool for diagnosing gallstones. They can be probed to evaluate different biochemicals and the changes in their levels in gallstone patients which can be correlated with early prediction of the formation of gallstones. In the present review, a thorough search of the available literature was done starting from the earliest approaches for the classification of gallstones up to the recent advancements. The alteration in the level of serum parameters was also studied in gallstone patients so that it can act as a potential diagnostic tool for early detection of gallstone formation. The earliest classification of gallstones was done in 1896 by Nauyn. He classified them into pure cholesterol stones, laminated cholesterol stones, ordinary gallbladder stones, mixed bilirubin stones, and rare forms. The most recent classification of gallstones was done by Peter et al in 2020 and they classified them as pure, mixed, composite cholesterol, carbonate stones, black and brown pigment stones. The altered of levels of serum parameters was analyzed by Reuben (1985) and in recent times by Peter et al (2020). The various serum parameters studied were as RDW-CV test (red blood cell distribution width), PCT (prolactin) test, MPV (mean platelet count), LYM (lymphocyte) test, and EOS (eosinophil and eosinophil count test). Also, we discussed some practical considerations for gallstones that can be taken into account for gallstone prevention and diagnosis. Further research is required to detect gallstone type in the gallbladder by using the alteration in the levels of serum parameters.

Dealkenylation of neoandrographolide, a phytochemical from Andrographis paniculata stimulates FXR (Farnesoid X Receptor) and enhances gallstone dissolution

FXR (Farnesoid X Receptor) is one of the nuclear receptors expressed in the liver performing a significant role in the maintenance of bile acid concentration. An imbalance of cholesterol and bile acid ratio due to any undefined reason could cause gallstone formation. Hence, this paper aims to screen phytochemicals that could maintain a requisite balance of cholesterol and bile acid by targeting FXR and thereby contributing to the dissolution of gallstone. Nineteen phytochemicals were selected and queried for Pa and Pi in the way2drug online server for hepatoprotective property, cholesterol synthesis and absorption inhibition property, and β-glucuronidase inhibiting activity. Cianidanol, neoandrographolide, cynarine, saponins, and tanins with satisfying stated properties were docked with the screened FXR (PDB ID- 1OSH) using HADDOCK server, followed by pharmacokinetics study utilizing SwissADME tool. Neoandrographolide fits best among the other selected literature-based phytochemicals with minor violation of 'Brenk's rule'. The violation was corrected with the removal of an alkene group in the provided ChemDraw space of SwissADME. This Dealkenylated compound was further docked with FXR. The promising response under the static condition of the Dealkenylated compound was analyzed for molecular dynamic simulation at physiological conditions for 100 ns. Dealkenylated Neoandrographolide (DN) exhibited hepatoprotective, cholesterol synthesis and absorption inhibition property, and β-glucuronidase inhibition activity with a superior binding score of -42.6+/-1.5 with FXR. The interaction of the FXR receptor and the DN showed exceptional stability at physiological conditions during MD simulation and fit for the ADME properties, therefore it could be a potent candidate to dissolve gallstones.Communicated by Ramaswamy H. Sarma.