Protective effect of fermented okara on the regulation of inflammation, the gut microbiota, and SCFA production in rats with TNBS-induced colitis

Butyrate attenuates intestinal inflammation in Crohn's disease by suppressing pyroptosis of intestinal epithelial cells via the cGSA-STING-NLRP3 axis

Butyrate can strengthen the intestinal epithelial barrier. However, the mechanisms by which butyrate affects intestinal epithelial cells (IECs) pyroptosis in Crohn's disease (CD) remain unclear. In this study, we collected colonic biopsy samples from CD patients and healthy controls to assess pyroptosis levels. Our findings indicated elevated expression of pyroptosis markers in CD patients, alongside distinct morphological evidence of pyroptosis in IECs. We further investigated the effects of tributyrin on pyroptosis and the cGAS-STING pathway in a trinitrobenzene sulfonic acid-induced colitis rat model. Tributyrin significantly mitigated intestinal inflammation, reduced pathological progression, and inhibited pyroptosis and cGAS-STING pathway activation in the colitis rat model. Similarly, in an in vitro model of IECs pyroptosis, sodium butyrate inhibited pyroptosis and cGAS-STING pathway activation in HT-29 cells. Co-treatment with a cGAS-STING pathway activator and butyrate demonstrated that the activator reversed the inhibitory effects of butyrate on pyroptosis and cGAS-STING pathway activation in both the colitis rat model and HT-29 cells. Mechanistically, the cGAS-STING pathway was found to interact with NLRP3. Taken together, butyrate may mitigate intestinal inflammation in CD by suppressing cGAS-STING-NLRP3 axis-mediated IECs pyroptosis. These findings offer new insights into potential therapeutic strategies for managing CD.

Effect of Propionate on Citrobacter rodentium Infection in Mice by Regulating NleH Expression

Propionate is one of the main short chain fatty acids in the gut. Previously, we found that propionate significantly down-regulated the expression of NleH. NleH is a virulence effector secreted by Citrobacter rodentium (C. rodentium, C.r.) and is essential for its intestinal colonisation and infection. Therefore, this study intends to explore the effect and mechanism of propionate on C.r. infection by regulating the expression of NleH. Wild-type C.r. and its NleH mutant (C.r.△NleH), E.coli and its NleH1 mutant (E.coli△NleH1) were co-cultured with propionate separately, changes in strain growth and invasion adhesion were detected. Meanwhile, C57BL/6J mice were infected with C.r. and C.r.△NleH to establish animal model, and propionate intervention was given. Through detecting the invasive and infectious ability of strains in mice and the changes related to colon inflammation, to analyse the effect of propionate on C.r. infection by regulating NleH expression. The results showed that propionate can reduce the adhesion of C.r. and intestinal damage by down-regulating NleH expression, meanwhile changes of microbial functional metabolism enhance the resistance to C.r. infection in mice.

Polysaccharides extracted from common buckwheat (Fagopyrum esculentum) attenuate cognitive impairment via suppressing RAGE/p38/NF-κB signaling and dysbiosis in AlCl3-treated rats

Patients may find it challenging to accept several FDA-approved drugs for Alzheimer's disease (AD) treatment due to their unaffordable prices and side effects. Despite the known antioxidant, anti-inflammatory, and microbiota-regulating effects of common buckwheat (Fagopyrum esculentum) polysaccharides (FEP), their specific role in preventing AD has not been determined. Here, this study investigated the preventive effects of FEP on AD development in AlCl3-treated rats. The physical properties of FEP were evaluated using X-ray diffraction, FTIR, TGA, DSC, monosaccharide composition, molecular weight, and scanning electron microscopy. The results demonstrated that FEP administration improved memory and learning ability in AlCl3-treated rats. Additionally, AD pathological biomarkers (APP, BACE1, Aβ1-42, and p-TauSer404), inflammatory-associated proteins (IL-1β, IL-6, TNF-α, and Iba1), and MDA and the RAGE/p38/NF-κB pathway were elevated in AlCl3-treated rats. Moreover, these effects were reversed by the upregulation of LRP1, anti-inflammatory cytokines (IL-4 and IL-10), antioxidant enzymes (SOD and catalase), and autophagy proteins (Atg5, Beclin-1, and LC3B). Furthermore, FEP treatment increased the levels of short-chain fatty acids (SCFAs) and the abundance of SCFAs-producing microbes ([Eubacterium]_xylanophilum_group, Lachnospiraceae_NK4A136_group, Lactobacillus). Overall, FEP mitigated oxidative stress, RAGE/p38/NF-κB-mediated neuroinflammation, and AD-associated proteins by upregulating autophagy and SCFA levels, which led to the amelioration of cognitive impairment through microbiota-gut-brain communication in AlCl3-treated rats.

Neohesperidin Dihydrochalcone Ameliorates Experimental Colitis via Anti-Inflammatory, Antioxidative, and Antiapoptosis Effects

Neohesperidin dihydrochalcone (NHDC) is a citrus-originated, seminatural sweetener. There is no investigation concerning the effect of NHDC on ulcerative colitis. The purpose of this study was to determine the therapeutic and protective effects of NHDC in Wistar Albino rats. NHDC was given for 7 days after or before colitis induction. The results showed that NHDC significantly reduced the interleukin-6 (IL-6), interleukin-10 (IL-10), transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) levels. Catalase levels did not show a significant difference between the groups. NHDC provided a remarkable decrease in the expression levels of cyclooxygenase-2 (COX-2), myeloperoxidase (MPO), malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and nuclear factor kappa B (NF-κB). Total antioxidant status (TAS) levels were significantly elevated in NHDC treatment groups, while total oxidant status (TOS) and oxidative stress index (OSI) levels were significantly decreased. NHDC provided remarkable improvement in histological symptoms such as epithelial erosion, edema, mucosal necrosis, inflammatory cell infiltration, and hemorrhage. Also, caspase-3 expression levels were statistically decreased in NHDC treatment groups. The results indicated that NHDC might be a protection or alternative treatment for ulcerative colitis.

Compound prebiotics as prophylactic and adjunctive treatments ameliorate DSS-induced colitis through gut microbiota modulation effects

The prophylactic and adjunctive impacts of compound prebiotics (CP), comprising galacto-oligosaccharides, fructo-oligosaccharides, and isomalto-oligosaccharides, on colitis remain unclear. This study aimed to elucidate the effects of CP on dextran sodium sulfate (DSS)-induced colitis via modulation of the gut microbiota. Mice received prophylactic CP (PCP) for three weeks and DSS in the second week. In the third week, therapeutic CP, mesalazine, and a combination of CP and mesalazine (CPM) were administered to mice with DSS-induced colitis. The administration of PCP and CPM was found to ameliorate colitis, as evidenced by increases in body weight and colon length, elevation of the anti-inflammatory cytokine IL-10, and reductions in the disease activity index, histological scores, and levels of pro-inflammatory cytokines in mice with DSS-induced colitis on days 14 or 21. Furthermore, an increase in the relative abundance of probiotics (Ligilactobacillus, Bifidobacterium, and Limosilactobacillus), alpha diversity indices, short-chain fatty acids (SCFA) contents, and microbial network complexity was observed following PCP or CPM treatment. Correlation analysis revealed positive associations between these probiotics and both SCFA and IL-10, and negative associations with pro-inflammatory cytokines. This study highlighted the potential of CP as novel prophylactic and adjunctive treatments for alleviating DSS-induced intestinal inflammation and maintaining gut microbiota homeostasis.

Soluble Dietary Fiber from Citrus unshiu Peel Promotes Antioxidant Activity in Oxidative Stress Mice and Regulates Intestinal Microecology

Aging is characterized by the progressive degeneration of bodily tissues and decline in physiological functions, a process that may be exacerbated by imbalances in intestinal flora. Soluble dietary fiber (PSDF) from Citrus unshiu peel has demonstrated strong free radical scavenging ability to regulate intestinal flora in vitro. However, further evidence is required to ascertain the effectiveness of PSDF in vivo. In our study, 8-week-old mice were artificially aged through subcutaneous injections of a 200 mg/kg/d D-galactose solution for 42 days, followed by a 28-day dietary intervention with varying doses of PSDF, insoluble dietary fiber (PIDF), and vitamin C. After the intervention, we observed a significant mitigation of D-galactose-induced oxidative stress, as evident by weight normalization and reduced oxidative damage. 16S rRNA gene sequencing revealed that PSDF significantly altered the composition of intestinal flora, increasing Firmicutes and reducing Bacteroidota percentages, while also enriching colonic short-chain fatty acids (SCFAs). Spearman correlation analysis further identified a positive correlation between Firmicutes and isovaleric acid, and negative correlations between Muribaculaceae and acetic acid, and between Lachnospiraceae_NK4A136_group and caproic acid. These findings support the potential of Citrus PSDF to alleviate oxidative stress.

Protective effect of cellulose and soluble dietary fiber from Saccharina japonica by-products on regulating inflammatory responses, gut microbiota, and SCFAs production in colitis mice

This study aimed to investigate the physicochemical properties of soluble dietary fiber (SDF) and cellulose enriched in Saccharina japonica by-products and to evaluate their anti-colitis effects. The water-holding capacity (WHC), swelling capacity (SC), cation exchange capacity (CEC), and antioxidant properties of SDF were superior to cellulose. The ΔH of SDF and cellulose was 340.73 J/g and 134.56 J/g, and the average particle size of them was 43.858 μm and 97.350 μm. The viscosity of SDF was positively correlated with the content. SEM revealed that the microstructure of SDF was porous, whereas cellulose was folded. SDF contained seven monosaccharides such as mannuronic acid and mannose, while cellulose had a single glucose composition. It was also shown that both SDF and cellulose reversed the pathological process of colitis by inhibiting weight loss, preventing colon injury, balancing oxidative stress, and regulating the level of inflammation, with the optimal dose being 1.5 g/kg. The difference was that SDF inhibited the expression of NF-кB and TNF-α, while cellulose up-regulated the expression of PPAR-γ and IL-10. Additionally, SDF could more positively control the expression of ZO-1, whereas cellulose was superior in improving the expression of Occludin. Interestingly, SDF could restore the structure of norank_f_Muribaculaceae and Lachnospiraceae_NK4A136_group to ameliorate ulcerative colitis (UC), whereas cellulose mainly regulated the abundance of norank_f_Muribaculaceae, Faecalibaculum, Bacteroides and unclassified_f__Lachnospiraceae. The production of short-chain fatty acids (SCFAs) was also found to be restored by SDF and cellulose. Overall, SDF and cellulose can be considered important dietary components for treating and preventing UC.

Notch Signaling Inhibition Alleviates Allergies Caused by Antarctic Krill Tropomyosin through Improving Th1/Th2 Imbalance and Modulating Gut Microbiota

Antarctic krill tropomyosin (AkTM) has been shown in mice to cause IgE-mediated food allergy. The objective of this work was to investigate the role of Notch signaling in AkTM-sensitized mice, as well as to determine the changes in gut microbiota composition and short-chain fatty acids (SCFAs) in the allergic mice. An AkTM-induced food allergy mouse model was built and N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) was used as an γ-secretase inhibitor to inhibit the activation of Notch signaling. Food allergy indices, some key transcription factors, histologic alterations in the small intestine, and changes in gut microbiota composition were examined. The results showed that DAPT inhibited Notch signaling, which reduced AkTM-specific IgE, suppressed mast cell degranulation, decreased IL-4 but increased IFN-γ production, and alleviated allergic symptoms. Quantitative real-time PCR and Western blotting analyses revealed that expressions of Hes-1, Gata3, and IL-4 were down-regulated after DAPT treatment, accompanied by increases in T-bet and IFN-γ, indicating that Notch signaling was active in AkTM-sensitized mice and blocking it could reverse the Th1/Th2 imbalance. Expressions of key transcription factors revealed that Notch signaling could promote Th2 cell differentiation in sensitized mice. Furthermore, 16S rRNA sequencing results revealed that AkTM could alter the diversity and composition of gut microbiota in mice, leading to increases in inflammation-inducing bacteria such as Enterococcus and Escherichia-Shigella. Correlation analysis indicated that reduced SCFA concentrations in AkTM-allergic mice may be related to decreases in certain SCFA-producing bacteria, such as Clostridia_UCG-014. The changes in gut microbiota and SCFAs could be partially restored by DAPT treatment. Our findings showed that inhibiting Notch signaling could alleviate AkTM-induced food allergy by correcting Th1/Th2 imbalance and modulating the gut microbiota.

Wallace melon juice fermented with Lactobacillus alleviates dextran sulfate sodium-induced ulcerative colitis in mice through modulating gut microbiota and the metabolism

Fermented foods have shown promise in preventing or treating ulcerative colitis (UC) via regulating intestinal flora and correcting metabolic disorders. However, the prevention effect of fermented Wallace melon juice (FMJ) on UC is unclear. In this study, the effects of FMJ on dextran sodium sulfate (DSS)-induced UC were investigated via 16S rRNA sequencing and non-targeted metabolomics. The results showed that FMJ was effective in alleviating the symptoms of UC, reducing histological damage and oxidative stress, decreasing the levels of pro-inflammatory cytokines. After FMJ treatment, the level of propionic acid, butyric acid, and valeric acid increased by 14.1%, 44.4%, and 52.4% compared to DSS-induced UC mice. Meanwhile, the levels of harmful bacteria such as Oscillospira, Bacteroidetes, and Erysipelotrichaceae and Clostridium decreased, while the levels of beneficial bacteria such as Akkermansia, Lactobacillus, and Bifidobacterium increased. Fecal metabolomics analysis identified 31 differential metabolites, which could regulate metabolic disorders in UC mice by controlling the primary bile acid biosynthesis, purine metabolism, and pantothenate and CoA biosynthesis pathway. Additionally, the abundances of butyric acid, bile acids, and pantothenic acid were positively correlated with Allobaculum, Bifidobacterium, and other beneficial bacteria (R2 > 0.80, p < 0.01). The results indicated that FMJ played a role in regulating the structure of intestinal flora, which in turn helped in repairing metabolic disorders and alleviated colitis inflammation.

Targeted delivery of Fc-fused PD-L1 for effective management of acute and chronic colitis

The PD-1/PD-L1 pathway in mucosal immunity is currently actively explored and considered as a target for inflammatory bowel disease (IBD) treatment. However, systemic PD-L1 administration may cause unpredictable adverse effects due to immunosuppression. Here we show that reactive oxygen species (ROS)-responsive nanoparticles enhance the efficacy and safety of PD-L1 in a mouse colitis model. The nanoparticles control the accumulation and release of PD-L1 fused to Fc (PD-L1-Fc) at inflammatory sites in the colon. The nanotherapeutics shows superiority in alleviating inflammatory symptoms over systemic PD-L1-Fc administration and mitigates the adverse effects of PD-L1-Fc administration. The nanoparticles-formulated PD-L1-Fc affects production of proinflammatory and anti-inflammatory cytokines, attenuates the infiltration of macrophages, neutrophils, and dendritic cells, increases the frequencies of Treg, Th1 and Tfh cells, reshapes the gut microbiota composition; and increases short-chain fatty acid production. In summary, PD-L1-Fc-decorated nanoparticles may provide an effective and safe strategy for the targeted treatment of IBD.

Phyllanthus emblica L. polysaccharides ameliorate colitis via microbiota modulation and dual inhibition of the RAGE/NF-κB and MAPKs signaling pathways in rats

Pharmacological treatments for colitis have limited efficacy and side effects. Plant polysaccharides improve colitis by modulating the gut microbiota. However, the specific benefits of Phyllanthus emblica L. polysaccharides (PEPs) in colitis remain unclear. Therefore, this study aimed to assess the physical characteristics and health advantages of PEP in rats subjected to 2,4,6-trinitrobenzene sulfonic acid (TNBS) treatment. The results showed that PEP (1.226 × 103 kDa) was an α-acidic pyran heteropolysaccharide rich in galactose and galacturonic acid. Prefeeding rats with PEP significantly decreased the levels of NO, MDA, proinflammatory cytokines (IL-6, IL-1β, TNF-α), apoptosis, and the activities of mucinase and β-glucuronidase. These changes were accompanied by increases in the levels of anti-inflammatory cytokines (IL-4, IL-10) and antioxidant enzymes (SOD, catalase, GPx) in colitis rats. Mechanistically, PEP suppressed the abundance of inflammatory-related bacteria (Bacteroides, Intestinimonas, and Parabacteroides) while promoting the growth of short-chain fatty acid (SCFA)-producing bacteria (Romboutsia, Clostridium_sensu_stricto_1, and Lactobacillus), along with an increase in SCFA secretion. SCFAs may engage with the GPR43 receptor and inhibit downstream HDAC3, consequently downregulating the activation of the RAGE/NF-κB and MAPK pathways. In conclusion, PEP demonstrated preventive effects through its antioxidant, anti-inflammatory, and microbiota modulation properties, thereby ameliorating TNBS-induced colitis in rats.

Targeting the gut microbiota-related metabolites for osteoporosis: The inextricable connection of gut-bone axis

Osteoporosis is a systemic skeletal disease characterized by decreased bone mass, destruction of bone microstructure, raised bone fragility, and enhanced risk of fractures. The correlation between gut microbiota and bone metabolism has gradually become a widespread research hotspot in recent years, and successive studies have revealed that the alterations of gut microbiota and its-related metabolites are related to the occurrence and progression of osteoporosis. Moreover, several emerging studies on the relationship between gut microbiota-related metabolites and bone metabolism are also underway, and extensive research evidence has indicated an inseparable connection between them. Combined with latest literatures and based on inextricable connection of gut-bone axis, this review is aimed to summarize the relation, potential mechanisms, application strategies, clinical application prospects, and existing challenges of gut microbiota and its-related metabolites on osteoporosis, thus updating the knowledge in this research field and providing certain reference for future researches.

The attenuating effect of fermented soymilk on DSS-induced colitis in mice by suppressing immune response and modulating gut microbiota

Fermented soymilk (FSM) as a new plant-based yoghurt has attracted attention for its nutritional and health benefits. The aim of this research is to explore the effect of consuming FSM before and during inflammatory bowel disease (IBD) on intestinal immune response, and to assess whether fermentation and sucrose can improve the anti-inflammatory activity of soymilk (SM) and FSM, and finally clarify their effect on the gut microbiota and levels of short-chain fatty acids (SCFAs). Consuming FSM in advance can effectively alleviate weight loss and bloody stools in mice with colitis and is associated with a 27% colon length repair rate. It can also prevent spleen and liver enlargement, inhibit immune response and oxidative stress, and increase the expression of the tight junction protein occludin gene (60%). Meanwhile, intaking FSM during IBD reduced weight loss, prevented liver damage, and repaired colon injury. In addition, fermentation enhance the inhibitory effects of FSM on colitis, whereas adding 3% sucrose to FSM had no effect on its intervention in colitis. Analysis of the composition of the gut microbiota in mice showed that the intake of FSM reduced the relative abundance of the pathogenic bacteria Parasutterella, Turicibater, and Bacteroide by 75%, 62%, and 50%, respectively, and increased the relative abundance of the beneficial bacteria Akkermansiaceae, Lachnospiraceae, Alloprevotella, and Dubosella by 28%, 50%, 80%, and 63%, respectively. It further restored the levels of SCFAs in the mouse intestine. The results provide a scientific basis for FSM as a natural anti-inflammatory food that can improve inflammatory intestinal microbiota imbalance and promote gut health.

Moutai Distiller's grains Polyphenol extracts and rutin alleviate DSS-induced colitis in mice: Modulation of gut microbiota and intestinal barrier function （R2）

Distiller's grains, byproducts of the brewing process, represent a valuable resource for extracting natural phenolic compounds due to their significant global production. This study presents the first evidence of the protective effects of Moutai distiller's grain polyphenol extract (MDGP) on dextran sulfate sodium (DSS)-induced colitis in mice. These protective effects manifest predominantly through the amelioration of general colitis indices and histopathological improvements. Utilizing liquid chromatography-high-resolution electrospray ionization mass spectrometry (LC-HR-ESI-MS), the main components of MDGP were identified as rutin, quercetin, naringenin, and dihydroquercetin. Moreover, a novel mechanism was elucidated by which rutin, the primary active component of MDGP, alleviates DSS-induced colitis. Assessment of intestinal barrier function, microbial sequencing, fecal transplantation, and antibiotic depletion experiments revealed that rutin suppresses the abundance of pathogenic bacteria (Helicobacter, Klebsiella, and Veillonella) while promoting the proliferation of beneficial bacteria (Ruminococcus_torques_group, Lachnoclostridium, and norank_f__Muribaculaceae). This modulation culminates in elevated butyric acid concentrations within short-chain fatty acids (SCFAs), amplified integrity of tight (ZO-1, occludin) and adherent (E-cadherin, β-catenin) junctional complexes, fortified intestinal barrier function, and diminished intestinal inflammation.This investigation accentuates the innovative therapeutic potential of MDGP and its main active component, rutin, in assuaging DSS-induced intestinal inflammation and fortifying the intestinal barrier through a mechanism predominantly mediated by the intestinal microbiota. Such insights potentially elevate the prominence of distiller's grains in the realm of functional food development.

Tripterygium hypoglaucum extract ameliorates adjuvant-induced arthritis in mice through the gut microbiota

Traditionally, Tripterygium hypoglaucum (Levl.) Hutch (THH) are widely used in Chinese folk to treat rheumatoid arthritis (RA). This study aimed to investigate whether the anti-RA effect of THH is related with the gut microbiota. The main components of prepared THH extract were identified by HPLC-MS. C57BL/6 mice with adjuvant-induced arthritis (AIA) were treated with THH extract by gavage for one month. THH extract significantly alleviated swollen ankle, joint cavity exudation, and articular cartilage destruction in AIA mice. The mRNA and protein levels of inflammatory mediators in muscles and plasma indicated that THH extract attenuated inflammatory responses in the joint by blocking TLR4/MyD88/MAPK signaling pathways. THH extract remarkably restored the dysbiosis of the gut microbiota in AIA mice, featuring the increases of Bifidobacterium, Akkermansia, and Lactobacillus and the decreases of Butyricimonas, Parabacteroides, and Anaeroplasma. Furthermore, the altered bacteria were closely correlated with physiological indices and drove metabolic changes of the intestinal microbiota. In addition, antibiotic-induced pseudo germ-free mice were employed to verify the role of the intestinal flora. Strikingly, THH treatment failed to ameliorate the arthritis symptoms and signaling pathways in pseudo germ-free mice, which validates the indispensable role of the intestinal flora. For the first time, we demonstrated that THH extract protects joint inflammation by manipulating the intestinal flora and regulating the TLR4/MyD88/MAPK signaling pathway. Therefore, THH extract may serve as a microbial modulator to recover RA in clincial practice.ver RA in clincial practice.

Lactobacillus co-fermentation of Cerasus humilis juice alters chemical properties, enhances antioxidant activity, and improves gut microbiota

Fermentation with Lactobacillus has been shown to improve the nutritional value of juice. In this study, Cerasus humilis juice was fermented using two commercial probiotics, namely, Lactobacillus acidophilus and Lactobacillus plantarum. The total antioxidant capacity (TAOC), viable count, chemical properties, antioxidant activity after in vitro digestion, and alterations in the gut microbiota composition of the fermented juice were investigated. After fermentation, the TAOC increased from 107.66 U mL-1 to 126.72 U mL-1; viable count increased from 5.85 lg (CFU mL-1) to 8.17 lg (CFU mL-1); and the contents of total phenols, total flavonoids, proanthocyanins, four organic acids, and 29 amino acids had changed. Overall, 47 compounds were identified in the juice, 20 of which were enriched after fermentation. Furthermore, Lactobacillus co-fermentation improved the antioxidant properties of the juice after in vitro digestion and increased the abundance of probiotics to regulate the gut microbiota. These findings illustrate the potential use of Lactobacillus acidophilus and Lactobacillus plantarum in the co-fermentation of C. humilis juice to enhance its nutritional and functional properties.

Potential Benefits of Egg White Proteins and Their Derived Peptides in the Regulation of the Intestinal Barrier and Gut Microbiota: A Comprehensive Review

Impaired intestinal barrier function can impede the digestion and absorption of nutrients and cause a range of metabolic disorders, which are the main causes of intestinal disease. Evidence suggests that proper dietary protein intake can prevent and alleviate intestinal diseases. Egg white protein (EWP) has received considerable attention, because of its high protein digestibility and rich amino acid composition. Furthermore, bioactive peptides may have an increased repair effect due to their high degradation efficiency in the gut. In this study, we aimed to review the effects of EWP and its bioactive peptides on intestinal structural repair. The potential modulation mechanisms by which EWP and their peptides regulate the gut microbiota and intestinal barrier can be summarized as follows: (1) restoring the structure of the intestinal barrier to its intact form, (2) enhancing the intestinal immune system and alleviating the inflammatory response and oxidative damage, and (3) increasing the relative abundance of beneficial bacteria and metabolites. Further in-depth analysis of the coregulation of multiple signaling pathways by EWP is required, and the combined effects of these multiple mechanisms requires further evaluation in experimental models. Human trials can be considered to understand new directions for development.

When less is more: Experimental Bishop-Koop technique for reduction in the use of laboratory animals for intestinal pathophysiological studies

The use of animals to gain knowledge and understanding of diseases needs to be reduced and refined. In the field of intestinal research, because of the complexity of the gut immune system, living models testing is mandatory. Based on the 3Rs (replacement, reduction and refinement) principles, we aimed to developed and apply the derived-intestinal surgical procedure described by Bishop and Koop (BK) in rats to refine experimental gastrointestinal procedures and reduce the number of animals used for research employing two models of intestinal inflammation: intestinal ischemia-reperfusion injury and chemical-induced colitis. Our results show the feasibility of the application of the BK technique in rodents, with good success after surgical procedure in both small and large intestine (100% survival, clinical recovery and weight regain). A considerable reduction in the use of the number of rats in both intestinal inflammation models (80% in case of intestinal ischemia-reperfusion damage and 66.6% in chemical-induced colitis in our experimental design) was achieved. Compared with conventional experimental models described by various research groups, we report excellent reproducibility of intestinal damage and functionality, survival rate and clinical status of the animals when BK is applied.

Eriocalyxin B ameliorated Crohn's disease-like colitis by restricting M1 macrophage polarization through JAK2/STAT1 signalling

BACKGROUND AND AIMS

M1 polarization of macrophages in the intestine is an important maintenance factor of the inflammatory response in Crohn's disease (CD). Eriocalyxin B (EriB) is a natural medicine that antagonizes inflammation. Our study aimed to determine the effects of EriB on CD-like colitis in mice, as well as the possible mechanism.

METHODS

2,4,6-trinitrobenzene sulfonic acid (TNBS) mice and Il-10^-/- mice were used as CD animal models, and the therapeutic effect of EriB on CD-like colitis in mice was addressed by the disease activity index (DAI) score, weight change, histological analysis and flow cytometry assay. To assess the direct role of EriB in regulating macrophage polarization, bone marrow-derived macrophages (BMDMs) were induced to M1 or M2 polarization separately. Molecular docking simulations and blocking experiments were performed to explore the potential mechanisms by which EriB regulates the macrophage polarization.

RESULTS

EriB treatment reduced body weight loss, DAI score and histological score, demonstrating the improvement of colitis symptoms in mice. In vivo and in vitro experiments both showed that EriB decreased the M1 polarization of macrophages, and suppressed the release of proinflammatory cytokines (IL-1β, TNF-α and IL-6) in mouse colons and BMDMs. The activation of Janus kinase 2/signal transducer and activator of transcription 1 (JAK2/STAT1) signals could be inhibited by EriB, which may be related to the regulation of EriB on M1 polarization.

CONCLUSIONS

EriB inhibits the M1 polarization of macrophages by attenuating the JAK2/STAT1 pathway, which partially explains the potential mechanism by which EriB ameliorates colitis in mice, and provides a new regimen for the clinical treatment of CD.

Dietary fiber modification: structure, physicochemical properties, bioactivities, and application-a review

There is increasing attention on the modification of dietary fiber (DF), since its effective improvement on properties and functions of DF. Modification of DF can change their structure and functions to enhance their bioactivities, and endow them with huge application potential in the field of food and nutrition. Here, we classified and explained the different modification methods of DF, especially dietary polysaccharides. Different modification methods exert variable effects on the chemical structure of DF such as molecular weight, monosaccharide composition, functional groups, chain structure, and conformation. Moreover, we have discussed the change in physicochemical properties and biological activities of DF, resulting from alterations in the chemical structure of DF, along with a few applications of modified DF. Finally, we have summarized the modified effects of DF. This review will provide a foundation for further studies on DF modification and promote the future application of DF in food products.

Ameliorative effect of buckwheat polysaccharides on colitis via regulation of the gut microbiota

Plant polysaccharides act as prebiotics by modulating gut microbiota. However, the functional characteristics of buckwheat Fagopyrum tataricum polysaccharides (FTP) and F. esculentum polysaccharides (FEP) on colitis prevention are not valid. This study evaluated the ameliorative effects of FTP and FEP against TNBS-induced colitis via gut microbiota modulation in rats. The characterizations of FTP and FEP were analyzed, including FTIR, TGA, DSC, and monosaccharide composition. In addition, the pathological features of colon length and symptoms in TNBS-induced colitis were improved via the intragastric preadministration of FTP and FEP. The results showed that prefeeding with FTP and FEP decreased inflammatory cytokines (IL-6, IL-1β, and TNF-α), β-glucuronidase, and mucinase, as well as increasing superoxide dismutase, catalase, and glutathione peroxidase levels, in TNBS-induced rats. A decrease in inflammatory signaling-associated proteins (NF-κB, MAPK, COX-2, and iNOS) improved the treatment of TNBS-induced colitis by buckwheat polysaccharides. Moreover, prefeeding with buckwheat polysaccharides increased the Firmicutes/Bacteroidetes ratio and short-chain fatty acid (SCFA) production and decreased the abundance of inflammation-related bacteria (Oscillospiraceae and Oscillibacter). In conclusion, FTP and FEP strongly improved TNBS-induced colitis through antioxidant, anti-inflammatory, and microbiota modulation properties, especially in the high-dose FEP group. Buckwheat polysaccharides have the potential for utilization in functional ingredients or food development.

Effects of Bacillus subtilis BSNK-5-Fermented Soymilk on the Gut Microbiota by In Vitro Fecal Fermentation

The gut microbiota of soymilk intervention is beneficial to maintaining human health. Bacillus subtilis fermented soymilk has brought much interest, due to its richness of thrombolytic nattokinase and the strain of potential probiotic properties. In this study, soymilk was fermented by B. subtilis BSNK-5, and the BSNK-5-fermented soymilk (SMF) on the production of short chain fatty acids (SCFAs) and the regulation of fecal microbiota was initially evaluated by in vitro fecal fermentation. SMF supplementation obviously increased the levels of SCFAs from 32.23 mM to 49.10 mM, especially acetic acid, propionic acid, and isobutyric acid. Additionally, SMF changed the composition and microbial diversity of gut microbiota. After 24 h of anaerobic incubation in vitro, SMF decreased the Firmicutes/Bacteroidota ratio favoring weight loss, increased Lachnospiraceae_UCG-004 and the other beneficial bacteria producing SCFAs, as well as suppressing pathogenic Streptococcus genus. These results revealed the potential use of BSNK-5-fermented soymilk as a potential candidate to promote gut health.

Structures and Anti-Inflammatory Evaluation of Phenylpropanoid Derivatives from the Aerial Parts of Dioscorea polystachya

Seven undescribed phenylpropanoid constituents, including three new bibenzyl derivatives (1–3) along with four new benzofuran stilbene derivatives (4–7), were isolated from the aerial parts of Dioscorea polystachya. The structures of these compounds were elucidated using a combination of spectroscopic analyses, including UV, IR, HRESIMS, 1D, and 2D NMR. Further, all the compounds were evaluated on the anti-inflammatory activity for their inhibition of nitric oxide (NO) production by RAW 264.7 macrophages cells, and some of them (1–3 and 6) displayed inhibitory activity with IC₅₀ values in the range of 9.3–32.3 μM. Moreover, compound 3 decreased the expression of iNOS in Western blot analysis, suggesting compound 3 is mediated via the suppression of an LPS-induced NF-κB inflammasome pathway.