Search Results (354)

Background: Imperatorin (IPT) is a natural furanocoumarin featuring robust anti-inflammatory, antifibrotic and antioxidant activities. However, poor aqueous solubility and insufficient oral bioavailability restrict its clinical application. Multiple gastrointestinal barriers, including the mucus barrier, limited epithelial penetration and P-glycoprotein-triggered drug efflux, are major obstacles hindering IPT oral absorption. Methods: N-acetylcysteine (NAC)-functionalized TPGS conjugates were synthesized first. Using Pluronic^® F108 and Lipoid^® S-100 as a matrix, imperatorin@N-acetylcysteine-TPGS/Pluronic^® F108/Lipoid^® S-100 (IPT@NAC-TFS) micelles were fabricated. We characterized their physicochemical features and in vitro release behavior. The Caco-2/HT29-MTX-E12 co-culture cell model was adopted to explore mucus permeation, cellular uptake and transepithelial transport mechanisms. In vivo intestinal distribution and pharmacokinetic tests in rats were carried out to confirm the oral absorption-enhancing effect of micelles. Results: Optimized micelles displayed a uniform shape and favorable encapsulation efficiency. Low CMC maintained structural stability upon gastrointestinal dilution. NAC modification conferred mucus-penetrating capacity on micelles. TPGS simultaneously improved epithelial barrier permeability and inhibited drug efflux, switching IPT transport mode. The micelles effectively cleared intracellular ROS, recovered SOD activity and lowered MDA levels in BLM-impaired MLg fibroblasts. In vivo results revealed enhanced intestinal drug accumulation, with the relative oral bioavailability of IPT increased by 6.07-fold. Conclusions: IPT@NAC-TFS micelles overcome multiple gastrointestinal barriers for oral IPT delivery. Combining mucus penetration, efflux suppression and antioxidative capacity, this system offers a promising strategy to develop oral formulations of poorly soluble antifibrotic natural products. Full article

Aquaculture production of Asian seabass is increasingly threatened by recurrent bacterial diseases, while practical vaccination strategies that provide protection against bacterial challenges involving multiple pathogens during extended grow-out periods remain limited. This study evaluated the immunological and protective effects of a sequential mucosal vaccination strategy in juvenile Asian seabass (Lates calcarifer; 200 fish per treatment, distributed among four replicate tanks of 50 fish) against four major bacterial pathogens: Flavobacterium covae, Vibrio harveyi, Vibrio vulnificus, and Photobacterium damselae. The vaccination regimen consisted of two nanoemulsion-based immersion vaccination events administered 14 days apart, followed by three oral chitosan–alginate hydrogel vaccination courses administered for 7, 5, and 3 consecutive days. Bacterial challenge experiments were conducted at three post-vaccination time points using immersion and intraperitoneal injection models. Growth performance and feed conversion were evaluated using replicate-tank means as the experimental units. Sequential vaccination did not significantly affect final body weight, weight gain, average daily gain, specific growth rate, or feed conversion ratio (p > 0.05). Vaccinated fish showed significantly higher antigen-specific IgM levels in skin mucus, intestinal mucus, and serum across the evaluated challenge conditions. Correspondingly, ighm, ighd, and ight expression was increased in the gills, skin, head kidney, and intestine, indicating enhanced immunoglobulin-associated responses in mucosal and lymphoid tissues. Full-length 16S rRNA gene sequencing showed vaccine-associated changes in gill and intestinal bacterial community composition, including a lower relative representation of several challenge-associated taxa and a higher relative representation of selected commensal-associated taxa. Vaccinated fish showed significantly higher cumulative survival following F. covae immersion, mixed V. harveyi/V. vulnificus/P. damselae immersion, and mixed-pathogen injection challenges (p < 0.05). These findings demonstrate that sequential nanoemulsion immersion priming and oral hydrogel boosting enhanced pathogen-specific humoral responses and increased immunoglobulin-gene expression. The sequential vaccination strategy improved survival following a separate Flavobacterium covae challenge and a combined Vibrio harveyi/Vibrio vulnificus/Photobacterium damselae challenge during the experimental period without adversely affecting growth. This needle-free strategy warrants further evaluation under commercial aquaculture conditions. Full article

The intestinal barrier is a key interface maintaining host–microbial segregation and systemic homeostasis. A broad range of viruses, including enteric, respiratory, and systemic pathogens, can disrupt this barrier through effects on epithelial integrity, vesicular transport, immune responses, and microbial ecology. Whether these diverse insults converge on shared regulatory nodes or act through distinct virus-specific pathways that ultimately result in barrier failure remains unclear. Building on this premise, this review systematically delineates the molecular and cellular mechanisms underlying virus-induced disruption of the intestinal barrier. Viral infection disrupts epithelial integrity through multiple converging processes, including disassembly of tight junction architecture, activation of programmed cell death pathways, degradation of the mucus layer, impaired regeneration driven by intestinal stem cells, and dysregulation of transcellular transport. These processes are interconnected and collectively drive epithelial dysfunction and barrier breakdown. Beyond epithelial damage, we further highlight the pivotal contribution of host immune responses to barrier breakdown. Viral infection induces dysregulated cytokine production and aberrant immune activation, which amplify epithelial damage and further increase barrier permeability. In parallel, increasing evidence supports a bidirectional interaction between viral infection and gut microbiota dysbiosis, in which each process reinforces the other to accelerate barrier disruption and disease progression. We also discuss emerging therapeutic strategies aimed at restoring intestinal homeostasis, including antiviral therapies, host-targeted interventions, and microbiota modulation. Despite recent progress, key questions remain, particularly regarding mechanisms of failed barrier repair after viral clearance and the multilayered regulatory networks linking viruses, immunity, and the microbiota. Together, this review provides a framework for understanding virus-induced intestinal barrier dysfunction and identifies potential therapeutic nodes for intervention. Full article

Background: Adult Schistosoma mansoni parasites inhabit the hepatic portal system of the vertebrate host, their deposited eggs causing granulomatous pathology in both the intestines and liver. In the intestines, egg secretions drive inflammatory processes involved in extravasation to the gut lumen. Methods: Here, we investigate parasite-host interactions in a mouse model during the acute phase of a patent infection at 5 and 7 weeks, using parallel histological and proteomic analysis of paraffin-embedded ileal tissues. Results: Histology at week 7 showed infected animals had more inflammation and longer villi than at week 5, as well as more Goblet cells reflecting enhanced mucus production. LC-MS/MS analysis of deparaffinized ileal sections, subjected to in-solution tryptic digestion, revealed a total of 1615 protein groups. Differentially abundant proteins were found early at week 5, coinciding with the onset of egg deposition. A contrasting scenario, dominated by upregulation of protein components from the innate and adaptive immune systems, was seen at week 7; at this point, egg migration and excretion are underway. Among the proteins were mast cell proteases, fibrinogens, arginase-1, and molecules associated with extracellular matrix remodeling. Conclusions: Our findings reflect intestinal proteome changes likely participating in S. mansoni egg passage from the vascular bed to the intestinal lumen. Full article

Microplastics and nanoplastics (MNPs) have been recognized as ubiquitous emerging global pollutants, which are extensively detectable in diverse environmental media and food matrices. Increasing evidence indicates that the intestine is a primary target of orally ingested MNPs and a critical initiating hub for systemic toxicity. Once ingested orally, MNPs can interact with the intestinal mucus layer and epithelial barrier, induce gut microbiota dysbiosis, remodel bile acid and short-chain fatty acid metabolism, and activate oxidative stress, inflammation, apoptosis, and immune imbalance. These gut-derived disturbances may subsequently propagate adverse signals to distal organs through the gut-liver, gut-brain, gut-kidney, gut-lung, gut-reproductive, and gut-mammary axes. Intestinal barrier dysfunction, endotoxin translocation, abnormal microbial metabolites, and microbiota-derived immune signals constitute common mediating pathways linking local intestinal injury to multi-organ toxicity. In addition, smaller particle size, surface oxidation, environmental aging, bio-corona/plastisphere formation, and co-exposure with other contaminants can further modulate the intensity and specificity of gut-organ axis disruption. Prior reviews are limited to separate analyses of single-organ toxicity or isolated gut-organ pathways. To fill this gap, this work synthesizes contemporary mechanistic and experimental evidence to establish a gut-initiated systemic toxicology framework for MNPs. We differentiate direct particle translocation from gut-derived indirect signaling, evaluate the varying robustness of supporting evidence for each gut-organ axis, and underscore nanoscale biointerface properties as key modulators of MNPs systemic toxic potency. Full article

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract. Current treatments, including anti-inflammatory drugs and biologics, often have limited efficacy and significant side effects, highlighting the need for novel therapeutic approaches. Phellodendrine (PHE) is a characteristic ingredient of Phellodendri chinensis, yet its effects and mechanisms on IBD remain elusive. The present study evaluated the potential of PHE for preventing dextran sulfate sodium-induced IBD in zebrafish. PHE effectively reduced inflammatory cell infiltration and modulated polarized macrophages. The qPCR results further confirmed the down-regulation of pro-inflammatory genes and up-regulation of anti-inflammatory factors. Consequently, PHE promoted the resolution of IBD inflammation. PHE also restored intestinal barrier integrity by enhancing MUC2 expression, increasing goblet cell counts, and reducing intestinal permeability of both chemical and physical barriers. In addition, PHE was associated with alterations in the gut microbiome, including a reduction in potentially pathogenic microbes and an increase in beneficial microbial populations. PHE also alleviated oxidative stress. Network pharmacology suggested the potential involvement of the IL-17 signaling pathway, the lipid and atherosclerosis pathway, and the TNF signaling pathway in the preventive effects of PHE against intestinal inflammation in the zebrafish model. In vivo gene expression analysis suggested that JUN, PTGS2, IL1B, DRD2, CALM1, and HSP90AA1 may serve as putative targets of PHE. Collectively, our results indicate that PHE demonstrates potential anti-inflammatory and barrier-protective activities in a zebrafish model of intestinal inflammation. The pharmacological mechanisms by which PHE restores intestinal barriers (microbial, chemical, physical, and immune barriers) include resolving inflammation, decreasing ROS production, and enhancing lipid accumulation in the lumen overlying the intestinal mucus barrier. This study provides novel insights into the preventive effects of PHE against intestinal inflammation in a zebrafish model, suggesting its potential as a candidate for further investigation. Full article

Imperatorin (IPT) is a naturally occurring coumarin with recognized antioxidant and anti-aging properties; unfortunately, its poor water solubility and low oral bioavailability severely limit its practical use. To get around these issues, we formulated IPT-loaded NLCs using grape seed oil and glyceryl monostearate—both food-grade excipients—with the goal of enhancing oral absorption. Optimized IPT@NLCs were prepared by high-pressure homogenization, featuring uniform spherical morphology, an average particle size of 186.63 ± 1.65 nm, a PDI of 0.188 ± 0.008, an encapsulation efficiency of 99.54 ± 0.10%, and a drug loading capacity of 9.08 ± 0.23%. IPT@NLCs remained stable in SGF, while their cumulative in vitro release over 48 h reached 90.56 ± 3.12% in SIF. We established a Caco-2/HT29-MTX-E12 co-culture monolayer to examine mucus penetration, cellular uptake, and transcellular transport routes. In parallel, oxidative stress experiments using 3T3-L1 cells, along with in vivo pharmacokinetic and gastrointestinal safety evaluations, were conducted to provide complementary evidence. Our results indicate that NLC encapsulation significantly improves both the dissolution and intestinal uptake of IPT, primarily by shifting the absorption mechanism from passive diffusion to energy-dependent active transport. In addition, IPT@NLCs effectively reduce intracellular oxidative damage through modulation of endogenous antioxidant enzyme activities. Animal studies further reveal an approximately 9-fold increase in relative oral bioavailability, with no notable irritation to gastrointestinal tissues. Overall, GSO-based NLCs offer safe and efficient oral delivery, enhancing IPT bioavailability and antioxidant activity, providing a strategy for developing natural-product-based formulations. Full article

Ulcerative colitis (UC) is a chronic inflammatory disease characterized by persistent colonic inflammation, excessive oxidative stress, and impaired barrier function. Transition metal-based nanoparticles offer promising antioxidant platforms to address oxidative stress-related pathologies. To overcome the poor gastrointestinal stability of the potent dietary antioxidant epigallocatechin gallate (EGCG), we utilized zinc-coordinated EGCG (EGCG-Zn) nanoparticles (NPs), which function as a transition metal–phenolic network, to achieve sustained colonic release and overcome the poor gastrointestinal stability of free EGCG. The therapeutic efficacy and underlying mechanisms were evaluated in dextran sulfate sodium (DSS)-induced colitis in mice. Oral administration of EGCG-Zn NPs effectively reduced oxidative stress, suppressed pro-inflammatory cytokine production, alleviated colitis symptoms, and repaired the intestinal mucus and mechanical barriers. Mechanistically, transcriptomic analysis revealed that EGCG-Zn NPs pretreatment markedly reversed DSS-induced transcriptional alterations. Integrated K-means clustering and KEGG enrichment analyses further demonstrated that these protective effects were mediated by down-regulating inflammation-associated genes and up-regulating tight junction proteins, primarily involving the modulation of calcium signaling, T-cell differentiation, and the PI3K-Akt, Wnt, NF-κB, and TNF pathways. Collectively, these findings suggest that EGCG-Zn NPs alleviate DSS-induced colitis by mitigating inflammation, suppressing oxidative stress, and promoting epithelial barrier repair, supporting their potential as a functional nutraceutical for UC management. Full article

The early post-weaning period in piglets is characterized by physiological and environmental stress that can impair intestinal function and growth performance. Plant-derived feed additives have gained interest as a nutritional strategy to support gut integrity and productivity. Extracts from Cynara scolymus stimulate bile secretion and exhibit antioxidant properties, whereas inulin may promote beneficial microbial populations and intestinal functionality through prebiotic activity. This study evaluated the biological activity of a feed additive containing Cynara scolymus extract and inulin on intestinal functional indicators and productive performance of post-weaned piglets under intensive production conditions. Four hundred and eight piglets were randomly assigned to two groups: a control group (CON) that was fed a basal diet, and a treatment group (CSI) that was supplemented with the additive (5% Cynara scolymus extract and 14% inulin) at 300 g/ton of feed. Plasma cortisol and citrulline concentrations were measured during the first 15 days post-weaning. On day 16 post-weaning, intestinal parameters were evaluated, including gastrointestinal pH; enterobacteria and lactic acid bacteria counts; volatile fatty acids; bacterial adhesion to ileal mucus; disaccharidase activity; and small intestinal histomorphology. Growth performance was monitored during the 50-day nursery phase. Compared with CON piglets, CSI piglets exhibited higher plasma citrulline concentrations (72.72 ± 20.87 vs. 47.54 ± 17.05 µM; p < 0.001), indicating improved intestinal epithelial functionality. CSI supplementation also increased the villus height-to-crypt depth ratio (3.67 ± 0.75 vs. 2.68 ± 0.64; p = 0.001), suggesting enhanced intestinal epithelial integrity. Furthermore, CSI piglets showed higher average daily gain (0.53 ± 0.07 vs. 0.44 ± 0.09 kg/day; p = 0.003) and a better feed conversion ratio (1.27 ± 0.20 vs. 1.57 ± 0.57; p = 0.004). These results suggest that Cynara scolymus extract and inulin supplementation has beneficial biological effects on intestinal epithelial functionality and productive performance in post-weaning piglets under commercial conditions. Full article

Sea urchins harbor diverse microbial communities that may contribute to host-associated ecological interactions, microbial competition, and chemical defense. However, the compartment-specific organization of sea urchin-associated microbiota and their predicted chemical-defense-related functional potential remain poorly understood under aquaculture conditions. In this study, 16S rRNA gene amplicon sequencing was used to characterize microbial communities in rearing water, coelomic fluid, intestine, stomach contents, and surface mucus of Hemicentrotus pulcherrimus (H. pulcherrimus). KEGG Orthology (KO)-based functional prediction was further performed to evaluate predicted chemical-defense-related functional potential, including predicted chemical-defense-related pathways, siderophore-related functions, quorum sensing-related functions, and bacterial competition- and secretion system-related functions. Rarefaction curves and Coverage values indicated sufficient sequencing depth. Alpha diversity and Nonmetric multidimensional scaling (NMDS) analyses revealed clear microbial differentiation among the five sample types, with rearing water showing higher microbial richness. Taxonomic analysis identified Pseudomonadota, Bacteroidota, Campylobacterota, Bacillota, Planctomycetota, and Spirochaetota as dominant phyla, with several discriminative taxa across compartments. KO prediction showed that total predicted abundance of predicted chemical-defense-related KOs differed significantly among sample types. Among host-associated compartments, surface mucus showed relatively higher predicted siderophore-related KO potential, whereas stomach contents showed higher predicted quorum sensing-related KO potential among host-associated compartments. These findings suggest compartment-specific microbial communities and predicted chemical-defense-related functional potential in cultured H. pulcherrimus under aquaculture conditions. Because these functions were inferred from 16S-based KO prediction, they should be interpreted as preliminary hypotheses for future metagenomic, metabolomic, and culture-dependent validation. Full article

Olive oil, particularly virgin (VOO) and extra-virgin olive oil (EVOO), is a central component of the Mediterranean diet and has been associated with cardiometabolic, anti-inflammatory, and intestinal health benefits. Increasing evidence suggests that these effects may involve interactions with the gut microbiota, intestinal barrier, and host inflammatory pathways. This narrative review summarizes current evidence on the impact of olive oil, olive-derived phenolics, and olive oil-rich dietary patterns on gut microbiota modulation, barrier function, inflammatory bowel diseases, and related systemic outcomes. The available literature indicates that olive oil may interact with the gut ecosystem through both its oleic acid-rich lipid matrix and its minor phenolic fraction. VOO and EVOO appear more consistently associated than refined oils with microbial or microbial metabolite profiles related to saccharolytic metabolism, short-chain fatty acid production, mucus-layer dynamics, and anti-inflammatory intestinal environments. Olive-derived phenolics, including hydroxytyrosol, tyrosol, oleuropein derivatives, and oleocanthal, can undergo microbial biotransformation and may influence bile acid metabolism, epithelial barrier integrity, and inflammatory signaling. Whole EVOO evidence is strongest in experimental colitis models, whereas human evidence mainly supports effects on postprandial endotoxemia, lipid oxidation, and selected inflammatory markers. However, findings remain heterogeneous and depend on oil quality, phenolic composition, comparator fat, dietary context, and host condition. Well-controlled human studies directly comparing EVOO, VOO, refined olive oil, and oleic acid-rich controls are needed to clarify reproducible microbiota-mediated effects and their relevance to intestinal and systemic health. Full article

The protective effect of Compound terminalia chebula extract (HL) against colonic injury induced by Porcine epidemic diarrhea virus (PEDV) infection in neonatal piglets remains unclear. This study aimed to evaluate the mitigating effects of HL on PEDV-induced colonic injury and elucidate the underlying mechanisms. Eighteen 7-day-old Duroc × Landrace × Large White piglets (2.58 ± 0.05 kg) were randomly assigned to three groups (n = 6/group): CON (blank control), PEDV (infected), and HL + PEDV (HL-supplemented + infected). The 11-day trial included 3 days of acclimatization (days 0–3) and an 8-day experimental period (days 4–11). HL (10 mg/kg BW) was orally administered daily to the HL + PEDV group. On day 8, PEDV and HL + PEDV groups were challenged with 3 mL PEDV (3 × 10⁶ TCID₅₀/mL), while CON received Dulbecco’s Modified Eagle Medium (DMEM). All piglets were euthanized on day 11 for colonic tissue collection. Results indicated that PEDV infection induced colonic injury, manifested by a significant increase in crypt depth and disruption of intestinal homeostasis. This was evidenced by impaired barrier integrity (upregulation of matrix metalloproteinase-7 gene [MMP7] and matrix metalloproteinase 13 gene [MMP13], mucus disorganization (elevation of mucin 5AC gene [MUC5AC]), oxidative stress (reduced catalase [CAT] activity and increased malondialdehyde [MDA] levels in serum and colon), and inflammation (upregulation of regenerative islet-derived protein 3γ gene [REG3G], S100 calcium-binding protein A8/A9 gene [S100A8/A9], and interleukin-1β gene [IL-1β]). Additionally, PEDV impaired colonic ion transport by downregulating calcium channel genes (Transient Receptor Potential Cation Channel Subfamily V Member 6 gene [TRPV6], Transient Receptor Potential Cation Channel Subfamily M Member 6 gene [TRPM6]). Notably, HL supplementation effectively reversed these adverse effects. HL restored colonic morphology, increased CAT activity, reduced MDA accumulation, and suppressed inflammatory gene expression. Furthermore, HL modulated the expression of genes involved in water and ion transport upregulating Aquaporin 7 gene (AQP7), Chloride Channel Accessory 4 gene (CLCA4), Sodium-Hydrogen Exchanger 3 gene (NHE3), Transient Receptor Potential Vanilloid 6 (TRPV6), and Transient Receptor Potential Melastatin 6 gene (TRPM6) and significantly inhibited PEDV replication, as indicated by the downregulation of the transcription levels of PEDV membranegene (M), nucleocapsid gene (N), and spike gene (S). Taken together, HL alleviates PEDV-triggered colonic tissue damage in suckling piglets via improving colonic antioxidant capacity, mitigating inflammatory response, partially regulating intestinal barrier and ion/water transport-related genes, and downregulating the transcription of PEDV structural genes at molecular and histological levels. Full article

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a major heat-induced contaminant in protein-rich foods, yet its effects on intestinal barrier homeostasis and luminal microecology remain insufficiently defined. In this study, adult zebrafish were exposed to dietary PhIP for 90 days at estimated intake doses of 0.006, 0.4, and 7.2 mg/kg bw/day to evaluate intestinal injury, microbial dysbiosis, and metabolic remodeling. PhIP exposure impaired growth-related indices and induced progressive intestinal lesions, accompanied by mucus barrier depletion, reduced goblet cell abundance, and downregulation of muc2. Tight junction integrity was disrupted, as indicated by decreased zo-1, occludin, and claudin1 expression, weakened ZO-1 and Claudin-1 immunofluorescence signals, and reduced tight junction-related protein levels. Serum LPS and intestinal pro-inflammatory cytokines were markedly elevated, whereas il-10 expression was suppressed, indicating increased endotoxin burden and inflammatory activation. 16S rRNA gene sequencing revealed Proteobacteria-enriched dysbiosis and exposure-associated shifts in candidate genera, including Chitinilyticum, Shewanella, Aeromonas, Acinetobacter, Microbacterium, and Reyranella. Untargeted metabolomics further identified luminal metabolic remodeling involving lipid-related compounds, organic acids, amino acid metabolism, arachidonic acid metabolism, the citrate cycle, and pathways related to choline and glycerophospholipid metabolism. Association analysis linked genus-level microbial variation and core pathway-related metabolites with LPS, inflammatory cytokines, and tight junction markers. These findings indicate that dietary PhIP exposure disrupts intestinal barrier homeostasis in parallel with Proteobacteria-related dysbiosis and luminal metabolic remodeling, providing an integrated microbiota-metabolite-barrier association framework for evaluating intestinal risks of heat-induced food contaminants. Full article

Tremella fuciformis polysaccharides (TFPS) exhibit anti-inflammatory and gut-microbiota-modulating activities, but conventional extraction methods often show limited efficiency and may affect polysaccharide structural integrity. This study optimized a deep eutectic solvent (DES)-based extraction method with potential environmental advantages for TFPS, characterized the major purified fraction, and evaluated its effects in a dextran sulfate sodium (DSS)-induced experimental colitis model. Extraction parameters for the choline chloride–lactic acid DES system were refined through single-factor testing combined with response surface methodology. The purified fraction TFPS-1 was characterized by chromatographic, spectroscopic, methylation, and NMR analyses, and its biological effects were assessed in DSS-treated mice. Under the optimized conditions, the TFPS yield reached 33.09 ± 1.52%, representing a 77.6% increase compared with hot-water extraction. TFPS-1 was identified as a low-molecular-weight glucan mainly containing α-(1→4)- and β-(1→6)-linked glucose residues. In experimental colitis mice, TFPS-1 alleviated body weight loss, colon shortening, and histopathological injury; increased mucus secretion and barrier-related gene expression; reduced pro-inflammatory cytokines; increased IL-10; and partially adjusted gut microbiota composition. These results indicate that DES-based extraction is an efficient strategy for preparing TFPS and provide evidence that TFPS-1 may be further explored as a food-derived polysaccharide ingredient for intestinal protection in experimental colitis-related contexts. Full article

Background: Postbiotics, including cell-free supernatants and their fractions, have emerged as a safe and effective alternative to live probiotics for managing intestinal inflammation. This study investigated the protective effects of low-molecular-weight fractions (<3 kDa) of the probiotic Limosilactobacillus fermentum CECT5716 (LMW-LF) in a murine model of experimental colitis. Methods: Male C57BL/6J mice were orally administered LMW-LF for 10 days prior to colitis induction with 3% dextran sodium sulfate (DSS) for 5 days. Colonic damage was assessed via the Disease Activity Index (DAI), histology, and immunofluorescence (Ocln and Ki67). Immune cell populations were analyzed by flow cytometry, while mucosal gene expression and gut microbiota composition were evaluated using RT-qPCR and 16S rRNA sequencing, respectively. Results: LMW-LF administration significantly attenuated clinical symptoms and macroscopic colonic damage. Treatment restored epithelial barrier integrity by upregulating tight junction proteins (Tjp1) and mucin genes (Muc1-3) while normalizing DSS-induced epithelial hyperproliferation. Immunologically, LMW-LF reduced pro-inflammatory monocyte infiltration; downregulated Il6, Tnfa, and Ifng; and promoted an immunoregulatory phenotype by enhancing Ampk expression and partially restoring regulatory T cell (Treg) populations. Furthermore, LMW-LF reshaped the gut microbiota by increasing alpha diversity and promoting the enrichment of beneficial taxa, specifically Akkermansia muciniphila, which correlated with improved mucus layer preservation. Conclusions: LMW-LF is an active fraction acting across the host–microbiota axis. By integrating epithelial protection, immunomodulation, and microbial reshaping, it represents a promising dietary strategy for the management of Inflammatory Bowel Diseases. Full article