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Preparation and characterization of EcN@YM. (A) LSCM images of EcN@YM. The red channel shows EcN expressing mCherry, and the blue channel indicates YMs stained with calcofluor-white. Scale bars, 20 m. (B) Typical TEM images of EcN and EcN@YM. Scale bars, 2 m. (C) Zeta potentials of EcN, YMs, and EcN@YM, respectively. **P < 0.01. (D and E) Flow cytometric analysis of EcN and EcN@YM. YMs were labeled with fluorescein isothiocyanate (FITC). Error bars represent SD (n = 3). (F) Bacterial viabilities of EcN and EcN@YM, respectively. The viability was evaluated by measuring optical density at 450 nm (OD 450 ) at 1-hour interval using CCK-8 assay. (G) Level of -glucan on YMs under different treatments including glass bead broken only (YMs-BRO), glass bead broken and incubation with SGF for 1 hour (YMs-SGF-1 h) or 4 hours (YMs-SGF-4 h), and glass bead broken and treatment with SIF for 1 hour (YMs-SIF-1 h) or 4 hours (YMs-SIF-4 h). FSC-A, forward scatter area; SSC-A, side scatter area.
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Methods capable of maintaining gut microbiota homeostasis to prevent bacterial translocation and infection under external threats are critical for multiple facets of human health but have been rarely reported. Here, we describe the elicitation of mucosal immunity to modulate the gut microbiota by oral delivery of living probiotics into Peyer’s patc...
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... Simply fusing EcN with YMs via physical extrusion through a porous polycarbonate membrane with an average size of 1 m could generate YM-coated EcN (EcN@YM). Under laser scanning confocal microscopy (LSCM) imaging, EcN expressing mCherry (red) were coated with YMs (blue) stained with calcofluor-white, a dye selectively binding to yeast wall ( Fig. 2A). The coating was further confirmed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) observation (Fig. 2B and fig. S2, A to C). In contrast to uncoated cells, EcN@YM were surrounded with an additional thick membrane. Zeta potential of EcN was increased from −25.0 ± 5.72 to −13.1 ± 1.77 mV after coating ...
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... YM-coated EcN (EcN@YM). Under laser scanning confocal microscopy (LSCM) imaging, EcN expressing mCherry (red) were coated with YMs (blue) stained with calcofluor-white, a dye selectively binding to yeast wall ( Fig. 2A). The coating was further confirmed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) observation (Fig. 2B and fig. S2, A to C). In contrast to uncoated cells, EcN@YM were surrounded with an additional thick membrane. Zeta potential of EcN was increased from −25.0 ± 5.72 to −13.1 ± 1.77 mV after coating with a less negatively charged YM membrane (Fig. 2C). Dynamic light scattering (DLS) measurement suggested that the average size of EcN@YM was 1186.3 ...
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... by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) observation (Fig. 2B and fig. S2, A to C). In contrast to uncoated cells, EcN@YM were surrounded with an additional thick membrane. Zeta potential of EcN was increased from −25.0 ± 5.72 to −13.1 ± 1.77 mV after coating with a less negatively charged YM membrane (Fig. 2C). Dynamic light scattering (DLS) measurement suggested that the average size of EcN@YM was 1186.3 nm ( fig. S2, D and E), which was suitable for the uptake by M cells (40). Flow cytometric analysis showed that the mean fluorescence intensity of EcN@YM was ~10 times higher than uncoated EcN, validating an encapsulation efficiency of ...
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... fig. S2, A to C). In contrast to uncoated cells, EcN@YM were surrounded with an additional thick membrane. Zeta potential of EcN was increased from −25.0 ± 5.72 to −13.1 ± 1.77 mV after coating with a less negatively charged YM membrane (Fig. 2C). Dynamic light scattering (DLS) measurement suggested that the average size of EcN@YM was 1186.3 nm ( fig. S2, D and E), which was suitable for the uptake by M cells (40). Flow cytometric analysis showed that the mean fluorescence intensity of EcN@YM was ~10 times higher than uncoated EcN, validating an encapsulation efficiency of 85.8% (Fig. 2, D and E). These results indicated that EcN were successfully yet highly efficiently coated with YMs ...
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... (Fig. 2C). Dynamic light scattering (DLS) measurement suggested that the average size of EcN@YM was 1186.3 nm ( fig. S2, D and E), which was suitable for the uptake by M cells (40). Flow cytometric analysis showed that the mean fluorescence intensity of EcN@YM was ~10 times higher than uncoated EcN, validating an encapsulation efficiency of 85.8% (Fig. 2, D and E). These results indicated that EcN were successfully yet highly efficiently coated with YMs via a simple mechanical extrusion. Cell counting kit-8 (CCK-8) assay showed limited fluctuations on the viability of bacteria after coating, demonstrating that both the preparation procedure and the coating itself had a negligible impact on EcN ...
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... E). These results indicated that EcN were successfully yet highly efficiently coated with YMs via a simple mechanical extrusion. Cell counting kit-8 (CCK-8) assay showed limited fluctuations on the viability of bacteria after coating, demonstrating that both the preparation procedure and the coating itself had a negligible impact on EcN vitality (Fig. 2F). Meanwhile, EcN@YM exhibited limited toxicity against Caco-2 cells even with bacterial number increasing up to 1 × 10 8 colony-forming units (CFUs) ( fig. S3). In consideration of the importance of -glucan on M cell uptake, the stability of the associated -glucan on YMs was monitored by culturing under simulated gastrointestinal ...
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... against Caco-2 cells even with bacterial number increasing up to 1 × 10 8 colony-forming units (CFUs) ( fig. S3). In consideration of the importance of -glucan on M cell uptake, the stability of the associated -glucan on YMs was monitored by culturing under simulated gastrointestinal conditions for the indicated time points. As shown in Fig. 2G, the level of -glucan remained consistent in both simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) even with incubation time extending up to 4 hours, suggesting an extraordinary stability of the membrane ...
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... Unfortunately, these inhibitors can target the kinases in different types of tissue as their catalytic domains are similar, inevitably leading to substantial toxicity that may cause hypotension, intestinal obstruction and death 8 . Given that the disruption of the mucosal barrier is closely related to dysregulated mucosal immunity, immunosuppressive agents or immunoadjuvants have been exploited to alleviate the impairment of the gut mucosal barrier by directly inhibiting mucosal inflammatory responses or evoking protective mucosal immunity to suppress pathogens and relieve infection-induced inflammation [9][10][11] . However, unilateral immune regu lation is often inadequate to achieve defensive intervention in the intestinal mucosal barrier and even causes undesirable side effects as a balance between immune responses to invaders and tolerance to antigens is required for intestinal mucosal immunity 12 . ...
... The intestine harbours a dense and diverse microbiota that plays a crucial role in a multitude of host physiological functions such as nutrient metabolism 14 , pathogenic infection 15 and immune modulation 9 . ...
... As plotted in Fig. 4e-h, the EPP group exhibited significantly enhanced counts in all the sectioned segments compared with those of unmodified EcN and EP, verifying preferential localization of EcN in the lower gastrointestinal tract following oral gavage. Next, the localization of EcN in the mucus layer was examined by directly delivering EPP into the intestinal lumen according to a previously described method 9 . Equivalent uncoated EcN and EP were separately applied as controls. ...
The breakdown of the gut’s mucosal barrier that prevents the infiltration of microorganisms, inflammatory cytokines and toxins into bodily tissues can lead to inflammatory bowel disease and to metabolic and autoimmune diseases. Here we show that the intestinal mucosal barrier can be reinforced via the oral administration of commensal bacteria coated with poly(ethylene glycol) (PEG) to facilitate their penetration into mucus. In mice with intestinal homoeostatic imbalance, mucus-penetrating PEGylated bacteria preferentially localized in mucus at the lower gastrointestinal tract, inhibited the invasion of pathogenic bacteria, maintained homoeostasis of the gut microbiota, stimulated the secretion of mucus and the expression of tight junctions, and prevented the mice from developing colitis and diabetes. Orally delivered PEGylated bacteria may help prevent and treat gastrointestinal disorders.
... The immune system plays a critical role in maintaining homeostasis and protecting the body against harmful pathogens. Within the intricate network of immune defenses, the gastrointestinal tract houses a complex and dynamic immune system that serves as the first line of defense against a myriad of microorganisms encountered through food and environmental exposure [1][2][3][4][5][6] . The gut immune system is tasked with the challenging dual role of tolerating and interacting with the vast community of commensal microorganisms residing in the intestine while swiftly responding to potential threats posed by invading pathogens [7][8][9] . ...
Researchers who aim to globally analyze the gastrointestinal immune system via flow cytometry have many protocol options to choose from, with specifics generally tied to gut wall layers of interest. To get a clearer idea of the approach we should use on full-thickness colon samples from mice, we first undertook a systematic comparison of three tissue dissociation techniques: two based on enzymatic cocktails and the other one based on manual crushing. Using flow cytometry panels of general markers of lymphoid and myeloid cells, we found that the presence of cell-surface markers and relative cell population frequencies were more stable with the mechanical method. Both enzymatic approaches were associated with a marked decrease of several cell-surface markers. Using mechanical dissociation, we then developed two minimally overlapping panels, consisting of a total of 26 antibodies, for serial profiling of lymphoid and myeloid lineages from the mouse colon in greater detail. Here, we highlight how we accurately delineate these populations by manual gating, as well as the reproducibility of our panels on mouse spleen and whole blood. As a proof-of-principle of the usefulness of our general approach, we also report segment- and life stage-specific patterns of immune cell profiles in the colon. Overall, our data indicate that mechanical dissociation is more suitable and efficient than enzymatic methods for recovering immune cells from all colon layers at once. Additionally, our panels will provide researchers with a relatively simple tool for detailed immune cell profiling in the murine gastrointestinal tract, regardless of life stage or experimental conditions.
... One of the key players is resident macrophages that molecularly interact with these gut microbes. Thus, modulating the gut microbiota itself presents a promising therapeutic opportunity to help treat the many associated diseases [6][7][8] . Current clinically available microbiota modulation using allogeneic fecal microbiota transplantation (FMT), however, suffers from low-quality control and sustainability issues for any regular patient recipient dosing. ...
Pathogenic gut microbiota is responsible for a few debilitating gastrointestinal diseases. While the host immune cells do produce extracellular vesicles to counteract some deleterious effects of the microbiota, the extracellular vesicles are of insufficient doses and at unreliable exposure times. Here we use mechanical stimulation of hydrogel-embedded macrophage in a bioelectronic controller that on demand boost production of up to 20 times of therapeutic extracellular vesicles to ameliorate the microbes’ deleterious effects in vivo. Our miniaturized wireless bioelectronic system termed inducible mechanical activation for in-situ and sustainable generating extracellular vesicles (iMASSAGE), leverages on wireless electronics and responsive hydrogel to impose mechanical forces on macrophages to produce extracellular vesicles that rectify gut microbiome dysbiosis and ameliorate colitis. This in vivo controllable extracellular vesicles-produced system holds promise as platform to treat various other diseases.
... 96,97 In addition, present on M cells is capable of recognizing and internalizing β-glucan-rich probiotics, thereby eliciting an immune response in the intestinal mucosa, emerging as a feasible strategy for the modulation of immunity by regulation in gut microbiota. 98 ...
The pathogenesis of severe acute pancreatitis-associated acute lung injury (SAP-ALI), which is the leading cause of mortality among hospitalized patients in the intensive care unit, remains incompletely elucidated. The intestinal mucosal immune barrier is a crucial component of the intestinal epithelial barrier, and its aberrant activation contributes to the induction of sustained pro-inflammatory immune responses, paradoxical intercellular communication, and bacterial translocation. In this review, we firstly provide a comprehensive overview of the composition of the intestinal mucosal immune barrier and its pivotal roles in the pathogenesis of SAP-ALI. Secondly, the mechanisms of its crosstalk with gut microbiota, which is called gut-lung axis, and its effect on SAP-ALI were summarized. Finally, a number of drugs that could enhance the intestinal mucosal immune barrier and exhibit potential anti-SAP-ALI activities were presented, including probiotics, glutamine, enteral nutrition, and traditional Chinese medicine (TCM). The aim is to offer a theoretical framework based on the perspective of the intestinal mucosal immune barrier to protect against SAP-ALI.
... Figure B described the preparation and the intestinal colonization of antibody-streptavidin-biotinylated probiotics [43]. Figure C show the preparation and the intestinal colonization of probiotics encapsulated by bacterial membrane [103,104]. ...
... For example, β-glucan in yeast membrane can be recognized and swallowed by micro-folded cells. Therefore, encapsulated EcN by yeast membrane through physical extrusion not only improves their tolerance to the harsh gastrointestinal environments, but also enables themselves to enter into the Pellet with improving immune response and maintaining intestinal homeostasis [103]. Besides, the bioavailability of oral Bacillus subtilis (BS) encapsulated by self-biomembrane was 125 times higher than that of free BS, and the intestinal colonization rate was 17 times higher in living pigs [72]. ...
... S7A-7D, the hydrodynamic size distribution, Zeta potential, as well as morphology of ZnPBA@YCW did not change significantly after 1 h incubation in SGF, indicating its good resistance under acidic conditions. This can be attributed to the fact that the special component of YCW and the PVP-modified ZnPBA together increase the stability of ZnPBA@YCW in gastric acid [42][43][44]. ...
Reactive oxygen species (ROS), immune dysregulation-induced inflammatory outbreaks and microbial imbalance play critical roles in the development of inflammatory bowel disease (IBD). Herein, a novel enzyme-like biomimetic oral-agent ZnPBA@YCW has been developed, using yeast cell wall (YCW) as the outer shell and zinc-doped Prussian blue analogue (ZnPBA) nanozyme inside. When orally administered, the ZnPBA@YCW is able to adhere to Escherichia coli occupying the ecological niche in IBD and subsequently release the ZnPBA nanozyme for removal of E. coli, meanwhile exhibiting improved intestinal epithelial barrier repair. Moreover, it is found that the ZnPBA nanozyme exhibits remarkable capability in restoring redox homeostasis by scavenging ROS and inhibiting NF-κB signaling pathway. More importantly, the 16S ribosomal RNA gene sequencing results indicate that post-oral of ZnPBA@YCW can effectively regulate gut microbiota by enhancing the bacterial richness and diversity, significantly increasing the abundance of probiotics with anti-inflammatory phenotype while downgrading pathogenic E. coli to the same level as normal mice. Such a novel nanomedicine provides a new idea for efficient treating those ROS-mediated diseases accompanying with flora disorders.
... In the intestinal mucosal immune system, probiotic bacteria or their metabolites can be acquired and recognized by mucosal M cells as antigens. Thus, this promotes the development of the intestinal mucosal immune system, activating macrophages and B lymphocytes, forming germinal centers in the intestinal mucosal lymphoid tissue, and finally, transforming B lymphocytes into plasma cells to secrete mucosal antibody IgA to mediate mucosal immunity [126,127]. Probiotic strains can increase the levels of antiinflammatory cytokines such as IL-10, reduce the levels of inflammatory cytokines such as TNF-α, IL-1β, and IL-8, and exert significant effects on reducing intestinal inflammation and improving colitis [128]. Additionally, different probiotics maintain gut health in different ways. ...
Functional dyspepsia (FD) is a common functional gastrointestinal disorder. The pathophys-iology remains poorly understood; however, alterations in the small intestinal microbiome have been observed. Current treatments for FD with drugs are limited, and there are certain safety problems. A class of active probiotic bacteria can control gastrointestinal homeostasis, nutritional digestion and absorption, and the energy balance when taken in certain dosages. Probiotics play many roles in maintaining intestinal microecological balance, improving the intestinal barrier function, and regulating the immune response. The presence and composition of intestinal microorganisms play a vital role in the onset and progression of FD and serve as a critical factor for both regulation and potential intervention regarding the management of this condition. Thus, there are potential advantages to alleviating FD by regulating the intestinal flora using probiotics, targeting intestinal microorganisms. This review summarizes the research progress of probiotics regarding improving FD by regulating intestinal flora and provides a reference basis for probiotics to improve FD.
... This interplay mirrors the Stag game in evolutionary game theory, where individuals must decide between hunting alone (the evolutionarily stable strategy) or collaborating in a group while considering the risks of uncooperative behaviour (Figure 1) (Luo et al., 2021). Commensal bacteria employ diverse mechanisms to counteract pathogenic invaders, encompassing colonization resistance (Sorbara and Pamer, 2019), immune modulation (Lin et al., 2021), and chemical secretions (Teng et al., 2023). A crucial Chronic wound spatio-temporal colonisation: Bacterial niche colonization involves a complex interplay of host and pathogenic factors. ...
Polymicrobial infections include various microorganisms, often necessitating different treatment methods than a monomicrobial infection. Scientists have been puzzled by the complex interactions within these communities for generations. The presence of specific microorganisms warrants a chronic infection and impacts crucial factors such as virulence and antibiotic susceptibility. Game theory is valuable for scenarios involving multiple decision-makers, but its relevance to polymicrobial infections is limited. Eco-evolutionary dynamics introduce causation for multiple proteomic interactions like metabolic syntropy and niche segregation. The review culminates both these giants to form evolutionary dynamics (ED). There is a significant amount of literature on inter-bacterial interactions that remain unsynchronised. Such raw data can only be moulded by analysing the ED involved. The review culminates the inter-bacterial interactions in multiple clinically relevant polymicrobial infections like chronic wounds, CAUTI, otitis media and dental carries. The data is further moulded with ED to analyse the niche colonisation of two notoriously competitive bacteria: S.aureus and P.aeruginosa. The review attempts to develop a future trajectory for polymicrobial research by following recent innovative strategies incorporating ED to curb polymicrobial infections.
... Live fungi and protozoa do not stimulate PC degranulation. When PCs in the mouse small intestine encounter pathogens or pathogen antigens, they secrete granules rich in antimicrobial peptides within a few minutes to kill pathogenic microorganisms [26]. This secretion activity is dose-dependent for the pathogens or pathogen antigens. ...
Inflammatory bowel disease (IBD) is a disorder of the immune system and intestinal microecosystem caused by environmental factors in genetically susceptible people. Paneth cells (PCs) play a central role in IBD pathogenesis, especially in Crohn's disease development, and their morphology, number and function are regulated by susceptibility genes. In the intestine, PCs participate in the formation of the stem cell microenvironment by secreting antibacterial particles and play a role in helping maintain the intestinal microecology and intestinal mucosal homeostasis. Moreover, PC proliferation and maturation depend on symbiotic flora in the intestine. This paper describes the interactions among susceptibility genes, PCs and intestinal microecology and their effects on IBD occurrence and development.
... 159 This interaction stimulates cytokine production, activates natural killer cells, and boosts the function of antigen-presenting cells, resulting in a more balanced and effective immune response. 160 Last, probiotics reduce the risk of infection by inhibiting the growth and colonization of pathogenic bacteria in the gut by producing antimicrobial substances such as rumenococcin C and organic acids. 161,162 4.3.2 ...
The gut microbiota and its homeostasis play a crucial role in human health. However, for some diseases related to the gut microbiota, current traditional medicines can only relieve symptoms, and it is difficult to solve the root causes or even cause side effects like disturbances in the gut microbiota. Increasing clinical studies and evidences have demonstrated that probiotics, prebiotics, and postbi-otics can prevent and treat various diseases, but currently they can only be used as dietary supplements rather than medicines, which restricts the application of probiotics in the field of medicine. Here, this review analyzes the importance of gut microbiota in human health and the current problems of traditional medicines, and systematically summarizes the effectiveness and mechanisms of probiotics, prebiotics, and postbiotics in maintaining health and treating diseases based on animal models and clinical trials. And based on current research outcomes and development trends in this field, the challenges and prospects of their clinical application in maintaining health, alleviating and treating diseases are analyzed. It is hoped to promote the application of probiotics, prebiotics, and postbiotics in disease treatment and open up new frontiers in probiotic research.
