The gut microbiota is an indispensable symbiotic entity within the human holobiont, serving as a critical regulator of host lipid metabolism homeostasis. Therefore, it has emerged as a central subject of research in the pathophysiology of metabolic disorders. This microbial consortium orchestrates key aspects of host lipid dynamics-including absorption, metabolism, and storage-through multifaceted mechanisms such as the enzymatic processing of dietary polysaccharides, the facilitation of long-chain fatty acid uptake by intestinal epithelial cells (IECs), and the bidirectional modulation of adipose tissue functionality. Mounting evidence underscores that gut microbiota-derived metabolites not only directly mediate canonical lipid metabolic pathways but also interface with host immune pathways, epigenetic machinery, and circadian regulatory systems, thereby establishing an intricate crosstalk that coordinates systemic metabolic outputs. Perturbations in microbial composition (dysbiosis) drive pathological disruptions to lipid homeostasis, serving as a pathogenic driver for conditions such as obesity, hyperlipidemia, and non-alcoholic fatty liver disease (NAFLD). This review systematically examines the emerging mechanistic insights into the gut microbiota-mediated regulation of intestinal lipid metabolism, while it elucidates its translational implications for understanding metabolic disease pathogenesis and developing targeted therapies.
Humans ; Gastrointestinal Microbiome/physiology* ; Lipid Metabolism ; Animals ; Intestinal Mucosa/metabolism* ; Homeostasis ; Dysbiosis ; Obesity/metabolism* ; Intestines/microbiology* ; Non-alcoholic Fatty Liver Disease/metabolism* ; Metabolic Diseases/metabolism*

OBJECTIVES: To investigate the therapeutic mechanism of nodakenin for Crohn's disease (CD)-like colitis in mice. METHODS: Using a colonic organoid model with lipopolysaccharide (LPS)- and ATP-induced pyroptosis, we investigated the effects of nodakenin on pyroptosis, intestinal barrier function and inflammatory response by detecting key pyroptosis-regulating factors and assessing changes in permeability and pro-inflammatory factors. In a mouse model of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced CD-like colitis, the therapeutic effect of nodakenin was evaluated by measuring changes in body weight, DAI score, colonic histopathologies, inflammation score, intestinal barrier function and intestinal epithelial cell pyroptosis. The mechanism of nodakenin protection against pyroptosis of intestinal epithelial cells was explored using network pharmacology analysis and in vivo and in vitro experiments. RESULTS: In LPS- and ATP-induced colonic organoids, treatment with nodakenin significantly inhibited the expressions of NLRP3, GSDMD-N, cleaved caspase-1 and caspase-11, improved intestinal FITC-dextran (FD4, 4000) permeability, and decreased the levels of IL-1β and IL-18. In the mouse model of TNBS-induced colitis, nodakenin treatment significantly alleviated weight loss, reduced DAI score, inflammatory cell infiltration and inflammation score, and decreased serum FD4 and I-FABP levels and bacteria translocation to the mesenteric lymph nodes, spleen and liver. The mice with nodakenin treatment had also lowered expressions of NLRP3, GSDMD-N, cleaved caspase-1 and caspase-11 in the intestinal mucosa. Network pharmacology analysis suggested that the inhibitory effect of nodakenin on colitis was associated with the PI3K/Akt pathway. In both the colonic organoid model and mouse models of colitis, nodakenin effectively inhibited the activation of the PI3K/Akt pathway, and the application of IGF-1, a PI3K/Akt pathway activator, strongly attenuated the protective effect of nodakenin against intestinal epithelial cell pyroptosis and intestinal barrier dysfunction. CONCLUSIONS Nodakenin protects intestinal barrier function and alleviates CD-like colitis in mice at least partly by inhibiting PI3K/Akt signaling to reduce intestinal epithelial cell pyroptosis.
Animals ; Pyroptosis/drug effects* ; Mice ; Trinitrobenzenesulfonic Acid ; Colitis/drug therapy* ; Epithelial Cells/drug effects* ; Intestinal Mucosa/cytology* ; Disease Models, Animal ; Coumarins/pharmacology* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Crohn Disease/drug therapy*

OBJECTIVES: To investigate the therapeutic effects of cimifugin on Crohn's disease (CD)-like colitis in mice and its possible mechanism. METHODS: Thirty adult male C57BL/6 mice were randomized equally into control group, 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced CD-like colitis model group, and cimifugin treatment (daily gavage at 12.5 mg/kg) group. The therapeutic effect of cimifugin was evaluated by observing changes in body weight, disease activity index (DAI) scores, colon length, histopathological inflammation scores, and inflammatory cytokine levels in the colonic mucosa. Intestinal barrier integrity in the mice was assessed using immunofluorescence assay and Western blotting for claudin-1 and ZO-1; T-helper (Th) cell subset ratios in the mesenteric lymph nodes were analyzed with flow cytometry. Network pharmacology, KEGG enrichment analysis and molecular docking were used to predict the targets of cimifugin and analyze the key pathways and cimifugin-MAPK protein interactions, which were validated by Western blotting in the mouse models. RESULTS: In mice with TNBS-induced colitis, cimifugin treatment significantly attenuated body weight loss and colon shortening, lowered DAI and histopathological scores, decreased IFN-γ and IL-17 levels, and increased IL-4 and IL-10 levels in the colonic mucosa. Cimifugin treatment also significantly improved TNBS-induced claudin-1 dislocation and reduction of goblet cells, upregulated claudin-1 and ZO-1 expressions, reduced Th1 and Th17 cell percentages, and increased Th2 and Treg cell percentages in the colonic mucosa of the mice. KEGG analysis suggested a possible connection between the effect of cimifugin and MAPK signaling, and molecular docking showed strong binding affinity between cimifugin and MAPK core proteins. Western blotting demonstrated significantly decreased phosphorylation levels of JNK, ERK, and p38 in the colonic mucosa of cimifugin-treated mouse models. CONCLUSIONS Cimifugin alleviates TNBS-induced CD-like colitis by repairing intestinal barrier damage and restoring Th1/Th2 and Th17/Treg balance via suppressing MAPK pathway activation.
Animals ; Mice, Inbred C57BL ; Male ; Mice ; Crohn Disease/immunology* ; Colitis/immunology* ; MAP Kinase Signaling System/drug effects* ; Trinitrobenzenesulfonic Acid ; T-Lymphocytes, Helper-Inducer/drug effects* ; Intestinal Mucosa ; Disease Models, Animal

OBJECTIVES: To investigate the effect of moslosooflavone (MOS) for ameliorating dextran sulfate sodium (DSS)-induced colitis in mice and the underlying molecular mechanism. METHODS: C57BL/6J mice with or without DSS exposure in the drinking water were both randomized into two groups for treatment with intraperitoneal injections with MOS (200 mg/kg) or normal saline for 7 days (n=6). Disease severity of the mice was assessed by observing changes in body weight, colon length, histopathology (HE staining), intestinal barrier function, and TUNEL staining. In the in vitro studies, lipopolysaccharide (LPS)-stimulated mouse colon organoids were treated with MOS (120 μmol/L) for 24 h, and the changes in barrier dysfunction and inflammation were analyzed. Network pharmacology and Western blotting were employed to identify functional pathways and apoptotic protein regulation associated with the therapeutic effect of MOS on colitis. RESULTS: In the mouse models of DSS-indcued colitis, MOS treatment significantly reduced body weight loss, disease activity index (DAI) scores and colon shortening, ameliorated colonic histopathological changes and inflammation, and lowered pro-inflammatory cytokine levels (TNF-α, IL-1β, IL-6, and IFN-γ). MOS effectively restored intestinal barrier integrity in the mice by reducing serum FITC-dextran and I-FABP concentrations while enhancing the tight junction proteins (ZO-1 and claudin-1). In the colon organoids, MOS significantly suppressed LPS-induced inflammatory responses and epithelial barrier disruption. Western blotting revealed that MOS downregulated C-caspase-3 and BAX and upregulated Bcl-2 expressions in both models. Mechanistically, MOS suppressed PI3K and AKT phosphorylation in both DSS-treated mouse colonic tissues and LPS-stimulated organoids. CONCLUSIONS MOS alleviates experimental colitis in mice by inhibiting intestinal epithelial apoptosis via inhibiting the PI3K/AKT pathway, thereby restoring intestinal barrier integrity and reducing inflammation.
Animals ; Dextran Sulfate ; Mice, Inbred C57BL ; Colitis/metabolism* ; Mice ; Signal Transduction/drug effects* ; Intestinal Mucosa/metabolism* ; Apoptosis/drug effects* ; Proto-Oncogene Proteins c-akt/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Flavones/pharmacology* ; Male

OBJECTIVES: To investigate the mechanism through which pinostrobin (PSB) alleviates dextran sulfate sodium (DSS)-induced colitis in mice. METHODS: C57BL/6 mice were randomized into control group, DSS model group, and PSB intervention (30, 60, and 120 mg/kg) groups. Colitis severity of the mice was assessed by examining body weight changes, disease activity index (DAI), colon length, and histopathology. The expressions of tight junction proteins ZO-1 and claudin-1 in the colon tissues were examined using immunofluorescence staining, and macrophage infiltration and polarization were analyzed with flow cytometry. ELISA and RT-qPCR were used for detecting the expressions of inflammatory factors (TNF‑α and IL-6) and chemokines (CCL₂, CXCL₁₀, and CX₃CL₁) in the colon tissues, and PI3K/AKT phosphorylation levels were analyzed with Western blotting. In cultured Caco-2 and RAW264.7 cells, the effect of PSB on CCL₂-mediated macrophage migration was assessed using Transwell assay. Network pharmacology analysis was performed to predict the key pathways that mediate the therapeutic effect of PSB. RESULTS: In DSS-induced mouse models, PSB at 60 mg/kg optimally alleviated colitis, shown by reduced weight loss and DAI scores and increased colon length. PSB treatment significantly upregulated ZO-1 and claudin-1 expressions in the colon tissues, inhibited colonic macrophage infiltration, and promoted the shift of macrophage polarization from M1 to M2 type. In cultured intestinal epithelial cells, PSB significantly inhibited PI3K/AKT phosphorylation and suppressed chemokine CCL₂ expression. PSB treatment obviously blocked CCL₂-mediated macrophage migration of RAW264.7 cells, which could be reversed by exogenous CCL₂. Network pharmacology analysis and rescue experiments confirmed PI3K/AKT and CCL₂ signaling as the core targets of PSB. CONCLUSIONS PSB alleviates DSS-induced colitis in mice by targeting intestinal epithelial PI3K/AKT signaling, reducing CCL₂ secretion, and blocking macrophage chemotaxis and migration, highlighting the potential of PSB as a novel natural compound for treatment of inflammatory bowel disease.
Animals ; Mice ; Mice, Inbred C57BL ; Phosphatidylinositol 3-Kinases/metabolism* ; Colitis/drug therapy* ; Dextran Sulfate ; Proto-Oncogene Proteins c-akt/metabolism* ; Macrophages ; Chemokine CCL2/metabolism* ; Humans ; Signal Transduction/drug effects* ; Caco-2 Cells ; RAW 264.7 Cells ; Epithelial Cells/drug effects* ; Intestinal Mucosa/metabolism*

OBJECTIVES: To investigate the effect of hypaphorine (HYP) on Crohn's disease (CD)‑like colitis in mice and its molecular mechanism. METHODS: Thirty male C57BL/6J mice were equally randomized into WT, TNBS, and HYP groups, and in the latter two groups, mouse models of CD-like colitis were established using TNBS with daily gavage of 15 mg/kg HYP or an equivalent volume of saline. The treatment efficacy was evaluated by assessing the disease activity index (DAI), body weight changes, colon length and histopathology. The effect of HYP was also tested in a LPS-stimulated Caco-2 cell model mimicking intestinal inflammation by evaluating inflammatory responses and barrier function of the cells using qRT-PCR and immunofluorescence staining. GO and KEGG analyses were conducted to explore the therapeutic mechanism of HYP, which was validated in both the cell and mouse models using Western blotting. RESULTS: In the mouse models of CD-like colitis, HYP intervention obviously alleviated colitis as shown by significantly reduced body weight loss, colon shortening, DAI and inflammation scores, and expressions of pro-inflammatory factors in the colon tissues. HYP treatment also significantly increased the TEER values, reduced bacterial translocation to the mesenteric lymph nodes, liver, and spleen, lowered serum levels of I-FABP and FITC-dextran, increased the number of colonic tissue cup cells, and upregulated colonic expressions of MUC2 and tight junction proteins (claudin-1 and ZO-1) in the mouse models. In LPS-stimulated Caco-2 cells, HYP treatment significantly inhibited the expressions of pro-inflammatory factors and increased the expressions of tight junction proteins. Western blotting showed that HYP downregulated the expressions of the key proteins in the TLR4/MyD88 signaling pathway in both the in vitro and in vivo models. CONCLUSIONS HYP alleviates CD-like colitis in mice possibly by suppressing intestinal epithelial inflammation and improving gut barrier function.
Animals ; Male ; Mice, Inbred C57BL ; Crohn Disease/drug therapy* ; Mice ; Humans ; Caco-2 Cells ; Intestinal Mucosa/metabolism* ; Colitis/drug therapy* ; Disease Models, Animal ; Inflammation ; Toll-Like Receptor 4/metabolism* ; Myeloid Differentiation Factor 88/metabolism* ; Intestinal Barrier Function

OBJECTIVES: To investigate the therapeutic effect of the natural compound niranthin on Crohn's disease-like colitis in mice and explore the underlying molecular mechanisms. METHODS: In a mouse model of colitis induced by 2,4,6-trinitro-benzenesulfonic acid (TNBS), the therapeutic effect of niranthin was evaluated by observing the changes in body weight, disease activity index (DAI), and colon length of the mice. The levels of inflammatory cytokines (IL-6, IL-1β, TNF-α, IL-17A and IL-10) in the intestinal mucosal tissue were detected using ELISA and quantitative real-time PCR (qRT-PCR). TUNEL staining and Western blotting were used to assess intestinal epithelial cell apoptosis and the expressions of Bcl-2 and Bax. The expression levels of tight junction proteins (ZO-1 and claudin-1) and the activation of the p38/JNK signaling pathway were investigated using Western blotting, and diprovocim intervention experiments were conducted to explore the molecular regulatory mechanism of niranthin. RESULTS: Niranthin treatment significantly increased body weight of TNBS-treated mice, lowered the DAI and histological inflammation scores, and increased colon length of the mice. The niranthin-treated mouse models showed obviously reduced protein and mRNA levels of IL-6, IL-1β, IL-17A, and TNF-α and upregulated expression of IL-10 in the colon tissue. TUNEL staining and Western blotting demonstrated that niranthin significantly inhibited intestinal epithelial cell apoptosis and activated the anti-apoptotic pathway in the mouse models. Niranthin treatment obviously upregulated the expression levels of ZO-1 and claudin-1 and downregulated the phosphorylation levels of p38 and JNK in the colon tissues of the mice. Diprovocim intervention obviously attenuated the inactivation of the p38/JNK signaling pathway induced by niranthin in the mouse models. CONCLUSIONS Niranthin ameliorates TNBS-induced Crohn's disease-like colitis in mice by inhibiting intestinal epithelial cell apoptosis and protecting the integrity of the intestinal barrier via regulating the activation of the p38/JNK signaling pathway.
Animals ; Apoptosis/drug effects* ; Mice ; Intestinal Mucosa/drug effects* ; Crohn Disease/drug therapy* ; MAP Kinase Signaling System/drug effects* ; Epithelial Cells/drug effects* ; Disease Models, Animal ; Signal Transduction/drug effects* ; p38 Mitogen-Activated Protein Kinases/metabolism* ; Male

OBJECTIVE: To observe the effect of moxibustion on small intestinal mucosal immune barrier in rats with diarrhea-predominant irritable bowel syndrome (IBS-D) and explore its underlying mechanisms. METHODS: Of 38 newborn rats from 4 healthy SPF pregnant rats, 12 neonatal rats were randomly selected in a normal group. IBS-D model was prepared by the combined measures for the rest rats, including neonatal maternal separation, acetic acid enema and chronic restraint stress. Twenty-four successfully-modeled rats were randomized into a model group and a moxibustion group, 12 rats in each one. In the moxibustion group, suspending moxibustion was delivered at bilateral "Tianshu" (ST25) and "Shangjuxu" (ST37), 20 min each time, once daily and for 7 consecutive days. Separately, before acetic acid enema (aged 35 days), after modeling (aged 45 days) and after intervention (aged 53 days), the body mass, loose stool rate (LSR) and and the minimum volume threshold when abdominal withdrawal reflex (AWR) scored 3 were observed in the rats of each group. After intervention (aged 53 days), using HE and PAS staining, the morphology of duodenum was observed, the length of villus and the depth of crypt were measured, the ratio of the length of villus to the depth of crypt was calculated; and the numbers of mucosal intraepithelial lymphocytes (IELs) and goblet cells were counted. With ELISA adopted, the contents of γ-interferon (IFN-γ), interleukin-4 (IL-4) and secretory immunoglobulin A (sIgA) in duodenal mucosa of rats were detected. The proportion of T cell subsets in duodenal mucosa was detected using flow cytometry. The microvilli and tight junctions of duodenal mucosal epithelial cells were observed by transmission electron microscopy, and the integrity of duodenal mucosa observed by scanning electron microscopy. RESULTS: Compared with the normal group, for the rats in the model group, the body mass, the minimum volume threshold when AWR scored 3, the length of duodenal villus and the the ratio of the length of villus to the depth of crypt, as well as the proportion of CD₈⁺ T subset were all reduced (P<0.01, P<0.05), the counts of goblet cells in duodenal mucosa decreased (P<0.01); LRS, the proportion of CD₄⁺ T subset and CD₄⁺/CD₈⁺, as well as the contents of IFN-γ, IL-4 and sIgA in duodenal mucosa and IFN-γ/IL-4 were all elevated (P<0.01); and the numbers of IELs rose (P<0.01). The morphology of duodenal mucosa was irregular, the villi got shorter, sparse and scattered, with uneven density. The morphology of epithelial cells was destroyed and the tight junctions damaged, with larger spaces. When compared with the model group, in the moxibustion group, the body mass, the minimum volume threshold when AWR scored 3, the length of duodenal villus and the ratio of the length of villus to the depth of crypt, as well as the counts of goblet cells in duodenal mucosa increased (P<0.01); LRS, the proportion of CD₄⁺ T subset, and CD₄⁺/CD₈⁺, as well as the contents of IFN-γ, IL-4 and sIgA in duodenal mucosa and IFN-γ/IL-4 were reduced (P<0.01); and the numbers of IELs was dropped (P<0.01). The morphology of duodenal mucosa was more regular, the villi were grew, got longer and arranged regularly, with even density. The morphology of epithelial cells was slightly destroyed, and the tight junctions partially damaged. CONCLUSION Moxibustion at "Tianshu" (ST25) and "Shangjuxu" (ST37) can reduce visceral hypersensitivity in IBS-D rats and relieve abdominal pain, diarrhea and other symptoms. Its effect mechanism may be related to the repair of small intestinal mucosal immune barrier and the improvement in the immune function in IBS-D.
Animals ; Irritable Bowel Syndrome/immunology* ; Rats ; Moxibustion ; Intestinal Mucosa/immunology* ; Female ; Diarrhea/therapy* ; Intestine, Small/immunology* ; Male ; Humans ; Rats, Sprague-Dawley ; Disease Models, Animal

The small intestine is essential for digestion, nutrient absorption, immune regulation, and microbial balance. Its epithelial lining, containing specialized cells like Paneth cells and tuft cells, is crucial for maintaining intestinal homeostasis. Paneth cells produce antimicrobial peptides and growth factors that support microbial regulation and intestinal stem cells, while tuft cells act as chemosensors, detecting environmental changes and modulating immune responses. Along with immune cells such as intraepithelial lymphocytes, innate lymphoid cells, T cells, and macrophages, they form a strong defense system that protects the epithelial barrier. Disruptions in this balance contribute to chronic inflammation, microbial dysbiosis, and compromised barrier function-key features of inflammatory bowel disease, celiac disease, and metabolic syndromes. Furthermore, dysfunctions in the small intestine and immune cells are linked to systemic diseases like obesity, diabetes, and autoimmune disorders. Recent research highlights promising therapeutic strategies, including modulation of epithelial and immune cell functions, probiotics, and gene editing to restore gut health and address systemic effects. This review emphasizes the pivotal roles of small intestinal epithelia and immune cells in maintaining intestinal homeostasis, their involvement in disease development, and emerging treatments for intestinal and systemic disorders.
Humans ; Intestinal Mucosa/cytology* ; Intestine, Small/cytology* ; Animals ; Inflammatory Bowel Diseases/immunology* ; Celiac Disease/immunology* ; Paneth Cells/immunology*

Juvenile idiopathic arthritis (JIA) is the most common condition of chronic rheumatic disease in children. JIA is an autoimmune or autoinflammatory disease, with unclear mechanism and limited treatment efficacy. Recent studies have found a number of alterations in gut microbiota and its metabolites in children with JIA, which are related to the development and progression of JIA. This review focuses on the influence of the gut microbiota and its metabolites on immune function and the intestinal mucosal barrier and discuss the key role of the gut-joint axis in the pathogenesis of JIA and emerging treatment methods based on gut microbiota and its metabolites. This review could help elucidate the pathogenesis of JIA and identify the potential therapeutic targets for the prevention and treatment of JIA.
Humans ; Arthritis, Juvenile/physiopathology* ; Gastrointestinal Microbiome/physiology* ; Child ; Intestinal Mucosa