Effect of chronic stress on gel-forming mucins in the small intestine of BALB/c mice.

Intestinal homeostasis involves the collaboration of gut barrier components, such as goblet cells and IgA-microbiota complexes, that are under the control of stress that promotes inflammatory responses addressed primarily in the colon. The aim of this study was to evaluate the effect of stress on mucins, goblet cells, and proinflammatory parameters in the proximal and distal regions of the small intestine. A group (n = 6) of female 8-week-old BALB/c mice underwent board immobilization stress (2 h per day for 4 days) and were sacrificed with isoflurane. Samples from proximal and distal small segments were collected to analyze the following: 1) goblet cells stained with periodic acid-Schiff (PAS) and with alcian blue (AB) to visualize histologically neutral and acidic mucins, respectively; 2) IgA-microbiota complexes identified by flow cytometry in intestinal lavages; and 3) MUC2, MUC5AC, and IL-18 mRNA levels in whole mucosal scrapings by reverse transcription-qPCR. Regarding the unstressed group, in the proximal region of small intestine both PAS+ and AB+ goblet cells were unchanged; however, MUC5AC and IL-18 mRNA levels were increased, and the percentage of IgA-microbiota complexes was reduced. In the distal segment, the number of PAS+ goblet cells was increased, whereas the number of AB+ goblet cells was reduced and did not affect the remaining parameters. The data suggest that stress induces inflammation in the proximal small intestine; these findings may provide an experimental reference for human diseases that may affect the proximal small intestine, such as Crohn's disease, in which stress contributes to the progression of intestinal inflammation or relapse.

Analysis of Mucin-Domain Glycoproteins Using Mass Spectrometry.

Mucin-domain glycoproteins are characterized by their high density of glycosylated serine and threonine residues, which complicates their analysis by mass spectrometry. The dense glycosylation renders the protein backbone inaccessible to workhorse proteases like trypsin, the vast heterogeneity of glycosylation often results in ion suppression from unmodified peptides, and search algorithms struggle to confidently analyze and site-localize O-glycosites. We have made a number of advances to address these challenges, rendering mucinomics possible for the first time. Here, we summarize these contributions and provide a detailed protocol for mass spectrometric analysis of mucin-domain glycoproteins. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Enrichment of mucin-domain glycoproteins Basic Protocol 2: Enzymatic digestion of mucin-domain glycoprotein(s) Basic Protocol 3: Mass spectrometry data collection for O-glycopeptides Basic Protocol 4: Mass spectrometry data analysis of O-glycopeptides.

Low-grade appendiceal mucinous neoplasms: Histomorphological spectrum in a tertiary care hospital.

BACKGROUND: Low-grade appendiceal mucinous neoplasms (LAMNs) are benign non-invasive epithelial proliferations of the appendix. These usually present clinically as mucoceles and these rarely exceed 2 cm in diameter. Lesions confined to the lumen are labelled as LAMN; however those in which mucin spreads outside the peritoneum are labeled as pseudomyxoma peritonei (PMP). AIMS AND OBJECTIVE: A retrospective study was conducted over a period of three years and all cases of appendectomies were studied. Twelve cases of LAMN were identified, which is a diagnostic dilemma for the pathologists and clinicians. RESULTS: LAMN was identified based on the histopathological features. Out of the 12 cases, 9 were classified as LAMN and 3 as appendiceal neoplasm with PMP. There was villous or flat proliferation of epithelial lining, loss lymphoid aggregates, and dissecting mucin within muscularis. CONCLUSION: LAMNs are rare neoplasms of the appendix, with clinical presentation similar to acute appendicitis. Mucinous collections within the appendiceal wall should be extensively searched for mucosal changes and, if found, should prompt a careful search for pushing invasion of LAMNs. A thorough and vigilant gross examination can be of great help. Appendicectomy is the treatment of benign and grossly intact mucinous neoplasm.

Reduced sialylation of airway mucin impairs mucus transport by altering the biophysical properties of mucin.

Mucus stasis is a pathologic hallmark of muco-obstructive diseases, including cystic fibrosis (CF). Mucins, the principal component of mucus, are extensively modified with hydroxyl (O)-linked glycans, which are largely terminated by sialic acid. Sialic acid is a negatively charged monosaccharide and contributes to the biochemical/biophysical properties of mucins. Reports suggest that mucin sialylation may be altered in CF; however, the consequences of reduced sialylation on mucus clearance have not been fully determined. Here, we investigated the consequences of reduced sialylation on the charge state and conformation of the most prominent airway mucin, MUC5B, and defined the functional consequences of reduced sialylation on mucociliary transport (MCT). Reduced sialylation contributed to a lower charged MUC5B form and decreased polymer expansion. The inhibition of total mucin sialylation de novo impaired MCT in primary human bronchial epithelial cells and rat airways, and specific α-2,3 sialylation blockade was sufficient to recapitulate these findings. Finally, we show that ST3 beta-galactoside alpha-2,3-sialyltransferase (ST3Gal1) expression is downregulated in CF and partially restored by correcting CFTR via Elexacaftor/Tezacaftor/Ivacaftor treatment. Overall, this study demonstrates the importance of mucin sialylation in mucus clearance and identifies decreased sialylation by ST3Gal1 as a possible therapeutic target in CF and potentially other muco-obstructive diseases.

Assessment of polymeric mucin-drug interactions.

Mucosal-delivered drugs have to pass through the mucus layer before absorption through the epithelial cell membrane. Although there has been increasing interest in polymeric mucins, a major structural component of mucus, potentially acting as important physiological regulators of mucosal drug absorption, there are no reports that have systematically evaluated the interaction between mucins and drugs. In this study, we assessed the potential interaction between human polymeric mucins (MUC2, MUC5B, and MUC5AC) and various drugs with different chemical profiles by simple centrifugal method and fluorescence analysis. We found that paclitaxel, rifampicin, and theophylline likely induce the aggregation of MUC5B and/or MUC2. In addition, we showed that the binding affinity of drugs for polymeric mucins varied, not only between individual drugs but also among mucin subtypes. Furthermore, we demonstrated that deletion of MUC5AC and MUC5B in A549 cells increased the cytotoxic effects of cyclosporin A and paclitaxel, likely due to loss of mucin-drug interaction. In conclusion, our results indicate the necessity to determine the binding of drugs to mucins and their potential impact on the mucin network property.

B3GNT7 regulates mucin O-glycosylation to alleviate colonic inflammation.

BACKGROUND: B3GNT7, a glycosyltransferase of significant importance that is highly expressed in intestinal epithelial cells, plays a pivotal role in intestinal physiological processes. This study elucidates novel insights into the potential role and underlying mechanisms of B3GNT7 in ulcerative colitis (UC). METHODS: An experimental colitis model was induced using DSS in mice to investigate B3GNT7 expression in the colon via transcriptomics and immunohistochemistry. Bioinformatics analysis was employed to delineate the biological functions of B3GNT7. Additionally, the correlation between the transcription levels of B3GNT7 in colonic tissues from patients with UC, sourced from the IBDMDB database, and the severity of colonic inflammation was analyzed to elucidate potential mechanisms. RESULTS: The DSS-induced colitis model was successfully established, and transcriptomic analysis identified a marked downregulation of B3GNT7 expression in the colonic tissues compared to the controls. Functional enrichment analysis indicated B3GNT7's predominant role in mucin O-glycosylation. Protein interaction analysis revealed that B3GNT7 predominantly interacts with members of the mucin MUC family, including MUC2, MUC3, and MUC6. In patients with UC, B3GNT7 transcription levels were significantly reduced, particularly in those with moderate to severe disease activity. The expression level of B3GNT7 exhibited a negative correlation with the endoscopic severity of UC. Gene set enrichment analysis (GSEA) further demonstrated significant enrichment of B3GNT7 in the mucin O-glycosylation synthesis pathway. CONCLUSION: The downregulation of B3GNT7 expression in the colonic tissues of UC patients may contribute to the compromised mucin barrier function and the exacerbation of colitis.

Genomic and functional insights of a mucin foraging Rhodopirellula halodulae sp. nov.

Nine novel strains were obtained from various algal and seagrass samples. The analysis of the 16S rRNA gene-based phylogenetic tree revealed monophyletic placement of all novel strains within the Rhodopirellula genus. The type strain was identified as JC737T, which shared 99.1 % 16S rRNA gene sequence identity with Rhodopirellula baltica SH1T, while strain JC740 was designated as an additional strain. The genome sizes of strains JC737T and JC740 were 6.6 and 6.7 Mb, respectively, and the G + C content was 56.2 %. The strains cladded distinctly in the phylogenomic tree, and the ANI and dDDH values of the strain JC737T were 75.8-76.1 % and 20.8-21.3 %, respectively, in comparison to other Rhodopirellula members. The strain demonstrated a versatile degradation capability, exhibiting a diverse array of complex polysaccharides, including mucin which had not been previously identified within the members of the phylum Planctomycetota. The phylogenomic, pan-genomic, morphological, physiological, and genomic characterization of the strain lead to the proposal to describe the strain as Rhodopirellula halodulae sp. nov.

Prostate Adenocarcinoma with Signet-Ring Cells and Features of Mucin: A Clinical Case and Literature Review.

Introduction: Signet-ring cells are typically associated with mucin-secreting epithelium; thus, they are most commonly found in the gastrointestinal tract, but not exclusively. Primary signet-ring cell carcinoma of the prostate is a rare and poorly differentiated, aggressive acinar adenocarcinoma variant with a grim prognosis. Clinical Case: In June of 2023, a 54-year-old Caucasian male presented with a complaint of lower urinary tract obstructive symptoms with occasional macrohematuria, non-specific body aches, and shortness of breath. A prostate specimen obtained in transurethral resection of the prostate was sent for histopathological examination. After a series of extraprostatic diagnostic workups, including fibrogastroduodenoscopy, colonoscopy computed tomography imaging, and immunohistochemical studies, the patient was diagnosed with primary prostatic signet-ring cell adenocarcinoma stage IV. Unfortunately, due to the advanced stage of the disease, PE, and third-degree thrombocytopenia, the patient was not a candidate for chemotherapy and died of cardiopulmonary insufficiency later that week. Discussion: Prostatic signet-ring cell carcinoma accounts for 0.02% of all prostate adenocarcinoma cases. Due to its nature and epidemiology, a diligent extraprostatic investigation has to be carried out. The disease often presents with unremarkable clinical symptoms and variable serum prostate-specific antigen results, which may contribute to its late diagnosis. Inconsistent immunohistochemical findings and an unpredictable response to hormonal treatment together pose both diagnostic and therapeutic challenges that negatively affect the prognosis. Conclusions: This study highlights the importance of a multidisciplinary approach and the need for diagnostic and therapeutic consensus within the research community in search of the primary site of the disease, which may positively influence the prognosis.

Differential Expression of Mucin in Salivary Gland Tumours.

Background and Objectives: Mucin has been implicated via various mechanisms in the development and growth of tumour cells. However, mucin expression studies in salivary gland tumours are limited, especially with samples from minor salivary glands. This study aims to investigate and compare mucin expression in benign and malignant salivary gland tumours of minor and major salivary gland origins. Materials and Methods: Special stains were used to stain neutral mucin (Periodic acid Schiff), sialomucin (Alcian Blue) and sulfomucin (Aldehyde Fuschin) within tissues from six normal salivary glands and 73 salivary gland tumours including 31 pleomorphic adenomas, 27 mucoepidermoid carcinomas, and 15 adenoid cystic carcinomas. A semi-quantitative approach was used to evaluate mucin expression within ductal lumens. Sialomucin was the most expressed mucin in all salivary gland tumours, regardless of origin. Results: A significant difference was observed in the mucin expression between benign and malignant salivary gland tumours, as pleomorphic adenoma showed three times significantly higher expression of sialomucin compared to mucoepidermoid carcinoma and adenoid cystic carcinoma (p = 0.028). Pleomorphic adenomas of major glands showed 42 times significantly higher expression of sialomucin compared to those of minor glands (p = 0.000). Conclusions: Sialomucin content in pleomorphic adenomas of major glands was vastly increased compared to that in minor glands. Differential sialomucin expression in benign and malignant salivary gland tumours suggests a role in diagnosing of borderline salivary gland tumours.

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.

Comprehensive Characterization of the Viscoelastic Properties of Bovine Submaxillary Mucin (BSM) Hydrogels and the Effect of Additives.

This study presents a comprehensive characterization of the viscoelastic and structural properties of bovine submaxillary mucin (BSM), which is widely used as a commercial source to conduct mucus-related research. We conducted concentration studies of BSM and examined the effects of various additives, NaCl, CaCl2, MgCl2, lysozyme, and DNA, on its rheological behavior. A notable connection between BSM concentration and viscoelastic properties was observed, particularly under varying ionic conditions. The rheological spectra could be well described by a fractional Kelvin-Voigt model with a minimum of model parameters. A detailed proteomics analysis provided insight into the protein, especially mucin composition within BSM, showing MUC19 as the main component. Cryo-scanning electron microscopy enabled the visualization of the porous BSM network structure. These investigations give us a more profound comprehension of the BSM properties, especially those pertaining to viscoelasticity, and how they are influenced by concentration and environmental conditions, aspects relevant to the field of mucus research.

Insights into the Chemistry, Structure, and Biological Activity of Human Salivary MUC7 Fragments and Their Cu(II) and Zn(II) Complexes.

Mucin 7 (MUC7) is one of the salivary proteins whose role in the innate immune system is widely known, but still, neither its mechanism of action nor the impact of its metal coordination is fully understood. MUC7 and its fragments demonstrate potent antimicrobial activity, serving as a natural defense mechanism for organisms against pathogens. This study delves into the bioinorganic chemistry of MUC7 fragments (L1─EGRERDHELRHRRHHHQSPK; L2─EGRERDHELRHRR; L3─HHHQSPK) and their complexes with Cu(II) and Zn(II) ions. The antimicrobial characteristics of the investigated peptides and their complexes were systematically assessed against bacterial and fungal strains at pH 5.40 and pH 7.40. Our findings highlight the efficacy of these systems against Streptococcus sanguinis, a common oral cavity pathogen. Most interestingly, Zn(II) coordination increased (or triggered) the MUC7 antimicrobial activity, which underscores the pivotal role of metal ion coordination in governing the antimicrobial activity of human salivary MUC7 fragments against S. sanguinis.

Ectoine Enhances Mucin Production Via Restoring IL-13/IFN-γ Balance in a Murine Dry Eye Model.

Purpose: This study aimed to explore protective effects and potential mechanism of ectoine, a natural osmoprotectant, on ocular surface mucin production in dry eye disease. Methods: A dry eye model was established in C57BL/6 mice exposed to desiccating stress (DS) with untreated (UT) mice as controls. DS mice were topically treated with 2.0% ectoine or PBS vehicle. Corneal epithelial defects were assessed by Oregon Green Dextran (OGD) fluorescent staining. Conjunctival goblet cells, ocular mucins, and T help (Th) cytokines were evaluated by immunofluorescent staining or ELISA, and RT-qPCR. Results: Compared with UT mice, corneal epithelial defects were detected as strong punctate OGD fluorescent staining in DS mice with vehicle, whereas ectoine treatment largely reduced OGD staining to near-normal levels. Conjunctival goblet cell density and cell size decreased markedly in DS mice, but was significantly recovered by ectoine treatment. The protein production and mRNA expression of two gel-forming secreted MUC5AC and MUC2, and 4 transmembrane mucins, MUC1, MUC4, MUC16, and MUC15, largely decreased in DS mice, but was restored by ectoine. Furthermore, Th2 cytokine IL-13 was inhibited, whereas Th1 cytokine IFN-γ was stimulated at protein and mRNA levels in conjunctiva and draining cervical lymph nodes (CLNs) of DS mice, leading to decreased IL-13/IFN-γ ratio. Interestingly, 2.0% ectoine reversed their alternations and restored IL-13/IFN-γ balance. Conclusions: Our findings demonstrate that topical ectoine significantly reduces corneal damage, and enhances goblet cell density and mucin production through restoring imbalanced IL-13/IFN-γ signaling in murine dry eye model. This suggests therapeutic potential of natural osmoprotectant ectoine for dry eye disease.

LC-HRMS-based metabolomics and lipidomics analyses of a novel probiotic Akkermansia Muciniphila in response to different nutritional stimulations.

The mucin-degrading gut commensal Akkermansia muciniphila (A. muciniphila) negatively correlates with various diseases, including metabolic disorders, neurodegenerative disorders, and cancers, through interacting with host receptors by diverse molecules. Still, their exact metabolic capability within the nutrient-rich environment (such as in the human gut) is not fully characterized. Therefore, in the present study, we investigated the comprehensive metabolome and lipidome of A. muciniphila after supplementation of four major gut microbial nutrients: mucin, inorganic salts, bile salts, and short-chain fatty acids (SCFAs). Our results showed that mucin is the predominant driver of the different lipidomic and metabolomic profiles of A. muciniphila, and it promotes the overall growth of this bacteria. While the addition of inorganic salts, bile salts, and SCFAs was found to inhibit the growth of A. muciniphila. Interestingly, inorganic salts affected the purine metabolism in A. muciniphila cultures, while adding bile salts significantly increased the production of other bile acids and N-acyl amides. Lastly, SCFAs were identified to alter the A. muciniphila energy utilization of triglycerides, fatty acyls, and phosphatidylethanolamines. To our knowledge, this is the first study to examine the comprehensive lipidome and metabolome of A. muciniphila, which highlights the importance of nutritional impacts on the lipidome and metabolome of A. muciniphila and hence providing foundational knowledge to unveil the potential effects of A. muciniphila on host health.

Comparing two mucin secretagogues for the treatment of dry eye disease: a prospective randomized crossover trial.

This study aimed to compare the clinical efficacy and investigate patients' preferences for two mucin secretagogues in the treatment of dry eye disease (DED). Thirty patients with DED were randomly treated with either 3% diquafosol or 2% rebamipide ophthalmic solution for 4 weeks, followed by an additional 4-week treatment using the other eye drop after a 2-week washout period. Objective and subjective assessments, including the corneal and conjunctival staining score, tear breakup time (TBUT), Schirmer 1 test, tear osmolarity, tear matrix metalloproteinase-9 (MMP-9), lipid layer thickness (LLT) and ocular surface disease index (OSDI), were performed at baseline, 4 weeks, 6 weeks, and 10 weeks. Patient preferences were assessed based on four categories (comfort, efficacy, convenience, willingness to continue) using a questionnaire and the overall subjective satisfaction score for each drug was obtained at the end of the trial. In total, 28 eyes from 28 patients were included in the analysis. Both diquafosol and rebamipide significantly improved the OSDI (p = 0.033 and 0.034, respectively), TBUT (p < 0.001 and 0.026, respectively), and corneal (p < 0.001 and 0.001, respectively) and conjunctival (p = 0.017 and 0.042, respectively) staining after 4 weeks of treatment. An increase in Schirmer test scores was observed only after rebamipide treatment (p = 0.007). No significant changes were detected in tear osmolarity, MMP-9, and LLT following both treatments. The patients' preference was slightly greater for diquafosol (46.4%) than rebamipide (36.7%), presumably due to rebamipide's bitter taste. The self-efficacy of both drugs and overall satisfaction scores were comparable. These findings indicate that two mucin secretagogues showed comparable effects in ameliorating symptoms and improving signs (TBUT, corneal and conjunctival staining) in patients with DED.

Revealing Glycosylation Patterns in In Vitro-Produced Mucus Exposed to Pasteurized Mucus-Associated Intestinal Microbes by MALDI-TOF-MS and PGC-LC-MS/MS.

The human intestinal mucus layer protects against pathogenic microorganisms and harmful substances, whereas it also provides an important colonization niche for mutualistic microbes. The main functional components of mucus are heavily glycosylated proteins, called mucins. Mucins can be cleaved and utilized by intestinal microbes. The mechanisms between intestinal microbes and the regulation of mucin glycosylation are still poorly understood. In this study, in vitro mucus was produced by HT29-MTX-E12 cells under Semi-Wet interface with Mechanical Stimulation. Cells were exposed to pasteurized nonpathogenic bacteria Akkermansia muciniphila, Ruminococcus gnavus, and Bacteroides fragilis to evaluate influence on glycosylation patterns. Following an optimized protocol, O- and N-glycans were efficiently and reproducibly released, identified, and semiquantified using MALDI-TOF-MS and PGC-LC-MS/MS. Exposure of cells to bacteria demonstrated increased diversity of sialylated O-glycans and increased abundance of high mannose N-glycans in in vitro produced mucus. Furthermore, changes in glycan ratios were observed. It is speculated that bacterial components interact with the enzymatic processes in glycan production and that pasteurized bacteria influence glycosyltransferases or genes involved. These results highlight the influence of pasteurized bacteria on glycosylation patterns, stress the intrinsic relationship between glycosylation and microbiota, and show the potential of using in vitro produced mucus to study glycosylation behavior.

Compendium of 5810 genomes of sheep and goat gut microbiomes provides new insights into the glycan and mucin utilization.

BACKGROUND: Ruminant gut microbiota are critical in ecological adaptation, evolution, and nutrition utilization because it regulates energy metabolism, promotes nutrient absorption, and improves immune function. To study the functional roles of key gut microbiota in sheep and goats, it is essential to construct reference microbial gene catalogs and high-quality microbial genomes database. RESULTS: A total of 320 fecal samples were collected from 21 different sheep and goat breeds, originating from 32 distinct farms. Metagenomic deep sequencing and binning assembly were utilized to construct a comprehensive microbial genome information database for the gut microbiota. We successfully generated the largest reference gene catalogs for gut microbiota in sheep and goats, containing over 162 million and 82 million nonredundant predicted genes, respectively, with 49 million shared nonredundant predicted genes and 1138 shared species. We found that the rearing environment has a greater impact on microbial composition and function than the host's species effect. Through subsequent assembly, we obtained 5810 medium- and high-quality metagenome-assembled genomes (MAGs), out of which 2661 were yet unidentified species. Among these MAGs, we identified 91 bacterial taxa that specifically colonize the sheep gut, which encode polysaccharide utilization loci for glycan and mucin degradation. CONCLUSIONS: By shedding light on the co-symbiotic microbial communities in the gut of small ruminants, our study significantly enhances the understanding of their nutrient degradation and disease susceptibility. Our findings emphasize the vast potential of untapped resources in functional bacterial species within ruminants, further expanding our knowledge of how the ruminant gut microbiota recognizes and processes glycan and mucins. Video Abstract.

Mucin-rich salivary gland tumors.

Salivary gland neoplasms characterized by abundant mucin production are rare but have long been recognized. Due to their scarcity, precise classification has long eluded these mucin-rich tumors. Recent molecular discoveries, however, have shed considerable light on the genetic underpinnings of mucin-rich salivary gland neoplasms. This manuscript will review the most up-to-date information on this fascinating group of salivary gland neoplasms.

Survival after Surgery among Cholangiocarcinoma Patients Comparing between Mucin Producing and Non-Mucin Producing.

BACKGROUND: Mucin-producing cholangiocarcinoma (MPCC) was rare biliary tract malignancy. Studies regarding this type of cholangiocarcinoma (CCA) were limited, particularly the survival outcome. We aim to evaluate the survival rate, median survival time after surgery among CCA patients and to determine the association between MPCC and survival. OBJECTIVE: To evaluate survival rate, median survival time after surgery among cholangiocarcinoma patients and to determine the association between mucin-producing cholangiocarcinoma and survival. METHODS: CCA patients who underwent surgery between 2013 and 2020 from the Cholangiocarcinoma Screening and Care Program (CASCAP), Northeast Thailand were included in the study. The MPCC was based on pathological findings after surgery. The survival of CCA patients was verified through medical records and civil registration. Survival rates and median survival time since the date of CCA surgery and its 95% confidence intervals (CI) were estimated. Multiple cox regression was performed to evaluate factors associated with survival which were quantified by adjusted hazard ratios (AHR) and their 95% CI. RESULTS: Of 1,249 CCA patients which constituted 24,593 person-months, 687 died at the completion of the study. The overall incidence rate was 2.79 per 100 patients per month, the median survival time was 21.77 months (95% CI: 19.87 - 23.84), and the 5-year survival rate was 28.29% (95% CI: 24.99 - 31.67). From these patients, 210 (16.81%) were MPCC, the incidence rate was 1.81 per 100 patients per month, median survival time was 41.21 months (95% CI: 26.16 - 81.97), and 5-year survival rate was 44.69% (95% CI: 32.47 - 56.16). MPCC were 35% less likely to died compared with non-MPCC (AHR = 0.65; 95% CI: 0.50 - 0.84). CONCLUSIONS: Our study revealed that CCA patients with MPCC had longer survival times and higher survival rates than those without MPCC. This classification will lead to appropriate treatment guidelines for CCA patients.

Enrichment and characterization of human-associated mucin-degrading microbial consortia by sequential passage.

Mucin is a glycoprotein secreted throughout the mammalian gastrointestinal tract that can support endogenous microorganisms in the absence of complex polysaccharides. While several mucin-degrading bacteria have been identified, the interindividual differences in microbial communities capable of metabolizing this complex polymer are not well described. To determine whether community assembly on mucin is deterministic across individuals or whether taxonomically distinct but functionally similar mucin-degrading communities are selected across fecal inocula, we used a 10-day in vitro sequential batch culture fermentation from three human donors with mucin as the sole carbon source. For each donor, 16S rRNA gene amplicon sequencing was used to characterize microbial community succession, and the short-chain fatty acid profile was determined from the final community. All three communities reached a steady-state by day 7 in which the community composition stabilized. Taxonomic comparisons amongst communities revealed that one of the final communities had Desulfovibrio, another had Akkermansia, and all three shared other members, such as Bacteroides. Metabolic output differences were most notable for one of the donor's communities, with significantly less production of acetate and propionate than the other two communities. These findings demonstrate the feasibility of developing stable mucin-degrading communities with shared and unique taxa. Furthermore, the mechanisms and efficiencies of mucin degradation across individuals are important for understanding how this community-level process impacts human health.