To clarify the effect of Dendrobium devonianum pulp (DP) on relieving constipation, the study evaluated the effect of DP on defecation function, colonic histomorphology, gastrointestinal regulatory peptides, gut microbiota composition, and short-chain fatty acid (SCFA) levels in a mouse model of slow-transit constipation induced by loperamide (LOP). The results showed that compared with the constipation group, DP intervention significantly promoted defecation in constipated mice, reducing the time to the first red fecal pellet discharge by 43.52% (P < 0.05). Additionally, it increased the number of fecal pellets, fecal water content, and colonic transit rate within 5 hours by 113.3%, 27.80%, and 193.33%, respectively, while improving fecal morphology. Histopathological analysis revealed that DP effectively alleviated constipation-induced damage to the colonic mucosal epithelium, restored villi morphology, and increased the number of goblet cells. Biochemical analysis showed that DP significantly increased the levels of excitatory gastrointestinal peptides and decreased the levels of inhibitory gastrointestinal peptides in both the serum and colon of constipated mice. Specifically, following DP intervention, the serum levels of motilin (MTL) and 5-hydroxytryptamine (5-HT) increased to 150.94% and 201.67% (P < 0.05) of the LOP group, respectively, while that of vasoactive intestinal peptide (VIP) decreased by 75.90% (P < 0.05). The colonic levels of MTL and 5-HT increased to 679.60% and 2261.09% (P < 0.05) of the LOP group, respectively, while that of VIP reduced by 59.61% (P < 0.05). 16S rRNA gene sequencing demonstrated that DP increased the Chao1, Shannon, and Simpson indices of the gut microbiota, elevated the Firmicutes/Bacteroidetes ratio, promoted the proliferation of Lactobacillus, and suppressed that of Lachnospira. Furthermore, DP significantly enhanced the levels of propionic and butyric acids in the feces of constipated mice. In conclusion, DP alleviates constipation through multiple mechanisms, including enhancing intestinal motility, repairing colonic tissue damage, balancing neuropeptide levels, optimizing gut microbiota structure, and promoting SCFA production. This study provides a scientific basis for the use of DP as a functional food for improving intestinal health and offers new insights into the application of natural products in gut function regulation.

Rosmarinic acid (RA) is a natural phenolic acid with multiple biological and pharmacological properties. However, its protective effect on ulcerative colitis (UC) remains uncertain. This study aims to explore the protective ability and potential mechanism of RA on UC, focusing on the intestinal barrier and homeostasis. UC mice model was established through the induction by dextran sulfate sodium (DSS) of 2.5%, and the progression of the UC after RA treatment was monitored using clinical manifestations, histopathological examination, and biochemical analysis. The mice’s composition of intestinal flora was assessed through 16S rRNA sequencing methods, while the concentrations of short-chain fatty acids (SCFAs) and bile acids (BAs) were analyzed using targeted metabolomics. The findings demonstrated that RA could prevent a decrease in body weight, reduce the scores of disease activity index (DAI), shorten colon length, and restore the claudin-1, zonula occludens-1 (ZO-1), and occludin levels in UC mice. Furthermore, RA effectively suppressed intestinal inflammation, modulated the compositin of gut microbiota, and influenced the levels of SCFAs and BAs. Hence, RA could offer therapeutic benefits for UC mice by enhancing intestinal barrier function and preserving intestinal homeostasis. Given the availability of scientific evidence, it may serve as a preventive agent or remedy for UC.

In this study, Panax notoginseng leaves (PNL) were separately fermented by Rhizopus oryzae, Neurospora crassa, Monascus and Mucor rouxianus, and changes in the contents of total saponins, total polysaccharides, total phenolics, and total flavonoids, as well as in vitro antioxidant activity and α-glucosidase inhibitory activity of PNL during the fermentation process were assessed. Additionally, the metabolite profiles of raw and fermented PNL were analyzed by ultrahigh performance liquid chromatography-mass spectrometry (UPLC-MS/MS). The results indicated that the contents of total saponins and total polysaccharides in PNL were significantly reduced by fermentation with each of these four fungi. Interestingly, R. oryzae, N. crassa and Monascus were found to increase the content of total phenols, while Rhizopus oryzae and Mucor rouxianus increased the total flavonoid content. Fermentation for 3–5 days significantly enhanced the antioxidant activity of PNL, and the most pronounced effect was achieved with Monascus fermentation for three days, which increased the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical cation scavenging capacity and ferric reducing capacity by 14.30%, 5.13%, and 18.40%, respectively. Moreover, the α-glucosidase inhibitory activity of PNL initially decreased and then increased during fungal fermentation, which increased by 16.03% after Monascus fermentation for six days. By untargeted metabolomics analysis, 573 metabolites were identified from PNL. After three days of Monascus fermentation, the up-regulated metabolites were significantly less than the down-regulated ones, and the predominant up-regulated metabolites were amino acids, alkaloids, carbohydrates, lipids, phenols, flavonoids, and terpenoids. Furthermore, analysis of the 21 saponins showed that only ginsenoside F2 was significantly up-regulated, while eight other saponins were significantly down-regulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that co-factor biosynthesis, flavonoid biosynthesis, purine metabolism, and pyrimidine metabolism were the most probable metabolic pathways during the fermentation process. In conclusion, fungal fermentation, especially Monascus fermentation, can effectively improve the functional activity of P. notoginseng by metabolic alterations through various pathways. Therefore, this study provides a scientific reference for the green processing of PNL.

In this study, an in vitro digestive model was established to determine changes in the contents of total saponins, total phenols, polysaccharides, and total flavonoids in Panax notogiseng leaves (PNL) during simulated digestion.Meanwhile, changes in the in vitro antioxidant activity and α-glucosidase-inhibiting activity were assessed. Ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was employed to further analyze the pattern of changes in 24 monomer saponins in PNL. The results showed that the contents of total saponins and total phenols were the highest at the intestinal digestion stage, reaching up to 188.32 and 17.43 mg/g, respectively. The change in polysaccharide content was insignificant during the entire digestion process. The content of total flavonoids was the highest in the oral digestion stage at 23.76 mg/g. Similarly, the antioxidant and α-glucosidase-inhibiting capacity of PNL were both the strongest in the intestinal digestion stage. The 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activity, iron-reducing capacity, and α-glucosidase-inhibiting capacity all showed a trend of initial decrease and then increase and reached the highest values of 84.97%, 37.80 mg/g, and 72.5%, respectively in the intestinal digestion stage. Furthermore, the large-molecular-mass ginsenosides Rb₁, Rb₂, Rb₃, Re, and Rd were cleaved into small-molecular-mass rare saponins such as compound K, Rg₃, Rg₅, and Rk₁. In conclusion, PNL still exhibited significant functional activity after digestion. The functional activities of PNL, such as antioxidant and α-glucosidase-inhibiting activity, increased as the digestion process proceeded, reaching their highest levels in the intestinal digestion stage. This might be related to the release of active ingredients and the production of small-molecule rare saponins. This study could provide a scientific basis for applying PNL to develop functional foods.