Chronic constipation is a prevalent functional gastrointestinal disorder with limited long-term treatment options. This study examined whether a fucoidan preparation derived from Sargassum fusiforme (SF) ameliorates loperamide (LOP)-induced constipation in male ICR mice. SF was administered by oral gavage at 50, 100 or 200 mg/kg/day for 35 days, and constipation was induced with LOP (5 mg/kg) during the final 7 days; the design is therefore preventive rather than therapeutic. Defecation endpoints were recorded at the cage level (n = 3 cages per group) and fecal moisture in individual mice (n = 7 per group), whereas colonic cytokine and myeloperoxidase (MPO) measurements (n = 3-4 per group) and Western blot analyses (n = 3 per group) were performed in a small subset of animals, and histological analyses in n = 6-8 per group. SF increased fecal output and fecal moisture content with increasing dose; at 200 mg/kg the relative fecal number returned to the level of the Vehicle control group, although the absolute daily pellet count remained lower than that of the Vehicle control and of the Positive control group. SF administration was associated with lower colonic TNF-α, IL-6, IL-1β and MPO concentrations, with reduced phosphorylation of p38, JNK and ERK, with higher C-kit and stem cell factor (SCF) levels, with normalization of the LOP-induced increase in aquaporin-3 (AQP3), and with recovery of colonic mucosal thickness and mucin content. 16S rRNA gene sequencing showed a shift in fecal microbiota community structure (PERMANOVA p = 0.0002) and a dose-related increase in the combined relative abundance of Lactobacillus and Bifidobacterium, without a reduction in alpha diversity. These findings indicate that SF ameliorates LOP-induced constipation in male mice and that this effect is accompanied by changes in colonic inflammatory signaling, motility-related protein expression, mucosal architecture and gut microbiota composition.

Probiotics have emerged as a promising therapeutic strategy for relieving constipation. The strategy of employing multi-strain probiotic combinations to achieve synergistic therapeutic effects is widely adopted in commercial applications. This study demonstrates that incorporating Ligilactobacillus acidipiscis YJ5 as a synergistic keystone strain into a base three-strain probiotic consortium (CP3-L) creates a potent low-dose formulation (CP4-L) with enhanced efficacy against loperamide-induced constipation in mice. Although the CP3-L consortium (Lactiplantibacillus plantarum SYS1 and T34, Limosilactobacillus fermentum W1) itself outperformed its constituent single strains, the CP4-L consortium provided improvement in defecation parameters, intestinal barrier integrity, and inflammatory markers. It effectively restored interstitial cells of Cajal (ICC) markers (c‑Kit/SCF) to enhance intestinal motility, downregulated colonic aquaporins to increase fecal water content, and selectively modulated the gut microbiota to raise beneficial Bifidobacterium and fecal butyrate levels. These findings validate a mechanism-guided approach to probiotic consortium design, where functional complementarity between strains yields synergistic, multi-target anti-constipation activity at a reduced dosage.

Therapeutic probiotic formulations are promising microbiome-directed interventions for constipation, but their dose-dependent mechanisms remain unclear. This study investigated whether probiotic treatment induces dose-dependent gut microbiota and fecal metabolome remodeling in a loperamide-induced rat model of constipation and identified microbiome-metabolome association signatures linked to intestinal recovery. Male SPF Sprague-Dawley rats were assigned to Control, Model, low-dose probiotic (1 × 10[9] CFU/day), high-dose probiotic (1 × 10[10] CFU/day), and PFK groups. Constipation was induced with loperamide (10 mg/kg/day) for 14 days, followed by 14 days of intervention. Intestinal function was assessed by body weight, food intake, fecal output, fecal water content, and intestinal transit rate. Gut microbiota was profiled by 16 S rRNA sequencing, and fecal untargeted LC-MS/MS metabolomics was performed in 36 samples. Differential metabolites were identified using VIP > 1 and p < 0.05, followed by microbiome-metabolome correlation analysis. Given the exploratory nature and limited group sizes, these metabolites were considered candidate features rather than statistically validated biomarkers. High-dose probiotic intervention significantly improved intestinal function and reshaped the gut microbiota, enriching short-chain fatty acid-associated genera including Blautia, Fusicatenibacter, and Muribaculaceae-related taxa. Despite reduced alpha diversity, functional recovery was accompanied by selective microbial restructuring. Metabolomics identified 5,257 annotated features, with high-dose probiotics producing the strongest remodeling (1,006 differential metabolites vs. Model). Reversal analysis identified 68 constipation-associated metabolites shifted in the opposite direction after treatment. Microbiome-metabolome correlation analysis identified associations between key genera and lipid-, organic acid-, and indole-related metabolites, highlighting potential immunometabolic interactions. High-dose probiotic intervention was associated with coordinated changes in the gut microbiota and fecal metabolome together with improved intestinal function, supporting further investigation of dose optimization for microbiome-based constipation therapies.

Slow transit constipation (STC) is a chronic gastrointestinal disorder marked by impaired intestinal motility and reduced frequency of bowel movements, often linked to the dysfunction of interstitial cells of Cajal (ICC). Endoplasmic reticulum (ER) stress and subsequent apoptosis in ICC play a pivotal role in the pathogenesis of STC. Shengxue Tongbian Granules, a Traditional Chinese Medicine formulation, have shown potential in treating constipation, though their mechanisms remain unclear. This study investigates the effects of Shengxue Tongbian Granules in a loperamide-induced STC mouse model. Mice were treated with varying doses of Shengxue Tongbian Granules and assessed for fecal output, intestinal motility, and histopathological changes. Results indicated a significant improvement in fecal output, water content, and intestinal propulsion in Shengxue Tongbian Granules-treated mice compared to controls. Furthermore, Shengxue Tongbian Granules alleviated histopathological damage in the colon, preserved ICC levels, and reduced ER stress-mediated apoptosis by modulating key markers, including p-PERK, p-eIF2α, IRE1α, ATF6, GRP78, CHOP, cleaved caspase-3, and calreticulin. The protective effects of Shengxue Tongbian Granules were further confirmed through siRNA-mediated calreticulin knockdown in ICC, which abolished the anti-apoptotic benefits of the treatment. These findings suggest that Shengxue Tongbian Granules exert therapeutic effects in STC by improving gut motility, preserving ICC function, and mitigating ER stress-mediated apoptosis, offering a potential alternative for managing STC.

Background: Glucagon-like peptide-1 receptor agonists and dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 (GIP/GLP-1) receptor agonists have substantially improved the management of obesity and cardiometabolic disease, providing significant benefits on weight reduction, glycemic control, and cardiovascular outcomes. Despite these advances, gastrointestinal (GI) adverse events remain a major cause of dose reduction, treatment interruption, and poor long-term adherence. Increasing evidence suggests that interactions between incretin-based therapies and the intestinal microenvironment may contribute to GI tolerability and influence treatment persistence. Methods: We conducted a narrative review of the literature examining the relationship between incretin-based therapies, gut microbiota, intestinal barrier function, and microbial metabolites. Evidence from randomized clinical trials, observational studies, systematic reviews, and mechanistic investigations was evaluated to explore potential gut-directed supportive strategies during incretin-based treatment. Results: Preclinical and mechanistic evidence suggests possible bidirectional interactions between incretin pharmacology and the intestinal microenvironment, whereas direct human evidence remains limited and inconsistent. Alterations in gastrointestinal motility induced by GLP-1 receptor agonists could theoretically influence microbial composition and fermentation dynamics, although human studies have not consistently demonstrated significant microbiota changes. Based on these observations, we propose the Incretin-Microbiota Tolerance Axis (IMTA) as a conceptual framework linking gut homeostasis, GI tolerability, and treatment adherence. Among potential supportive interventions, partially hydrolyzed guar gum (PHGG) may promote SCFA-producing microbiota and improve bowel function, whereas simethicone may provide symptomatic relief of gas-related discomfort during dose escalation. SCFA-supportive nutritional approaches may further contribute to maintenance of intestinal homeostasis. Conclusions: Optimization of the intestinal microenvironment may represent a complementary strategy to improve GI tolerability and support long-term adherence during incretin-based therapy. Although the IMTA framework is supported by biological plausibility and emerging evidence, prospective clinical studies are required to determine whether microbiota-targeted interventions improve treatment persistence and cardiometabolic outcomes in patients receiving GLP-1 receptor agonists or dual GIP/GLP-1 receptor agonists.

Slow transit constipation (STC) involves impaired colonic motility, and effective therapies remain limited. Inulin-type fructans (ITFs) are prebiotic polysaccharides linked to intestinal function, but mixtures with broad chain-length distributions hinder structure-function interpretation. In this study, we adopted a degree of polymerization (DP)-anchored strategy to compare two structurally related ITFs from Asparagus cochinchinensis: ACO (DP = 6) and ACNP (DP = 15). In a loperamide (LOP)-induced STC model, ACNP, but not ACO, improved fecal output and water content, shortened the time to first black stool, and enhanced intestinal transit. ACNP alleviated colonic injury, restored mucus-associated protection, improved epithelial barrier integrity, and preserved enteric neurons and nerve-fiber networks. Multi-omics analyses showed that ACNP treatment was associated with enrichment of Akkermansia muciniphila (AKK), restoration of kynurenic acid (KYNA), reduced proinflammatory mediators, and attenuated NLRP3 inflammasome activation. Antibiotic depletion largely abolished these benefits, whereas fecal microbiota transplantation (FMT) restored them. Moreover, live AKK supplementation and exogenous KYNA reproduced key protective effects and were associated with reduced NLRP3 inflammasome activation. Overall, this DP-anchored comparison identified ACNP as the more effective fructan fraction and supports a microbiota-dependent protective response involving AKK enrichment, KYNA restoration, NLRP3 inflammasome attenuation, barrier protection, and enteric nervous system (ENS) preservation.

The rising incidence of constipation and side effects of clinical drugs have spurred research on natural functional ingredients for its prevention and treatment. Probiotics and dietary fibers have diverse bioactivities but are limited by poor stability and low bioavailability. Herein, a novel microcapsule system co-loading Ganoderma lucidum dietary fiber (GLDF) and Lactobacillus fermentum CECT5716 was constructed using whey protein (WP) and xanthan gum (XG) via hybrid spray drying-complex coacervation. Optimal WP-XG interaction (driven by electrostatic forces and hydrogen bonds) was achieved at pH 3.75 and 5:1 mass ratio; microcapsules with 1:1 wall-to-core ratio showed the best performance, with 72.3% post-encapsulation probiotic viability and enhanced stability under simulated gastrointestinal conditions and storage. Animal experiments confirmed that the microcapsules effectively alleviated loperamide (LOP)-induced constipation in mice, associated with regulating gut microbiota, promoting short-chain fatty acids (SCFAs) production, inhibiting colonic inflammation, repairing intestinal tight junctions, and downregulating aquaporins. In conclusion, the microcapsules prepared in this study provide a feasible strategy for the efficient co-delivery of probiotics and dietary fibers, and the developed composite functional ingredient holds great application potential in the field of constipation prevention and treatment.