Mucus Layer Research Articles

A high salt diet impairs the bladder epithelial barrier and activates the NLRP3 and NF‑κB signaling pathways to induce an overactive bladder in vivo.

Overactive bladder (OAB) is a condition characterized by an urgency to urinate, which is associated with the urodynamic observation of detrusor overexcitation. Although the etiology of OAB is currently unclear, it has been suggested that in patients with OAB, disruption of bladder epithelial barrier integrity can disturb the normal contractile function of the detrusor. Additionally, dietary preferences have been suggested to influence the severity of OAB. Therefore, the aim of the present study was to investigate the effect of a high salt diet (HSD) on the development of OAB in a murine model. Mice were fed either a HSD or standard diet for 8 weeks, following which voiding characteristics and bladder barrier function were assessed. The present study demonstrated that a HSD in mice was associated with OAB-like symptoms such as increased urinary frequency and non-voiding bladder contractions. The HSD group demonstrated a thinner bladder mucus layer and decreased expression of bladder barrier markers, tight junction protein-1 and claudin-1, which may be potentially indicative of induced bladder damage. A HSD for 8 weeks in mice and a high salt treatment at the uroepithelium cellular (SV-HUC-1s) level resulted in increased uroepithelial oxidative stress and inflammatory cell infiltration, as indicated by increased expression levels of TNF-α and IL-1β, as well as activation of the nucleotide-binding domain leucine-rich-containing family pyrin domain-containing 3 (NLRP3) and NF-κB signaling pathways in vivo and in vitro. Therefore, the present study indicated that a HSD could be a potentially important risk factor for the development of OAB, as it may be associated with overactivation of contractile function of the bladder by impairing the integrity of the bladder epithelial barrier and activation of the NLRP3 and NF-κB signaling pathways. Remodeling of the bladder barrier and reduction of the inflammatory response may be potential targets for the treatment of OAB in the future.

Ruminococcus torques is a keystone degrader of intestinal mucin glycoprotein, releasing oligosaccharides used by Bacteroides thetaiotaomicron.

Symbiotic interactions between humans and our communities of resident gut microbes (microbiota) play many roles in health and disease. Some gut bacteria utilize mucus as a nutrient source and can under certain conditions damage the protective barrier it forms, increasing disease susceptibility. We investigated how Ruminococcus torques-a known mucin degrader that has been implicated in inflammatory bowel diseases (IBDs)-degrades mucin glycoproteins or their component O-linked glycans to understand its effects on the availability of mucin-derived nutrients for other bacteria. We found that R. torques utilizes both mucin glycoproteins and released oligosaccharides from gastric and colonic mucins, degrading these substrates with a panoply of mostly constitutively expressed, secreted enzymes. Investigation of mucin oligosaccharide degradation by R. torques revealed strong α-L-fucosidase, sialidase and β1,4-galactosidase activities. There was a lack of detectable sulfatase and weak β1,3-galactosidase degradation, resulting in accumulation of glycans containing these structures on mucin polypeptides. While the Gram-negative symbiont, Bacteroides thetaiotaomicron grows poorly on mucin glycoproteins, we demonstrate a clear ability of R. torques to liberate products from mucins, making them accessible to B. thetaiotaomicron. This work underscores the diversity of mucin-degrading mechanisms in different bacterial species and the probability that some species are contingent on others for the ability to more fully access mucin-derived nutrients. The ability of R. torques to directly degrade a variety of mucin and mucin glycan structures and unlock released glycans for other species suggests that it is a keystone mucin degrader, which might contribute to its association with IBD.IMPORTANCEAn important facet of maintaining healthy symbiosis between host and intestinal microbes is the mucus layer, the first defense protecting the epithelium from lumenal bacteria. Some gut bacteria degrade the various components of intestinal mucins, but detailed mechanisms used by different species are still emerging. It is imperative to understand these mechanisms as they likely dictate interspecies interactions and may illuminate species associated with bacterial mucus damage and subsequent disease susceptibility. Ruminococcus torques is positively associated with IBD in multiple studies. We identified mucin glycan-degrading enzymes in R. torques and found that it shares mucin degradation products with another species of gut bacteria, Bacteroides thetaiotaomicron. Our findings underscore the importance of understanding mucin degradation mechanisms in different gut bacteria and their consequences on interspecies interactions, which may identify keystone bacteria that disproportionately affect mucus damage and could therefore be key players in effects that result from reductions in mucus integrity.

Urolithin A-mediated augmentation of intestinal barrier function through elevated secretory mucin synthesis

Maintaining the mucus layer is crucial for the innate immune system. Urolithin A (Uro A) is a gut microbiota-derived metabolite; however, its effect on mucin production as a physical barrier remains unclear. This study aimed to elucidate the protective effects of Uro A on mucin production in the colon. In vivo experiments employing wild-type mice, NF-E2-related factor 2 (Nrf2)-deficient mice, and wild-type mice treated with an aryl hydrocarbon receptor (AhR) antagonist were conducted to investigate the physiological role of Uro A. Additionally, in vitro assays using mucin-producing cells (LS174T) were conducted to assess mucus production following Uro A treatment. We found that Uro A thickened murine colonic mucus via enhanced mucin 2 expression facilitated by Nrf2 and AhR signaling without altering tight junctions. Uro A reduced mucosal permeability in fluorescein isothiocyanate-dextran experiments and alleviated dextran sulfate sodium-induced colitis. Uro A treatment increased short-chain fatty acid-producing bacteria and propionic acid concentration. LS174T cell studies confirmed that Uro A promotes mucus production through the AhR and Nrf2 pathways. In conclusion, the enhanced intestinal mucus secretion induced by Uro A is mediated through the actions of Nrf-2 and AhR, which help maintain intestinal barrier function.

Intestinal epithelial Cldn-7 regulates intestinal inflammation by altering the gut microbiota

Background and aimTight junctions maintain gut homeostasis by forming a physical barrier that protects the gut from invasion by microbiota. Cldn-7 is an important component involved in this protection, but the relationship between Cldn-7, intestinal inflammation, and gut microbiota has not been clarified. Here, we hypothesize that Cldn-7 depletion affects intestinal inflammation by altering the gut microbiota. MethodsBased on the induced intestinal condition of Cldn-7 knockout mice (Cldn7fl/fl;villin-CreaERT2), we established the intestinal flora depletion model and colitis model by antibiotic drinking and feeding with dextran sodium sulfate (DSS). The environment of Cldn-7 gene deletion mice was changed by co-housing experiment. AB-PAS staining and Muc2 were used to detect the effect of co-housing and Cldn-7 deficiency on the mucus layer after flora depletion. qRT-PCR was used to detect the expression of intestinal inflammatory factors and AMPs in mice. Feces were collected and proportions of microbiota were analyzed by 16 S rRNA amplicon sequencing. ResultsMice in the co-housing experiment had altered intestinal microbiota, including diversity, composition, and functional prediction, compared to controls. Intestinal inflammation was restored to some extent following altered intestinal microbiota. The intestinal inflammation caused by Cldn-7 deficiency and susceptibility to DSS could be reduced after antibiotic administration compared to controls, in terms of phenotype, pathological changes, inflammatory factors, mucus barrier, and expression of AMPs. ConclusionsIn analyses of intestinal tissues, colitis induction, and gut microbiota in mice with intestinal disruption of Cldn-7, we found this protein to prevent intestinal inflammation by regulating the gut microbiota. Cldn-7might therefore be an important mediator of host–microbiome interactions. Our research has revealed that Cldn-7 plays an indispensable role in maintaining intestinal homeostasis by regulating the gut microbiota and impacting intestinal inflammation. These findings provide new insights into the pathogenesis of ulcerative colitis.

Gastroprotective Effect of Isoferulic Acid Derived from Foxtail Millet Bran against Ethanol-Induced Gastric Mucosal Injury by Enhancing GALNT2 Enzyme Activity.

Excessive alcohol consumption has led to the prevalence of gastrointestinal ailments. Alleviating gastric disorders attributed to alcohol-induced thinning of the mucus layer has centered on enhancing mucin secretion as a pivotal approach. In this study, foxtail millet bran polyphenol BPIS was divided into two components with MW < 200 D and MW > 200 D by molecular interception technology. Combined with MTT, cell morphology observation, and trypan blue staining, isoferulic acid (IFA) within the MW < 200 D fraction was determined as the effective constituent to mitigate ethanol-induced damage of gastric epithelial cells. Furthermore, a Wistar rat model with similar clinical features to alcohol-induced gastric mucosal injury was established. Then, gastric morphological observation, H&E staining, and assessments of changes in gastric hexosamine content and gastric wall binding mucus levels were carried out, and the results revealed that IFA (10 mg/Kg) significantly ameliorated alcohol-induced gastric mucosal damage. Finally, we applied techniques including Co-IP, molecular docking, and fluorescence spectroscopy and found that IFA inhibited the alcohol-induced downregulation of N-acetylgalactosamintransferase 2 (GALNT2) activity related to mucus synthesis through direct interaction with GALNT2 in gastric epithelial cells, thus promoting mucin synthesis. Our study lays a foundation for whole grain dietary intervention tailored to individuals suffering from alcoholic gastric mucosal injury.

Neonatal microbiota colonization drives maturation of primary and secondary goblet cell mediated protection in the pre-weaning colon.

In the distal colon, mucus secreting goblet cells primarily confer protection from luminal microorganisms via generation of a sterile inner mucus layer barrier structure. Bacteria-sensing sentinel goblet cells provide a secondary defensive mechanism that orchestrates mucus secretion in response to microbes that breach the mucus barrier. Previous reports have identified mucus barrier deficiencies in adult germ-free mice, thus implicating a fundamental role for the microbiota in programming mucus barrier generation. In this study, we have investigated the natural neonatal development of the mucus barrier and sentinel goblet cell-dependent secretory responses upon postnatal colonization. Combined in vivo and ex vivo analyses of pre- and post-weaning colonic mucus barrier and sentinel goblet cell maturation demonstrated a sequential microbiota-dependent development of these primary and secondary goblet cell-intrinsic protective functions, with dynamic changes in mucus processing dependent on innate immune signalling via MyD88, and development of functional sentinel goblet cells dependent on the NADPH/Dual oxidase family member Duox2. Our findings therefore identify new mechanisms of microbiota-goblet cell regulatory interaction and highlight the critical importance of the pre-weaning period for the normal development of colonic barrier function.

Impact of polyethylene nanoplastics on human intestinal cells

Polyethylene (PE) is one of the most widely used plastics in the world. Its degradation leads to the production of small particles including microplastics and nanoplastics (NPs). Plastic particles’ presence poses a health risk. The aim of this work was to investigate the toxicity of two model surfactant-free PE NPs prepared by polymerization of ethylene from cationic and anionic water-soluble initiators on human cell lines Caco-2 and HT29-MTX. After physicochemical characterization, their acute and subacute toxicity profile, including cytotoxicity, oxidative stress, and genotoxicity, was evaluated on both cell lines. Results showed a size increase of PE NPs in culture medium. Zeta potential values close to −10 mV were no longer dependent on the initiator charge after adsorption of serum components in culture medium. However, the cellular toxicity of the cationic and anionic PE NPs was very different. A time-and-concentration dependent cytotoxic, oxidative, and genotoxic effects on Caco-2 cells were only observed for PE NPs prepared with cationic initiators. No toxicity was observed on HT29-MTX, likely due to the protective mucus layer. Genotoxicity correlated with oxidative stress of some PE NPs on Caco-2 cells was observed from a concentration of 0.1 mg.mL−1 after 48-h exposure.

β-Cyclodextrin/dialdehyde glucan-coated keratin nanoparticles for oral delivery of insulin

Successful oral insulin administration can considerably enhance the quality of life (QOL) of diabetes patients who must frequently take insulin injections. However, Oral insulin administration is seriously hampered by gastrointestinal enzymes, wide pH range, mucus and mucosal layers, which limit insulin oral bioavailability to ≤2 %. Herein, we developed a simple, inexpensive and safe dual β-cyclodextrin/dialdehyde glucan-coated keratin nanoparticle (β-CD-K-IN-DG). The resulted β-CD-K-IN-DG not only gave the ultra-high insulin loading (encapsulation efficiency (98.52 %)), but also protected insulin from acid and enzymatic degradation. This β-CD-K-IN-DG had a notable hypoglycemic effect, there was almost 80 % insulin release after 4 h of incubation under hyperglycemic conditions. Ex vivo results confirmed that β-CD-K-IN-DG possessed high mucus-penetration ability. Transepithelial transport and uptake mechanism studies revealed that bypass transport pathway and endocytosis promoted β-CD-K-IN-DG entered intestinal epithelial cells, thus increased the bioavailability of insulin (12.27 %). The improved stability of insulin during in vivo transport implied that β-CD-K-IN-DG might be a potential tool for the effective oral insulin administration.

Bioactivity responses to changes in mucus-associated bacterial composition between healthy and bleached Porites lobata corals

This study aims to investigate how bioactivities of the coral surface mucus layer (SML) respond to changes in mucus-associated bacterial communities between bleached and healthy Porites lobata corals in Nha Trang Bay, Vietnam. The findings suggested that significant shifts in the mucus-associated bacterial communities were related to changes in coral health states from bleached to healthy P. lobata colonies (p < 0.05), while bacterial compositions were not significantly different across seasons and locations (p > 0.05). Of which 8 genera, Shewanella, Fusibacter, Halodesulfovibrio, Marinifilum, Endozoicomonas, Litoribacillus, Algicola, and Vibrio were present only in the SML of bleached coral while absent in the SML of the healthy one. As compared with the bleached SML, the healthy SML demonstrated stronger antibacterial activity against a coral bleaching pathogen, V. coralliilyticus, higher antitumor activity against HCT116 cell accompanied with increased induction of cleaved PARP and accelerated cell nucleic apoptosis and cycle arrest at S and G2/M phases exhibiting several typical characteristics, cell shrinkage, lost cell contact, and apoptotic body formation. Moreover, putative compounds detected at 280 nm in the healthy SML were obviously higher than those in the bleached one, probably they could be bioactive molecules responsible for competitively exclusion of pathogens, Algicola and Vibrio, from the healthy SML.

Bottlebrush Polyethylene Glycol Nanocarriers Translocate across Human Airway Epithelium via Molecular Architecture-Enhanced Endocytosis.

Pulmonary drug delivery is critical for the treatment of respiratory diseases. However, the human airway surface presents multiple barriers to efficient drug delivery. Here, we report a bottlebrush poly(ethylene glycol) (PEG-BB) nanocarrier that can translocate across all barriers within the human airway surface. Guided by a molecular theory, we design a PEG-BB molecule consisting of a linear backbone densely grafted by many (∼1000) low molecular weight (∼1000 g/mol) polyethylene glycol (PEG) chains; this results in a highly anisotropic, wormlike nanocarrier featuring a contour length of ∼250 nm, a cross-section of ∼20 nm, and a hydrodynamic diameter of ∼40 nm. Using the classic air-liquid-interface culture system to recapitulate essential biological features of the human airway surface, we show that PEG-BB rapidly penetrates through endogenous airway mucus and periciliary brush layer (mesh size of 20-40 nm) to be internalized by cells across the whole epithelium. By quantifying the cellular uptake of polymeric carriers of various molecular architectures and manipulating cell proliferation and endocytosis pathways, we show that the translocation of PEG-BB across the epithelium is driven by bottlebrush architecture-enhanced endocytosis. Our results demonstrate that large, wormlike bottlebrush PEG polymers, if properly designed, can be used as a carrier for pulmonary and mucosal drug delivery.

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.

Enhancing pulmonary delivery and immunomodulation of respiratory diseases through virus-mimicking nanoparticles

This study introduces the nanobromhexine lipid particle (NBL) platform designed for effective pulmonary drug delivery. Inspired by respiratory virus transport mechanisms, NBL address challenges associated with mucus permeation and inflammation in pulmonary diseases. Composed of low molecular weight polyethylene glycol-coated lipid nanoparticles with bromhexine hydrochloride, NBL exhibit a size of 118 ± 24 nm, a neutral zeta potential, osmolarity of 358 ± 28 mOsmol/kg, and a pH of 6.5. Nebulizing without leakage and showing no toxicity to epithelial cells, NBL display mucoadhesive properties with a 60% mucin-binding efficiency. They effectively traverse the dense mucus layer of Calu-3 cultures in an air-liquid interface, as supported by a 55% decrease in MUC5AC density and a 29% increase in nanoparticles internalization compared to non-exposed cells. In assessing immunomodulatory effects, NBL treatment in SARS-CoV-2-infected lung cells leads to a 40-fold increase in anti-inflammatory MUC1 gene expression, a proportional reduction in pro-inflammatory IL-6 expression, and elevated anti-inflammatory IL-10 expression. These findings suggest a potential mechanism to regulate the excessive IL-6 expression triggered by virus infection. Therefore, the NBL platform demonstrates promising potential for efficient pulmonary drug delivery and immunomodulation, offering a novel approach to addressing mucus permeation and inflammation in pulmonary diseases.

Cy3-Based Nanoviscosity Determination of Mucus: Effect of Mucus Collection Methods and Antibiotics Treatment.

The integrity of the protective mucus layer as a primary defense against pathogen invasion and microbial leakage into the intestinal epithelium can be compromised by the effects of antibiotics on the commensal microbiome. Changes in mucus integrity directly affect the solvent viscosity in the immediate vicinity of the mucin network, that is, the nanoviscosity, which in turn affects both biochemical reactions and selective transport. To assess mucus nanoviscosity, a reliable readout via the viscosity-dependent fluorescence lifetime of the molecular rotor dye cyanine 3 is established and nanoviscosities from porcine and murine ex vivo mucus are determined. To account for different mucin concentrations due to the removal of digestive residues during mucus collection, the power law dependence of mucin concentration on viscosity is used. The impact of antibiotics combinations (meropenem/vancomycin, gentamycin/ampicillin) on ex vivo intestinal mucus nanoviscosity is presented. The significant increase in viscosity of murine intestinal mucus after treatment suggests an effect of antibiotics on the microbiota that affects mucus integrity. This method will be a useful tool to assess how drugs, directly or indirectly, affect mucus integrity. Additionally, the method can be utilized to analyze the role of mucus nanoviscosity in health and disease, as well as in drug development.

Effect of Papaya Leaf Solution (Carica papaya Linn) on the Hatching Percentage and Survival Rate of Dumbo Catfish Larvae (Clarias sp.)

Eggs of dumbo catfish are known to stick to the substrate due to the presence of a mucus layer, which causes suboptimal oxygen supply and low hatching percentage. This indicates that the mucus layer must be lowered while also eliminating the need for a substrate during the hatching process. One of the natural ingredients that can be used for this purpose is papaya leaf containing the proteolytic enzyme papain. Therefore, this study aims to determine the effect of papaya leaf solution on the percentage of live embryos after soaking, hatching percentage, hatching time, survival rate, and abnormality percentage of dumbo catfish larvae. This research was carried out at the Basic Fisheries Laboratory, Aquaculture Study Program, Fisheries Department, Faculty of Agriculture, Sriwijaya University in August-October 2022. A Completely Randomized Design (CRD) was used, which consisted of four treatments and three repetitions. The treatment given was the soaking of eggs in papaya leaf solution with different concentrations of (P0/control), 2 g/0.96 L (P1), 4 g/0.96 L (P2), and 6 g/0.96 L (P3). The results showed that P2 was the best treatment with 100% live embryos after soaking, 94.06% hatching percentage, 20.24 hours hatching time, 92.78% survival rate, and 0.93% abnormality percentage. Based on these results, the soaking of dumbo catfish eggs on papaya leaf solution could increase the hatching percentage and survival rate.

Ultrasound semiotics of solitary rectal ulcer

AIM: to develop ultrasound semiotics of solitary rectal ulcer (SRU).PATIENTS AND METHODS: fifty-eight patients with a histologically verified SRU were included in the retrospective study. All patients underwent colonoscopy and transrectal ultrasound (TRUS). Changes in rectal wall detected by TRUS were compared with colonoscopy data.RESULTS: On TRUS SRU is represented by a significantly thickened rectal wall (median thickness of the rectal wall in the region of SRU is 9 (7–10) mm and 5 (4–6) mm outside, p &lt; 0.001), most often with a predominance of muscular and submucosal layers (46/58, 79%). The structure and echogenicity of these layers are changed: the connective tissue layer is visualized in muscular layer (51/58, 88%), submucosal layer is hypoechogenic (47/58, 81%), boundaries between rectal wall layers are faded (50/58, 86%). Ulcers in SRU are characterized by presence of areas where the mucous layer cannot be traced (sensitivity 100%, specificity 95%), its extent is comparable to extent of ulcers detected on colonoscopy (p = 0.528). Polypoid SRU is characterized by local thickening of the mucosa (sensitivity 89%, specificity 95%). TRUS location of the SRU in height (p = 0.644) is comparable with colonoscopy data.CONCLUSION: the study determined general ultrasound signs of SRU and made it possible to differentiate macroscopic forms of SRU from each other with TRUS.

Hydrogel-Integrated Millifluidic Systems: Advancing the Fabrication of Mucus-Producing Human Intestinal Models.

The luminal surface of the intestinal epithelium is protected by a vital mucus layer, which is essential for lubrication, hydration, and fostering symbiotic bacterial relationships. Replicating and studying this complex mucus structure in vitro presents considerable challenges. To address this, we developed a hydrogel-integrated millifluidic tissue chamber capable of applying precise apical shear stress to intestinal models cultured on flat or 3D structured hydrogel scaffolds with adjustable stiffness. The chamber is designed to accommodate nine hydrogel scaffolds, 3D-printed as flat disks with a storage modulus matching the physiological range of intestinal tissue stiffness (~3.7 kPa) from bioactive decellularized and methacrylated small intestinal submucosa (dSIS-MA). Computational fluid dynamics simulations were conducted to confirm a laminar flow profile for both flat and 3D villi-comprising scaffolds in the physiologically relevant regime. The system was initially validated with HT29-MTX seeded hydrogel scaffolds, demonstrating accelerated differentiation, increased mucus production, and enhanced 3D organization under shear stress. These characteristic intestinal tissue features are essential for advanced in vitro models as they critically contribute to a functional barrier. Subsequently, the chamber was challenged with human intestinal stem cells (ISCs) from the terminal ileum. Our findings indicate that biomimicking hydrogel scaffolds, in combination with physiological shear stress, promote multi-lineage differentiation, as evidenced by a gene and protein expression analysis of basic markers and the 3D structural organization of ISCs in the absence of chemical differentiation triggers. The quantitative analysis of the alkaline phosphatase (ALP) activity and secreted mucus demonstrates the functional differentiation of the cells into enterocyte and goblet cell lineages. The millifluidic system, which has been developed and optimized for performance and cost efficiency, enables the creation and modulation of advanced intestinal models under biomimicking conditions, including tunable matrix stiffness and varying fluid shear stresses. Moreover, the readily accessible and scalable mucus-producing cellular tissue models permit comprehensive mucus analysis and the investigation of pathogen interactions and penetration, thereby offering the potential to advance our understanding of intestinal mucus in health and disease.

Common dietary emulsifiers promote metabolic disorders and intestinal microbiota dysbiosis in mice

Dietary emulsifiers are linked to various diseases. The recent discovery of the role of gut microbiota–host interactions on health and disease warrants the safety reassessment of dietary emulsifiers through the lens of gut microbiota. Lecithin, sucrose fatty acid esters, carboxymethylcellulose (CMC), and mono- and diglycerides (MDG) emulsifiers are common dietary emulsifiers with high exposure levels in the population. This study demonstrates that sucrose fatty acid esters and carboxymethylcellulose induce hyperglycemia and hyperinsulinemia in a mouse model. Lecithin, sucrose fatty acid esters, and CMC disrupt glucose homeostasis in the in vitro insulin-resistance model. MDG impairs circulating lipid and glucose metabolism. All emulsifiers change the intestinal microbiota diversity and induce gut microbiota dysbiosis. Lecithin, sucrose fatty acid esters, and CMC do not impact mucus–bacterial interactions, whereas MDG tends to cause bacterial encroachment into the inner mucus layer and enhance inflammation potential by raising circulating lipopolysaccharide. Our findings demonstrate the safety concerns associated with using dietary emulsifiers, suggesting that they could lead to metabolic syndromes.

In vitro Models for Predicting Bioadhesion Fracture Strength to Ex Vivo Animal Buccal Tissue.

Commitment to the 3Rs principle (Replacement, Reduction, and Refinement) led to the development of a cell-based system to measure buccal bioadhesion in vitro and replace the use of porcine buccal and esophageal tissues (PBT and PET, respectively). Additionally, the aim is to bridge the gap in knowledge regarding the bioadhesion properties of PBT and PET. The in vitro models are based on the human buccal epithelial cell line-TR146 without ("Model I") or with ("Model II") 5% (w/v) mucous layer. The in vitro setup also provides a method to evaluate the bioadhesion between two soft materials. Standard bioadhesive hydrogels (alginate, chitosan, and gelatin) are used to test and compare the results from the in vitro models to the ex vivo tissues. The ex vivo and in vitro models show increased bioadhesion as the applied force and contact time increases. Furthermore, Model I exhibits bioadhesion values-of alginate, chitosan, and gelatin-comparable to those obtained with PBT. It is also found that contact time and applied force similarly affect PBT and PET bioadhesion, while PET exhibits greater values. In conclusion, Model I can replace PBT for measuring bioadhesion and be incorporated into the experimental design of bioadhesive DDS, thus minimizing animal tissue usage.

Natural products for Gut-X axis: pharmacology, toxicology and microbiology in mycotoxin-caused diseases.

Introduction: The gastrointestinal tract is integral to defending against external contaminants, featuring a complex array of immunological, physical, chemical, and microbial barriers. Mycotoxins, which are toxic metabolites from fungi, are pervasive in both animal feed and human food, presenting substantial health risks. Methods: This review examines the pharmacological, toxicological, and microbiological impacts of natural products on mycotoxicosis, with a particular focus on the gut-x axis. The analysis synthesizes current understanding and explores the role of natural products rich in polysaccharides, polyphenols, flavonoids, and saponins. Results: The review highlights that mycotoxins can disrupt intestinal integrity, alter inflammatory responses, damage the mucus layer, and disturb the bacterial balance. The toxins' effects are extensive, potentially harming the immune system, liver, kidneys, and skin, and are associated with serious conditions such as cancer, hormonal changes, genetic mutations, bleeding, birth defects, and neurological issues. Natural products have shown potential anticancer, anti-tumor, antioxidant, immunomodulatory, and antitoxic properties. Discussion: The review underscores the emerging therapeutic strategy of targeting gut microbial modulation. It identifies knowledge gaps and suggests future research directions to deepen our understanding of natural products' role in gut-x axis health and to mitigate the global health impact of mycotoxin-induced diseases.

Anthocyanin-loaded milk-derived extracellular vesicles nano-delivery system: Stability, mucus layer penetration, and pro-oxidant effect on HepG2 cells

Anthocyanin (ACN) has attracted considerable attention due to its wide range of physiological effects. However, challenges such as poor stability and limited bioavailability have hindered its utilization in functional foods. To address these issues, this research utilized milk-derived extracellular vesicles (MEV) as carriers for encapsulating and binding ACN through various techniques, including ultrasonic, electroporation, saponin treatment, incubation, and freeze-thaw cycles. The objective of these approaches was to enhance the stability of ACN and improve its oral delivery. Notably, the ACN-loaded MEV (MEV-ACN) prepared through ultrasonic exhibited small particle sizes and good stability under processing, storage, and simulated digestion conditions. Cellular studies revealed that MEV-ACN exhibited pro-oxidant properties and induced oxidative stress, leading to cell apoptosis with greater efficacy compared to free ACN. These findings suggest that encapsulating ACN within MEV can significantly enhance its processing and oral stability, as well as strengthening its dietary defense capabilities in anti-tumor applications.