Microfluidic-based multifunctional microspheres for enhanced oral co-delivery of probiotics and postbiotics

Probiotic-based therapies have shown great potential in the prevention and treatment of many diseases by positively regulating intestinal flora homeostasis. However, the efficacy of oral probiotics is severely limited due to the loss of bioactivity, short intestinal retention time, and insufficient therapeutic effect. Here, based on droplet microfluidics, we developed a hydrogel microsphere with colonic targeting and mucoadhesive capabilities as a multifunctional delivery platform, which can be used for co-delivery of probiotics (Escherichia coli Nissle 1917, EcN) and auxiliary molecules (indole-3-propionic acid, IPA), achieving synergistic therapeutic effects. In vivo studies shown that the integrated multifunctional microspheres can significantly reduce intestinal inflammation, repair intestinal barrier function, enhance probiotic colonization in the intestine, and modulate disordered intestinal flora, demonstrating enhanced therapeutic effects in a mouse model of colitis. This work reveals that microfluidic-based smart droplet microspheres can provide a versatile platform for advanced microbial therapies.

Clostridioides difficile Colitis

Clostridioides difficile colitis is an important source of hospital-acquired diarrhea associated with antibiotic use. Symptoms are profuse watery diarrhea, typically following a course of antibiotics; however, some cases of fulminant disease may manifest with shock, ileus, or megacolon. Nonfulminant colitis is treated with oral fidaxomicin. C difficile colitis has a high potential for recurrence, and recurrent episodes are also treated with fidaxomicin. Bezlotoxumab is another medication that may be used in populations at high risk for further recurrence. Fulminant disease is treated with maximal medical therapy and early surgical consultation. Antibiotic stewardship is critical to preventing C difficile colitis.

Melatonin pretreatment improves endometrial regenerative cell-mediated therapeutic effects in experimental colitis

BACKGROUND

Endometrial regenerative cells (ERCs) have been proven to be an effective strategy for attenuating experimental colitis, but the complex in vivo microenvironment such as oxidative stress may largely limit and weaken ERC efficacy. Melatonin (MT) works as an anti-oxidative agent in a variety of preclinical diseases, and has been identified to promote mesenchymal stem cell-mediated therapeutic effects in different diseases. However, the ability of MT to enhance ERC-mediated effects in colitis is currently poorly understood.

METHODS

Menstrual blood was collected from healthy female volunteers to obtain ERCs and identified. In vitro, H2O2-induced oxidative stress was introduced to test if MT could prevent ERCs from damage through detection of intracellular reactive oxidative species (ROS) and apoptosis assay. In vivo, dextran sodium sulfate (DSS)-induced acute colitis was treated by ERCs and MT-primed ERCs, therapeutic effects were assayed by the disease activity index (DAI), histological features, and macrophage and CD4+ T cell in the spleen and colon, and cytokine profiles in the sera and colon were also measured.

RESULTS

In vitro, ERCs that underwent MT-precondition were found to possess more anti-oxidative potency in comparison to naïve ERCs, which were characterized by decreased apoptosis rate and intracellular ROS under H2O2 stimulation. In vivo, MT pretreatment can significantly enhance the therapeutic effects of ERCs in the attenuation of experimental colitis, including decreased DAI index and damage score. In addition, MT pretreatment was found to promote ERC-mediated inhibition of Th1, Th17, and M1 macrophage and pro-inflammatory cytokines, increase of Treg, and immunomodulation of cytokines in the spleen and colon.

CONCLUSIONS

MT pretreatment facilitates the promotion of cell viability under oxidative stress in vitro, while also enhancing ERC-mediated therapeutic effects in experimental colitis.

Bifidobacterium pseudocatenulatum In Vitro In Vivo

The genus Bifidobacterium has been widely used in functional foods for health promotion due to its beneficial effects on human health, especially in the gastrointestinal tract (GIT). In this study, we characterize the anti-inflammatory potential of the probiotic strain Bifidobacterium pseudocatenulatum G7, isolated from a healthy male adult. G7 secretion inhibited inflammatory response in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Moreover, oral administration of bacteria G7 alleviated the severity of colonic inflammation in dextran sulfate sodium (DSS)-treated colitis mice, which was evidenced by a decreased disease activity index (DAI) and enhanced structural integrity of the colon. The 16S rRNA gene sequencing result illustrated that the G7 alleviated DSS-induced gut microbiota dysbiosis, accompanied by the modulated bile acids and short-chain fatty acid (SCFA) levels. Overall, our results demonstrated the potential anti-inflammatory effects of Bifidobacterium pseudocatenulatum G7 on both in vitro and in vivo models, which provided a solid foundation for further development of a novel anti-inflammatory probiotic.

Targeted delivery of the probiotic Saccharomyces boulardii to the extracellular matrix enhances gut residence time and recovery in murine colitis

Probiotic and engineered microbe-based therapeutics are an emerging class of pharmaceutical agents. They represent a promising strategy for treating various chronic and inflammatory conditions by interacting with the host immune system and/or delivering therapeutic molecules. Here, we engineered a targeted probiotic yeast platform wherein Saccharomyces boulardii is designed to bind to abundant extracellular matrix proteins found within inflammatory lesions of the gastrointestinal tract through tunable antibody surface display. This approach enabled an additional 24-48 h of probiotic gut residence time compared to controls and 100-fold increased probiotic concentrations within the colon in preclinical models of ulcerative colitis in female mice. As a result, pharmacodynamic parameters including colon length, colonic cytokine expression profiles, and histological inflammation scores were robustly improved and restored back to healthy levels. Overall, these studies highlight the potential for targeted microbial therapeutics as a potential oral dosage form for the treatment of inflammatory bowel diseases.

Bone marrow mesenchymal stromal cells support regeneration of intestinal damage in a colitis mouse model, independent of their CXCR4 expression

Inflammatory bowel disease (IBD) is characterized by a chronically dysregulated immune response in the gastrointestinal tract. Bone marrow multipotent mesenchymal stromal cells have an important immunomodulatory function and support regeneration of inflamed tissue by secretion of soluble factors as well as through direct local differentiation. CXCR4 is the receptor for CXCL12 (SDF-1, stromal-derived factor-1) and has been shown to be the main chemokine receptor, required for homing of MSCs. Increased expression of CXCL12 by inflamed intestinal tissue causes constitutive inflammation by attracting lymphocytes but can also be used to direct MSCs to sites of injury/inflammation. Trypsin is typically used to dissociate MSCs into single-cell suspensions but has also been shown to digest surface CXCR4. Here, we assessed the regenerative effects of CXCR4high and CXCR4low MSCs in an immune-deficient mouse model of DSS-induced colitis. We found that transplantation of MSCs resulted in clinical improvement and histological recovery of intestinal epithelium. In contrary to our expectations, the levels of CXCR4 on transplanted MSCs did not affect their regenerative supporting potential, indicating that paracrine effects of MSCs may be largely responsible for their regenerative/protective effects.

Metal-Phenolic Network Directed Coating of Single Probiotic Cell Followed by Photoinitiated Thiol-Ene Click Fortification to Enhance Oral Therapy

Probiotics-based oral therapy has become a promising way to prevent and treat various diseases, while the application of probiotics is primarily restricted by loss of viability due to adverse conditions in the gastrointestinal (GI) tract during oral delivery. Layer-by-layer (LbL) single-cell encapsulation approaches are widely employed to improve the bioavailability of probiotics. However, they are generally time- and labor-intensive owing to multistep operation. Herein, a simple yet efficient LbL technique is developed to coat a model probiotic named Escherichia coli Nissle 1917 (EcN) through polyphenol-Ca2+ network directed allyl-modified gelatin (GelAGE) adsorption followed by cross-linking of GelAGE via photoinitiated thiol-ene click reaction to protect EcN from harsh microenvironments of GI tract. LbL single-cell encapsulation can be performed within 1 h through simple operation. It is revealed that coated EcN exhibits significantly improved viability against acidic gastric fluid and bile salts, and enhanced colonization in the intestinal tract without loss of proliferation capabilities. Furthermore, oral therapy of coated EcN remarkably relieves the pathological symptoms associated with colitis in mice including down-regulating inflammation, repairing epithelial barriers, scavenging reactive oxygen species (ROS), and restoring the homeostasis of gut microbiota. This simplified LbL coating strategy has great potential for various probiotics-mediated biomedical and nutraceutical applications.

Helminth-derived proteins as immune system regulators: a systematic review of their promise in alleviating colitis

Helminth-derived proteins have immunomodulatory properties, influencing the host's immune response as an adaptive strategy for helminth survival. Helminth-derived proteins modulate the immune response by inducing anti-inflammatory cytokines, promoting regulatory T-cell development, and ultimately favouring a Th2-biased immune response. This systematic review focused on helminth-derived proteins and explored their impact on reducing inflammatory responses in mouse models of colitis. A systematic search across Medline, EMBASE, Web of Science, and Cochrane Library identified fourteen relevant studies. These studies reported immunomodulatory changes, including increased production of anti-inflammatory cells and cytokines. In mouse models of colitis treated with on helminth-derived proteins, significant improvements in pathological parameters such as body weight, colon length, and microscopic inflammatory scores were observed compared to control groups. Moreover, helminth-derived proteins can enhance the function of Tregs and alleviate the severity of inflammatory conditions. The findings underscore the pivotal role of helminth-derived proteins in immunomodulation, specifically in the axis of cytokine secretion and immune cell polarization. The findings offer new opportunities for treating chronic inflammatory conditions such Crohn's disease.

Potential application mechanism of traditional Chinese medicine in treating immune checkpoint inhibitor-induced colitis

Cancer ranks among the foremost causes of mortality worldwide, posing a significant threat to human lives. The advent of tumor immunotherapy has substantially transformed the therapeutic landscape for numerous advanced malignancies, notably non-small cell lung cancer and melanoma. However, as immune checkpoint inhibitors (ICIs) are increasingly applied in clinical settings, a spectrum of undesired reactions, termed immune-related adverse events (irAEs), has emerged. These adverse reactions are associated with immunotherapy and can result in varying degrees of harm to the human body. Among these reactions, Immune checkpoint inhibitor-induced colitis (ICIIC) stands out as one of the most prevalent clinical adverse events. In contemporary times, traditional Chinese medicine (TCM) has demonstrated remarkable efficacy in addressing various maladies. Consequently, investigating the potential application and mechanisms of Chinese medicine in countering immune checkpoint inhibitor-induced colitis assumes significant importance in the treatment of this condition.

Colitis reduces active social engagement in mice and is ameliorated by supplementation with human microbiota members

Multiple neurological disorders are associated with gastrointestinal (GI) symptoms, including autism spectrum disorder (ASD). However, it is unclear whether GI distress itself can modify aspects of behavior. Here, we show that mice that experience repeated colitis have impaired active social engagement, as measured by interactions with a foreign mouse, even though signs of colitis were no longer present. We then tested the hypothesis that individuals with ASD harbor a microbiota that might differentially influence GI health by performing microbiota transplantation studies into male germfree animals, followed by induction of colitis. Animals that harbor a microbiota from ASD individuals have worsened gut phenotypes when compared to animals colonized with microbiotas from familial neurotypical (NT) controls. We identify the enrichment of Blautia species in all familial NT controls and observe an association between elevated abundance of Bacteroides uniformis and reductions in intestinal injury. Oral treatment with either of these microbes reduces colon injury in mice. Finally, provision of a Blautia isolate from a NT control ameliorates gut injury-associated active social engagement in mice. Collectively, our data demonstrate that past intestinal distress is associated with changes in active social behavior in mice that can be ameliorated by supplementation of members of the human microbiota.

Mannose enhances intestinal immune barrier function and dextran sulfate sodium salt-induced colitis in mice by regulating intestinal microbiota

Background

Inflammatory bowel disease (IBD) greatly affects human quality of life. Mannose has been reported to be used to treat IBD, but the mechanism is currently unknown.

Methods

C57/BL mice were used as research subjects, and the mouse acute colitis model was induced using dextran sulfate sodium salt (DSS). After oral administration of mannose, the body weights and disease activity index (DAI) scores of the mice were observed. The colon lengths, histopathological sections, fecal content microbial sequencing, colon epithelial inflammatory genes, and tight junction protein Occludin-1 expression levels were measured. We further used the feces of mice that had been orally administered mannose to perform fecal bacterial transplantation on the mice with DSS-induced colitis and detected the colitis-related indicators.

Results

Oral administration of mannose increased body weights and colon lengths and reduced DAI scores in mice with DSS-induced colitis. In addition, it reduced the expression of colon inflammatory genes and the levels of serum inflammatory factors (TNF-α, IL-6, and IL-1β), further enhancing the expression level of the colonic Occludin-1 protein and alleviating the toxic response of DSS to the intestinal epithelium of the mice. In addition, gut microbial sequencing revealed that mannose increased the abundance and diversity of intestinal flora. Additionally, after using the feces of the mannose-treated mice to perform fecal bacterial transplantation on the mice with DSS-induced colitis, they showed the same phenotype as the mannose-treated mice, and both of them alleviated the intestinal toxic reaction induced by the DSS. It also reduced the expression of intestinal inflammatory genes (TNF-α, IL-6, and IL-1β) and enhanced the expression level of the colonic Occludin-1 protein.

Conclusion

Mannose can treat DSS-induced colitis in mice, possibly by regulating intestinal microorganisms to enhance the intestinal immune barrier function and reduce the intestinal inflammatory response.

Human umbilical cord/placenta mesenchymal stem cell conditioned medium attenuates intestinal fibrosis in vivo and in vitro

BACKGROUND

A significant unmet need in inflammatory bowel disease is the lack of anti-fibrotic agents targeting intestinal fibrosis. This study aimed to investigate the anti-fibrogenic properties and mechanisms of the conditioned medium (CM) from human umbilical cord/placenta-derived mesenchymal stem cells (UC/PL-MSC-CM) in a murine intestinal fibrosis model and human primary intestinal myofibroblasts (HIMFs).

METHODS

UC/PL-MSC-CM was concentrated 15-fold using a 3 kDa cut-off filter. C57BL/6 mice aged 7 weeks old were randomly assigned to one of four groups: (1) control, (2) dextran sulfate sodium (DSS), (3) DSS + CM (late-phase treatment), and (4) DSS + CM (early-phase treatment). Chronic DSS colitis and intestinal fibrosis was induced by three cycles of DSS administration. One DSS cycle consisted of 7 days of oral DSS administration (1.75%, 2%, and 2.5% DSS), followed by 14 days of drinking water. UC/PL-MSC-CM was intraperitoneally administered in the late phase (from day 50, 10 times) or early phase (from day 29, 10 times) of DSS cycles. HIMFs were treated with TGF-β1 and co-treated with UC/PL-MSC-CM (10% of culture media) in the cellular model.

RESULTS

In the animal study, UC/PL-MSC-CM reduced submucosa/muscularis propria thickness and collagen deposition, which improved intestinal fibrosis in chronic DSS colitis. The UC/PL-MSC-CM significantly reduced the expressions of procollagen1A1 and α-smooth muscle actin, which DSS significantly elevated. The anti-fibrogenic effect was more apparent in the UC-MSC-CM or early-phase treatment model. The UC/PL-MSC-CM reduced procollagen1A1, fibronectin, and α-smooth muscle actin expression in HIMFs in the cellular model. The UC/PL-MSC-CM downregulated fibrogenesis by suppressing RhoA, MRTF-A, and SRF expression.

CONCLUSIONS

Human UC/PL-MSC-CM inhibits TGF-β1-induced fibrogenic activation in HIMFs by blocking the Rho/MRTF/SRF pathway and chronic DSS colitis-induced intestinal fibrosis. Thus, it may be regarded as a novel candidate for stem cell-based therapy of intestinal fibrosis.

Immune-Related Colitis Is Associated with Fecal Microbial Dysbiosis and Can Be Mitigated by Fecal Microbiota Transplantation

Colitis induced by treatment with immune-checkpoint inhibitors (ICI), termed irColitis, is a substantial cause of morbidity complicating cancer treatment. We hypothesized that abnormal fecal microbiome features would be present at the time of irColitis onset and that restoring the microbiome with fecal transplant from a healthy donor would mitigate disease severity. Herein, we present fecal microbiota profiles from 18 patients with irColitis from a single center, 5 of whom were treated with healthy-donor fecal microbial transplantation (FMT). Although fecal samples collected at onset of irColitis had comparable α-diversity to that of comparator groups with gastrointestinal symptoms, irColitis was characterized by fecal microbial dysbiosis. Abundances of Proteobacteria were associated with irColitis in multivariable analyses. Five patients with irColitis refractory to steroids and biologic anti-inflammatory agents received healthy-donor FMT, with initial clinical improvement in irColitis symptoms observed in four of five patients. Two subsequently exhibited recurrence of irColitis symptoms following courses of antibiotics. Both received a second "salvage" FMT that was, again, followed by clinical improvement of irColitis. In summary, we observed distinct microbial community changes that were present at the time of irColitis onset. FMT was followed by clinical improvements in several cases of steroid- and biologic-agent-refractory irColitis. Strategies to restore or prevent microbiome dysbiosis in the context of immunotherapy toxicities should be further explored in prospective clinical trials.

Akkermansia muciniphila improves chronic colitis-induced enteric neuroinflammation in mice

BACKGROUND

Inflammatory bowel diseases (IBD) are chronic diseases that are not fully understood. Drugs in use can only be applied for a short time due to their side effects. Therefore, research is needed to develop new treatment approaches. In addition, it has been proven that IBD causes degeneration in the enteric nervous system (ENS). In recent years, it has been discussed that probiotics may have positive effects in the prevention and treatment of inflammatory enteric degeneration. Akkermansia muciniphila (A. muciniphila) is an anaerobic bacterium found in the mucin layer of the intestinal microbiota. It has been found that the population of A. muciniphila decreases in the case of different diseases. In light of this information, the curative effect of A. muciniphila application on colitis-induced inflammation and enteric degeneration was investigated.

METHODS

In this study, 5 weeks of A. muciniphila treatment in Trinitro-benzene-sulfonic acid (TNBS)-induced chronic colitis model was investigated. Colon samples were examined at microscopic, biochemical, and molecular levels. Fecal samples were collected before, during, and after treatment to evaluate the population changes in the microbiota. Specific proteins secreted from the ENS were evaluated, and enteric degeneration was examined.

RESULTS

As a result of the research, the ameliorative effects of A. muciniphila were shown in the TNBS colitis model-induced inflammation and ENS damage.

DISCUSSION

In light of these results, A. muciniphila can potentially be evaluated as a microbiome-based treatment for IBD with further clinical and experimental studies.

Oat-based postbiotics ameliorate high-sucrose induced liver injury and colitis susceptibility by modulating fatty acids metabolism and gut microbiota

High-sucrose (HS) consumption leads to metabolic disorders and increases susceptibility to colitis. Postbiotics hold great potentials in combating metabolic diseases and offer advantages in safety and processability, compared with living probiotics. We developed innovative oat-based postbiotics and extensively explored how they could benefit in rats with long-term high-sucrose consumption. The postbiotics fermented with Lactiplantibacillus plantarum (OF-1) and OF-5, the one fermented with the optimal selection of five probiotics (i.e., L. plantarum, Limosilactobacillus reuteri, Lacticaseibacillus rhamnosus, Lactobacillus acidophilus, and Bifidobacterium lactis) alleviated HS induced liver injury, impaired fatty acid metabolism and inflammation through activating AMPK/SREBP-1c pathways. Moreover, oat-based postbiotics restored detrimental effects of HS on fatty acid profiles in liver, as evidenced by the increases in polyunsaturated fatty acids and decreases in saturated fatty acids, with OF-5 showing most pronounced effects. Furthermore, oat-based postbiotics prevented HS exacerbated susceptibility to dextran sodium sulfate caused colitis and reconstructed epithelial tight junction proteins in colons. Oat-based postbiotics, in particular OF-5 notably remodeled gut microbiota composition, e.g., enriching the relative abundances of Akkermansia, Bifidobacterium, Alloprevotella and Prevotella, which may play an important role in the liver-colon axis responsible for improvements of liver functions and reduction of colitis susceptibility. The heat-inactivated probiotics protected against HS-induced liver and colon damage, but such effects were less pronounced compared with oat-based postbiotics. Our findings emphasize the great value of oat-based postbiotics as nutritional therapeutics to combat unhealthy diet induced metabolic dysfunctions.

The antioxidant strain Lactiplantibacillus plantarum AS21 and Clostridium butyricum ameliorate DSS-induced colitis in mice by remodeling the assembly of intestinal microbiota and improving gut functions

Probiotics are known for their beneficial effects on improving intestinal function by alleviating the gut microbial diversity. However, the influences of antioxidant lactic acid bacteria (LAB) and anti-inflammatory Clostridium butyricum (CB) on ameliorating enteritis remain unclear. In this study, we investigated the effects of the antioxidant strain Lactiplantibacillus plantarum AS21 and CB alone, or in combination on intestinal microbiota, barrier function, oxidative stress and inflammation in mice with DSS-induced colitis. All probiotic treatments relieved the pathological development of colitis by improving the integrity of the intestinal mucosal barrier and the length of the colon. The probiotics also suppressed inflammation and oxidative stress by improving gut short-chain fatty acids and inhibiting the p38-MAPK/NF-κB pathway in colon tissues. According to the meta-network analysis, three distinct modules containing sensitive OTUs of the gut bacterial community specific to the control, DSS and DSS + probiotics groups were observed, and unlike the other two modules, Lachnospiraceae and Clostridia dominated the sensitive OTUs in the DSS + probiotics group. In addition, administration of the present probiotics particularly increased antioxidant and anti-inflammatory microbes Muribaculaceae, Bifidobacterium, Prevotellaceae and Alloprevotella. Furthermore, combined probiotic strain treatment showed a more stable anti-colitis effect than a single probiotic strain. Collectively, the present probiotics exhibited protective effects against colitis by suppressing the inflammation and oxidative damage in the colon, improving the gut microbiota and their functions, and consequently preventing the gut leak. The results indicate that the combination of the antioxidant properties of LAB and the anti-inflammatory properties of CB as nutritional intervention and adjuvant therapy could be an effective strategy to prevent and alleviate colitis.

Living, Heat-Killed Limosilactobacillus mucosae and Its Cell-Free Supernatant Differentially Regulate Colonic Serotonin Receptors and Immune Response in Experimental Colitis

Lactobacillus species have been shown to alleviate gut inflammation and oxidative stress. However, the effect of different lactobacilli components on gut inflammation has not been well studied. This study aims to identify the differences in the effect and mechanisms of different forms and components of Limosilactobacillus mucosae (LM) treatment in the alleviation of gut inflammation using a colitis mouse model that is induced by dextran sodium sulfate (DSS). Seventy-two C57BL/6 mice were divided into six groups: control, DSS, live LM+DSS (LM+DSS), heat-killed LM+DSS (HKLM+DSS), LM cell-free supernatant + DSS (LMCS+DSS), and MRS medium + DSS (MRS+DSS). The mice were treated with different forms and components of LM for two weeks before DSS treatment. After that, the mice were sacrificed for an assessment of their levels of inflammatory cytokines, serotonin (5-HT) receptors (HTRs), and tryptophan metabolites. The results showed that, compared to other treatments, LMCS was more effective (p < 0.05) in the alleviation of DSS-induced body weight loss and led to an increase in the disease activity index score. All three forms and components of LM increased (p < 0.05) the levels of indole-3-acetic acid but reduced (p < 0.05) the levels of 5-HT in the colon. HKLM or LMCS reduced (p < 0.05) the percentages of CD3+CD8+ cytotoxic T cells but increased (p < 0.05) the percentages of CD3+CD4+ T helper cells in the spleen. LM or HKLM increased (p < 0.05) abundances of CD4+Foxp3+ regulatory T cells in the spleen. The LM and LMCS treatments reduced (p < 0.05) the expression of the pro-inflammatory cytokines Il6 and Il17a. The mice in the HKLM+DSS group had higher (p < 0.05) mRNA levels of the anti-inflammatory cytokine Il10, the cell differentiation and proliferation markers Lgr5 and Ki67, the 5-HT degradation enzyme Maoa, and HTRs (Htr1a, Htr2a, and Htr2b) in the colon. All three forms and components of LM reduced the phosphorylation of STAT3. The above findings can help to optimize the functionality of probiotics and develop new dietary strategies that aid in the maintenance of a healthy gut.

A case of refractory immune checkpoint inhibitor-induced colitis improved by the treatment with vedolizumab and granulocyte-monocyte apheresis combination therapy

A 68-year-old man developed immune-related adverse event (irAE) colitis after the initiation of nivolumab and ipilimumab combination therapy for malignant melanoma. We diagnosed the patient with grade 3 irAE colitis and started prednisolone (1 mg/kg/day). Although the symptom improved once, it worsened along with the tapering of prednisolone. Therefore, we started infliximab (IFX). However, symptoms did not improve after two doses of IFX. We discontinued IFX and initiated vedolizumab (VED). Because VED alone did not improve the symptom, we started granulocyte-monocyte apheresis (GMA). Twelve weeks after the onset, the colitis was in remission. Therefore, in addition to vedolizumab, GMA may be considered in cases refractory to treatment.

Electroacupuncture at Sensitized Acupoints Relieves Somatic Referred Pain in Colitis Rats by Inhibiting Sympathetic-Sensory Coupling to Interfere with 5-HT Signaling Pathway

OBJECTIVE

To investigate whether electroacupuncture (EA) at sensitized acupoints could reduce sympathetic-sensory coupling (SSC) and neurogenic inflammatory response by interfering with 5-hydroxytryptamine (5-HT)ergic neural pathways to relieve colitis and somatic referred pain, and explore the underlying mechanisms.

METHODS

Rats were treated with 5% dextran sodium sulfate (DSS) solution for 7 days to establish a colitis model. Twelve rats were randomly divided into the control and model groups according to a random number table (n=6). According to the "Research on Rat Acupoint Atlas", sensitized acupoints and non-sensitized acupoints were determined. Rats were randomly divided into the control, model, Zusanli-EA (ST 36), Dachangshu-EA (BL 25), and Xinshu (BL 15) groups (n=6), as well as the control, model, EA, and EA + GR113808 (a 5-HT inhibitor) groups (n=6). The rats in the control group received no treatment. Acupuncture was administered on 2 days after modeling using the stimulation pavameters: 1 mA, 2 Hz, for 30 min, with sparse and dense waves, for 14 consecutive days. GR113808 was injected into the tail vein at 5 mg/kg before EA for 10 min for 7 consecutive days. Mechanical sensitivity was assessed with von Frey filaments. Body weight and disease activity index (DAI) scores of rats were determined. Hematoxylin and eosin staining was performed to observe colon histopathology. SSC was analyzed by immunofluorescence staining. Immunohistochemical staining was performed to detect 5-HT and substance P (SP) expressions. The calcitonin gene-related peptide (CGRP) in skin tissue and tyrosine hydroxylase (TH) protein levels in DRG were detected by Western blot. The levels of hyaluronic acid (HA), bradykinin (BK), prostaglandin I2 (PGI2) in skin tissue, 5-HT, tryptophan hydroxylase 1 (TPH1), serotonin transporters (SERT), 5-HT 3 receptor (5-HT3R), and 5-HT 4 receptor (5-HT4R) in colon tissue were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

BL 25 and ST 36 acupoints were determined as sensitized acupoints, and BL 15 acupoint was used as a non-sensitized acupoint. EA at sensitized acupoints improved the DAI score, increased mechanical withdrawal thresholds, and alleviated colonic pathological damage of rats. EA at sensitized acupoints reduced SSC structures and decreased TH and CGRP expression levels (P<0.05). Furthermore, EA at sensitized acupoints reduced BK, PGI2, 5-HT, 5-HT3R and TPH1 levels, and increased HA, 5-HT4R and SERT levels in colitis rats (P<0.05). GR113808 treatment diminished the protective effect of EA at sensitized acupoints in colitis rats (P<0.05).

CONCLUSION

EA at sensitized acupoints alleviated DSS-induced somatic referred pain in colitis rats by interfering with 5-HTergic neural pathway, and reducing SSC inflammatory response.

Sacral Nerve Stimulation Alleviates Intestinal Inflammation Through Regulating the Autophagy of Macrophages and Activating the Inflammasome Mediated by a Cholinergic Antiinflammatory Pathway in Colitis Rats

BACKGROUND

Inflammatory bowel disease (IBD) is characterized by chronic progressive intestinal inflammation. Sacral nerve stimulation (SNS) ameliorates colon inflammation caused by IBD. The aim of this study was to investigate the antiinflammatory benefits of SNS in colitis rats and explore the roles of the cholinergic antiinflammatory pathway, macrophage autophagy, and nucleotide oligomerization domain-like receptor thermal protein domain associated protein 3 (NLRP3) inflammatory bodies.

MATERIALS AND METHODS

Rats were divided into four groups: healthy control, dextran sulfate sodium (DSS), DSS + sham-SNS, and DSS + SNS groups. An electrode was surgically placed in the right sacral nerve (S3) for stimulation. The disease activity index (DAI) score was recorded each day, and the degree of inflammatory injury was evaluated using hematoxylin and eosin staining. The alpha7 nicotinic acetylcholine receptor (α7nAChR) and autophagy- and NLRP3-related factors were assessed using immunofluorescence staining and Western blotting.

RESULTS

The DSS group showed a higher DAI score, colon shortening, upregulated proinflammatory action, and colon damage, and the DSS + SNS group showed significantly improved symptoms. The number of α7nAChR+ cells and the expression level of autophagy decreased in the DSS group but increased in the DSS + SNS group. Conversely, the DSS group showed increased activation of NLRP3 inflammatory bodies, whereas the DSS + SNS group showed decreased activation of NLRP3 inflammatory bodies.

CONCLUSION

In this study, SNS ameliorated colon inflammation by enhancing macrophage autophagy and inhibiting the activation of NLRP3 inflammatory bodies, which may be related to the opening of the cholinergic antiinflammatory pathway.

Enteral nutrition promotes the remission of colitis by gut bacteria-mediated histidine biosynthesis

BACKGROUND

Exclusive enteral nutrition (EEN) is an important alternative strategy for patients with Crohn's disease (CD), and during this process, microbiota alterations have been observed. However, the underlying mechanisms by which EEN reduces intestinal inflammation are currently unclear.

METHODS

The therapeutic potential of enteral nutrition (EN) was assessed using various mouse models. Fecal full-length 16S rDNA sequencing analysis and several CD metagenome datasets were used to identify the candidate therapeutic bacteria Faecalibaculum rodentium (F. rodentium). Whole genome sequencing of F. rodentium and widely-targeted metabolome analysis of the supernatant showed that EN-induced F. rodentium accumulation protected against colitis via histidine biosynthesis.

FINDINGS

The therapeutic potential of EN therapy was observed in both dextran sulfate sodium (DSS)-induced colitis and Il10-/- spontaneous colitis mouse models. Accumulation of F. rodentium after EN therapy was determined using full-length 16S rDNA sequencing and verified with several metagenome datasets from patients with CD. Colonization of an isolated F. rodentium could reduce colitis in Il10-/- mice. Significant histidine enrichment was observed in the F. rodentium culture supernatant, and a series of histidine biosynthesis genes were observed in the F. rodentium genome. Engineered Escherichia coli Nissle 1917 (EcN), encoding the heterologous hisG of F. rodentium (EcN-hisG), which was a key driver of histidine biosynthesis in F. rodentium, was found to protect against colitis.

INTERPRETATION

This study suggests that EN-induced F. rodentium accumulation protects against colitis in mice via gut bacteria-mediated histidine biosynthesis.

FUNDING

A full list of funding bodies can be found in the Acknowledgements section.

Synbiotic Combination between Lactobacillus paracasei VL8 and Mannan-Oligosaccharide Repairs the Intestinal Barrier in the Dextran Sulfate Sodium-Induced Colitis Model by Regulating the Intestinal Stem Cell Niche

Previously, Lactobacillus paracasei VL8, a lactobacillus strain isolated from the traditional Finnish fermented dairy product Viili, demonstrated immunomodulatory and antibacterial effects. The prebiotic mannan-oligosaccharide (MOS) further promoted its antibacterial activity and growth performance, holding promise for maintaining intestinal health. However, this has not been verified in vivo. In this study, we elucidated the process by which L. paracasei VL8 and its synbiotc combination (SYN) with MOS repair the intestinal barrier function in dextran sodium sulfate (DSS)-induced colitis mice. SYN surpasses VL8 or MOS alone in restoring goblet cells and improving the tight junction structure. Omics analysis on gut microbiota reveals SYN's ability to restore Lactobacillus spp. abundance and promote tryptophan metabolism. SYN intervention also inhibits the DSS-induced hyperactivation of the Wnt/β-catenin pathway. Tryptophan metabolites from Lactobacillus induce intestinal organoid differentiation. Co-housing experiments confirm microbiota transferability, replicating intestinal barrier repair. In conclusion, our study highlights the potential therapeutic efficacy of the synbiotic combination of Lactobacillus paracasei VL8 and MOS in restoring the damaged intestinal barrier and offers new insights into the complex crosstalk between the gut microbiota and intestinal stem cells.

Microfluidics-Derived Microparticles with Prebiotics and Probiotics for Enhanced In Situ Colonization and Immunoregulation of Colitis

Oral administration of probiotics orchestrates the balance between intestinal microbes and the immune response. However, effective delivery and in situ colonization are limited by the harsh environment of the gastrointestinal tract. Herein, we provide a microfluidics-derived encapsulation strategy to address this problem. A novel synergistic delivery system composed of EcN Nissle 1917 and prebiotics, including alginate sodium and inulin gel, for treating inflammatory bowel disease and colitis-associated colorectal cancer is proposed. We demonstrated that EcN@AN microparticles yielded promising gastrointestinal resistance for on-demand probiotic delivery and colon-retentive capability. EcN@AN microparticles efficiently ameliorated intestinal inflammation and modulated the gut microbiome in experimental colitis. Moreover, the prebiotic composition of EcN@AN enhanced the fermentation of relative short-chain fatty acid metabolites, a kind of postbiotics, to exert anti-inflammatory and tumor-suppressive effects in murine models. This microfluidcis-based approach for the coordinated delivery of probiotics and prebiotics may have broad implications for gastrointestinal bacteriotherapy applications.

Exclusive Enteral Nutrition Beneficially Modulates Gut Microbiome in a Preclinical Model of Crohn's-like Colitis

Exclusive enteral nutrition (EEN) is an established dietary treatment for Crohn's disease (CD) by alleviating inflammation and inducing remission. However, the mechanisms of action of EEN are incompletely understood. As CD is associated with gut microbiome dysbiosis, we investigated the effect of EEN on the microbiome in a rat model of CD-like colitis. The rat model of CD-like colitis was established by an intracolonic instillation of TNBS at 65 mg/kg in 250 µL of 40% ethanol. Sham control rats were instilled with saline. Rats were fed ad libitum with either regular pellet food or EEN treatment with a clear liquid diet (Ensure). Rats were euthanized at 7 days. Fecal pellets were collected from the distal colon for 16S rRNA sequencing analysis of gut microbiota. In addition, colon tissues were taken for histological and molecular analyses in all the groups of rats. EEN administration to TNBS-induced CD rats significantly improved the body weight change, inflammation scores, and disease activity index. The mRNA expression of IL-17A and interferon-γ was significantly increased in the colonic tissue in TNBS rats when fed with regular food. However, EEN treatment significantly attenuated the increase in IL-17A and interferon-γ in TNBS rats. Our 16S rRNA sequencing analysis found that gut microbiota diversity and compositions were significantly altered in TNBS rats, compared to controls. However, EEN treatment improved alpha diversity and increased certain beneficial bacteria such as Lactobacillus and Dubosiella and decreased bacteria such as Bacteroides and Enterorhabdus in CD-like rats, compared to CD-like rats with the regular pellet diet. In conclusion, EEN treatment increases the diversity of gut microbiota and the composition of certain beneficial bacteria. These effects may contribute to the reduced inflammation by EEN in the rat model of CD-like colitis.

Trichinella-derived protein ameliorates colitis by altering the gut microbiome and improving intestinal barrier function

BACKGROUND

Inflammatory bowel disease (IBD) encompasses Crohn's Disease and Ulcerative Colitis. Reports have highlighted the potential use of helminths or their byproducts as a possible treatment for IBD; however, the mechanisms underlying their ability to modulate inflammation remain incompletely understood. In the present study, we analyze the possible mechanism of a serine protease inhibitor from adult T. spiralis excretion-secretion products (rTsSPI) on the improvement of colitis.

METHODS

The immune protective effect of rTsSPI was studied by using DSS or Salmonella-induced colitis in female C56BL/6 mice. The effect of rTsSPI on the immune and inflammatory responses, gut microbiota, permeability of colon epithelium and junction proteins was analyzed.

RESULTS

Treating mice with rTsSPI induced type 2 immunity and significantly attenuated clinical symptoms, macroscopical and histological features of DSS or bacteria-induced colonic inflammation. This was accompanied by decreasing neutrophil recruitment in the colonic lamina propria, and reducing TNF-α mRNA levels in the colon; in contrast, the recruitment of M2 macrophages, the expression level of IL-10 and adhesion molecules increased in the colon tissue. Moreover, treatment with rTsSPI led to an improvement in gut microbiota diversity, as well as an increase in the abundance of the bacterial genera Bifidobacterium and Ruminclostridium 5.

CONCLUSIONS

Collective findings suggest that pretreatment with rTsSPI can ameliorate colitis in mice by inducing a Th2-type response with M2 macrophages. Data also indicate that immunotherapy with rTsSPI represents an additional strategy to ameliorate inflammatory processes in IBD by enhancing probiotic colonization and maintaining intestinal epithelial barrier function.

Alkaline Phosphatase Relieves Colitis in Obese Mice Subjected to Forced Exercise via Its Anti-Inflammatory and Intestinal Microbiota-Shaping Properties

Intestinal alkaline phosphatase (IAP) is an enzyme that plays a protective role in the gut. This study investigated the effect of IAP treatment on experimental colitis in mice subjected to forced exercise on a high-fat diet. C57BL/6 mice with TNBS colitis were fed a high-fat diet and subjected to forced treadmill exercise with or without IAP treatment. Disease activity, oxidative stress, inflammatory cytokines, and gut microbiota were assessed. Forced exercise exacerbated colitis in obese mice, as evidenced by increased disease activity index (DAI), oxidative stress markers, and proinflammatory adipokines and cytokines. IAP treatment significantly reduced these effects and promoted the expression of barrier proteins in the colonic mucosa. Additionally, IAP treatment altered the gut microbiota composition, favoring beneficial Verrucomicrobiota and reducing pathogenic Clostridia and Odoribacter. IAP treatment ameliorates the worsening effect of forced exercise on murine colitis by attenuating oxidative stress, downregulating proinflammatory biomarkers, and modulating the gut microbiota. IAP warrants further investigation as a potential therapeutic strategy for ulcerative colitis.

Integrated multi-omics reveal gut microbiota-mediated bile acid metabolism alteration regulating immunotherapy responses to anti-α4β7-integrin in Crohn's disease

Gut microbiota and related metabolites are both crucial factors that significantly influence how individuals with Crohn's disease respond to immunotherapy. However, little is known about the interplay among gut microbiota, metabolites, Crohn's disease, and the response to anti-α4β7-integrin in current studies. Our research utilized 2,4,6-trinitrobenzene sulfonic acid to induce colitis based on the humanized immune system mouse model and employed a combination of whole-genome shotgun metagenomics and non-targeted metabolomics to investigate immunotherapy responses. Additionally, clinical cases with Crohn's disease initiating anti-α4β7-integrin therapy were evaluated comprehensively. Particularly, 16S-rDNA gene high-throughput sequencing and targeted bile acid metabolomics were conducted at weeks 0, 14, and 54. We found that anti-α4β7-integrin therapy has shown significant potential for mitigating disease phenotypes in remission-achieving colitis mice. Microbial profiles demonstrated that not only microbial composition but also microbially encoded metabolic pathways could predict immunotherapy responses. Metabonomic signatures revealed that bile acid metabolism alteration, especially elevated secondary bile acids, was a determinant of immunotherapy responses. Especially, the remission mice significantly enriched the proportion of the beneficial Lactobacillus and Clostridium genera, which were correlated with increased gastrointestinal levels of BAs involving lithocholic acid and deoxycholic acid. Moreover, most of the omics features observed in colitis mice were replicated in clinical cases. Notably, anti-α4β7 integrin provided sustained therapeutic benefits in clinical remitters during follow-up, and long-lasting remission was linked to persistent changes in the microbial-related bile acids. In conclusion, gut microbiota-mediated bile acid metabolism alteration could play a crucial role in regulating immunotherapy responses to anti-α4β7-integrin in Crohn's disease. Therefore, the identification of prognostic microbial signals facilitates the advancement of targeted probiotics that activate anti-inflammatory bile acid metabolic pathways, thereby improving immunotherapy responses. The integrated multi-omics established in our research provide valuable insights into potential mechanisms that impact treatment responses in complex diseases.

Probiotic Bacillus licheniformis ZW3 Alleviates DSS-Induced Colitis and Enhances Gut Homeostasis

Despite Bacillus species having been extensively utilized in the food industry and biocontrol as part of probiotic preparations, limited knowledge exists regarding their impact on intestinal disorders. In this study, we investigated the effect of Bacillus licheniformis ZW3 (ZW3), a potential probiotic isolated from camel feces, on dextran sulfate sodium (DSS)-induced colitis. The results showed ZW3 partially mitigated body weight loss, disease activity index (DAI), colon shortening, and suppressed immune response in colitis mice, as evidenced by the reduction in the levels of the inflammatory markers IL-1β, TNF-α, and IL-6 (p < 0.05). ZW3 was found to ameliorate DSS-induced dysfunction of the colonic barrier by enhancing mucin 2 (MUC2), zonula occluden-1 (ZO-1), and occludin. Furthermore, enriched beneficial bacteria Lachnospiraceae_NK4A136_group and decreased harmful bacteria Escherichia-Shigella revealed that ZW3 improved the imbalanced gut microbiota. Abnormally elevated uric acid levels in colitis were further normalized upon ZW3 supplementation. Overall, this study emphasized the protective effects of ZW3 in colitis mice as well as some potential applications in the management of inflammation-related diseases.

Electrical carotid sinus nerve stimulation attenuates experimental colitis induced by acetic acid in rats

AIMS

The carotid bodies are sensors that detect physiological signals and convey them to the central nervous system, where the stimuli are processed inducing reflexes through efferent pathways. Recent studies have demonstrated that electrical stimulation of the carotid sinus nerve (CSN) triggers the anti-inflammatory reflex under different conditions. However, whether this electrical stimulation attenuates colitis was never examined. This study aimed to evaluate if the electrical CSN stimulation attenuates the experimental colitis induced by intrarectal administration of acetic acid in rats.

METHODS

Electrodes were implanted around the CSN to stimulate the CSN, and a catheter was inserted into the left femoral artery to record the arterial pressure. The observation of hypotensive responses confirmed the effectiveness of the electrical CNS stimulation. This maneuver was followed by a 4 % acetic acid or saline administered intrarectally. After 24 h, colons were segmented into distal and proximal parts for macroscopy, histological and biochemical assessment.

KEY FINDINGS

As expected, the electrical CSN stimulation was effective in decreasing arterial pressure in saline and colitis rats. Moreover, electrical CSN stimulation effectively reduced colonic tissue lesions, colitis scores, and histopathologic parameters associated with colitis. In addition, the CSN stimulation also reduced the colonic mucosa pro-inflammatory cytokine interleukin-1 beta, and increased the anti-inflammatory interleukin-10, in rats submitted to colitis.

SIGNIFICANCE

These findings indicated that electrical CSN stimulation breaks the vicious cycle of local colon inflammation in colitis, which might contribute to its better outcome.

Immortalized Canine Adipose-Derived Mesenchymal Stem Cells Maintain the Immunomodulatory Capacity of the Original Primary Cells

Mesenchymal stem cells (MSCs) are a promising cell source for stem cell therapy of intractable diseases in veterinary medicine, but donor-dependent cellular heterogeneity is an issue that influences therapeutic efficacy. Thus, we previously established immortalized cells that maintain the fundamental properties of primary cells, but functional evaluation had not been performed. Therefore, we evaluated the immunomodulatory capacity of the immortalized canine adipose-derived MSCs (cADSCs) in vitro and in vivo to investigate whether they maintain primary cell functions. C57BL/6J mice were treated with dextran sulfate sodium (DSS) to induce colitis, injected intraperitoneally with immortalized or primary cADSCs on day 2 of DSS treatment, and observed for 10 days. Administration of immortalized cADSCs improved body weight loss and the disease activity index (DAI) in DSS-induced colitic mice by shifting peritoneal macrophage polarity from the M1 to M2 phenotype, suppressing T helper (Th) 1/Th17 cell responses and inducing regulatory T (Treg) cells. They also inhibited the proliferation of mouse and canine T cells in vitro. These immunomodulatory effects were comparable with primary cells. These results highlight the feasibility of our immortalized cADSCs as a cell source for stem cell therapy with stable therapeutic efficacy because they maintain the immunomodulatory capacity of primary cells.

Effects of mesenchymal stem cells on Treg cells in rats with colitis

The aim was to investigate the therapeutic effect of bone marrow mesenchymal stem cells (BM-MSC) on dextran sulfate sodium (DSS) induced colitis in rats and its effect on regulatory T cells (Treg). A model of DSS-induced colitis was established. BM-MSC was isolated and cultured to observe the efficacy of BM-MSC on colitis, including general vital signs, weight changes, colonic length changes, colonic histopathological changes, and colonic tissue MPO activity. The expression of inflammatory factors (IFN-γ, IL-4, IL-17, TGF-β) in colonic tissues was measured by real-time PCR. The amount of CD4 + CD25 + Treg was detected by flow cytometry. Real-time PCR was used to detect Foxp3+mRNA in CD4 + CD25 + Treg, western to detect Foxp3+protein expression in CD4 + CD25 + Treg, and ELISA was used to detect IL-35 and IL-10 cytokines in CD4 + CD25 + Treg culture supernatant. Results show that intravenous injection of BM-MSC significantly improved the clinical manifestations and histopathological changes in rats with experimental DSS colitis; significantly down-regulated the expression of inflammatory factors IFN-γ, IL-4, and IL-17 and up-regulated the expression of TGF-β in colon tissues; BM-MSC also increased the number of CD4+CD25+Foxp3+Treg and enhanced the function of CD4+CD25+Foxp3+Treg in colon tissues, and up-regulated the expression of IL-35. In conclusion, BM-MSC has a certain therapeutic effect on DSS-induced colitis. It can improve the general signs of colitis rats and reduce intestinal injury and inflammatory response. The immunoregulatory effect of BM-MSC is achieved by enhancing the function of CD4+CD25+Foxp3+Treg and up-regulating the secretion of immunosuppressive inflammatory factors.

Fiber-deficient diet inhibits colitis through the regulation of the niche and metabolism of a gut pathobiont

Exclusive enteral nutrition (EEN) with fiber-free diets is an effective steroid-sparing treatment to induce clinical remission in children with Crohn's disease (CD). However, the mechanism underlying the beneficial effects of EEN remains obscure. Using a model of microbiota-dependent colitis with the hallmarks of CD, we find that the administration of a fiber-free diet prevents the development of colitis and inhibits intestinal inflammation in colitic animals. Remarkably, fiber-free diet alters the intestinal localization of Mucispirillum schaedleri, a mucus-dwelling pathobiont, which is required for triggering disease. Mechanistically, the absence of dietary fiber reduces nutrient availability and impairs the dissimilatory nitrate reduction to ammonia (DNRA) metabolic pathway of Mucispirillum, leading to its exclusion from the mucus layer and disease remission. Thus, appropriate localization of the specific pathobiont in the mucus layer is critical for disease development, which is disrupted by fiber exclusion. These results suggest strategies to treat CD by targeting the intestinal niche and metabolism of disease-causing microbes.

Moxibustion improved the effect of fecal microbiota transplantation donor to dextran sulfate sodium-induced colitis in mice

Fecal microbiota transplantation (FMT) is beneficial for several gastrointestinal diseases because it alters the intestinal microbiota of recipients. The efficacy of FMT is related to the microbial structure and composition of the donor. Mild moxibustion is a non-invasive and safe traditional Chinese therapy that can regulate the gut microbiota. In this study, we investigated whether moxibustion improved the efficacy of FMT in donors using a dextran sulfate sodium (DSS)-induced colitis mouse model. Normal mice were treated with mild moxibustion at acupoints ST25 and ST36 for 7 days. DSS (2%) was administered for 7 days to induce colitis. FMT was performed on Day 8 and lasted for 7 days. The effect of FMT on mice with DSS was observed on Day 21. Using hematoxylin and eosin staining and immunofluorescence, we analyzed the pathology and cell proliferation after FMT in DSS mice. In addition, using 16 S rDNA sequencing analysis, we investigated the gut microbiota of mice. The results indicated that moxibustion altered the colonic microbial community and increased the relative abundance of specific bacteria without changes in morphology and physiological function in normal mice. FMT using donors with moxibustion reduced body weight loss, inflammation, abnormal microbial community structure, and the relative abundance of some bacteria. These results provide potential strategies for the safe and targeted improvement of FMT donors.

Human umbilical cord mesenchymal stem cells alleviated TNBS-induced colitis in mice by restoring the balance of intestinal microbes and immunoregulation

AIMS

Human umbilical cord mesenchymal stem cells (HUMSCs) have been documented to be effective for several immune disorders including inflammatory bowel diseases (IBD). However, it remains unclear how HUMSCs function in regulating immune responses and intestinal flora in the trinitrobenzene sulfonic acid (TNBS)-induced IBD model.

MATERIALS AND METHODS

We assessed the regulatory effects of HUMSCs on the gut microbiota, T lymphocyte subpopulations and related immune cytokines in the TNBS-induced IBD model. The mice were divided into the normal, TNBS, and HUMSC-treated groups. The effect of HUMSCs was evaluated by Hematoxylin and Eosin (H&E) staining, fluorescence-activated cell sorting (FACS), and enzyme-linked immunosorbent assay (ELISA) analyses. Metagenomics Illumina sequencing was conducted for fecal samples.

KEY FINDINGS

We demonstrated that the disease symptoms and pathological changes in the colon tissues of TNBS-induced colitis mice were dramatically ameliorated by HUMSCs, which improved the gut microbiota and rebalanced the immune system, increasing the abundance of healthy bacteria (such as Lactobacillus murinus and Lactobacillus johnsonii), the Firmicutes/Bacteroidetes ratio, and the proportion of Tregs; the Th1/Th17 ratio was decreased. Consistently, the expression levels of IFN-γ and IL-17 were significantly decreased, and transforming growth factor-β1 (TGF-β1) levels were significantly increased in the plasma of colitis mice HUMSC injection.

SIGNIFICANCE

Our experiment revealed that HUMSCs mitigate acute colitis by regulating the rebalance of Th1/Th17/Treg cells and related cytokines and remodeling the gut microbiota, providing potential future therapeutic targets in IBD.

Lactiplantibacillus plantarum and faecal microbiota transplantation can improve colitis in mice by affecting gut microbiota and metabolomics

Gut microbiota may have therapeutic effects on inflammatory bowel disease (IBD). Regulating intestinal microbiota through Lactiplantibacillus plantarum (L. plantarum) and faecal microbiota transplantation (FMT) is a novel approach to treating IBD. This study aimed to explore the effect of L. plantarum and FMT pretreatment in alleviating colitis in mice. Five groups of mice (n = 6 per group) were included: CON group, DSS group (dextran sodium sulphate-induced colitis mice), LP-DSS pretreatment group (colitis mice were given strain L. plantarum and 5% DSS), DSS-FMT group (mice pretreated with faecal microbiota transplantation were given 5% DSS), and LP-FMT pretreatment group (mice pretreated with faecal microbiota transplantation and L. plantarum were given 5% DSS). Serum metabolites and intestinal microbiota were analysed by 16S rRNA sequencing liquid chromatography-mass spectrometry (LC-MS). The results demonstrated that L. plantarum and FMT improved gut microbiota in mice by increasing Firmicutes and decreasing the Bacteroidetes. In the serum metabolomics analysis, there were 11 differential metabolites in the DSS-FMT and LP-FMT pretreatment groups, and these differential metabolites were mainly glycerophospholipids and sphingolipids. It is worth noting that Lachnospira and Lactobacillus were positively associated with 8 differential metabolites. These results suggest that L. plantarum and FMT can regulate intestinal microorganisms and serum metabolomics to alleviate inflammation.

Thermally engineered MSC-derived extracellular vesicles ameliorate colitis in mice by restoring the imbalanced Th17/Treg cell ratio

Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) have garnered extensive interest for their immunomodulatory properties in immune-mediated inflammatory diseases. However, the development of EVs as clinical drugs often faces challenges such as low production yield and suboptimal therapeutic efficacy. In this study, we discovered that thermally engineering was able to enhance the yield of MSC-EVs. Moreover, the PD-L1 expression of EVs released from the thermal engineering MSCs was found to be upregulated significantly, and these EVs ameliorated the symptoms and pathological damages in murine dextran sulfate sodium (DSS)-induced colitis model. The therapeutic effect on DSS-induced colitis was mediated through the regulation of the Th17/Treg cell balance, demonstrating the immunomodulatory properties of the thermally engineering MSC-EVs. Overall, our findings suggest that thermal engineering can be utilized as a promising strategy for enhancing EV production and may provide a potential therapeutic approach for clinical treatment of colitis.

The Anti-Inflammatory Effect of a Probiotic Cocktail in Human Feces Induced-Mouse Model

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract due to altered interaction between the immune system and the gut microbiota. The aim of this study was to investigate the role of a probiotic cocktail in modulating immune dysregulation induced in mice. Mice were divided into 5 groups (n = 5/group), and inflammation was induced in two separate groups by fecal microbiota transplantation (FMT) from the stool of human with IBD and dextran sulfate sodium (DSS). In the other two groups, the cocktail of Lactobacillus spp. and Bifidobacterium spp. (108CFU/kg/day) was administered daily for a total of 28days in addition to inducing inflammation. A group as a contcxsrol group received only water and food. The alteration of the selected genera of gut microbiota and the expression of some genes involved in the regulation of the inflammatory response were studied in the probiotic-treated and untreated groups by quantitative real-time PCR. The selected genera of gut microbiota of the FMT and DSS groups showed similar patterns on day 28 after each treatment. In the probiotic-treated groups, the population of the selected genera of gut microbiota normalized and the abundance of Firmicutes and Actinobacteria increased compared to the DSS and FMT groups. The expression of genes related to immune response and tight junctions was positively affected by the probiotic. Changes in the gut microbiota could influence the inflammatory status in the gut, and probiotics as a preventive or complementary treatment could improve the well-being of patients with inflammatory bowel disease symptoms.

Thiostrepton alleviates experimental colitis by promoting RORγt ubiquitination and modulating dysbiosis

Thiostrepton (TST) is a natural antibiotic with pleiotropic properties. This study aimed to elucidate the therapeutic effect of TST on experimental colitis and identify its targets. The effect of TST on colon inflammation was evaluated in a dextran sulfate sodium (DSS)-induced colitis model and a T-cell transfer colitis model. The therapeutic targets of TST were investigated by cytokine profiling, immunophenotyping and biochemical approaches. The effect of TST on the gut microbiota and its contribution to colitis were evaluated in mice with DSS-induced colitis that were subjected to gut microbiota depletion and fecal microbiota transplantation (FMT). Alterations in the gut microbiota caused by TST were determined by 16S rDNA and metagenomic sequencing. Here, we showed that TST treatment significantly ameliorated colitis in the DSS-induced and T-cell transfer models. Specifically, TST targeted the retinoic acid-related orphan nuclear receptor RORγt to reduce the production of IL-17A by γδ T cells, type 3 innate lymphoid cells (ILC3s) and Th17 cells in mice with DSS-induced colitis. Similarly, TST selectively prevented the development of Th17 cells in the T-cell transfer colitis model and the differentiation of naïve CD4+ T cells into Th17 cells in vitro. Mechanistically, TST induced the ubiquitination and degradation of RORγt by promoting the binding of Itch to RORγt. Moreover, TST also reversed dysbiosis to control colonic inflammation. Taken together, these results from our study describe the previously unexplored role of TST in alleviating colonic inflammation by reducing IL-17A production and modulating dysbiosis, suggesting that TST is a promising candidate drug for the treatment of IBD.

PVA enema ameliorates DSS-induced acute colitis in mice

BACKGROUND

Ulcerative colitis (UC) represents a clinically challenging condition characterized by persistent damage to the colonic epithelial mucosa as the principal pathological feature. Polyvinyl alcohol (PVA) solution, primarily composed of glue, is a biodegradable polymer material that has found utility in the medical field. This research endeavors to investigate the therapeutic potential of PVA water solution in ameliorating UC in mice.

METHODS

UC was induced in 48 C57BL/6 mice by administering 2.5% DSS in their diet for 6 days. Mice were treated with different concentrations of PVA (0.1 mg/ml PVA, 0.3 mg/ml PVA, 1 mg/ml PVA, 3 mg/ml PVA, 10 mg/ml PVA) enemas (n = 6). Disease Activity Index (DAI) and histologic score were evaluated for inflammation degree. Furthermore, mouse colon organoids were cultured, which were used to assess the effects of PVA on expansion in vitro.

RESULTS

PVA aqueous solutions (1 mg/ml and 3 mg/ml) were able to alleviate the DAI in mice. By DAY 6, there was a significant 3/5-fold decrease in DAI within the 1 mg/ml PVA group (p = 0.02). Histopathology scores demonstrated improvements, while the levels of inflammatory factors in the intestinal mucosal tissue were reduced. Additionally, it was confirmed that PVA could promote the expansion of colonic organoids in vitro.

CONCLUSIONS

In summary, our investigation has yielded findings indicating that PVA holds the potential to ameliorate symptoms associated with colitis in murine subjects afflicted by DSS-induced colitis, primarily through its facilitation of intestinal stem cell expansion. This study might provide a new candidate for the clinical treatment of ulcerative colitis.

Lactobacillus plantarum Zhang-LL Inhibits Colitis-Related Tumorigenesis by Regulating Arachidonic Acid Metabolism and CD22-Mediated B-Cell Receptor Regulation

Colorectal cancer (CRC) is a significant health concern and is the third most commonly diagnosed and second deadliest cancer worldwide. CRC has been steadily increasing in developing countries owing to factors such as aging and epidemics. Despite extensive research, the exact pathogenesis of CRC remains unclear, and its causes are complex and variable. Numerous in vitro, animal, and clinical trials have demonstrated the efficacy of probiotics such as Lactobacillus plantarum in reversing the adverse outcomes of CRC. These findings suggest that probiotics play vital roles in the prevention, adjuvant treatment, and prognosis of CRC. In this study, we constructed a mouse model of CRC using an intraperitoneal injection of azomethane combined with dextran sodium sulfate, while administering 5-fluorouracil as well as high- and low-doses of L. plantarum Zhang-LL live or heat-killed strains. Weight changes and disease activity indices were recorded during feeding, and the number of polyps and colon length were measured after euthanasia. HE staining was used to observe the histopathological changes in the colons of mice, and ELISA was used to detect the expression levels of IL-1β, TNF-α, and IFN-γ in serum. To investigate the specific mechanisms involved in alleviating CRC progression, gut microbial alterations were investigated using 16S rRNA amplicon sequencing and non-targeted metabolomics, and changes in genes related to CRC were assessed using eukaryotic transcriptomics. The results showed that both viable and heat-killed strains of L. plantarum Zhang-LL in high doses significantly inhibited tumorigenesis, colon shortening, adverse inflammatory reactions, intestinal tissue damage, and pro-inflammatory factor expression upregulation. Specifically, in the gut microbiota, the abundance of the dominant flora Acutalibacter muris and Lactobacillus johnsonii was regulated, PGE2 expression was significantly reduced, the arachidonic acid metabolism pathway was inhibited, and CD22-mediated B-cell receptor regulation-related gene expression was upregulated. This study showed that L. plantarum Zhang-LL live or heat-inactivated strains alleviated CRC progression by reducing the abundance of potentially pathogenic bacteria, increasing the abundance of beneficial commensal bacteria, mediating the arachidonic acid metabolism pathway, and improving host immunogenicity.

Multifunctional effects of Lactobacillus sakei HEM 224 on the gastrointestinal tract and airway inflammation

Mucosal tissues serve as the first defense line and their commensal microbiota play a role in sustaining of host health. This study aimed to isolate and evaluate a putative probiotic strain on various mucosal regions. Lactobacillus sakei HEM 224 was isolated from traditional Korean kimchi and identified. In the safety assessment L. sakei HEM 224 showed negative results for hemolysis, biogenic amine production and transferable antibiotic resistance. The probiotic potential of strain HEM 224 in diverse mucosal areas was shown in two different models, viz. a murine model with colitis induced by dextran sulfate sodium (DSS) and an allergic airway inflammation model induced by ovalbumin (OVA). In the colitis model, oral administration of L. sakei HEM 224 improved colitis physiology with immunomodulation, enhancing barrier components and gut microbiota alteration. In the allergic airway inflammation model, the intranasal administration of the strain decreased type 2 inflammation and enhanced epithelial barrier integrity from the airways. These results demonstrate that L. sakei HEM 224 can ameliorate inflammatory conditions in both the gastrointestinal and respiratory tracts through the reinforcement of the epithelial barrier and immunomodulation.

Human umbilical cord mesenchymal stem cells ameliorate colon inflammation via modulation of gut microbiota-SCFAs-immune axis

BACKGROUND

Inflammatory bowel disease (IBD) is a global health problem in which gut microbiota dysbiosis plays a pivotal pathogenic role. Mesenchymal stem cells (MSCs) therapy has emerged as a prospective novel tool for managing IBD, and which can also regulate the composition of gut microbiota. However, the functional significance of MSCs-induced changes in gut microbiome is poorly understood.

METHODS

Here, we investigated for the first time the role of gut microbiota in mediating the protective effect of human umbilical cord MSCs (HUMSCs) on DSS-induced colitis. Gut microbiota alteration and short-chain fatty acids (SCFAs) production were analyzed through 16S rRNA sequencing and targeted metabolomics. Spectrum antibiotic cocktail (ABX), fecal microbiota transplantation (FMT) and sterile fecal filtrate (SFF) were employed to evaluate the protective effect of intestinal flora and its metabolites. Cytokine microarray, Enzyme-linked immunosorbent assay (ELISA), and flow cytometry were conducted to assess the effect on CD4+T homeostasis.

RESULTS

Here, we investigated for the first time the role of gut microbiota in mediating the protective effect of MSCs on DSS-induced colitis. By performing gut microbiota depletion and fecal microbiota transplantation (FMT) experiments, we revealed that MSCs derived from human umbilical cord ameliorated colon inflammation and reshaped T-cells immune homeostasis via remodeling the composition and diversity of gut flora, especially up-regulated SCFAs-producing bacterial abundance, such as Akkermansia, Faecalibaculum, and Clostridia_UCG_014. Consistently, targeted metabolomics manifested the increased SCFAs production with MSCs administration, and there was also a significant positive correlation between differential bacteria and SCFAs. Meanwhile, combined with sterile fecal filtrate (SFF) gavage experiments, the underlying protective mechanism was further associated with the improved Treg/Th2/Th17 balance in intestinal mucosa mediated via the increased microbiota-derived SCFAs production.

CONCLUSION

The present study advances understanding of MSCs in the protective effects on colitis, providing evidence for the new role of the microbiome-metabolite-immune axis in the recovery of colitis by MSCs.

Fecal microbiota transplant for treatment of diarrhea in adult hospitalized horses-111 cases (2013-2018)

Background

Fecal microbiota transplant (FMT) is increasingly administered as part of the treatment of colitis in horses, yet there is little data as to its effectiveness.

Aim

Retrospective evaluation of the effects of FMT on discharge status, fecal consistency, length of hospitalization, and improvement in clinical signs in horses hospitalized for diarrhea.

Methods

Retrospective case-control study. Medical records of adult horses (>1 year old) that received at least one transfaunation treatment (2013-2018) in two referral hospitals were identified through a medical records database search. Medical records of contemporary adult horses with diarrhea who did not receive FMT at the same study centers were used as controls.

Results

Control horses had statistically significant shorter hospitalization [7 (1-21)] as compared to the transfaunation group [12 (3-31)] ( p = 0.0006). There were no significant differences between groups in the number of days to the improvement of feces (p = 0.38), or in days to normalization of fecal consistency (p = 0.43), respiratory rate (p = 0.42), heart rate (p = 0.27), body temperature (p = 0.12), peripheral white blood cell count (p = 0.37), improvement in appetite (p = 0.81), or attitude (p = 0.06). There was also no significant difference in survival to discharge (transfaunation 28/37, 75.7%; control 56/74, 75.7%, p = 1.0).

Conclusion

There were no significant advantages of performing FMTs in horses with diarrhea in this retrospective study. This highlights the need for prospective, randomized studies to evaluate the efficacy of FMT, as well as different formulations, in horses with colitis before this can become standard practice.

Fecal microbiota transplantation alleviates experimental colitis through the Toll-like receptor 4 signaling pathway

BACKGROUND

Fecal microbiota transplantation (FMT) has shown promising therapeutic effects on mice with experimental colitis and patients with ulcerative colitis (UC). FMT modulates the Toll-like receptor 4 (TLR4) signaling pathway to treat some other diseases. However, it remains unknown whether this modulation is also involved in the treatment of UC.

AIM

To clarify the necessity of TLR4 signaling pathway in FMT on dextran sodium sulphate (DSS)-induced mice and explain the mechanism of FMT on UC, through association analysis of gut microbiota with colon transcriptome in mice.

METHODS

A mouse colitis model was constructed with wild-type (WT) and TLR4-knockout (KO) mice. Fecal microbiota was transplanted by gavage. Colon inflammation severity was measured by disease activity index (DAI) scoring and hematoxylin and eosin staining. Gut microbiota structure was analyzed through 16S ribosomal RNA sequencing. Gene expression in the mouse colon was obtained by transcriptome sequencing.

RESULTS

The KO (DSS + Water) and KO (DSS + FMT) groups displayed indistinguishable body weight loss, colon length, DAI score, and histology score, which showed that FMT could not inhibit the disease in KO mice. In mice treated with FMT, the relative abundance of Akkermansia decreased, and Lactobacillus became dominant. In particular, compared with those in WT mice, the scores of DAI and colon histology were clearly decreased in the KO-DSS group. Microbiota structure showed a significant difference between KO and WT mice. Akkermansia were the dominant genus in healthy KO mice. The ineffectiveness of FMT in KO mice was related to the decreased abundance of Akkermansia. Gene Ontology enrichment analysis showed that differentially expressed genes between each group were mainly involved in cytoplasmic translation and cellular response to DNA damage stimulus. The top nine genes correlating with Akkermansia included Aqp4, Clca4a, Dpm3, Fau, Mcrip1, Meis3, Nupr1 L, Pank3, and Rps13 (|R| > 0.9, P < 0.01).

CONCLUSION

FMT may ameliorate DSS-induced colitis by regulating the TLR4 signaling pathway. TLR4 modulates the composition of gut microbiota and the expression of related genes to ameliorate colitis and maintain the stability of the intestinal environment. Akkermansia bear great therapeutic potential for colitis.

Bifidobacterium breve CBT BR3 is effective at relieving intestinal inflammation by augmenting goblet cell regeneration

BACKGROUND AND AIM

Bifidobacterium breve was the first bacteria isolated in the feces of healthy infants and is a dominant species in the guts of breast-fed infants. Some strains of B. breve have been shown to be effective at relieving intestinal inflammation, but the modes of action have yet to be elucidated. In this study, we investigated the mechanisms of action of B. breve CBT BR3 isolated from South Korean infant feces in relieving colitis in vitro and in vivo.

METHODS

Colitis was induced in mice with dextran sodium sulfate (DSS) and dinitrobenzene sulfonic acid (DNBS). Quantitative reverse-transcription polymerase chain reaction, in vitro FITC-dextran flux permeability assay, and aryl hydrocarbon receptor (AhR) luciferase assay are performed using Caco-2 cells and HT29-Lucia™ AhR cells.

RESULTS

B. breve CBT BR3 was orally administered. B. breve CBT BR3 improved colitis symptoms in both DSS- and DNBS-induced colitis models. B. breve CBT BR3 increased the number of goblet cells per crypt. B. breve increased the mRNA expressions of Notch, Spdef, Muc5, and Il22. The mRNA expressions of Occludin, which encodes a membrane tight-junction protein, and Foxo3, which encodes a protein related to butyrate metabolism, were also increased in the DSS- and DNBS-induced colitis models. B. breve CBT BR3 protected inflammation-induced epithelial cell permeability and improved goblet cell function by inducing aryl hydrocarbon receptor in vitro.

CONCLUSIONS

These results indicate that B. breve CBT BR3 is effective at relieving intestinal inflammation by augmenting goblet cell regeneration.

Chlorella vulgaris Modulates Gut Microbiota and Induces Regulatory T Cells to Alleviate Colitis in Mice

Chlorella vulgaris (C. vulgaris) is unicellular green algae consumed worldwide as a functional food. The immune stimulatory function of C. vulgaris is known; however, no study has elucidated its immune regulatory potential and associated microbiome modulation. In the current study, we aimed to validate the immune regulatory role of C. vulgaris mediated through two mechanisms. Initially, we assessed its ability to promote the expansion of the regulatory T cell (Treg) population. Subsequently, we investigated its impact on gut microbiota composition and associated metabolites. The supplementation of C. vulgaris altered the gut microbiota composition, accompanied by increased short-chain fatty acid (SCFAs) production in mice at homeostasis. We later used C. vulgaris in the treatment of a DSS-induced colitis model. C. vulgaris intervention alleviated the pathological symptom of colitis in mice, with a corresponding increase in Treg levels. As C. vulgaris is a safe and widely used food supplement, it can be a feasible strategy to instigate cross-talk between the host immune system and the intestinal flora for the effective management of inflammatory bowel disease (IBD).

Effects of Probiotics on Colitis-Induced Exacerbation of Alzheimer's Disease in AppNL-G-F Mice

Alzheimer's disease (AD) is characterized by progressive cognitive decline and is a leading cause of death in the United States. Neuroinflammation has been implicated in the progression of AD, and several recent studies suggest that peripheral immune dysfunction may influence the disease. Continuing evidence indicates that intestinal dysbiosis is an attribute of AD, and inflammatory bowel disease (IBD) has been shown to aggravate cognitive impairment. Previously, we separately demonstrated that an IBD-like condition exacerbates AD-related changes in the brains of the AppNL-G-F mouse model of AD, while probiotic intervention has an attenuating effect. In this study, we investigated the combination of a dietary probiotic and an IBD-like condition for effects on the brains of mice. Male C57BL/6 wild type (WT) and AppNL-G-F mice were randomly divided into four groups: vehicle control, oral probiotic, dextran sulfate sodium (DSS), and DSS given with probiotics. As anticipated, probiotic treatment attenuated the DSS-induced colitis disease activity index in WT and AppNL-G-F mice. Although probiotic feeding significantly attenuated the DSS-mediated increase in WT colonic lipocalin levels, it was less protective in the AppNL-G-F DSS-treated group. In parallel with the intestinal changes, combined probiotic and DSS treatment increased microglial, neutrophil elastase, and 5hmC immunoreactivity while decreasing c-Fos staining compared to DSS treatment alone in the brains of WT mice. Although less abundant, probiotic combined with DSS treatment demonstrated a few similar changes in AppNL-G-F brains with increased microglial and decreased c-Fos immunoreactivity in addition to a slight increase in Aβ plaque staining. Both probiotic and DSS treatment also altered the levels of several cytokines in WT and AppNL-G-F brains, with a unique increase in the levels of TNFα and IL-2 being observed in only AppNL-G-F mice following combined DSS and probiotic treatment. Our data indicate that, while dietary probiotic intervention provides protection against the colitis-like condition, it also influences numerous glial, cytokine, and neuronal changes in the brain that may regulate brain function and the progression of AD.