The Tight Junction Protein ZO-1 Is Dispensable for Barrier Function but Critical for Effective Mucosal Repair

Targeted modulation of intestinal barrier and mucosal immune-related microbiota attenuates IgA nephropathy progression

IgA nephropathy (IgAN) is related to the balance of gut microbiota. However, it is unclear whether changes in the gut microbiota can cause IgAN or attenuate its progression. This study employed IgAN and human microbiota-associated (HMA)-IgAN models to investigate the impact of IgAN on gut microbiota alteration and the mechanisms by which gut microbiota might trigger IgAN. Furthermore, this study examined the effects of chitooligosaccharides (COS) and COS formulation (COSF) with microbiota-targeting function on enhancing intestinal barrier and renal functions. These results revealed that IgAN led to a reduction in α-diversity and structural alterations in the gut microbiota, characterized by an increase in Shigella sonnei, Streptococcus danieliae, Desulfovibrio fairfieldensis, and a decrease in Bifidobacterium pseudolongum and Clostridium leptum. There was also an imbalance in intestinal B-cell immunity and a decrease in the level of tight junction proteins (ZO-1 and Occludin). Intestinal barrier and mucosal immune-related microbiota (Clostridium leptum, unclassified Lachnospiraceae NK4Al36 group, unclassified Clostridia vadinBB60 group, unclassified Oscillospiraceae, and unclassified Roseburia) were enriched through targeted modulation with COS/COSF, enhancing intestinal ZO-1 expression and reducing APRIL/BAFF overexpression, thereby reducing renal damage in IgAN. In conclusion, this study clarified the kidney-gut crosstalk between gut microbiota and IgAN, providing scientific evidence for developing microbiota-targeted food interventions to improve IgAN outcomes.

Nanozyme-functionalized microalgal biohybrid microrobots in inflammatory bowel disease treatment

Oral drugs are the most direct and effective strategy for the treatment of gastrointestinal diseases. However, the harsh environment of gastric juice, lack of targeted lesion sites, and rapid metabolism present difficulties in the development of oral drugs. This research introduces a nanozyme-functionalized microalgal biohybrid microrobot (Hp@CS-PNAs@PAA) with a novel mechanism for treating inflammatory bowel disease (IBD) by leveraging the therapeutic advantages of microalgae and nanozymes. The microrobot uniquely combines the natural antioxidant capacity of Hematococcus pluvialis (Hp) microalgae and the catalytically active enzyme-mimicking properties of platinum-based nanoparticle assemblies (PNAs), enabling enhanced scavenging of reactive oxygen species (ROS) and targeted anti-inflammatory effects. Through its layered design, the Hp@CS-PNAs@PAA microrobot can navigate the gastrointestinal tract, resist degradation, and target inflamed colon tissues via electrostatic interactions, achieving extended retention and prolonged therapeutic action at inflammation sites. This study demonstrated that the synergistic anti-inflammatory effects of the microrobot derive from its ability to reduce ROS, inhibit proinflammatory cytokines, and promote the expression of tight junction proteins critical for preserving the integrity of the intestinal barrier. Both in vitro and in vivo tests in a DSS-induced colitis mouse model revealed that this system effectively restores damaged tissues by reducing oxidative stress and inflammation, indicating significant potential for clinical application in the management of colitis and similar inflammatory diseases.

Intestinal alterations of mucosal barrier integrity, motility and enteric nerve in cynomolgus monkey model of Parkinson's disease

The most prevalent non-motor symptoms in individuals with Parkinson's disease (PD) such as constipation and bloating that significantly impact patients' quality of life. However, the pathophysiological mechanisms underlying these symptoms remain unclear. PD model with typical and stable symptoms was induced by individualized dosing of MPTP with Kurlan score increased to 10 or above and remained steady for three months or more. TH-positive neurons in the injured substantia nigra (SN) of the brain of PD monkeys showed up to 83.95 % reduction. Histopathological examination indicated severe damage to both enteric nerve and TH neurons, along with significant disruption of mucosal structure, intestinal barrier integrity and motility in PD monkeys across all four intestinal segments, including the duodenum, ileum, transverse colon, and rectum. The association between dopaminergic neuronal deficits in SN and these above mentioned intestinal disorders, that might be attributed to the abnormal regulation of gastrointestinal function due to the breakdown of the integrity of the nigrostriatal dopaminergic nervous system. Therefore, the abnormal alterations found in gut of PD monkeys and its triggered possible secondary pathophysiological cascade reactions might be a potential mechanism underlying the presence of constipation and other intestinal symptoms observed in PD patients. These findings in this study provide a valuable scientific basis for investigating the pathogenesis of gastrointestinal symptoms in PD patients and potential therapeutic approaches. (The graphical abstract is by Figdraw).

Geniposide via enema alleviates colitis by modulating intestinal flora and bile acid metabolites, inhibiting S100A8/S100A9/NF-κB, and promoting TGR5 inhibition of NLRP3 inflammasome

BACKGROUND

Geniposide (GE) has potential efficacy in treating ulcerative colitis (UC). However, its reactivity can be affected by rapid degradation after oral administration. Furthermore, increasing oral doses may lead to hepatotoxicity. Thus, We used enema administration, characterized by smaller dose and higher localized concentration in the lesion, to improve the above situation.

PURPOSE

We aimed to confirm that enema administration is a better modality than oral administration for GE against UC and to explore its mechanism.

STUDY DESIGN/METHOD

We established UC mouse model, monitoring Disease Activity Index (DAI), inflammatory cytokines levels, and histopathology. Macrogenomics and bile acid (BAs) metabolomics analysed the major intestinal flora and BAs. Simultaneouslly, we conducted quantitative proteomics analysis and screened core proteins and pathway. In vitro validation was taken by qPCR, immunofluorescence and immunoblotting experiments.

RESULTS

GE via enema alleviate UC by inhibiting inflammatory factor production through downregulating S100A8/S100A9/NF-κB pathway. Analysis of the intestinal flora and BAs revealed that the enhanced abundance of Lachnospiraceae, which improves the ratio of primary to secondary BAs, and the reduced abundance of Provocaceae, which increases intestinal permeability and promotes inflammation, favored the restoration of the intestinal barrier. In addition, in vitro experiments confirmed that the key BA metabolites (mainly UDCA, DCA, and LCA) stimulated TGR5 signal to inhibit the assembly of the NLRP3 inflammasome and alleviated inflammation.

CONCLUSION

We firstly confirmed that GE alleviates UC via the enema route in a better manner than the oral route, through enhancing the intestinal barrier, restoring intestinal flora and BAs homeostasis, and inhibiting inflammatory injury. This study initially revealed that GE can alleviate UC through elevating UDCA, DCA, and LCA levels at the colonic site to activate TGR5 receptor for inhibiting the NLRP3 inflammasome, in addition to downregulating the S100A8/S100A9/-TLR4-NF-κB pathway related inflammatory response directly. The evidences offer a promising strategy and profround meaning for UC treatment.

Structure-function relationship of the brown seaweed Undaria pinnatifida laminaran: Protein kinase C-mediated mucus secretion and gut barrier restoration

Ulcerative colitis is a chronic inflammatory condition of the intestine characterized by mucosal damage and a compromised epithelial barrier. This study explored the protective and therapeutic potential of laminaran derived from the brown seaweed Undaria pinnatifida in promoting mucin secretion and restoring mucosal barrier integrity. Physicochemical analysis revealed laminaran as having a β-(1 → 3)-linked glucose backbone with β-(1 → 6)-linked branches and a molecular weight of 14.41 kDa. In vitro experiments revealed that laminaran enhanced the expression of mucin-related proteins in a lipopolysaccharide-induced LS174T model. Laminaran also upregulated the expression of sulfotransferases, which are essential for mucin sulfation, and promoted vesicular transport by increasing the expression of vesicle-associated membrane protein 8 and synaptosome-associated protein-23, facilitating mucin secretion. These effects are mediated through the protein kinase C (PKC) pathway, which involves PKCα and PKCβII. In an in vivo model, laminaran alleviated dextran sulfate sodium-induced colitis, increasing mucus thickness and overall intestinal barrier function. These results suggest that laminaran is a promising therapeutic agent for treating ulcerative colitis, suggesting a novel approach to restoring the mucosal barrier and reducing intestinal inflammation. This study lays the groundwork for developing laminaran-based treatments for ulcerative colitis and other intestinal diseases associated with epithelial barrier dysfunction.

Anti-inflammatory and gut microbiota regulatory effects of ultrasonic degraded polysaccharides from Auricularia auricula-judae in DSS-induced colitis mice

Auricularia auricula-judae is a widely cultivated mushroom species known for its edible and medicinal properties. Polysaccharides have been the focus of research because of their potential bioactivities; nonetheless, the structural complexity and molecular weight have hindered a complete understanding of their bioactivities. In this study, AP-1 polysaccharide was isolated from A. auricula-judae and subjected to ultrasonic degradation at different time points to improve their anti-inflammatory effects. The results showed that when AP-1 was degraded for 9 min (AP-2) and 20 min (AP-3), the NO inhibition rate was significantly increased in LPS-stimulated RAW 264.7 cells. The structural and physiochemical properties of native and degraded polysaccharides were analyzed, and it was found that the degradation process significantly reduced molecular weight and altered the particle size, viscosity, crystallinity, and helical structure. Furthermore, native and degraded polysaccharides (AP-1, AP-2, and AP-3) anti-inflammatory effects were investigated in the DSS-induced colitis mouse model. Degraded polysaccharides resulted in significant improvements, including recovery from weight loss, reduced disease activity, shortened colon length, and decreased inflammation, while AP-3 showed the most promising effects. Gut microbiota 16S rRNA sequencing revealed that AP-3 potentially increases healthy gut microbiota and inhibits unhealthy gut microbiota. Overall, this study demonstrates that ultrasonic degradation could be a great technique to modify polysaccharides' MW and physiochemical properties to improve anti-inflammatory and gut microbiota regulatory effects.

Lacticaseibacillus paracasei CCFM1222 Ameliorated the Intestinal Barrier and Regulated Gut Microbiota in Mice with Dextran Sulfate Sodium-Induced Colitis

Lacticaseibacillus paracasei has been regarded as a probiotic bacterium because of its role in anti-inflammatory properties and maintenance of intestinal barrier permeability. Here, we explored the anticolitic effects and mechanism of L. paracasei CCFM1222. The results showed that L. paracasei CCFM1222 supplementation could suppress the disease activity index (DAI) and colon length shortening in colitis mice, accompanied by a moderate increase in colonic tight junction proteins (ZO-1, occludin and claudin-1). L. paracasei CCFM1222 intervention significantly suppressed the levels of inflammatory cytokines (TNF-α, IL-1β, and IL-6) and significantly elevated the activities of antioxidant enzymes (including SOD, GSH-Px, and CAT) in the colon by regulating the TLR4/MyD88/NF-κB and Nrf2 signaling pathways in colitis mice. In addition, L. paracasei CCFM1222 significantly shifted the gut microbiota, including elevating the abundance of Catabacter, Ruminiclostridium 9, Alistipes, and Faecalibaculum, as well as reducing the abundance of Mucispirillum, Escherichia-Shigella, and Salmonella, which was associated with the improvement of colonic barrier damage. Overall, these results suggest that L. paracasei CCFM1222 is a good candidate for probiotic of improving colonic barrier damage and associated diseases.

Dietary 3-aminobenzoic acid enhances intestinal barrier integrity and attenuates experimental colitis

Disruption of intestinal epithelial integrity and increased permeability is central to the pathogenesis of ulcerative colitis (UC). In this study, we identified 3-aminobenzoic acid (3-ABA), a dietary component abundant in azuki beans, soybeans, and chickpeas as a regulator of epithelial permeability and inflammation in the colon. Screening 119 gut microbial metabolites revealed the ability of 4-ABA, a structural isomer of 3-ABA, to enhance barrier function in Caco2 cells. Further analysis of structural isomers identified 3-ABA as the most effective, significantly increasing transepithelial electrical resistance and reducing epithelial permeability. Using liquid chromatography-mass spectrometry, 3-ABA was detected in dietary beans and human fecal samples. Fecal 3-ABA levels were significantly lower in patients with UC compared with healthy individuals. Metagenomic and functional prediction analyses revealed dysbiosis in patients with UC, characterized by an enrichment of bacterial genes involved in ABA degradation. Gene expression analysis of 3-ABA-stimulated Caco2 cells demonstrated upregulation of tight junction molecules, such as CLDN1 and TJP1, enhancing epithelial barrier integrity. In a dextran sodium sulfate-induced colitis mouse model, rectal 3-ABA administration ameliorated colitis by enhancing epithelial barrier function and reducing inflammation. These findings highlight 3-ABA's potential as a dietary therapeutic agent for UC, offering a novel strategy to enhance intestinal integrity and mitigate inflammation.NEW & NOTEWORTHY Increased intestinal epithelial permeability is central to the pathogenesis of ulcerative colitis (UC). 3-Aminobenzoic acid (3-ABA), a dietary component abundant in beans, decreased epithelial permeability and attenuated colonic inflammation in a mouse experimental colitis model. Reduced fecal 3-ABA levels in patients with UC were associated with dysbiosis-driven accelerated degradation. These findings highlight the therapeutic potential of 3-ABA in UC by targeting colonic epithelium.

Probiotics: a promising future in the treatment of ulcerative colitis?

Ulcerative colitis is an idiopathic and chronic inflammatory bowel disease, characterized by inflammation of the mucosa of the colon and rectum. Clinical manifestations commonly include abdominal pain, diarrhea (with or without hematochezia), and weight loss. The pathogenesis of ulcerative colitis is multifactorial, involving a combination of genetic predispositions and lifestyle factors. High consumption of processed food, sedentary habits, alcohol intake, and stress are among the lifestyle factors implicated in disease onset and progression. Current treatment strategies focus on managing symptoms and inducing remission, however, the chronic nature of the disease, along with the adverse effects of conventional therapies, often compromises patient's quality of life. Therefore, exploring alternative therapies that can prolong remission and reduce symptom burden is important. Experimental evidence suggests that probiotics may extend remission duration in ulcerative colitis. Moreover, probiotics exhibit efficacy in amelioration clinical symptoms by reducing inflammation markers, preserving, and restoring intestinal epithelial. This review explores the advantages of the administration of probiotics in the treatment of ulcerative colitis, elucidating their mechanism of action.

Ameliorative effect of "intestinal-vaginal" probiotics on 5-fluorouracil-induced microbial dysbiosis in colorectal cancer

The interaction between the gut microbiome and cancer chemotherapy has been extensively studied. However, the exact role of the vaginal microbiome in chemotherapy remains unknown. To address this issue, we established a colorectal cancer chemotherapy mouse model. Here, we confirmed that 5-fluorouracil induced dysbiosis in both the vaginal and gut microbiomes, presenting a new challenge for conventional chemotherapy. Therefore, we innovatively propose an "intestinal-vaginal" probiotics administration strategy, which involves the simultaneous delivery of probiotics to both the gut and vagina, aiming to enhance chemotherapy efficacy while alleviating dysbiosis and associated side effects. Our results indicate that, compared to gut-only probiotic intervention, "intestinal-vaginal" probiotics administration significantly enhanced the anticancer efficacy of 5-fluorouracil by upregulating the p53 pathway. Furthermore, regarding gastrointestinal side effects, "intestinal-vaginal" probiotics more effectively reduced the release of vomit-associated neurotransmitters (e.g., 5-HT and SP), while also alleviating mucositis by downregulating the NF-κB pathway. Additionally, "intestinal-vaginal" probiotics outperformed the oral probiotic by increasing beneficial microbiota and reducing pathogenic bacteria. Notably, regarding vaginal side effects, "intestinal-vaginal" probiotics significantly inhibited the NF-κB inflammatory pathway and pro-apoptotic proteins, and improved vaginal dysbiosis compared to vaginal-only probiotics. These findings provide the first evidence of the significant potential of the "intestinal-vaginal" probiotics delivery approach as an adjunctive cancer therapy, which offers a novel perspective on the synergistic interactions between host microbiota communities.

Mechanism of hedysari radix praeparata cum melle and curcumae rhizoma herb pair in colitis-associated colorectal cancer through the MAPK/NF-κB signaling pathway: an investigation in vivo and in vitro

Introduction

Astragali Radix (AR) - Curcumae Rhizoma (vinegar processed, CR) herb pair was recorded in 'YIXUE ZHONGZHONG CANXILU' to treat colitis-associated colorectal cancer (CAC). Hedysari Radix (HR) was categorized under the AR entry in 'SHENNONG BENCAO JING'. HR is still an alternative to AR paired with CR clinically in northwest China. Hedysari Radix Praeparata Cum Melle (HRPCM) is a product that HR fries with honey to enhance the therapeutic effect. However, the mechanism of HRPCM paired with CR (HRCR) in CAC needs to be further elucidated.

Methods

HRCR-MIAS were prepared using the eversion intestinal sac method. UHPLC Q-Exactive-MS investigated the compositions in HRCR-MIAS. Then, the mechanism of HRCR in CAC mice was predicted based on network pharmacology analysis in combination with the compositions in HRCR-MIAS. The pharmacodynamic effects of HRCR-MIAS for SW620 colon cancer cells were invested in vitro. The efficacies of HRCR low-, middle-, and high-dose groups (HRCR-L, 3.413 g/kg; HRCR-M, 6.825 g/kg; HRCR-H, 13.650 g/kg) in CAC mice were explored. Enzyme-linked immunosorbent assay (ELISA) kits were employed to assay The inflammatory factors levels, like IL-1β, IL-6, IL-10, and TNF-α in serum. The expressions of the intestinal permeability proteins, such as Claudin-1, Occludin, and ZO-1, were detected via immunohistochemical (IHC) analysis. Finally, the predicted signalling was verified by Western blot (WB).

Results

855 common components were identified in HRCR and HRCR-MIAS, and 25 specific components in HRCR-MIAS were pointed out. Based on network pharmacology analysis, the inflammatory response and the cross-linked MAPK signalling and NF-kB signalling were predicted to be the main reasons for HRCR in CAC. HRCR-MIAS inhibited the proliferation, induced apoptosis, regulated the cell cycle progression, and restrained the SW620 cells' ability to migrate and invade in vitro. The outcomes of the WB experiment exhibited that HRCR-MIAS inhibited the expression of key proteins such as MEKK1, RAS, ERK, IKB and NF-kB in the MAPK/NF-kB signalling pathway of SW620 cells. The study in vivo found that the different doses of HRCR recovered the loss of body weight, the shortened colon length, the increased tumour counts, the abnormal changes in spleen and thymus indices, the colonic lesions, the unbalanced inflammatory factors levels like IL-10, IL-6, IL-1β, and TNF-α in serum, and the down-regulated intestinal permeability proteins such as Claudin-1, Occludin, and ZO-1. Experimental validation by WB confirmed that HRCR inhibited the expression of the key proteins, including MEKK1 RAS, ERK, IKB, and NF-kB, in the MAPK/NF-kB signalling in CAC mice.

Discussion

HRCR not only suppresses the process of colonic inflammation and improves intestinal permeability but also relieves CAC by inhibiting the activated MAPK/NF-kB signalling cascade to alleviate CAC.

IsoalloLCA-intervened regulatory T cell exosomes alleviate inflammatory bowel disease by inhibiting NF-κB-associated inflammation in intestinal epithelial cells

Regulatory T cells (Tregs) are the principal immune cells that exert anti-inflammatory effects within the organism. Their exosomes exhibit therapeutic efficacy across a broad spectrum of diseases owing to their high stability, low immunogenicity, and substantial penetration capacity. Recent research have indicated that isoallolithocholic acid (isoalloLCA), a metabolite associated with bile acid metabolism, may enhance Treg activity by upregulating forkhead box protein3 (Foxp3) expression. Hence, metabolite-based strategies for reinforcing Tregs may offer novel intervention options for treating related diseases. In this study, tumor necrosis factor (TNF)-α and dextran sulfate sodium (DSS) were employed to establish cellular and animal models of inflammatory bowel disease (IBD), further evaluating the therapeutic efficacy of isoalloLCA-intervened regulatory T cell exosomes (isoalloLCA-Exo) within this model. Our findings demonstrated that isoalloLCA-Exo effectively inhibit colitis progression in a murine model, as indicated by reduced inflammation, decreased apoptosis of intestinal epithelial cells, and improved intestinal barrier function. Furthermore, in vitro analyses elucidated the molecular mechanisms underlying the anti-inflammatory effects of isoalloLCA-Exo, revealing that the intervention effectively reversed TNF-α-induced inflammation and apoptosis in intestinal epithelial cells by modulating the NF-κB pathway. In conclusion, isoalloLCA-Exo can decelerate inflammatory bowel disease progression and suppress inflammatory response in intestinal epithelial cells by inhibiting NF-κB pathway. Notably, isoalloLCA-Exo exhibit superior efficacy to the traditional drug mesalazine and conventional treg exosome(NC-Exo). These findings have significant implications for optimizing Treg-derived exosome-based therapies for inflammation-related diseases.

Investigating the Impact of hsa_circ_0005255 on Proliferation and Autophagy in Crohn's Disease Intestinal Epithelial Cells Through miR-23a-3p-Mediated NCOA3 Expression

Crohn's Disease (CD), an inflammatory bowel disorder, is influenced by genetic, immune, and environmental factors. The present study highlights the pioneering role of circular RNAs (circRNAs) in the etiology of CD, with a specific focus on hsa_circ_0005255 and its regulatory role. Utilizing both bioinformatic and experimental approaches, we exposed the mechanistic and therapeutic significance of hsa_circ_0005255 within the pathophysiological framework of CD. Our findings revealed a significant underexpression of hsa_circ_0005255 in tissue samples from CD patients and in DSS-induced CD mouse models. The overexpression of hsa_circ_0005255 markedly mitigated inflammatory responses, as indicated by decreased serum levels of tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6, and reduced histopathological indications of inflammation in colonic tissues. It substantially improved the integrity of the epithelial barrier, evidenced by the upregulation of Zonula Occludens-1 expression and the reduction of apoptosis in colonic epithelial cells. Furthermore, this regulatory effect extended to the enhancement of epithelial cell proliferation and autophagy, characterized by the elevated expression of Ki-67, microtubule-associated protein 1A/1B-light chain 3 II, and Beclin-1, along with the suppression of cleaved caspase-3 and sequestosome 1. Mechanistically, hsa_circ_0005255 functioned as a competitive endogenous RNA, absorbing miR-23a-3p and thereby regulating Nuclear Receptor Coactivator 3. This investigation not only broadens our understanding of the involvement of circRNAs in CD pathogenesis but also identifies hsa_circ_0005255 as a potent biomarker and therapeutic target.

Plantamajoside alleviates DSS-induced ulcerative colitis by modulating gut microbiota, upregulating CBS, and inhibiting NF-κB

BACKGROUND

Plantamajoside (PMS) is a natural bioactive compound derived from medicinal, food homologous plants of the genus Plantago.

PURPOSE AND METHODS

This study aimed to investigate the protective effects of PMS on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice and explore the associated mechanisms.

RESULTS

We found that PMS treatment significantly alleviated UC symptoms in mice by preventing body weight loss, increasing colon length, and reducing disease activity index scores. Moreover, PMS alleviated colonic lesions, increased the number of goblet cells, upregulated the expression of intestinal barrier proteins (ZO-1, occludin, and claudin-3), and decreased the levels of pro-inflammatory factors. PMS treatment modulated the gut microbiota by increasing the relative abundance of Bacteroidota and Verrucomicrobiota and decreasing that of Firmicutes and Proteobacteria at the phylum level. At the genus level, PMS suppressed the abundance of pathogenic bacteria, such as Turicibacter and upregulated the abundance of [Eubacterium]_xylanophilum_group. Fecal microbiota transplantation experiments further confirmed that PMS treatment alleviated UC by modulating the gut microbiota. Transcriptomic analysis of colon tissues, coupled with reverse transcription-quantitative polymerase chain reaction and western blotting, showed that PMS treatment upregulated cystathionine beta-synthase (CBS) expression and inhibited NF-κB pathway activation. In a lipopolysaccharide-induced inflammation model in RAW264.7 cells, PMS treatment inhibited the secretion of pro-inflammatory cytokines, upregulated CBS expression, and prevented NF-κB pathway activation.

CONCLUSION

PMS protects against UC in mice via multiple mechanisms, including modulating the gut microbiota, increasing the expression levels of CBS, and inhibiting the NF-κB pathway.

Probiotic Administration Contributes to the Improvement in Intestinal Dysregulation Induced by Allergic Contact Dermatitis

Recent studies have emphasized the impact of gut microbiota on skin health, but the reverse, how skin diseases affect gut homeostasis, has received less attention. Allergic contact dermatitis (ACD), a common skin disorder affecting one in four people worldwide, can be accompanied by intestinal disturbances. To explore this, we used an experimental model of ACD to investigate the intestinal changes induced by the disease. Parameters assessed included intestinal microbiota, short-chain fatty acids (SCFAs), gene expression related to intestinal permeability, inflammatory cytokines, and mucus production. To evaluate potential therapeutic interventions, the probiotic Bifidobacterium longum strain BB536 was administered via gavage, starting 10 days before dermatitis induction and continuing until the last day of disease induction. ACD caused alterations in the composition of intestinal microbiota compared to naïve mice but did not affect SCFA production. The probiotic altered microbiota composition and increased acetate production in dermatitis-induced mice. ACD decreased the gene expression of TjP1, ATHO1, and MUC2, while probiotic treatment restored TjP1 and ATHO1 to normal levels. The cytokine IL-6 increased in the ACD group compared to naïve mice, whereas IL-10 decreased; probiotic treatment also restored these levels. Intestinal mucus production, affected by ACD, was partially restored by probiotic treatment. The findings suggest that probiotics could be a therapeutic strategy to prevent intestinal issues caused by skin diseases.

Biomimetic culture substrates for modelling homeostatic intestinal epithelium in vitro

The increasing interest in utilizing three-dimensional (3D) in vitro models with innovative biomaterials to engineer functional tissues arises from the limitations of conventional cell culture methods in accurately reproducing the complex physiological conditions of living organisms. This study presents a strategy for replicating the intricate microenvironment of the intestine by cultivating intestinal cells within bioinspired 3D interfaces that recapitulate the villus-crypt architecture and 3D tissue arrangement of the intestine. Intestinal cells cultured on these biomimetic substrates exhibited phenotypes and differentiation characteristics resembling intestinal-specific cell types, effectively replicating intestinal tissue. Notably, tissue proliferation and differentiation were achieved within 72-120 h-significantly faster than the several weeks required by conventional bioengineered materials, which often pose risks of tissue necrosis or cross-contamination. Additionally, the differentiated cells on these villi-crypts mimicking bio-interfaces exhibit higher production of natural antimicrobial peptides, resulting in reduced pathogenic infection compared to control samples. Furthermore, our method stands out for simplicity in fabrication, eliminating the need for cleanroom procedures and complex microfabrication techniques.

The role of brain-liver-gut Axis in neurological disorders

In recent years, with the increasing volume of related research, it has become apparent that the liver and gut play important roles in the pathogenesis of neurological disorders. Considering the interactions among the brain, liver, and gut, the brain-liver-gut axis has been proposed and gradually recognized. In this article, we summarized the complex network of interactions within the brain-liver-gut axis, encompassing the vagus nerve, barrier permeability, immunity and inflammation, the blood-brain barrier, gut microbial metabolites, the gut barrier, neurotoxic metabolites, and beta-amyloid (Aβ) metabolism. We also elaborated on the impact of the brain-liver-gut axis on various neurological disorders. Furthermore, we outline several therapies aimed at modulating the brain-liver-gut axis, including antibiotics, probiotics and prebiotics, fecal microbiota transplantation (FMT), vagus nerve stimulation (VNS), and dietary interventions. The focus is on elucidating possible mechanisms underlying neurological disorders pathogenesis and identifying effective treatments that are based on our understanding of the brain-liver-gut axis.

Therapeutic effect of Faecalibacterium longum CM04-06 on DSS-induced ulcerative colitis in mice

AIMS

This study explores the impact of Faecalibacterium longum CM04-06 on inflammatory bowel disease (IBD) by regulating gut microbiota in mice.

METHODS AND RESULTS

We reanalyzed the distribution of the CM04-06 genome in the metagenome of the IBD cohort and observed a significantly higher abundance of CM04-06 in healthy individuals compared to patients with UC or CD. The prophylactic administration of CM04-06 was evaluated for its effects on intestinal microbial diversity and community composition after a two-week trial in mice. The intestinal microbiota was characterized using metagenomic sequencing of fecal samples on the DNBSEQ platform. CM04-06 treatment resulted in a significant reduction in the Disease Activity Index (DAI) and histological scores, as well as a decrease in the levels of pro-inflammatory cytokines, including IL-1β, IL-6, and TNF-α, in both the colon and serum of DSS-induced mice. Furthermore, supplementation with CM04-06 significantly reduced the levels of pro-inflammatory cytokines in both the colon and serum. Additionally, CM04-06 enhanced the integrity of the intestinal epithelial barrier by increasing the expression of tight junction proteins and mucin. Moreover, we observed greater abundances of Faecalibaculum rodentium, Alistipes onderdonkii, Alistipes shahii, and Bifidobacterium animalis after CM04-06 treatment.

CONCLUSIONS

CM04-06 prevents and alleviates intestinal inflammation by modulating the composition of the microbiota community, increasing the abundance of beneficial probiotics, and suppressing pro-inflammatory cytokine levels.

β-1,3-glucans from Euglena Gracilis protects against ulcerative colitis via modulating the gut barrier, T-cell immunity and gut microbiota

Ulcerative colitis (UC) is characterized by impaired gut barrier, dysregulated immune responses and pronounced gut dysbiosis. Euglena gracilis (EG), rich in β-1,3-glucan (EGP), exhibits immunomodulatory properties, yet its effects on colitis and EGP's role as a core bioactive component are unclear. The aim of this study was to investigate the protective effects of EGP against UC by targeting gut barrier, T-cell immunity and gut microbiota. Results indicated that EG and EGP effectively improved the body weight, colon growth and reduced disease activity index of the DSS-induced mice. Both treatments also significantly suppressed the level of TNF-α and IL-6, restored gut barrier by upregulating ZO-1 and balanced Th17/Treg cells ratio. Microbiota analysis revealed EG and EGP reshaped gut microbiota composition, with an increase in beneficial strains, particularly within the Bacteroidota phylum. Metabolomics linked these changes to enhanced amino acid metabolism. Bacteroides fragilis, a Bacteroidota member, displayed similar anti-colitis bioactivity. In vitro fermentation with fecal samples from UC patients confirmed EGP's role in reshaping gut microbiota, increasing beneficial families such as Clostridiaceae and Lactobacillaceae, while enhancing tryptophan metabolism with anti-inflammatory indoles. These findings identify EGP as the core active component of EG, highlighting its potential in UC prevention through microbiota modulation, gut barrier support and immune regulation.

Improvement of chronic metabolic inflammation and regulation of gut homeostasis: Tea as a potential therapy

Chronic metabolic inflammation is a common mechanism linked to the development of metabolic disorders such as obesity, diabetes, and cardiovascular disease (CVD). Chronic metabolic inflammation often related to alterations in gut homeostasis, and pathological processes involve the activation of endotoxin receptors, metabolic reprogramming, mitochondrial dysfunction, and disruption of intestinal nuclear receptor activity. Recent investigations into homeostasis and chronic metabolic inflammation have revealed a novel mechanism which is characterized by a timing interaction involving multiple components and targets. This article explores the positive impact of tea consumption on metabolic health of populations, with a special focus on the improvement of inflammatory indicators and the regulation of gut microbiota. Studies showed that tea consumption is related to the enrichment of gut microbiota. The relative proportion of Firmicutes/Bacteroidetes (F/B) is altered, while the abundance of Lactobacillus, Bifidobacterium, and A. muciniphila increased significantly in most of the studies. Thus, tea consumption could provide potential protection from the development of chronic diseases by improving gut homeostasis and reducing chronic metabolic inflammation. The direct impact of tea on intestinal homeostasis primarily targets lipopolysaccharide (LPS)-related pathways. This includes reducing the synthesis of intestinal LPS, inhibiting LPS translocation, and preventing the binding of LPS to TLR4 receptors to block downstream inflammatory pathways. The TLR4/MyD88/NF-κB p65 pathway is crucial for anti-metaflammatory responses. The antioxidant properties of tea are linked to enhancing mitochondrial function and mitigating mitochondria-related inflammation by eliminating free radicals, inhibiting NLRP3 inflammasomes, and modulating Nrf2/ARE activity. Tea also contributes to safeguarding the intestinal barrier through various mechanisms, such as promoting the synthesis of short-chain fatty acids in the intestine, activating intestinal aryl hydrocarbon receptor (AhR) and farnesoid X receptor (FXR), and improving enteritis. Functional components that improve chronic metabolic inflammation include tea polyphenols, tea pigments, TPS, etc. Tea metabolites such as 4-Hydroxyphenylacetic acid and 3,4-Dihydroxyflavan derivatives, etc., also contribute to anti-chronic metabolic inflammation effects of tea consumption. The raw materials and processing technologies affect the functional component compositions of tea; therefore, consuming different types of tea may result in varying action characteristics and mechanisms. However, there is currently limited elaboration on this aspect. Future research should conduct in-depth studies on the mechanism of tea and its functional components in improving chronic metabolic inflammation. Researchers should pay attention to whether there are interactions between tea and other foods or drugs, explore safe and effective usage and dosage, and investigate whether there are individual differences in the tea-drinking population leading to different effects of tea intervention. Ultimately, the application of tea drinking could be a universal therapy for regulating intestinal homeostasis, anti-chronic metabolic inflammatory responses, and promoting metabolic health.

Platelet activation stimulates macrophages to enhance ulcerative colitis through PF4/CXCR3 signaling

Platelets are involved in hemostasis and immune regulation, but little is currently known regarding their role in inflammatory bowel disease. In the present study, the mechanism by which platelet activation affects macrophage C‑X‑C motif chemokine receptor 3 (CXCR3) by releasing platelet factor 4 (PF4), thus aggravating ulcerative colitis (UC) disease progression, was investigated. A dextran sulfate sodium‑induced mouse model showed co‑localization of the platelet marker PF4 with the macrophage M1 marker inducible nitric oxide synthase. Furthermore, co‑culturing platelets with monocytes (THP‑1) in vitro led to the transformation of monocytes into macrophages, as well as the activation of macrophages exhibiting proinflammatory properties. Meanwhile, reverse transcription‑quantitative PCR (RT‑qPCR) showed that inflammatory factors, such as IL‑1β, IL‑6 and TNF‑α were significantly increased in macrophages after platelet co‑culture. It was therefore hypothesized that the PF4/CXCR3 pathway may serve an important role in cell‑to‑cell communication. Furthermore, intervention with PF4 in THP‑1 cells induced the M1 macrophage phenotype and inflammatory cytokine expression, which was consistent with co‑culturing, whereas inhibition of CXCR3 (AMG487) reversed the effects of PF4. In addition, following treatment with PF4, THP‑1 cells were found to be under oxidative stress and apoptosis was enhanced, as determined by detecting reactive oxygen species, mitochondrial membrane potential and Annexin‑V, as well as the classical apoptotic proteins Bcl‑2/Bax/caspase‑3 through western blotting. In addition, changes in MAPK and NF‑κB, two classic inflammatory signaling pathways, were detected. Furthermore, mice were treated with an anti‑platelet medication or CXCR3 inhibitor to observe in vivo inflammatory changes; through phenotypic assessment, immunofluorescence staining, RT‑qPCR and TUNEL assay, it was demonstrated that the PF4/CXCR3 pathway may aggravate inflammation in mice with UC. In conclusion, platelets and macrophages may interact in UC through the PF4/CXCR3 pathway to exacerbate inflammation, providing novel options for the treatment of UC.

Polysaccharide from Atractylodes macrocephala Koidz. alleviates pyrotinib-induced diarrhea through regulating cAMP/LKB1/AMPK/CFTR pathway and restoring gut microbiota and metabolites

Polysaccharide from Atractylodes macrocephala Koidz. (PAMK), a bioactive component of Atractylodes macrocephala Koidz. (AMK), demonstrates a wide range of pharmacological activities, including the enhancement of gastrointestinal function and regulation of internal homeostasis. This study explores the potential of PAMK in alleviating pyrotinib-induced diarrhea and modulating gut microbiota and its metabolites. Pyrotinib is a tyrosine kinase inhibitor used in cancer treatment, is known for its side effect of diarrhea, which significantly diminishes patients' quality of life. Our prior research suggests that pyrotinib-induced diarrhea may be linked to CFTR-mediated dysregulation of chloride secretion. The present findings indicate that PAMK alleviates pyrotinib-induced diarrhea by reducing cAMP levels, activating the LKB1/AMPK pathway, and inhibiting CFTR activity, as confirmed by enzyme-linked immunosorbent assay (ELISA), qRT-PCR, and western blot analyses. PAMK effectively decreased CFTR-mediated chloride ion secretion in pyrotinib-treated cells, as shown by the MQAE assay. At specific doses, PAMK alleviated pyrotinib-induced diarrhea in rats and significantly restored intestinal barrier integrity. Furthermore, PAMK treatment rebalanced the gut microbiota, reversing the pyrotinib-induced increase in Clostridium and Erysipelotrichi species. Metabolomic profiling further highlighted the involvement of the AMPK signaling pathway. These findings provide a basis for future research aimed at developing cancer treatments with reduced side effects.

Chronic Exposure to Fluxapyroxad Exacerbated Susceptibility to Colitis in Mice via a Gut Microbiota-Indole Derivatives-Th17/Treg Cell Balance Axis

Fluxapyroxad is the most commonly used succinate dehydrogenase inhibitor fungicide. This work investigated its adverse effects on colitis susceptibility and explored the underlying mechanisms based on a mouse model. After 13 weeks of exposure at the acceptable daily intake (ADI) level, fluxapyroxad exacerbated the susceptibility to colitis, impaired the intestinal barrier, and elevated proinflammatory cytokines and chemokines of the colon in mice. It was found that this toxic effect was caused by the disruption of the gut microbiome. Specifically, the abundance of Lachnospiraceae and Muribaculaceae decreased, while Desulfovibrionaceae and Eggerthellaceae increased. Altered microbiota reduced fecal indole derivatives, including indole-3-lactic acid (ILA), indole-3-acetic acid (IAA), and indole-3-acrylic acid (IArA), inhibiting aryl hydrocarbon receptor (AHR) activation, disrupting immune homeostasis by overactivating Th17 cells and insufficient Treg cell differentiation, and causing mild colonic inflammation. Oral antibiotic-treated mice and fecal transfer experiments validated the pathway. Susceptibility to colitis induced by fluxapyroxad was not detected in the oral antibiotic-treated mice. Fecal transfer of the disordered gut microbiota caused by fluxapyroxad could aggravate the severity of colitis in recipient oral antibiotic-treated mice that did not receive fluxapyroxad exposure. In conclusion, chronic fluxapyroxad exposure at the ADI level exacerbated colitis via a gut microbiota-indole derivatives-Treg/Th17 cell balance axis, offering a new risk assessment perspective of fluxapyroxad.

Genomic Characterization and Functional Evaluation of Eurotium cristatum EC-520: Impacts on Colon Barrier Integrity, Gut Microbiota, and Metabolite Profile in Rats

Eurotium cristatum (EC), the dominant fungus in Fuzhuan brick tea, has significant applications in food fermentation and pharmaceutical industries, exhibiting probiotic properties, but further investigation of its intestinal benefits is required. This study characterized the EC-520 strain through whole genome sequencing and evaluated its effects on rat colons using histomorphology, 16S rRNA sequencing, and untargeted metabolomics. The genomic analysis revealed that EC-520 possessed a 28.37 Mb genome distantly related to Aspergillus flavus. The 16S results demonstrated that EC-520 significantly increased the abundance of Bacteroidota (p < 0.05) while decreasing the Proteobacteria and Firmicutes/Bacteroidota ratio (the F/B ratio); at the genus level, it elevated Muribaculaceae and Clostridia_UCG-014 while reducing harmful bacteria. The metabolomic results showed that EC-520 also significantly altered tryptamine, caproic acid, isocaproic acid, and erucic acid (p < 0.05). Additionally, the Spearman's correlation analysis revealed that Muribaculaceae_unclassified and Clostridia_UCG-014_unclassified were significantly positively correlated with tryptamine, caproic acid, isocaproic acid, and erucic acid. Therefore, this study suggested that EC-520 enhanced the colon barrier and increased the abundance of Muribaculaceae_unclassified and Clostridia_UCG-014_unclassified, thus promoting the secretion of tryptamine and affecting the release of 5-hydroxytryptamine (5-HT). It also promoted the secretion of certain fatty acids, enhancing the balance of the colonic microbiota. This study provides a new view for a comprehensive understanding of EC's regulatory role in the colon.

Exploring the tissue distribution propensity of active alkaloids in normal and stomach heat syndrome rats following oral administration of Zuojin Pill based on pharmacokinetics and mass spectrometry imaging

ETHNOPHARMACOLOGICAL RELEVANCE

Zuojin Pill (ZJP) is a traditional Chinese medicine (TCM) formula composed of Coptidis Rhizoma and Euodiae Fructus in a ratio of 6:1 (w/w), which has been widely used for treating gastrointestinal disorders, especially stomach heat syndrome (SHS). However, the active alkaloids in ZJP showed low plasma exposure in rats following oral administration, which failed to explain their potent pharmacological effects, thereby limiting further mechanism studies.

AIM OF THE STUDY

This study aimed to investigate the in vivo exposure and tissue distribution propensities of the active alkaloids in normal and SHS rats following oral administration of ZJP.

MATERIAL AND METHODS

A rat model of SHS was induced by oral administration of chili pepper decoction and anhydrous ethanol. Then, the plasma and tissue pharmacokinetics of active alkaloids, including four protoberberine alkaloids (PBAs) and three indole alkaloids (IDAs), were investigated following oral administration of ZJP. Furthermore, desorption electrospray ionization mass spectrometry imaging (DESI-MSI) was employed to characterize the spatial distribution of active alkaloids in the stomach and liver. Western blot and immunofluorescence were used to evaluate the gastric mucosal barrier integrity.

RESULTS

Based on the tissue-to-plasma partition coefficient (Kp) values, the in vivo exposure levels of berberine (BBR), palmatine (PAL), coptisine (COP), and dehydroevodiamine (DHE) were found to be higher in tissues than in plasma, indicating a distinct tissue distribution propensity. Each alkaloid displayed the highest exposure in the gastrointestinal tissues, due to local penetration facilitated by its direct contact with the mucosal lining. Pathological states reduced the overall exposure of PBAs in the gastric mucosa. In non-gastrointestinal tissues, most alkaloids, especially BBR and COP, exhibited a potent liver distribution propensity with minimal impact from pathological states. According to DESI-MSI results, PBAs showed high exposure in the damaged regions of gastric mucosa, which was attributed to mucosal barrier damage and enhanced permeability. In the liver, PBAs were primarily localized in the parenchyma surrounding the central vein and portal area.

CONCLUSION

This study demonstrated the stomach and liver distribution propensity of the active alkaloids in ZJP, providing a scientific basis for these alkaloids as the pharmacodynamic material basis of ZJP against SHS from the perspective of drug exposure.

Enteromorpha prolifera soluble dietary fiber alleviates ulcerative colitis through restoration of mucosal barrier and gut microbiota homeostasis

Background

Ulcerative colitis (UC), a recurrent chronic colon inflammation, presents substantial therapeutic challenges due to the frequent adverse effects associated with conventional pharmacological treatments. These limitations underscore the critical need for developing alternative dietary interventions with improved safety profiles. The present study investigated the therapeutic potential of Enteromorpha prolifera soluble dietary fiber microparticles (EDFM) in UC management, focusing on restoring mucosal barrier integrity and modulating gut microbiota homeostasis.

Methods

EDFM was fabricated through aqueous extraction of E. prolifera soluble dietary fiber via boiling followed by spray-drying. A mouse UC model was induced by dextran sulfate sodium (DSS). The severity of UC was evaluated through daily disease activity index (DAI) scoring; quantification of pro-inflammatory cytokines (TNF-α, IL-1β) via ELISA; histopathological analysis of colon sections with H&E staining; immunofluorescence detection of tight junction proteins (ZO-1, occludin); and 16S rRNA sequencing for gut microbiota.

Results

EDFM treatment significantly reduced the expression of pro-inflammatory cytokines (TNF-α and IL-1β), enhanced the expression of tight junction proteins (ZO-1 and occludin), and stimulated mucin (MUC2) production. Additionally, EDFM promoted the proliferation of beneficial probiotics (Alloprevotella, Lachnospiraceae_NK4A136_group, and Ruminococcaceae_UCG-014), while inhibiting pathogenic bacteria (Escherichia-Shigella, Parabacteroides, Rikenellaceae_RC9_gut_group, Odoribacter, and [Ruminococcus]_torques_group).

Conclusion

EDFM supplementation significantly ameliorates UC through dual modulation of gut microbiota and intestinal barrier integrity, indicating its potential as a functional food ingredient for UC prevention and treatment.

Probiotic Potential of Pediococcus pentosaceus M6 Isolated from Equines and Its Alleviating Effect on DSS-Induced Colitis in Mice

Colitis in equines has high morbidity and mortality rates, which severely affects the development of the equine-breeding industry. With the issuance of antibiotic bans, there is an urgent need for healthier and more effective alternatives. In recent years, probiotics have been widely used as microbial feed additives in animal husbandry, playing a crucial role in preventing and treating diarrhea and regulating host immune function. In this study, we isolated and screened a strain with rapid and stable acid production using bromocresol purple, litmus milk coloration tests, and acid production performance assessments. Based on morphological characteristics, physiological and biochemical properties, and 16S rDNA identification, the strain was identified as Pediococcus pentosaceus and named M6. The Pediococcus pentosaceus M6 exhibited stable growth and tolerance to high temperatures, acid and bile salt concentrations, and simulated gastrointestinal fluid environments. The M6 strain demonstrated good antibacterial effects against Escherichia coli, Staphylococcus aureus, and Salmonella. The M6 strain did not produce hemolysis zones on Columbia blood agar plates, indicating its high safety, and was found to be insensitive to 12 antibiotics, including cephalexin and neomycin. Additionally, intervention in mice with dextran sulfate sodium (DSS)-induced colitis alleviated weight loss and shortened colon length. To a certain extent, it regulated the expression of inflammatory cytokines and the gut microbiota within the body and reduced inflammatory cell infiltration and intestinal barrier damage. In summary, the isolated Pediococcus pentosaceus M6 strain exhibited excellent probiotic properties and could alleviate DSS-induced colitis in mice, suggesting its potential application value as a probiotic in animal husbandry.

Exploring the role of gut microbiota modulation in the long-term therapeutic benefits of early MSC transplantation in MRL/lpr mice

BACKGROUND

Systemic lupus erythematosus (SLE), influenced by gut microbiota dysbiosis, is characterized by autoimmune and inflammatory responses. Human umbilical cord-derived mesenchymal stem cell (hUC-MSC) transplantation is an effective and safe treatment for refractory or severe SLE; however, the long-term efficacy and mechanisms of early hUC-MSC therapeutic benefits in SLE need further investigation.

METHODS

Here, lupus-prone MRL/MpJ-Faslpr (MRL/lpr) mice were divided into three groups: the control (Ctrl) group received saline injections, while the MSC and MSC-fecal microbiota transplantation (FMT) groups received early hUC-MSC transplants at weeks 6, 8, and 10. The MSC-FMT group also underwent FMT from the Ctrl group between weeks 9 and 13.

RESULTS

Our results showed that early MSC treatment extended therapeutic effects up to 12 weeks, reducing autoantibodies, proinflammatory cytokines, B cells, and improving lupus nephritis. It also modulated the gut microbiota, increasing the abundance of beneficial bacteria, such as Lactobacillus johnsonii and Romboutsia ilealis, which led to higher levels of plasma tryptophan and butyrate metabolites. These metabolites activate the aryl hydrocarbon receptor (AHR), upregulate the Cyp1a1 and Cyp1b1 gene, enhance the zonula occludens 1 (ZO-1) protein, promote intestinal repair, and mitigate SLE progression. Notably, FMT from lupus mice significantly reversed hUC-MSC benefits, suggesting that the modulation of the gut microbiota plays a crucial role in the therapeutic response observed in MRL/lpr mice.

CONCLUSIONS

This research innovatively explores the early therapeutic window for MSCs in SLE, highlighting the partial mechanisms through which hUC-MSCs modulate the gut microbiota-tryptophan-AHR axis, thereby ameliorating SLE symptoms.

Molecular and Functional Recovery of Esophageal Barrier Integrity After Laparoscopic Anti-reflux Surgery

BACKGROUND

Patients undergoing laparoscopic anti-reflux surgery (LARS) often experience improved quality of life and reduced gastroesophageal reflux disease (GERD) symptoms. This study aimed to assess the impact of LARS on epithelial remodeling and repair in the esophageal mucosa.

METHODS

Upper gastrointestinal (GI) endoscopy was performed once on healthy controls (HC) and twice on GERD patients before and approximately 6 month after surgery, with esophageal biopsies collected. The expressions of E-cadherin (ECAD), Occludin (OCLN), Claudin 1 (CLDN1), Claudin 4 (CLDN4), Zonula Occludens -1 (ZO-1), and ZO-2 were analyzed in the biopsies, and dilated intercellular spaces (DIS) were examined under light microscopy.

RESULTS

The study included 22 GERD patients who were underwent for LARS, and 20 HCs. All patients had pathological reflux episodes. In the Post-LARS group, TEER increased significantly compared to Pre-LARS and HC (p < 0.05), while mucosal permeability decreased (p < 0.05). A significant negative correlation was found between TEER and permeability (p = 0.0002). DIS remained dilated in both Pre- and Post-LARS patients compared to HC (p < 0.05). Gene expression analysis revealed significant increases in ZO-1, OCLN, and ZO-2 Post-LARS (p < 0.05).

CONCLUSION

LARS improves mucosal integrity by enhancing TEER and reducing permeability in GERD patients, although DIS remains unchanged. The upregulation of tight junction genes such as ZO-1 and OCLN Post-LARS suggests that surgical intervention may support epithelial barrier restoration. DIS remains dilated after LARS; this might be reason that it is not an early marker in GERD pathogenesis. These findings enhance our understanding of GERD nature and may inform future target therapeutic strategies.

MCT4 inhibition attenuates inflammatory response to Mycobacterium avium paratuberculosis infection and restores intestinal epithelial integrity in vitro

Introduction

Mycobacterium avium paratuberculosis (MAP) plays a significant role in Crohn's disease (CD). Monocarboxylate transporter 4 (MCT4) is a proton-coupled symporter of lactate that facilitates the inflammatory shift in macrophages and increases their reliance on glycolysis. MCT4 is also involved in the negative regulation of intestinal epithelial barrier function.

Methods

In this in vitro study, we examined the role of MCT4 in macrophages and its effect on intestinal epithelial homeostasis during MAP infection. We used cultured THP-1 macrophages infected with a clinical strain of MAP (UCF4) as well as intestinal cell lines, Caco-2 and HT-29. MCT4 was inhibited using α-cyano-4-hydroxycinnamic acid (CHCα).

Results

Infection of THP-1 cells with MAP upregulated MCT4 expression (2 folds) and resulted in a significant increase in lactate export (1.3 folds), TNFα (13.8 folds), and IL-6 (1.3) via TLR2 activation. Consequently, intestinal damage markers were also upregulated, including MUC2 (2.5 folds), NOX-1 (2 folds), SERPINE1 (2.1 folds), IL-6 (1.6 folds), and CLDN2 (1.4 folds). Inhibition of MCT4 during MAP infection with CHCα significantly reduced TNF-α and IL-6 levels. This effect on macrophages restored baseline oxidative status and mucin production in HT-29 intestinal cells. Moreover, MCT4 inhibition in a MAP-infected THP-1-Caco-2 co-culture system restored IL-6 and SERPINE1 to normal levels and enhanced tight junction protein, TJP1 (ZO-1), expression.

Conclusion

Collectively, this study revealed the significant role of MCT4 in CD pathophysiology during MAP infection and highlighted MCT4 as a potential therapeutic target for CD treatment.

Balance between bile acid conjugation and hydrolysis activity can alter outcomes of gut inflammation

Conjugated bile acids (BAs) are multi-functional detergents in the gastrointestinal (GI) tract produced by the liver enzyme bile acid-CoA:amino acid N-acyltransferase (BAAT) and by the microbiome from the acyltransferase activity of bile salt hydrolase (BSH). Humans with inflammatory bowel disease (IBD) have an enrichment in both host and microbially conjugated BAs (MCBAs), but their impacts on GI inflammation are not well understood. We investigated the role of host-conjugated BAs in a mouse model of colitis using a BAAT knockout background. Baat-/- KO mice have severe phenotypes in the colitis model that were rescued by supplementation with taurocholate (TCA). Gene expression and histology showed that this rescue was due to an improved epithelial barrier integrity and goblet cell function. However, metabolomics also showed that TCA supplementation resulted in extensive metabolism to secondary BAs. We therefore investigated the BSH activity of diverse gut bacteria on a panel of conjugated BAs and found broad hydrolytic capacity depending on the bacterium and the amino acid conjugate. The complexity of this microbial BA hydrolysis led to the exploration of bsh genes in metagenomic data from human IBD patients. Certain bsh sequences were enriched in people with Crohn's disease particularly that from Ruminococcus gnavus. This study shows that both host and microbially conjugated BAs may provide benefits to those with IBD, but this is dictated by a delicate balance between BA conjugation/deconjugation based on the bsh genes present.

A Cascade of Microbiota-Leaky Gut-Inflammation- Is it a Key Player in Metabolic Disorders?

PURPOSE OF REVIEW

This review addresses critical gaps in knowledge and provides a literature overview of the molecular pathways connecting gut microbiota dysbiosis to increased intestinal permeability (commonly referred to as "leaky gut") and its contribution to metabolic disorders. Restoring a healthy gut microbiota holds significant potential for enhancing intestinal barrier function and metabolic health. These interventions offer promising therapeutic avenues for addressing leaky gut and its associated pathologies in metabolic syndrome.

RECENT FINDINGS

In metabolic disorders such as obesity and type 2 diabetes (T2D), beneficial microbes such as those producing short-chain fatty acids (SCFAs) and other key metabolites like taurine, spermidine, glutamine, and indole derivatives are reduced. Concurrently, microbes that degrade toxic metabolites such as ethanolamine also decline, while proinflammatory, lipopolysaccharide (LPS)-enriched microbes increase. These microbial shifts place a higher burden on intestinal epithelial cells, which are in closest proximity to the gut lumen, inducing detrimental changes that compromise the structural and functional integrity of the intestinal barrier. Such changes include exacerbation of tight junction protein (TJP)s dysfunction, particularly through mechanisms such as destabilization of zona occludens (Zo)-1 mRNA or post-translational modifications. Emerging therapeutic strategies including ketogenic and Mediterranean diets, as well as probiotics, prebiotics, synbiotics, and postbiotics have demonstrated efficacy in restoring beneficial microbial populations, enhancing TJP expression and function, supporting gut barrier integrity, reducing leaky gut and inflammation, and ultimately improving metabolic disorders. This review summarizes the mechanisms by which gut microbiota contribute to the development of leaky gut and inflammation associated with metabolic syndrome. It also explores strategies for restoring gut microbiota balance and functionality by promoting beneficial microbes, increasing the production of beneficial metabolites, clearing toxic metabolites, and reducing the proportion of proinflammatory microbes. These approaches can alleviate the burden on intestinal epithelial cells, reduce leaky gut and inflammation, and improve metabolic health.

Fluxapyroxad induces chronic colonic inflammation via inhibiting intestinal aryl hydrocarbon receptors in mice

Fluxapyroxad, the most extensively utilized succinate dehydrogenase inhibitor (SDHI) fungicide, lacks comprehensive research on potential risks associated with chronic toxicity. To investigate its effects on chronic colonic inflammation and elucidate the underlying mechanisms, a mouse model was employed to assess oral exposure to fluxapyroxad at no observed adverse effect level (NOEL) for 13 weeks, in vitro and in silico models were utilized as well. The results revealed reduced body weight gain, colon length reduction, crypt damage, goblet cell loss in the colon, impaired intestinal barrier integrity, and an elevation of proinflammatory cytokines, including IL-6, IL-1β, and TNF-α following fluxapyroxad exposure in mice. These findings suggested that fluxapyroxad induced chronic colonic inflammation. Furthermore, fluxapyroxad decreased interleukin 22 levels and antibacterial peptide secretion by inhibiting Aryl hydrocarbon receptors (AhR) activation, which was confirmed in vitro experiments. Molecular docking analysis indicated that fluxapyroxad spontaneously formed halogen bonds and bound hydrophobic interactions with AhR, which might act as an AhR inhibitor. These results indicated that AhR inhibition may represent one of the primary mechanisms for chronic colonic inflammation induced by fluxapyroxad exposure. This study shed light on the association between low acute pesticide exposure to fluxapyroxad and chronic colonic inflammation development while contributing to pesticide safety assessment.

Proteomic analysis reveals that Acalypha australis L. mitigates chronic colitis by modulating the FABP4/PPARγ/NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Acalypha australis L. (AAL), a traditional medicinal herb from the Euphorbiaceae family, has been widely used in Chinese medicine for its heat-clearing, detoxifying, and diuretic properties, as well as for treating gastrointestinal disorders such as diarrhea and dysentery. Its reported anti-inflammatory and hemostatic effects are closely linked to inflammatory pathways. While previous studies have demonstrated AAL's efficacy in acute colitis, its therapeutic potential in chronic colitis and the underlying mechanisms remain largely unexplored.

AIM OF THE STUDY

This study aims to investigate the therapeutic efficacy of AAL in dextran sulfate sodium (DSS)-induced chronic colitis and elucidate its anti-inflammatory and barrier-protective mechanisms, with a specific focus on the FABP4/PPARγ/NF-κB signaling pathway.

MATERIALS AND METHODS

The chemical composition of AAL was characterized using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). Chronic colitis was induced in mice through three cycles of DSS administration, and the therapeutic effects of AAL were evaluated by assessing body weight, Disease Activity Index (DAI), colon length, and pathological alterations. Enzyme-linked immunosorbent assay (ELISA) was used to quantify inflammatory cytokine levels. Immunohistochemistry and Western blotting were performed to assess mucosal barrier proteins, including Mucin 2 (MUC2), zonula occludens-1 (ZO-1), and Occludin, as well as key signaling proteins such as fatty acid-binding protein 4 (FABP4), peroxisome proliferator-activated receptor gamma (PPARγ), and phosphorylated P65 (p-P65). Proteomic analysis combined with Gene Set Enrichment Analysis (GSEA) was conducted to identify differentially expressed proteins and enriched pathways. The role of the FABP4/PPARγ/NF-κB axis was further validated using the PPARγ antagonist GW9662. Additionally, molecular docking and molecular dynamics simulations were employed to identify bioactive components in AAL and their interactions with FABP4 and PPARγ.

RESULTS

UPLC-QTOF-MS analysis identified 47 compounds in AAL, including flavonoids, terpenoids, and polyphenols. Bergaptol and corilagin were identified as major constituents with potential anti-inflammatory properties. AAL treatment significantly alleviated chronic colitis symptoms, as evidenced by reduced DAI scores, restoration of body weight, and improved colon length. Pathological and immunohistochemical analyses demonstrated that AAL preserved intestinal mucosal integrity by upregulating MUC2, ZO-1, and Occludin expression. Proteomic and GSEA analyses identified the FABP4/PPARγ/NF-κB pathway as a key target of AAL. Western blotting confirmed that AAL suppressed FABP4 expression, enhanced PPARγ levels, and reduced p-P65 expression, indicating inhibition of NF-κB activation. Notably, the therapeutic effects of AAL were abolished by GW9662, further validating the involvement of PPARγ signaling. Molecular docking and molecular dynamics simulations demonstrated strong binding affinities of bergaptol and corilagin to FABP4 and PPARγ, suggesting their role as active compounds responsible for AAL's therapeutic effects.

CONCLUSIONS

AAL effectively mitigates chronic colitis by preserving intestinal barrier integrity, suppressing inflammatory responses, and modulating the FABP4/PPARγ/NF-κB pathway. The bioactive compounds bergaptol and corilagin may contribute to these therapeutic effects, highlighting AAL as a promising natural therapeutic agent for ulcerative colitis.

Gut microbiota in cancer: From molecular mechanisms to precision medicine applications

The gut microbiota-cancer interaction functions through multi-level biological mechanisms, forming the basis for both diagnostic and therapeutic applications. Current technical and biological challenges drive the field toward precision medicine approaches, aiming to integrate multi-dimensional data for optimized, personalized cancer treatments.

Mechanisms of the effects of turpiniae folium extract on growth performance, immunity, antioxidant activity and intestinal barrier function in LPS-challenged broilers

Turpiniae folium extract (TFE) has shown anti-inflammatory and immunomodulatory effects in broilers. However, its mechanisms remain unclear. The aim of this study is to investigate the underlying mechanisms by which TFE influences growth performance, jejunal morphology, immune function, antioxidant capacity and barrier integrity in broilers challenged with Lipopolysaccharide (LPS). A total of 240 one-day-old female broilers were randomly divided into four groups with six replicates of ten birds each. A 2 × 2 factorial design with TFE (basal diets supplemented with 0 or 500 mg/kg TFE) and LPS challenge (intraperitoneal injection of 1 mg/kg body weight of sterile saline or LPS at 21, 23 and 25 days of age). The trial lasted for 26 days. The results showed that: Prior to the LPS challenge, dietary supplementation with TFE for 21 days increased both average daily gain (ADG) (P = 0.037) and average daily feed intake (ADFI) (P = 0.045) in broilers. During the LPS challenge period, LPS challenge led to a decline in growth performance and a negative impact on intestinal morphology, while TFE supplementation significantly reversed these adverse effects, as evidenced by increases in ADG (P = 0.004), ADFI (P = 0.046), jejunal villus height (VH) (P = 0.035), the villus height to crypt depth ratio (VH/CD) (P = 0.007) and decreases in the feed-to-gain ratio (F/G) (P = 0.025), jejunal crypt depth (CD) (P = 0.049). LPS induced inflammatory responses and oxidative stress in the jejunum, leading to a significant upregulation of pro-inflammatory factor gene and protein expression, and a marked downregulation of anti-inflammatory and antioxidant gene and protein expression. TFE supplementation mitigated these effects by yielding completely opposite results except for the expression of toll-like receptor 4 (TLR4) protein (P = 0.916). LPS negatively regulates the expression of genes and proteins involved in intestinal mucosal barrier function. In contrast, TFE supplementation significantly upregulated the expression of zonula occludens-1 (ZO-1) (P < 0.001) gene and ZO-1 (P < 0.001), occludin (OCLN) (P < 0.001), claudin (CLDN) (P < 0.001) proteins. In conclusion, dietary supplementation with TFE effectively counteracts the intestinal immune and oxidative stress induced by LPS challenge in broilers, improves intestinal mucosal barrier integrity and tissue morphology, and ultimately mitigates the negative impact of LPS on broiler growth performance. This effect may involve the modulation of the Nrf2 and nuclear factor kappa B (NF-κB) signaling pathways.

Alleviation effects of Lactobacillus plantarum in colitis aggravated by a high-salt diet depend on intestinal barrier protection, NF-κB pathway regulation, and oxidative stress improvement

A high-salt diet (HSD) can result in numerous health issues, including exacerbation of intestinal inflammation. Therefore, there is an immediate necessity of developing dietary supplements that can mitigate colitis exacerbated by a HSD. This study examined the impact of Lactobacillus plantarum HGD228 on colitis exacerbated by a HSD and the mechanisms underlying its alleviation. HGD228 treatment significantly enhanced colonic goblet cells and MUC2, upregulated ZO-1 and occludin, inhibited epithelial cell apoptosis, and mitigated colitis exacerbated by a HSD. Moreover, HGD228 significantly regulated oxidative stress-related enzymes, including SOD, GSH-PX, and CAT. HGD228 treatment significantly suppressed the NF-κB pathway induced by a HSD and regulated the levels of cytokines, including TNF-α, IL-10, and IL-1β. Furthermore, HGD228 reestablished the gut microbiota altered by HSDDSS, increasing Bifidobacterium while decreasing Escherichia-Shigella and Clostridium sensu stricto 1. HGD228 treatment also enhanced the production of butyric acid and acetic acid, suppressed pro-inflammatory cytokines, and strengthened the intestinal mucosal barrier. Therefore, HGD228 enhanced the production of beneficial metabolites by regulating inflammatory cytokines and oxidative stress, preserving the mucosal barrier, and enhancing gut microbiota, and mitigated colitis aggravated by a HSD. These results will aid in clinical trials of probiotics and the development of dietary supplements for colitis, with promising application value.

Gancao Xiexin decoction attenuated experimental colitis through suppressing ACSL4-mediated ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

The Gancao Xiexin decoction (GCXXD), comprising Glycyrrhiza glabra L., Pinellia ternata (Thunb.) Makino, Scutellaria baicalensis Georgi, Zingiber officinale Roscoe, Panax ginseng C.A.Mey. , Coptis chinensis Franch. , Ziziphus jujuba Mill. , represents a traditional Chinese medicinal formulation utilized for the treatment of ulcerative colitis (UC). Nevertheless, the potential mechanism behind GCXXD treatment for UC is not yet fully elucidated.

AIM OF THE STUDY

Ulcerative colitis is a chronic inflammatory disorder of the gastrointestinal system distinguished by intestinal barrier destruction. Previous studies have indicated that excessive ferroptosis activation in intestinal epithelial cells (IECs) can worsen damage and focal permeability abnormalities in the colon. One of the main mechanisms of ferroptosis is lipid peroxides, which are dependent on long-chain acyl-CoA synthetase 4 (ACSL4) for the synthesis of membrane phospholipids. Recent research findings have provided evidence that GCXXD significantly reduces the symptoms of ulcerative colitis (UC) by preserving the intestinal mucosal barrier. So, we aim to demonstrate that the pharmacological mechanism of GCXXD is related to ferroptosis mediated by ACSL4 in this research.

MATERIALS AND METHODS

In this investigation, we evaluated the GSE134025 datasets and established an experimental colitis model caused by DSS and treated with a 20 mg/kg ACSL4 inhibitor (rosiglitazone). Colon pathological alterations and Alcian blue staining were used to confirm ACSL4 inhibition as a possible therapy for UC. We then examined illness symptoms, intestinal mucosa repair, and ferroptosis markers in UC mice after treated with GCXXD (9,12,15 g/kg). Transcriptome study of colon tissues revealed more about the underlying mechanism of GCXXD in the treatment of UC. Finally, we co-administered the ACSL4 upstream agonist with GCXXD in the treatment of UC to show that GCXXD reduced inflammation in UC by modifying ACSL4-induced ferroptosis.

RESULTS

Through GSE134025 dataset analysis, we discovered that ACSL4 was substantially expressed in UC patients and that its inhibitors successfully reduced the clinical signs and symptoms of UC colon. Furthermore, we found that GCXXD improved colon length and body weight while increasing the expression of mucin, occuldin, and Claudin-1. It also lowered colon inflammatory cell infiltration and levels of IL-1β and TNF-α. In the meantime, GCXXD efficiently decreased ferroptosis-related indicators in colitis mice, such as MDA, Fe2+, COX2, and ACSL4, while also upregulated GPX4 expression. Using KEGG analysis of the genes that were differently expressed between the 3% DSS and GCXXD treatment group, we were able to discover important connections between the hippo signaling pathway, Arachidonic acid metabolism with GCXXD treatment. Due to the fact that TEAD4 functions as an upstream transcription factor for ACSL4, we combined GCXXD and Py-60, a YAP agonist in the treatment of UC. It was worth noting that GCXXD's inhibitory effect of on intestinal mucosa damage and ferroptosis was lessened when the ACSL4 upstream pathway was activated.

CONCLUSION

Gancao Xiexin decoction attenuated ferroptosis in UC which might through TEAD4/ACSL4 pathway.

Protective Effects of a Polyherbal Mixture on Intestinal Injury via the NF-κB Signaling Pathway and Gut Microbiota Modulation in Hyperuricemic Mice

This study investigated the protective effects of a polyherbal tea (PHT) on intestinal injury in hyperuricemia (HUA) mice and the underlying mechanisms. PHT was orally administered to mice for 49 days, while potassium oxonate and hypoxanthine were administered 7 days after PHT administration and continued for 42 days to cause HUA. Treatment with PHT significantly reduced serum uric acid and blood urea nitrogen levels in HUA mice. It also inhibited liver xanthine oxidase activity and promoted intestinal uric acid excretion through the upregulation of transporters GLUT9 and ABCG2. Intestinal barrier integrity was reinforced, as evidenced by the restoration of the villous structure, reduction in edema, and upregulation of tight junction proteins (occludin, ZO-1) and mucin (MUC2). Moreover, PHT suppressed serum LPS levels and inhibited the NF-κB pathway, leading to a reduction in TNF-α and IL-6 levels in the gut. Gut microbiota analysis revealed PHT reversed dysbiosis, enriching beneficial bacteria like Duncaniella sp. and Heminiphilus faecis. By UPLC-MS analysis, 154 compounds of PHT persisted in the gut, suggesting that these compounds are likely to modulate both intestinal barrier function and gut microbiota. These findings suggest that this PHT may have potential as a functional food for the prevention of hyperuricemia.

Recent Advances in the Application of Hydrogels as Drug Carriers in Inflammatory Bowel Disease: A Review

Inflammatory bowel disease (IBD) is a chronic and refractory disease with increasing incidence, adversely impacting millions of patients worldwide. Current therapeutic strategies for IBD often exhibit considerable adverse effects, limited efficacy, and a high tendency for recurrence, highlighting the urgent need for novel therapeutic agents. Hydrogel, a three-dimensional hydrophilic network polymer material known for its excellent biocompatibility and responsiveness to stimuli, has been effectively utilized as a drug carrier across various therapeutic systems. The hydrogels' application in IBD treatment holds significant promise for enhancing therapeutic outcomes. This review synthesizes recent advancements in leveraging hydrogels as drug carriers for IBD management. The discussion encompasses the response mechanisms of hydrogels, their application in IBD therapy, and methods of administration. As drug delivery matrices, hydrogels exhibit considerable potential for treating IBD.

Korean Mistletoe (Viscum album var. coloratum) Ethanol Extracts Enhance Intestinal Barrier Function and Alleviate Inflammation

Korean mistletoe (Viscum album var. coloratum, KML) offers remarkable therapeutic potential for a variety of diseases. This study aims to evaluate the effects and potential molecular mechanisms of KML ethanol extracts (KMLE), focusing on intestinal barrier function and tight junctions (TJs) in an interleukin (IL)-6-induced Caco-2 cell monolayer model and a dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) mouse model. KMLE is non-cytotoxic in Caco-2 cells and demonstrated strong antioxidant activity. KMLE alleviated significant barrier dysfunction and protected tight junction proteins (TJPs) in vitro. Furthermore, KMLE alleviated clinical symptoms and histopathological damage, upregulated TJPs, and suppressed the inflammatory cytokines in vivo. Additionally, six bioactive compounds were identified in KMLE by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In conclusion, KMLE ameliorated intestinal barrier dysfunction in vitro and in vivo. These findings underscore the potential of KMLE as a therapeutic agent for UC, providing insights into the mechanisms through anti-inflammatory properties and its ability to restore TJ integrity.

CKMT1 deficiency contributes to mitochondrial dysfunction and promotes intestinal epithelial cell apoptosis via reverse electron transfer-derived ROS in colitis

Mitochondrial dysfunction contributes to the pathogenesis of ulcerative colitis (UC). As a mitochondrial isozyme of creatine kinases, which control energy metabolism, CKMT1 is thought to be a critical molecule in biological processes. However, the specific role of CKMT1 in intestinal inflammation remains largely unknown. Here, we observed markedly decreased CKMT1 expression in the colon tissues of UC patients and dextran sodium sulfate (DSS)-induced colitis mice. We generated intestinal epithelial-specific CKMT1 knockout mice and demonstrated the key role of CKMT1 in mitochondrial homeostasis, intestinal epithelial barrier function, oxidative stress, and apoptosis. In the in vitro experiments, CKMT1 expression limited the activation of the intrinsic and extrinsic apoptotic pathways in IECs. Mechanistically, the loss of CKMT1 expression in IECs increased TNF-α-induced mitochondrial reactive oxygen species (ROS) generation via reverse electron transfer (RET). RET-ROS promoted mitochondrial permeability transition pore (mPTP) opening, ultimately resulting in cell apoptosis during intestinal inflammation. In conclusion, our data demonstrated that CKMT1 is important in maintaining intestinal homeostasis and mitochondrial function. This study provides a promising basis for future research and a potential therapeutic target for inflammatory bowel disease (IBD).

Single-cell RNA sequencing revealed changes in the tumor microenvironment induced by radiotherapy for cervical cancer and the molecular mechanism of mast cells in immunosuppression

Radiotherapy (RT) is an important treatment for cervical cancer (CC), effectively controlling tumor growth and improving survival rates. However, radiotherapy-induced cell heterogeneity and its underlying mechanisms remain unclear, which may potentially impact treatment efficacy. This study aims to investigate tumor microenvironment changes following radiotherapy for CC, hoping to provide evidence to improve the therapeutic effects of radiotherapy. For the first time, we applied single-cell RNA sequencing (scRNA-seq) to analyze tissue samples from three CC patients pre- and post-radiotherapy. We obtained gene expression data from 52,506 cells to identify the cellular changes and molecular mechanisms induced by radiotherapy. Radiotherapy significantly alters cellular composition and gene expression within the tumor microenvironment (TME), notably upregulating mast cell expression. Mast cells are involved in multiple cell axes in the CC ecosystem after radiotherapy, and play a pivotal role in tumor immunosuppression and matrix remodeling. scRNA-seq revealed gene expression variations among cell types after radiotherapy, underscoring the importance of specific cell types in modulating the TME post-treatment. This study revealed the molecular mechanism of radiotherapy for CC and the role of mast cells, providing a foundation for optimizing the personalized treatment of CC.

Fuzi Lizhong Pill inhibited inflammatory response and promoted colon mucosal healing in dextran sulfate sodium-induced ulcerative colitis mice by down-regulating PI3K/AKT/NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Fuzi Lizhong Pill (FLP), a traditional Chinese herbal formula, has been historically used for treating gastrointestinal disorders characterized by cold deficiency patterns. Its application in ulcerative colitis (UC) stems from its warming and tonifying properties.

AIM OF THE STUDY

To evaluate the efficacy of FLP in the treatment of UC and investigate its mechanism of action.

MATERIALS AND METHODS

The chemical constituents of FLP were identified using UPLC-Q-Orbitrap HRMS. By establishing a preclinical UC mouse model with DSS and treating with FLP, we evaluated the effect of FLP on UC mice in terms of clinical symptoms, physiological indices, and histopathological examination. The anti-inflammatory and mucosal repair effects of FLP were examined at three levels: cellular, organoid, and animal, using immunohistochemistry, western blotting, RT-PCR, and other techniques.

RESULTS

We characterized the chemical composition of FLP and identified 99 compounds, including alkaloids, coumarins, and flavonoids. In UC mice, FLP alleviated clinical symptoms such as weight loss, blood in stools, and loose stools in UC mice; significantly reduced DAI scores in UC mice; significantly reversed splenomegaly and thymic atrophy caused by DSS; improved hemorrhage and inflammation-related hematological indices. In vitro and ex vivo studies showed that FLP inhibited the expression of TNF-α and IL-6, promoted the expression of the tight junction proteins ZO-1, Occludin, and Claudin 1, and promoted the proliferation of colonic epithelial cells in vivo. FLP also inhibited the transcription levels of PI3K, Akt, and NF-κB genes, as well as the expression or phosphorylation levels of related proteins in vitro and in vivo.

CONCLUSION

FLP may play a role in the treatment of UC by inhibiting the inflammatory response and repairing the colonic mucosal barrier by downregulating the PI3K/Akt/NF-κB signaling pathway.

Housed feeding improves rumen health by influencing the composition of the microbiota in Honghe cattle

Rumen is one of the most vital organs for the digestion of ruminants and is influenced by factors including feeding patterns and nutrition. How rumen microbiota and barrier function change are affected feeding patterns requires attention, particularly for beef cattle. In the present study, the Honghe cattle under grazing (CON group, n = 10) and housed feeding (HES group, n = 10) conditions were selected as a model of different rumen microbiota and observed for 180 days. The indicators of immunity and antioxidants in serum and rumen epithelium of cattle were measured; and the rumen microbiota were evaluated by using 16S rRNA and ITS sequencing techniques. In the present study, the concentrations of total protein, albumin and glucose in serum of Honghe cattle were significantly increased by the HES group when compared with CON group (p < 0.05). The HES group reduced the levels of complement 3, complement 4, interleukin-4, interleukin-10, interleukin-1β and tumor necrosis factor α, but increased the levels of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) (p < 0.05). We found that the HES group enhanced the levels of T-AOC and SOD in rumen epithelium (p < 0.05). Furthermore, there was a significant up-regulation of the relative mRNA expressions of ZO-1, OCC, SOD1, SOD2, Nrf2, NQO-1 and HO-1 observed in the HES group (p < 0.05). For rumen microbiota, the HES group significantly decreased alpha diversity. The core rumen bacterial communities were Bacteroidata, Firmicutes and Proteobacteria. The relative abundances of Prevotella and Ruminococcus were increased by the HES group, but norank_f_Bacteroidales_UCG-001, Rikenellaceae_RC9_gut_group and Prevotellaceae_UCG-003 were decreased (p < 0.05). Moreover, The HES group enhanced the relative abundance of Pichia, Cyllamyces, Sterigmatomyces and Wallemia (p < 0.05), but decreased Aspergillus and Candida (p < 0.05). There was a positive correlation between microorganisms such as Prevotella, Ruminococcus and Pichia and rumen epithelial barrier and antioxidant-related genes (p < 0.05). Overall, housed feeding contributed to the improvement of antioxidant capacity and rumen health in Honghe cattle, which may be related to the modulation of rumen microbiota including bacteria and fungi.

Immunomodulation of Glycyrrhiza Polysaccharides In Vivo Based on Microbiome and Metabolomics Approaches

Glycyrrhiza uralensis Fisch. is a medicinal herb that can be added to food to provide therapeutic effects and reduce the burden of medications. Herein, the immunomodulatory effects of Glycyrrhiza polysaccharides (GPs) were verified and illustrated by intervening immunocompromised rats treated with different doses of GPs, which were reflected for adjusting the composition and structure of the intestinal microbiota and altering the metabolic profile. The immunomodulatory effects of GPs were exerted by regulating the intestinal microenvironment. In particular, GPs could promote the growth of probiotic bacteria Allobaculum, norank__o_Clostridia_UCG-014, Dubosiella, and g__norank_o___RF39 and curb the growth of harmful bacteria Enterococcus. The results showed that GPs had a prebiotic effect, which contributed to improving the intestinal environment and maintaining intestinal health. In addition, the content of beneficial differential metabolites was up-regulated, especially short-chain fatty acids, with alanine, aspartate, and glutamate metabolism; arginine biosynthesis; glyoxylate and dicarboxylate metabolism being the most enriched pathways. These metabolic pathways imply the metabolic process of GPs, and the metabolic pathways and differential effector metabolites of it are focused. Overall, the purpose of this article lies in providing support for the application of GPs for regulating immune function.

The Non-Antibacterial Effects of Azithromycin and Other Macrolides on the Bronchial Epithelial Barrier and Cellular Differentiation

The respiratory epithelium maintains the barrier against inhaled harmful agents. When barrier failure occurs, as in several respiratory diseases, acute or chronic inflammation leading to destructive effects and exacerbations can occur. Macrolides are used to treat a spectrum of infections but are also known for off-label use. Some macrolides, particularly azithromycin (AZM), reduce exacerbations in chronic obstructive pulmonary disease (COPD), whereby its efficacy is thought to be due to its effects on inflammation and oxidative stress. In vitro data indicate that AZM reduces epithelial barrier failure, evidenced by increased transepithelial electrical resistance (TEER). Here, we compared the effects of macrolides on differentiation and barrier integrity in VA10 cells, a bronchial epithelial cell line for 14 and 21 days. Erythromycin, clarithromycin, roxithromycin, AZM, solithromycin, and tobramycin (an aminoglycoside) were analyzed using RNA sequencing, barrier integrity assays, and immunostaining to evaluate effects on the epithelium. All macrolides affected the gene expression of pathways involved in epithelial-to-mesenchymal transition, metabolism, and immunomodulation. Treatment with AZM, clarithromycin, and erythromycin raised TEER and induced phospholipid retention. AZM treatment was distinct in terms of enhancement of the epithelial barrier, retention of phospholipids, vesicle build-up, and its effect on gene sets related to keratinocyte differentiation and establishment of skin barrier.

Seleno-chitooligosaccharide-induced modulation of intestinal barrier function: Role of inflammatory cytokines, tight junction proteins, and gut microbiota in mice

This study aimed to explore the function of Seleno-chitooligosaccharide (SOA) on the intestinal barrier through regulation of inflammatory cytokines, tight junction protein, and gut microbiota in mice. The results of ELISA assay demonstrated that SOA significantly increased the levels of IL-2, IL-10, and IFN-γ in serum and ileum. Meanwhile, SOA increased the levels of IL-4 in the ileum (p < 0.05). In addition, Diamine Oxidase (DAO) concentration was decreased in ileum by SOA treatments (p < 0.05). The administration of SOA significantly upregulated the expression of ZO-1 and Occludin in the ileum (p < 0.05). By 16S rDNA sequencing, reduced ratio of Bacillota/Bacteroidota was observed in SOA treated mice. Within the phylum of Bacteroidota, SOA increased the relative abundance of Deferribacterota, uncultured Bacteroidales bacterium, and Bacteroides. Within the phylum of Bacillota, increased relative abundance of Erysipelatoclostridium and Lachnoclostridium, and reduced relative abundance of Ruminococcaceae UCG-010 were observed with SOA supplement. In summary, SOA has the potential to modulate the function of intestinal barrier function and prevent intestinal diseases.

A high cholesterol diet aggravates experimental colitis through SREBP2-modulated endocytosis and degradation of occludin and Zo-1 proteins

Disrupted cholesterol homeostasis plays a critical role in the development of multiple diseases, such as cardiovascular disease and cancer. However, the role of cholesterol in inflammatory bowel disease (IBD) remains unclear. In the present study, we investigated whether and how high levels of cholesterol in the diet affect experimental colitis in mice. A normal diet supplemented with 1.25% cholesterol (high cholesterol diet) caused more severe colitis and aggravated the disruption of intestinal tight junction structure, accompanied by higher colonic tissue total cholesterol (TC) levels in a dextran sulfate sodium (DSS)-induced experimental colitis mouse model. Cholesterol aggravated DSS-induced intestinal epithelial barrier impairment and nuclear sterol regulatory element-binding protein 2 (nSREBP2) inhibition both in vivo and in vitro. In addition, nSREBP2 overexpression ameliorated cholesterol-induced intestinal epithelial barrier disruption in Caco2 cells. Interestingly, inhibition of SREBP2 disrupted intestinal epithelial barrier in the absence of cholesterol. Furthermore, SREBP2 regulated the protein expression of tight junction proteins (occludin/Zo-1) via modulating caveolin-1-mediated endocytosis and lysosomal degradation. Analysis of UK Biobank data indicated that, in fully adjusted models, higher serum TC concentrations were an independent protective factor for IBD incidence. The sterol regulatory element-binding factor 2 (SREBF2) gene rs2228313 (G/C) genetic variant was associated with the incidence of IBD and the CC genotype of SREBF2 rs2228313 was associated with higher serum TC levels and decreased the risk of IBD. In summary, a high cholesterol diet aggravates DSS-induced colitis in mice by down-regulating nSREBP2 expression, thereby promoting the endocytic degradation of tight junction proteins. In humans, SREBF2 gene single nucleotide polymorphism rs2228313 and serum TC levels are associated with IBD incidence.

Mare milk and fermented mare milk alleviate dextran sulfate sodium salt-induced ulcerative colitis in mice by reducing inflammation and modulating intestinal flora

Mare milk (MM) and fermented mare milk (FM) are specialized animal milks with high nutritional value, containing a variety of functionally active substances that are capable of resisting inflammatory responses and oxidative stress. However, little relevant research on the maintenance of intestinal homeostasis has been performed. This study aimed to investigate the effects of MM and FM on the prevention of dextran sulfate sodium salt (DSS)-induced ulcerative colitis in a mouse model and to preliminarily elucidate the underlying mechanisms. The results showed that MM and FM had different degrees of protective effects against the damage caused by DSS and alleviated ulcerative colitis by inhibiting weight loss, reducing colon length shortening, and restoring intestinal structure. Additionally, MM and FM maintained intestinal tight junction protein levels to repair barrier function, downregulated inflammatory cytokines (e.g., IL-1β, TNF-α, IL-6, and iNOS) and bolstered the body's antioxidant defense system. Moreover, MM and FM regulated dysregulation of the intestinal microenvironment by improving the diversity of the gut microbiota and reshaping its structure, including increasing the proportion of Firmicutes and Bacteroidetes and the relative abundance of beneficial bacterial genera (e.g., Akkermansia). In summary, MM and FMM can serve as dietary resources for preventing ulcerative colitis and maintaining intestinal homeostasis.