Dietary Intake of Whole Strawberry Inhibited Colonic Inflammation in Dextran-Sulfate-Sodium-Treated Mice via Restoring Immune Homeostasis and Alleviating Gut Microbiota Dysbiosis

Complementary foods in infants: an in vitro study of the faecal microbial composition and organic acid production

The transition from breastmilk to complementary foods is critical for maturing the colonic microbiota of infants. Dietary choices at weaning can lead to long-lasting microbial changes, potentially influencing health later in life. However, the weaning phase remains underexplored in colonic microbiome research, and the current understanding of how complementary foods impact the infant's colonic microbiota is limited. To address this knowledge gap, this study assessed the influence of 13 food ingredients on the in vitro microbial composition and production of organic acids by the faecal microbiota in New Zealand infants aged 5 to 11 months. To better represent real feeding practices, ingredients were combined with infant formula, other complementary foods, or both infant formula and other foods. Among the individual food ingredients, fermentation with peeled kūmara (sweet potato) increased the production of lactate and the relative abundance of the genus Enterococcus. Fermentation with blackcurrants, strawberries, or raspberries enhanced acetate and propionate production. Additionally, fermentation with blackcurrants increased the relative abundance of the genus Parabacteroides, while raspberry fermentation increased the relative abundance of the genera Parabacteroides and Eubacterium. When combined with infant formula or with blackcurrants, fermenting black beans increased butyrate production and stimulated the relative abundance of Clostridium sensu stricto 1. These foods are promising candidates for future clinical trials.

Anti-inflammatory Effect of Microwave-Assisted Opuntia humifusa Extract (MA-OHE) against DSS-Induced Colitis

Ulcerative colitis (UC), including chronic colitis, is characterized by severe inflammation and oxidative stress in the colon. This study investigated the therapeutic potential of microwave-assisted Opuntia humifusa extract (MA-OHE), prepared using water (WE) and water-methanol (WME) solvents, in a chronic colitis model in mice induced by dextran sodium sulfate (DSS). Chemical profiling using UV-vis, FTIR, and HPLC analyses revealed that WME contains significantly higher concentrations of phenolic and flavonoid compounds than WE. These bioactive compounds enhance the antioxidant capacity of WME, as demonstrated by the superior radical scavenging activity in DPPH and ABTS assays and more pronounced suppression of nitric oxide (NO) synthesis in RAW 264.7 cells activated with LPS. In the DSS-induced chronic colitis model, treatment with WME notably enhanced colitis indicators, such as by restoring body weight, lowering the disease activity index (DAI) score, and maintaining colon length. Additionally, MA-OHE (WME) treatment decreased proinflammatory cytokine levels, such as TNF-α, IL-6, and IL-1β, in a dose-dependent manner, demonstrating strong anti-inflammatory effects. Histological examination additionally validated the recovery of colonic crypts and goblet cells and the reduction in inflammatory infiltration in groups treated with MA-OHE. These findings highlight the enhanced therapeutic potential of WME compared with that of WE, which is attributed to its richer composition of bioactive compounds. MA-OHE, particularly WME, demonstrated strong antioxidant, anti-inflammatory, and tissue-protective effects, indicating its potential as a natural treatment for chronic colitis management. Proinflammatory cytokine level modulation underscores its effectiveness in mitigating inflammation and supporting colonic tissue recovery.

Identification of the key tryptophan metabolic characteristics of Lactiplantibacillus plantarum for aryl hydrocarbon receptor activation and ulcerative colitis alleviation

Lactiplantibacillus plantarum can activate aryl hydrocarbon receptor (AHR) signaling in the gut by metabolizing tryptophan, thereby counteracting inflammation. However, the tryptophan metabolic characteristics of microorganisms are strain-specific and significantly influence their AHR-activating effects. In this study, four strains with different tryptophan metabolic profiles were screened, and a dextran sulfate sodium-induced colitis model was established in C57BL/6 mice. The key tryptophan metabolic characteristics of L. plantarum involved in AHR downstream signaling activation to alleviate colitis were explored. The results showed that strain SFFI50, characterized by poor tryptophan metabolism, and strain SFFI175, which produced high levels of IAA and ICA, did not alleviate colitis. Strain SFFI118, capable of metabolizing tryptophan to produce IAA, ICA, and ILA, could slightly restore mouse body weight, DAI, and IL-22 expression. L. plantarum SFFI23 significantly restored body weight, colon length, histopathological damage, and cytokine expression in mice. Moreover, it activated the downstream signaling of AHR, specifically CYP1A1, and repairs the intestinal barrier function. Targeted metabolomic analysis revealed a significant increase in indole-3-lactic acid (ILA) in the mouse intestine. Correlation analysis revealed a significant positive correlation between high ILA production of L. plantarum, CYP1A1 expression, intestinal barrier function restoration, ILA levels in vivo, and colitis alleviation. Therefore, we inferred that high ILA production is a key tryptophan metabolic characteristic of L. plantarum which activated AHR downstream signaling (such as CYP1A1, IL-22, and STAT3) to alleviate colitis. This study provides a theoretical basis for the development of personalized dietary interventions to improve gut health.

Capilliposide A alleviates DSS-induced colitis by regulating the intestinal flora and its metabolites of origin

Ulcerative colitis is a chronic idiopathic inflammatory disease that impacts the mucous membrane of the colon. Lately, the incidence and prevalence of UC has been increasing globally. However, there are significant side effects of existing drugs for UC intervention. Accordingly, there is a pressing demand to explore novel bioactive substances for addressing UC. Natural product saponins have attracted great attention due to their obvious anti-colitis potential. Capilliposide A is a triterpenoid saponin, which is derived from Lysimachia capillipes Hemsl., exhibits good anti-inflammatory activity. Nonetheless, the impact and mechanism of CPS-A on ulcerative colitis remains obscure. This study aimed to investigate the therapeutic effects of CPS-A on the dextran sulphate sodium induced colitis mouse model and explore its mechanism. The efficacy and safety of CPS-A were evaluated in a well-established dextran sodium sulfate (DSS)-induced colitis mice model. Disease progression was monitored via clinical symptoms, histopathological examination, quantification of inflammatory cytokines, and epithelial barrier function evaluation. Plasma samples and intestinal contents were collected for non-targeted metabolomics and 16sRNA sequencing, respectively, to jointly evaluate the mechanism of action. CPS-A alleviated colitis by improving weight, Disease activity index score, histopathology, goblet cell, colon length, and expression of inflammatory factors. Moreover, CPS-A effectively preserved the integrity of the intestinal barrier by enhancing the expression of tight junction proteins and mucin in the colonic tissue of mice. Furthermore, CPS-A exerted a regulatory effect on the composition of the gut microbiota, promoting bacterial richness and diversity. It not only suppressed the abundance of detrimental bacteria while enhancing the abundance of advantageous bacteria, but also modulated the metabolites derived from the intestinal flora. Importantly, correlation analysis shows that these indicators are highly correlated. This study revealed that CPS-A exhibits a favorable therapeutic efficacy against colitis, primarily attributed to its ability to modulate the gut microbiota their associated metabolites as the key mechanisms of action.

Diverse domains of raspberry pectin: critical determinants for protecting against IBDs

Inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis (UC), are chronic conditions characterized by periods of intestinal inflammation and have become global diseases. Dietary pectins have shown protective effects on IBD models. However, the development of pectin-based diet intervention for IBD individuals requires knowledge of both the bioactive structural patterns and the mechanisms underlying diet-microbiota-host interactions. Here, dextran sulfate sodium (DSS) induced colitis mice were fed with different pectins with various domain compositions, including AG, P37, P55 and P85, in order to understand why different structural patterns function differently on colitis mouse models. The structural diversity of pectin manifests in the different percentages of the homogalacturonan (HG) backbone, Ara sidechains, and Gal sidechains. AG comprises only neutral sugar chains consisting of 14% Ara and 86% Gal, and P85 is a commercial HG pectin mainly composed of 85% HG. P37 and P55 were isolated from raspberry pulps with different domain ratios (P37 = 37% HG + 22% Ara + 32% Gal; P55 = 55% HG + 16% Ara + 18% Gal). Compared to the monotonous structure of AG and P85, the domain-diverse pectins P37 and P55 show superior protective effects against colitis through inhibiting the proliferation of the mucin-consuming bacteria and the pro-inflammatory microorganisms, potentiating the MUC2 expression and the mucus layer and regulating the gut-spleen axis. The HG structure promoted the proliferation of the mucin-degrading microbiota and potentiated mucus erosion. AG enhanced the mucus thickness but increased the growth of the pro-inflammatory microbiota. Our study revealed that the specific domain composition of pectic fibers was a key factor on which the diet-induced alterations in the gut microbiota and the intestinal barrier function highly depended.

Fructo-oligosaccharides Alleviated Ulcerative Colitis via Gut Microbiota-Dependent Tryptophan Metabolism in Association with Aromatic Hydrocarbon Receptor Activation in Mice

Fructo-oligosaccharide (FOS) is a typical prebiotic with intestinal health-promoting effects. Here, we explored the anticolitis activity of FOS and clarified the underlying mechanisms. Dextran sulfate sodium (DSS)-induced mice were gavaged with FOS (400 mg/kg) for 37 days, and administration of FOS alleviated DSS-induced colitis symptoms. Besides, FOS improved gut microbiota dysbiosis and modulated the intestinal microbiota-controlled tryptophan metabolic pathways. Targeted metabolomic results showed that FOS significantly increased the colonic levels of indole-3-acetic acid (IAA) and indole-3-propionic acid (IPA) and subsequently increased the expressions of aromatic hydrocarbon receptors (AhR) in the colon and further promoted the expressions of interleukin-22 (IL-22) and intestinal tight junction proteins in the colitis mice. These findings for the first time highlight a novel anticolitis mechanism of FOS by alleviating intestinal microbiota dysbiosis and modulating microbial tryptophan metabolism to promote IAA and IPA production for triggering AhR/IL-22 axis activation.

Dietary Porphyra tenera ameliorated dextran sodium sulfate-induced colitis in mice via modulating gut microbiota dysbiosis

Bioactive components from Porphyra tenera (PT) have been reported to confer various health benefits. The role of PT in inflammatory bowel disease (IBD) has not been fully investigated. This study aimed to explore the anti-inflammatory properties of PT on dextran sodium sulfate (DSS)-treated mice. PT supplementation attenuated the severity of colitis in DSS-treated mice, evidenced by the reduction of disease activity index (DAI), restoration of colonic histological damage and suppression of abnormal inflammatory response. Sequencing analysis indicated that intake of PT alleviated DSS-induced gut microbiota dysbiosis, accompanied by reversing the generation of short-chain fatty acids (SCFAs) and bile acids (BAs). Overall, our findings demonstrated that supplementation of PT attenuated the severity of intestinal inflammation and ameliorated gut microbiota dysbiosis in a murine colitis model, which provided a rationale for further application of edible seaweeds for preventing inflammation-related disorders in humans.

Structure-anti-inflammatory activity relationship of garlic fructans in mice with dextran sulfate sodium-induced colitis: Impact of chain length

The present study identified the protective effects of garlic oligo/poly-saccharides of different chain lengths against dextran sulfate sodium (DSS)-induced colitis in mice and elucidated the structure-function relationships. The results showed that oral intake of garlic oligo/poly-saccharides decreased disease activity index, reduced colon shortening and spleen enlargement, and ameliorated pathological damage in the mouse colon. The dysregulation of colonic pro/anti-inflammatory cytokines was significantly alleviated, accompanied by up-regulated antioxidant enzymes, blocked TLR4-MyD88-NF-κB signaling pathway, enhanced intestinal barrier integrity, and restored SCFA production. Garlic oligo/poly-saccharides also reversed gut microbiota dysbiosis in colitic mice by expanding beneficial bacteria and suppressing the growth of harmful bacteria. High-molecular-weight polysaccharides exhibited stronger alleviating effects on DSS-induced colitic symptoms in mice than low-molecular-weight oligo/poly-saccharides did, probably due to their greater ability to be fermented in the colon. Taken together, this study demonstrated the anti-inflammatory effects of garlic oligo/poly-saccharides and revealed that high-molecular-weight polysaccharide fractions were more effective in alleviating DSS-induced colitis.

Kiwifruit Polysaccharides Alleviate Ulcerative Colitis via Regulating Gut Microbiota-Dependent Tryptophan Metabolism and Promoting Colon Fucosylation

A previous study showed that kiwifruit polysaccharide (KFP) has benefits in relieving intestinal inflammation, while the underlying mechanism remains unresolved. The objective of this study was to investigate the regulatory effect of KFP on the gut microbiota metabolism and intestinal barrier of ulcerative colitis (UC) mice induced by dextran sulfate sodium (DSS). KFP significantly improved the UC symptoms including weight loss, shortened colon length, splenomegaly, diarrhea, hematochezia, and colon inflammation of mice. In addition, KFP could alleviate DSS-caused gut microbiota dysbiosis and increase the levels of short-chain fatty acids in the cecal contents of mice. Furthermore, the results of nontargeted and targeted metabolomics analysis combined with antibiotic treatment revealed that KFP could regulate gut microbiota-dependent tryptophan metabolism, activate the aryl hydrocarbon receptor (AhR) in colon cells, and enhance interleukin-22 production and tight junction proteins' (ZO-1, occludin, and claudin3) expression to repair the intestinal barrier in UC mice. Immunofluorescence results showed that KFP significantly upregulated the conjunction of lectin WGA and UEA1 in the UC mouse colon, implying that KFP promoted fucosylation in the colon. These results suggest that KFP alleviates UC primarily via targeting the gut microbiota involved in the AhR pathway and upregulating colon fucosylation.

PPARγ/NF-κB axis contributes to cold-induced resolution of experimental colitis and preservation of intestinal barrier

BACKGROUND

Environmental stress is a significant contributor to the development of inflammatory bowel disease (IBD). The involvement of temperature stimulation in the development of IBD remains uncertain. Our preliminary statistical data suggest that the prevalence of IBD is slightly lower in colder regions compared to non-cold regions. The observation indicates that temperature changes may play a key role in the occurrence and progression of IBD. Here, we hypothesized that cold stress has a protective effect on IBD.

METHODS

The cold exposure model for mice was placed in a constant temperature and humidity chamber, maintained at a temperature of 4 °C. Colitis models were induced in the mice using TNBS or DSS. To promote the detection methods more clinically, fluorescence confocal endoscopy was used to observe the mucosal microcirculation status of the colon in the live model. Changes in the colonic wall of the mice were detected using 9.4 T Magnetic Resonance Imaging (MRI) imaging and in vivo fluorescence imaging. Hematoxylin and eosin (H&E) and Immunofluorescence (IF) staining confirmed the pathological alterations in the colons of sacrificed mice. Molecular changes at the protein level were assessed through Western blotting and Enzyme-Linked Immunosorbent Assay (ELISA) assays. RNA sequencing (RNA-seq) and metabolomics (n = 18) were jointly analyzed to investigate the biological changes in the colon of mice treated by cold exposure.

RESULTS

Cold exposure decreased the pathologic and disease activity index scores in a mouse model. Endomicroscopy revealed that cold exposure preserved colonic mucosal microcirculation, and 9.4 T MRI imaging revealed alleviation of intestinal wall thickness. In addition, the expression of the TLR4 and PP65 proteins was downregulated and epithelial cell junctions were strengthened after cold exposure. Intriguingly, we found that cold exposure reversed the decrease in ZO-1 and occludin protein levels in dextran sulfate sodium (DSS)- and trinitrobenzenesulfonic acid-induced colitis mouse models. Multi-omics analysis revealed the biological landscape of DSS-induced colitis under cold exposure and identified that the peroxisome proliferator-activated receptor (PPAR) signaling pathway mediates the effects of cold on colitis. Subsequent administration of rosiglitazone (PPAR agonist) enhanced the protective effect of cold exposure on colitis, whereas GW9662 (PPAR antagonist) administration mitigated these protective effects. Overall, cold exposure ameliorated the progression of mouse colitis through the PPARγ/NF-κB signaling axis and preserved the intestinal mucosal barrier.

CONCLUSION

Our study provides a mechanistic link between intestinal inflammation and cold exposure, providing a theoretical framework for understanding the differences in the prevalence of IBD between the colder regions and non-cold regions, and offering new insights into IBD therapy.

Lentil Waste Extracts for Inflammatory Bowel Disease (IBD) Symptoms Control: Anti-Inflammatory and Spasmolytic Effects

BACKGROUND/OBJECTIVES

In the contest of agro-industrial waste valorization, we focused our attention on lentil seed coats as a source of health-promoting phytochemicals possibly useful in managing inflammatory bowel diseases (IBDs), usually characterized by inflammation and altered intestinal motility.

METHODS

Both traditional (maceration) and innovative microwave-assisted extractions were performed using green solvents, and the anti-inflammatory and spasmolytic activities of the so-obtained extracts were determined through in vitro and ex vivo assays, respectively.

RESULTS

The extract obtained through the microwave-assisted procedure using ethyl acetate as the extraction solvent (BEVa) proved to be the most useful in inflammation and intestinal motility management. In LPS-activated Caco-2 cells, BEVa down-regulated TLR4 expression, reduced iNOS expression and the pro-inflammatory cytokine IL-1 production, and upregulated the anti-inflammatory cytokine IL-10 production, thus positively affecting cell inflammatory responses. Moreover, a significant decrease in the longitudinal and circular tones of the guinea pig ileum, with a reduction of transit speed and pain at the ileum level, together with reduced transit speed, pain, and muscular tone at the colon level, was observed with BEVa. HPLC separation combined with an Orbitrap-based high-resolution mass spectrometry (HRMS) technique indicated that 7% of all the identified metabolites were endowed with proven anti-inflammatory and antispasmodic activities, among which niacinamide, apocynin, and p-coumaric acid were the most abundant.

CONCLUSIONS

Our results suggest that lentil hull extract consumption could contribute to overall intestinal health maintenance, with BEVa possibly representing a dietary supplementation and a promising approach to treating intestinal barrier dysfunction.

Food-breastmilk combinations alter the colonic microbiome of weaning infants: an in silico study

The introduction of solid foods to infants, also known as weaning, is a critical point for the development of the complex microbial community inhabiting the human colon, impacting host physiology in infancy and later in life. This research investigated in silico the impact of food-breastmilk combinations on growth and metabolite production by colonic microbes of New Zealand weaning infants using the metagenome-scale metabolic model named Microbial Community. Eighty-nine foods were individually combined with breastmilk, and the 12 combinations with the strongest influence on the microbial production of short-chain fatty acids (SCFAs) and branched-chain fatty acids (BCFAs) were identified. Fiber-rich and polyphenol-rich foods, like pumpkin and blackcurrant, resulted in the greatest increase in predicted fluxes of total SCFAs and individual fluxes of propionate and acetate when combined, respectively, with breastmilk. Identified foods were further combined with other foods and breastmilk, resulting in 66 multiple food-breastmilk combinations. These combinations altered in silico the impact of individual foods on the microbial production of SCFAs and BCFAs, suggesting that the interaction between the dietary compounds composing a meal is the key factor influencing colonic microbes. Blackcurrant combined with other foods and breastmilk promoted the greatest increase in the production of acetate and total SCFAs, while pork combined with other foods and breastmilk decreased the production of total BCFAs.IMPORTANCELittle is known about the influence of complementary foods on the colonic microbiome of weaning infants. Traditional in vitro and in vivo microbiome methods are limited by their resource-consuming concerns. Modeling approaches represent a promising complementary tool to provide insights into the behavior of microbial communities. This study evaluated how foods combined with other foods and human milk affect the production of short-chain fatty acids and branched-chain fatty acids by colonic microbes of weaning infants using a rapid and inexpensive in silico approach. Foods and food combinations identified here are candidates for future experimental investigations, helping to fill a crucial knowledge gap in infant nutrition.

Theabrownin from Pu-erh Tea Improves DSS-Induced Colitis via Restoring Gut Homeostasis and Inhibiting TLR2&4 Signaling Pathway

BACKGROUND

Theabrownin (TB) is a dark brown pigment from Pu-erh tea or other dark teas. It is formed by further oxidization of theaflavins and thearubigins, in combination with proteins, polysaccharides, and caffeine etc. TB is a characteristic ingredient and bioactive substance of Pu-erh tea. However, the effects of TB on ulcerative colitis (UC) remains unclear.

PURPOSE

This study aims to elucidate the mechanism of TB on UC in terms of recovery of intestinal homeostasis and regulation of toll-like receptor (TLR) 2&4 signaling pathway.

METHODS

The colitis models were established by administering 5% dextran sulfate sodium (DSS) to C57BL/6 mice for 5 days to evaluate the therapeutic and preventive effects of TB on UC. Mesalazine was used as a positive control. H&E staining, complete blood count, enzyme-linked immunosorbent assay, immunohistochemistry, flow cytometry, and 16S rRNA sequencing were employed to assess histological changes, blood cells analysis, content of cytokines, expression and distribution of mucin (MUC)2 and TLR2&4, differentiation of CD4+T cells in lamina propria, and changes in intestinal microbiota, respectively. Western blot was utilized to study the relative expression of tight junction proteins and the key proteins in TLR2&4-mediated MyD88-dependent MAPK, NF-κB, and AKT signaling pathways.

RESULTS

TB outstanding alleviated colitis, inhibited the release of pro-inflammatory cytokines, reduced white blood cells while increasing red blood cells, hemoglobin, and platelets. TB increased the expression of occludin, claudin-1 and MUC2, effectively restored intestinal barrier function. TB also suppressed differentiation of Th1 and Th17 cells in the colon's lamina propria, increased the fraction of Treg cells, and promoted the balance of Treg/Th17 to tilt towards Tregs. Moreover, TB increased the Firmicutes to Bacteroides (F/B) ratio, as well as the abundance of Akkermansia, Muribaculaceae, and Eubacterium_coprostanoligenes_group at the genus level. In addition, TB inhibited the activation of TLR2&4-mediated MAPK, NF-κB, and AKT signaling pathways in intestinal epithelial cells of DSS-induced mice.

CONCLUSION

TB acts in restoring intestinal homeostasis and anti-inflammatory in DSS-induced UC, and exhibiting a preventive effect after long-term use. In a word, TB is a promising beverage, health product and food additive for UC.

Narirutin mitigates dextrose sodium sulfate-induced colitis in mice by modulating intestinal flora

BACKGROUND

Ulcerative colitis (UC) is a prolonged inflammatory disease of the gastrointestinal tract. Current therapeutic options remain limited, underscoring the imperative to explore novel therapeutic strategies. Narirutin (NR), a flavonoid naturally present in citrus fruits, exhibits excellent anti-inflammatory effects in vitro, yet its in vivo efficacy, especially in UC, remains underexplored.

OBJECTIVE

This work examined the effect of NR on dextrose sodium sulfate (DSS)-induced UC in mice in vivo, with a specific focus on the role of gut flora in it.

METHODS

The effects of NR (10, 20, and 40 mg/kg) on DSS-induced UC in mice were investigated by monitoring changes in body weight, disease activity index (DAI) scores, colon length, and histological damage. Colonic levels of pro-inflammatory mediators, tight junction (TJ) proteins, and inflammation-related signaling pathway proteins were analyzed via enzyme-linked immunosorbent assay, western blot, and immunofluorescence. The role of gut microbiota in NR against colitis was analyzed through 16S rRNA sequencing, flora clearance assays, and fecal microbiota transplantation (FMT) assays.

RESULTS

NR administration suppressed DSS-induced colitis as reflected in a decrease in body weight loss, DAI score, colon length shortening, and histological score. Furthermore, NR administration preserved the integrity of the DSS-induced intestinal barrier by inhibiting the reduction of TJ proteins (claudin3, occludin, and zonula occludens-1). Moreover, NR administration markedly repressed the activation of the toll-like receptor 4-mitogen-activated protein kinase/nuclear factor-κB pathway and reduced the amount of pro-inflammatory mediators in the colon. Importantly, the results of 16S rRNA sequencing showed that the intestinal flora of mice with colitis exhibited richer microbial diversity following NR administration, with elevated abundance of Lactobacillaceae (Lactobacillus) and decreased abundance of Bacteroidaceae (Bacteroides) and Shigella. In addition, the anti-colitis effect of NR almost disappeared after gut flora clearance. Further FMT assay also validated this gut flora-dependent protective mechanism of NR.

CONCLUSION

Our findings suggest that NR is a prospective natural compound for the management of UC by modulating intestinal flora.

Intracellular Polysaccharides of Eurotium cristatum Exhibited Anticolitis Effects in Association with Gut Tryptophan Metabolism

This study is to investigate the protective effects of Eurotium cristatum intracellular polysaccharides (ECIP) on dextran sodium sulfate (DSS)-induced ulcerative colitis (UC). The oral administration of ECIP could downregulate the disease activity index (DAI) and ameliorate the colonic shortening, immune stress, and damage caused by DSS. In addition, ECIP treatment increased the colonic contents of SCFAs including acetic, propionic, and butyric acids in UC mice. Targeted and untargeted metabolic analysis suggested that ECIP dramatically altered the tryptophan metabolism in the feces of UC mice and promoted the conversion of tryptophan into indole metabolites including indolepyruvate and indole-3-acetic acid (IAA) and indolealdehyde (IAId). Moreover, ECIP observably increased the content of colonic IL-22 and stimulated the relative concentration and relative expression of tight junction molecules in mRNA and proteins levels. Conclusively, consumption of ECIP can improve colon damage and its related effects of UC by promoting the production of IAA and IAId to reinforce intestinal barriers.

The chemical composition, protective effect of Rheum officinale leaf juice and its mechanism against dextran sulfate sodium-induced ulcerative colitis

BACKGROUND

Rhubarb is widely distributed and cultivated worldwide, and its leaves presented antioxidant activity and could be used as food additive. However, the chemical ingredients, and protective effect of Rheum officinale leaf juice (JROL) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) are still unclear.

PURPOSE

This paper sought to the characterization and functional properties of JROL, and explore the underlying mechanism on UC mice.

METHODS

UPLC-ESI-Q-TOF/MS and other analytical instruments were employed to determine the chemical ingredients of JROL. After inducing UC model using 3% DSS, multiple biological methods were used to evaluate its protective effect and the potential mechanism.

RESULTS

JROL is rich in proximate compositions and minerals and has high nutritional value, and contains reducing sugars, polysaccharides and pectin. Fifteen compounds were identified using UPLC-ESI-Q-TOF/MS. Among them, rutin has the highest content (2.22 %) in UPLC analysis. JROL presented protective effect on DSS-induced UC, and alleviated morphological alterations and ultra-structural feature of tissue, and the polysaccharides and flavonoids may contribute to its protective effect. JROL inhibited NF-κB/NLRP3 signaling pathway to alleviate inflammatory response, oxidative stress and intestinal injury by decreasing the expression of p-p65, p-IκBα, NLRP3, ASC, etc.. Moreover, it up-regulated the expression of tight junction proteins, and re-balanced the disturbance of gut microbiota to regulate the inflammatory response. Finally, a correlation among the inflammatory response, NF-κB/NLRP3 pathway and gut microbiota was established. Moreover, JROL presented the safety in the acute toxicity test.

CONCLUSION

JROL could be used as a potential new source for treating UC.

A Gestational Pectin Diet Could Improve the Health of Multiparous Sows by Modulating the Gut Microbiota and Cytokine Level during Late Pregnancy

This study aimed to investigate the effects of the dietary fiber pectin on the gut microbiota and health of parturient sows. A total of 30 parity 5-7, multiparous gestation sows (Large White × Landrace) were randomly assigned to two treatment groups after mating: Con (control, basic diet) and Pec (pectin, 3%). The sows received the two diets during gestation, and all sows were fed the same standard basic diet during lactation. The results of β-diversity showed that the composition of the gut microbiota was different in the Con and Pec groups. Compared with the sows in the Con group, the Pec sows showed a higher abundance of the gut bacteria Clostridium and Romboutsia and a lower abundance of harmful bacteria (Micrococcaceae, Coriobacteriaceae, Dorea, Actinomyces). On the other hand, the SCFA plasma concentration was increased in the Pec group, while pro-inflammatory cytokine (IL-6, IL-1β, and TNF-α) concentrations were decreased. In conclusion, the soluble dietary fiber pectin could improve the reproductive performance and health of sows by increasing the abundance of some commensal bacteria enhancing the metabolite SCFA levels and reducing the pro-inflammatory cytokine plasma levels.

Bifidobacterium pseudocatenulatum In Vitro In Vivo

The genus Bifidobacterium has been widely used in functional foods for health promotion due to its beneficial effects on human health, especially in the gastrointestinal tract (GIT). In this study, we characterize the anti-inflammatory potential of the probiotic strain Bifidobacterium pseudocatenulatum G7, isolated from a healthy male adult. G7 secretion inhibited inflammatory response in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Moreover, oral administration of bacteria G7 alleviated the severity of colonic inflammation in dextran sulfate sodium (DSS)-treated colitis mice, which was evidenced by a decreased disease activity index (DAI) and enhanced structural integrity of the colon. The 16S rRNA gene sequencing result illustrated that the G7 alleviated DSS-induced gut microbiota dysbiosis, accompanied by the modulated bile acids and short-chain fatty acid (SCFA) levels. Overall, our results demonstrated the potential anti-inflammatory effects of Bifidobacterium pseudocatenulatum G7 on both in vitro and in vivo models, which provided a solid foundation for further development of a novel anti-inflammatory probiotic.

Dietary intake of whole king oyster mushroom (Pleurotus eryngii) attenuated obesity via ameliorating lipid metabolism and alleviating gut microbiota dysbiosis

There is a growing interest in employing whole food-based strategies to prevent chronic diseases, owing to the potential synergistic interactions among various bioactive components found within whole foods. The current research aimed to determine inhibitory effects of the whole edible mushroom Pleurotus eryngii (WPE) on high-fat diet (HFD)-induced obesity in mice. Our results showed that dietary intake of WPE significantly inhibited the abnormal gain of body weight and adipose tissue weight, improved glucose tolerance, and ameliorated the serum biochemical parameters in HFD-fed mice. The histological analysis illustrated that the severity of non-alcoholic fatty liver induced by HFD was significantly reduced by WPE. Oral intake of WPE profoundly modulated the mRNA levels of hepatic genes involved in lipid metabolism and also increased the level of short-chain fatty acids in the mouse cecum. Moreover, WPE alleviated the HFD-induced gut microbiota dysbiosis, increasing the abundance of beneficial bacteria (Akkermansia, Lactobacillus, Bifidobacterium, and Sutteralla), and decreasing the harmful ones (rc4-4, Dorea, Coprococcus, Oscillospira, and Ruminococcus). These findings presented new evidence supporting that WPE could be used as a whole food-based strategy to protect against obesity and obesity-driven health problems.

Dual-ROS Sensitive Moieties Conjugate Inhibits Curcumin Oxidative Degradation for Colitis Precise Therapy

Curcumin, a natural bioactive polyphenol with diverse molecular targets, is well known for its anti-oxidation and anti-inflammatory potential. However, curcumin exhibits low solubility (<1 µg mL-1), poor tissue-targeting ability, and rapid oxidative degradation, resulting in poor bioavailability and stability for inflammatory therapy. Here, poly(diselenide-oxalate-curcumin) nanoparticle (SeOC-NP) with dual-reactive oxygen species (ROS) sensitive chemical moieties (diselenide and peroxalate ester bonds) is fabricated by a one-step synthetic strategy. The results confirmed that dual-ROS sensitive chemical moieties endowed SeOC-NP with the ability of targeted delivery of curcumin and significantly suppress oxidative degradation of curcumin for high-efficiency inflammatory therapy. In detail, the degradation amount of curcumin for SeOC is about 4-fold lower than that of free curcumin in an oxidative microenvironment. As a result, SeOC-NP significantly enhanced the antioxidant activity and anti-inflammatory efficacy of curcumin in vitro analysis by scavenging intracellular ROS and suppressing the secretion of nitric oxide and pro-inflammatory cytokines. In mouse colitis models, orally administered SeOC-NP can remarkably alleviate the symptoms of IBD and maintain the homeostasis of gut microbiota. This work provided a simple and effective strategy to fabricate ROS-responsive micellar and enhance the oxidation stability of medicine for precise therapeutic inflammation.

Potential mitigation of titanium dioxide nanoparticles against 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis through inhibiting the canonical NF-κB pathway

Titanium dioxide nanoparticles (TiO2 NPs) have been widely employed in various industry fields, which makes consumers concerned about their health impact. Our previous work displayed that TiO2 NPs participated in the mitigation of TNBS-induced colitis, but the mechanism is still unknown. This work aimed to explore the role of oxidative stress and NF-κB pathway in the effect of TiO2 NPs on TNBS-induced colitis. The results showed that TiO2 NPs administration reduced the DAI score of colitis mice after TNBS enema. TiO2 NPs did not alter oxidative stress status (GSH/GSSG), but repaired the gut dysbacteriosis and inhibited the canonical NF-κB pathway activation in TNBS-induced colitis mice, manifested as a decrease in pathogenic bacteria and an increase in beneficial bacteria, as well as down-regulation of toll-like receptors (TLRs), IKKα, IKKβ, p65 and pro-inflammatory cytokines (IL-1β, IL-6, TNF-α and IFN-γ) in mRNA level, and the increased transcription of anti-inflammatory cytokines (IL-10, TGF-β, and IL-12), along with the declined protein level of TNF-α in TiO2 NPs treated colitis mice. The present study suggested that oral TiO2 NPs administration inhibited the canonical NF-κB pathway activation by repairing gut dysbacteriosis, which made a predominant role in alleviating colitis. These findings provided a new perspective for exploring the safety of TiO2 NPs.

Comparative anti-inflammatory effect of extract from novel Korean strawberry cultivars (Fragaria × ananassa) on lipopolysaccharide-induced RAW264.7 macrophages and mouse model

BACKGROUND

Dietary interventions are crucial in modulating inflammation in humans. Strawberries are enjoyed by people of different ages as a result of their attractive phenotype and taste. In addition, the active compounds in strawberries may contribute to the reduction of inflammation. When developing new strawberry cultivars to address agricultural and environmental threats, the bioactivity of strawberries must be improved to maintain their health benefits.

RESULTS

We determined the phytochemical contents of extracts from a new Korean strawberry cultivar, with the CN7 cultivar extract possessing the highest total polyphenol and flavonoid contents compared to the CN5 and Seolhyang cultivar extracts. The new Korean strawberry cultivars reduced the expression of inflammatory-related genes in lipopolysaccharide (LPS)-induced RAW264.7 cells via the nuclear factor-kappa B signaling pathway, indicating an anti-inflammatory effect. The CN7 cultivar showed greater bioactivity potential and the highest ellagic acid content; hence, we assessed the effect of the CN7 cultivar in an LPS-stimulated mouse model. The CN7 cultivar treatment demonstrated its effectiveness in reducing inflammation via the downregulation of inflammatory cytokines secretion and gene expression.

CONCLUSION

The results obtained in the present study have revealed the observable differences of the newly developed strawberry cultivars with Seolhyang in mitigating inflammation induced by LPS. The enhanced phytochemical content of the CN7 cultivar extract may contribute to its improved anti-inflammatory effect. Therefore, it is crucial to maintain the nutritive benefits of strawberry during the development of new cultivation. © 2023 Society of Chemical Industry.

Amygdalin Alleviates DSS-Induced Colitis by Restricting Cell Death and Inflammatory Response, Maintaining the Intestinal Barrier, and Modulating Intestinal Flora

Inflammatory bowel disease (IBD) refers to a cluster of intractable gastrointestinal disorders with an undetermined etiology and a lack of effective therapeutic agents. Amygdalin (Amy) is a glycoside extracted from the seeds of apricot and other Rosaceae plants and it exhibits a wide range of pharmacological properties. Here, the effects and mechanisms of Amy on colitis were examined via 16S rRNA sequencing, ELISA, transmission electron microscopy, Western blot, and immunofluorescence. The results showed that Amy administration remarkably attenuated the signs of colitis (reduced body weight, increased disease activity index, and shortened colon length) and histopathological damage in dextran sodium sulfate (DSS)-challenged mice. Further studies revealed that Amy administration significantly diminished DSS-triggered gut barrier dysfunction by lowering pro-inflammatory mediator levels, inhibiting oxidative stress, and reducing intestinal epithelial apoptosis and ferroptosis. Notably, Amy administration remarkably lowered DSS-triggered TLR4 expression and the phosphorylation of proteins related to the NF-κB and MAPK pathways. Furthermore, Amy administration modulated the balance of intestinal flora, including a selective rise in the abundance of S24-7 and a decline in the abundance of Allobaculum, Oscillospira, Bacteroides, Sutterella, and Shigella. In conclusion, Amy can alleviate colitis, which provides data to support the utility of Amy in combating IBD.

Effect of a multi-strain probiotic mixture consumption on anxiety and depression symptoms induced in adult mice by postnatal maternal separation

BACKGROUND

Intestinal microbial composition not only affects the health of the gut but also influences centrally mediated systems involved in mood, through the "gut-brain" axis, a bidirectional communication between gut microbiota and the brain. In this context, the modulation of intestinal microbiota and its metabolites through the administration of probiotics seems to represent a very promising approach in the treatment of the central nervous system alterations. Early postnatal life is a critical period during which the brain undergoes profound and essential modulations in terms of maturation and plasticity. Maternal separation (MS), i.e., the disruption of the mother-pup interaction, represents a pivotal paradigm in the study of stress-related mood disorders, by inducing persistent changes in the immune system, inflammatory processes, and emotional behavior in adult mammals.

RESULTS

We conducted experiments to investigate whether sustained consumption of a multi-strain probiotic formulation by adult male mice could mitigate the effects of maternal separation. Our data demonstrated that the treatment with probiotics was able to totally reverse the anxiety- and depressive-like behavior; normalize the neuro-inflammatory state, by restoring the resting state of microglia; and finally induce a proneurogenic effect. Mice subjected to maternal separation showed changes in microbiota composition compared to the control group that resulted in permissive colonization by the administered multi-strain probiotic product. As a consequence, the probiotic treatment also significantly affected the production of SCFA and in particular the level of butyrate.

CONCLUSION

Gut microbiota and its metabolites mediate the therapeutic action of the probiotic mix on MS-induced brain dysfunctions. Our findings extend the knowledge on the use of probiotics as a therapeutic tool in the presence of alterations of the emotional sphere that significantly impact on gut microbiota composition. Video Abstract.

Structural characterization of a polysaccharide from Alhagi honey and its protective effect against inflammatory bowel disease by modulating gut microbiota dysbiosis

The Alhagi honey polysaccharide (AHP) exhibits notable anti-inflammatory, antioxidant, and immunomodulatory properties, positioning it as a promising candidate in traditional Chinese medicine. In this investigation, we successfully isolated and purified a neutral AHP, designated AHPN50-1a, subsequently elucidating its structural attributes. AHPN50-1a was found to have a molecular weight of 1.756 × 106 Da, featuring a structural motif characterized by a recurring (1→6)-α-GlcP linker. To comprehensively evaluate its therapeutic potential, we explored the protective effects of AHPN50-1 in a murine model of dextran sodium sulfate-induced colitis. Administration of AHPN50-1 at doses of 200 and 400 mg/kg/day resulted in improved food intake, increased body weight, and increased colon length in mice with acute colitis. Simultaneously, a reduction in the disease activity index and histological scores was observed. AHPN50-1 effectively mitigated colon tissue damage, down-regulated the expression levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) in colon tissue, restored intestinal microbiota diversity, and concentrations of short-chain fatty acids (SCFAs) of gut microbiota metabolites, thus alleviating intestinal inflammation in mice. In summary, our findings underscore the promise of AHPN50-1 as a valuable nutritional or dietary supplement for the treatment and prevention of inflammatory bowel disease.

Blueberry, cranberry, raspberry, and strawberry as modulators of the gut microbiota: target for treatment of gut dysbiosis in chronic kidney disease? From current evidence to future possibilities

Gut dysbiosis is common in patients with chronic kidney disease (CKD) and is associated with uremic toxin production, inflammation, oxidative stress, and cardiovascular disease development. Therefore, healthy dietary patterns are essential modulators of gut microbiota. In this context, studies suggest that consuming berry fruits, rich in polyphenols and nutrients, may positively affect the gut microbiota, promoting the selective growth of beneficial bacteria and improving clinical status. However, studies on the effects of berry fruits on gut microbiota in CKD are scarce, and a better understanding of the possible mechanisms of action of berry fruits on gut microbiota is needed to guide future clinical studies and clinical practice in CKD. The objective was to discuss how berry fruits (blueberry, cranberry, raspberry, and strawberry) could be a therapeutic strategy to modulate the gut microbiota and possibly reverse the dysbiosis in CKD. Overall, available evidence shows that berry fruits can promote an increase in diversity by affecting the abundance of mucus-producing bacteria and short-chain fatty acids. Moreover, these fruits can increase the expression of mRNA involved in tight junctions in the gut such as occludin, tight junction protein 1 (TJP1), and mucin. Studies on the exact amount of berries leading to these effects show heterogeneous findings. However, it is known that, with 5 mg/day, it is already possible to observe some effects in animal models. Wild berries could possibly improve the uremic condition by reducing the levels of uremic toxins via modulation of the gut microbiota. In the long term, this could be an excellent strategy for patients with CKD. Therefore, clinical studies are encouraged to evaluate better these effects on CKD as well as the safe amount of these fruits in order to promote a better quality of life or even the survival of these patients.

Dietary tangeretin improved antibiotic-associated diarrhea in mice by enhancing the intestinal barrier function, regulating the gut microbiota, and metabolic homeostasis

Antibiotic-associated diarrhea is mediated by antibiotic treatment and is usually caused by the disruption of the intestinal barrier, gut microbiota, and metabolic balance. To identify a dietary strategy that can mitigate the side effects of antibiotics, this study investigated the effect of tangeretin on antibiotic-associated diarrhea in C57BL/6 mice. The results revealed that dietary tangeretin significantly ameliorated symptoms of antibiotic-associated diarrhea, as evidenced by the decreased diarrhea status scores, the reduced fecal water content, the decreased caecum/body weight ratio, and the alleviated colonic tissue damage. Dietary tangeretin also exhibited a protective effect on the intestinal barrier function by upregulating the mRNA and protein expression of claudin-1 and ZO-1. Furthermore, analysis of the gut microbiota using 16S rRNA gene sequencing indicated that dietary tangeretin modulated the gut microbiota of mice with antibiotic-associated diarrhea via increasing the gut microbiota diversity and the abundance of beneficial bacteria, e.g., Lactobacillaceae and Ruminococcaceae, and decreasing the abundance of harmful bacteria, e.g., Enterococcus and Terrisporobacter. Additionally, dietary tangeretin restored the levels of short-chain fatty acids and modulated metabolic pathways by enriching purine metabolism, bile acid metabolism, ABC transporters, and choline metabolism in cancer. Collectively, these findings provide a solid scientific basis for the rational use of tangeretin as a preventive and therapeutic agent for antibiotic-associated diarrhea.

Maize near-isogenic lines with enhanced flavonoids alleviated dextran sodium sulfate-induced murine colitis via modulation of the gut microbiota

The rising incidence of inflammatory bowel disease (IBD) has necessitated the search for safe and effective novel therapeutic strategies. Dietary flavonoids exhibited antioxidant, antiproliferative, and anticarcinogenic activities in several model systems with proven abilities to reduce inflammation and oxidative stress, thus they could be promising therapeutic agents for IBD prevention/treatment. However, understanding the role of a specific class of compounds in foods that promote health is difficult because of the chemically complex food matrices. This study aimed to utilize four maize near-isogenic lines to determine the anti-colitis effects of specific classes of flavonoids, anthocyanins and/or phlobaphenes, in a whole-food matrix. Results showed that the intake of anthocyanin and phlobaphene-enriched maize diets effectively alleviated dextran sodium sulfate (DSS)-induced colitis in mice via reducing the intestinal permeability and restoring the barrier function. Anthocyanin diets were more effective in maintaining the crypt structure and muc2 protein levels and reducing inflammation. Bacterial communities of mice consuming diets enriched with anthocyanins and phlobaphenes were more similar to the healthy control compared to the DSS control group, suggesting the role of flavonoids in modulating the gut microbiota to retrieve intestinal homeostasis. Microbiota depletion rendered these compounds ineffective against colitis. Lower serum concentrations of several phenolic acids were detected in the microbiota-depleted mice, indicating that gut microbiota plays a role in flavonoid metabolism and bioavailability.

Lonicera caerulea Pomace Alleviates DSS-Induced Colitis via Intestinal Barrier Improvement and Gut Microbiota Modulation

The objective of this investigation was to appraise the mitigative effects of Lonicera caerulea pomace (LCP)-supplemented diets on Dextran Sulfate Sodium (DSS)-induced colitis, and to discuss the potential mechanisms. LCP, a by-product of fruit juice processing, harbors a higher content of polyphenols and dietary fiber compared to the L. caerulea pulp. In a murine model of colitis, the LCP diet attenuated the symptoms of colitis, as evidenced by the reduction in the disease activity index (DAI), extension of colon length, and amelioration of histopathological damage. The anti-inflammatory attributes of LCP were substantiated by a decrease in myeloperoxidase (MPO) activity and suppression of inflammatory cytokine expressions within the colon. Meanwhile, LCP mediated the repair of the intestinal barrier, characterized by the upregulation of gene expressions of tight junction (TJ) proteins and Muc2. Furthermore, LCP altered the composition of the gut microbiota, manifested in increased alpha diversity, enhancement of the abundance of beneficial bacteria (Akkermansia, Coprococcus and Bifidobacterium), and diminishment in the abundance of pathogenic bacteria (Escherichia, Enterococcus, Mucispirillum and Clostridium). Dietary LCP also increased the concentrations of SCFAs within the intestinal luminal contents of colitis mice. Given the affirmative impact of LCP on colitis, LCP may possess great potential in promoting intestinal health.

Colon-Targeted Release of Turmeric Nonextractable Polyphenols and Their Anticolitis Potential via Gut Microbiota-Dependent Alleviation on Intestinal Barrier Dysfunction in Mice

Solid evidence has emerged supporting the role of nonextractable polyphenols (NEPs) and dietary fibers (DFs) as gut microbiota modulators. This study aims to elucidate gut microbiota-dependent release of turmeric NEPs and examine the possible anti-inflammatory mechanism in the dextran sulfate sodium-induced ulcerative colitis (UC) model. 1.5% DSS drinking water-induced C57BL/6J mice were fed a standard rodent chow supplemented with or without 8% extractable polyphenols (EPs), NEPs, or DFs for 37 days. The bound curcumin, demethoxycurcumin, and bisdemethoxycurcumin in NEPs were released up to 181.5 ± 10.6, 65.2 ± 6.0, and 69.5 ± 7.6 μg/mL by in vitro gut microbiota-simulated fermentation and released into the colon of NEP-supplemented mice by 5.7-, 11.0-, and 7.8-fold higher than pseudo germ-free mice, respectively (p < 0.05). NEPs also enhanced the colonic microbiota-dependent production of short-chain fatty acids in vitro and in vivo (p < 0.05). Interestingly, NEP feeding significantly improved the DSS-caused gut microbiota disorder, epithelial barrier damage, and inflammation of UC mice better than EPs or DFs (p < 0.05). Meanwhile, the pseudo germ-free mice supplemented with NEPs failed to ameliorate UC symptoms. These findings manifest that turmeric NEPs as macromolecular carriers exert the target delivery of polyphenols into the colon for regulating gut microbiota to restore the impaired gut barrier function for alleviation of inflammation.

Bile acid metabolism and signaling: Emerging pharmacological targets of dietary polyphenols

Beyond their role as emulsifiers of lipophilic compounds, bile acids (BAs) are signaling endocrine molecules that show differential affinity and specificity for a variety of canonical and non-canonical BA receptors. Primary BAs (PBAs) are synthesized in the liver while secondary BAs (SBAs) are gut microbial metabolites of PBA species. PBAs and SBAs signal to BA receptors that regulate downstream pathways of inflammation and energy metabolism. Dysregulation of BA metabolism or signaling has emerged as a feature of chronic disease. Dietary polyphenols are non-nutritive plant-derived compounds associated with decreased risk of metabolic syndrome, type-2 diabetes, hepatobiliary and cardiovascular disease. Evidence suggests that the health promoting effects of dietary polyphenols are linked to their ability to alter the gut microbial community, the BA pool, and BA signaling. In this review we provide an overview of BA metabolism and summarize studies that link the cardiometabolic improvements of dietary polyphenols to their modulation of BA metabolism and signaling pathways, and the gut microbiota. Finally, we discuss approaches and challenges in deciphering cause-effect relationships between dietary polyphenols, BAs, and gut microbes.

Healthy regulation of Tibetan Brassica rapa L. polysaccharides on alleviating hyperlipidemia: A rodent study

Hyperlipidemia is a common metabolic disorder, which can lead to obesity, hypertension, diabetes, atherosclerosis and other diseases. Studies have shown that polysaccharides absorbed by the intestinal tract can regulate blood lipids and facilitate the growth of intestinal flora. This article aims to investigate whether Tibetan turnip polysaccharide (TTP) plays a protective role in blood lipid and intestinal health via hepatic and intestinal axes. Here we show that TTP helps to reduce the size of adipocytes and the accumulation of liver fat, playing a dose-dependent effect on ADPN levels, suggesting an effect on lipid metabolism regulation. Meantime, TTP intervention results in the downregulation of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and serum inflammatory factors (interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α)), implying that TTP suppresses the progression of inflammation in the body. The expression of key enzymes associated with cholesterol and triglyceride synthesis, such as 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), cholesterol 7α-hydroxylase (CYP7A1), peroxisome proliferator-activated receptors γ (PPARγ), acetyl-CoA carboxylase (ACC), fatty acid synthetase (FAS) and sterol-regulatory element binding proteins-1c (SREBP-1c), can be modulated by TTP. Furthermore, TTP also alleviates the damage to intestinal tissues caused by high-fat diet, restores the integrity of the intestinal barrier, improves the composition and abundance of the intestinal flora and increases the levels of SCFAs. This study provides a theoretical basis for the regulation of body rhythm by functional foods and potential intervention in patients with hyperlipidemia.

Saccharina japonica Ethanol Extract Ameliorates Dextran Sulfate Sodium-Induced Colitis via Reshaping Intestinal Microenvironment and Alleviating Inflammatory Response

Saccharina japonica belongs to brown macro-alga with various potential health benefits; its antioxidant and anti-inflammatory activities indicate the potential to improve inflammatory bowel diseases. Here, the potential anti-colitis effect of Saccharina japonica extract (SJE) was evaluated on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in C57B/L6 mice. The mice were treated with mesalazine (MES) and various doses of SJE by gavage for 14 days. Results showed that both MES and SJE treatment decreased the disease activity index scores, relieving the short colon. SJE increased the occludin and zonula occludens-1 levels, and the beneficial effects were better than MES. MES and SJE exerted similar effects in decreasing inflammatory cytokines and oxidative stress. Moreover, SJE reshaped the intestinal microbiota by increasing α-diversity and reducing plenty of harmful bacteria. Dietary SJE was significant to relieving the reduction in short-chain fatty acids. The results revealed the protective effect of SJE on colitis and potential mechanisms, which is important for the rational use of SJE in UC prevention.

Smilax china L. Polysaccharide Alleviates Dextran Sulphate Sodium-Induced Colitis and Modulates the Gut Microbiota in Mice

This work aimed to investigate the preventive effect of Smilax china L. polysaccharide (SCP) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice. Smilax china L. polysaccharide was isolated by hot water extraction, ethanol precipitation, deproteinization, and purification using DEAE-cellulose column chromatography to yield three polysaccharides: SCP_C, SCP_A, and SCP_N. Acute colitis was induced by administering 3% (w/v) DSS in drinking water for 7 days. Sulfasalazine, SCP_C, SCP_A, and SCP_N were administered by gavage for 9 days. SCP_C, SCP_A, and SCP_N could significantly improve symptoms, as evidenced by the declining disease activity index (DAI), decreased spleen weight, increased length of the colon, and improved colonic histology. Moreover, SCP_C, SCP_A, and SCP_N increased serum glutathione and decreased the levels of pro-inflammatory cytokines, malondialdehyde, nitric oxide, and myeloperoxidase in colon tissues. Additionally, SCP_C, SCP_A, and SCP_N modulated gut microbiota via ascending the growth of Lachnospiraceae, Muribaculaceae, Blautia, and Mucispirillum and descending the abundance of Akkermansiaceae, Deferribacteraceae, and Oscillibacter in mice with UC. The results suggested that Smilax china L. polysaccharide ameliorates oxidative stress, balances inflammatory cytokines, and modulates gut microbiota, providing an effective therapeutic strategy for UC in mice.

Goji berry leaf exerts a comparable effect against colitis and microbiota dysbiosis to its fruit in dextran-sulfate-sodium-treated mice

Goji berry and mulberry are both popular berries with anti-colitis effects, but their leaves have received less attention. In this study, the anti-colitis effects of goji berry leaf and mulberry leaf were investigated in dextran-sulfate-sodium-induced colitis C57BL/6N mice compared with their fruits. Goji berry leaf and goji berry reduced colitic symptoms and ameliorated tissue damage, while mulberry leaf did not. ELISA and western blotting analysis suggested that goji berry showed the best performance in inhibiting the overproduction of pro-inflammatory cytokines (TNF-α, IL-6 and IL-10) and improving damaged colonic barrier (occludin and claudin-1). Besides, goji berry leaf and goji berry reversed the gut microbiota dysbiosis by increasing the abundance of beneficial bacteria like Bifidobacterium and Muribaculaceae, and decreasing the abundance of harmful bacteria like Bilophila and Lachnoclostridium. Goji berry, mulberry and goji berry leaf could restore acetate, propionate, butyrate and valerate to ameliorate inflammation, while mulberry leaf could not restore butyrate. To the best of our knowledge, this is the first report on the comparison of the anti-colitis effects of goji berry leaf, mulberry leaf and their fruits, which is meaningful for the rational utilization of goji berry leaf as a functional food.

Polysaccharides from the seeds of Gleditsia sinensis Lam. attenuate DSS-induced colitis in mice via improving gut barrier homeostasis and alleviating gut microbiota dybiosis

The seeds from Gleditsia sinensis Lam., a common ecologically and economically useful tree, have high economic and nutritional value. The protective effect of polysaccharides from Gleditsia sinensis Lam. seeds (ZJMP) against dextran sulfate sodium-induced colitis in mice was investigated in this study. ZJMP alleviated weight loss, reduced the disease activity index, prevented colon shortening, alleviated colonic tissue damage, and restored goblet cell secretion in colitic mice. Dietary ZJMP reduced proinflammatory cytokine overproduction in the colonic mucosa and serum, which was accompanied by suppression of NO levels and MPO and SOD activities. The addition of ZJMP increased the expression of Muc2 and tight junction proteins. Furthermore, dietary ZJMP partially reversed the alteration of gut microbiota in colitic mice by boosting the abundance of beneficial bacteria like Akkermansia, Lactobacillus, and Christensenella while lowering the abundance of harmful bacteria like Bacteroides, Prevotella, and Mucispirillum. Additionally, the decreased production of short-chain fatty acids in the colitic mice was recovered by ZJMP administration. The findings demonstrated the anti-inflammatory properties and mechanism of dietary ZJMP in the colon, which is essential for the sensible application of ZJMP in the prevention and amelioration of inflammation-related diseases as a nutritional supplement.

Eurotium cristatum Exhibited Anti-Colitis Effects via Modulating Gut Microbiota-Dependent Tryptophan Metabolism

Fu-brick tea (FBT) has attracted the attention of researchers because of its unique nutritional value, but it remains unknown whether Eurotium cristatum, the critical fungus from FBT, is responsible for the observed anti-colitis effects of FBT. Herein, the effects of E. cristatum on dextran sulfate sodium (DSS)-induced ulcerative colitis was first discussed. The results illustrated that the oral administration of E. cristatum inhibited DSS-induced colon damage. Microbiota analysis revealed that E. cristatum improved the intestinal homeostasis of colitis mice, especially increased the proportion of Lactobacillus, followed by an obvious increase in fecal short-chain fatty acids (SCFAs). Besides, E. cristatum markedly promoted tryptophan metabolism and increased the fecal contents of tryptophan metabolites in colitis mice. Furthermore, E. cristatum drastically increased the content of colonic IL-22 and the expression of tight-junction proteins. Conclusively, these results suggest that E. cristatum can resist colon damage and other implications of colitis by regulating the microbiota and enhancing tryptophan metabolism to strengthen intestinal barriers.

Impact of grape polyphenols on Akkermansia muciniphila and the gut barrier

A healthy gastrointestinal tract functions as a highly selective barrier, allowing the absorption of nutrients and metabolites while preventing gut bacteria and other xenobiotic compounds from entering host circulation and tissues. The intestinal epithelium and intestinal mucus provide a physical first line of defense against resident microbes, pathogens and xenotoxic compounds. Prior studies have indicated that the gut microbe Akkermansia muciniphila, a mucin-metabolizer, can stimulate intestinal mucin thickness to improve gut barrier integrity. Grape polyphenol (GP) extracts rich in B-type proanthocyanidin (PAC) compounds have been found to increase the relative abundance of A. muciniphila, suggesting that PACs alter the gut microbiota to support a healthy gut barrier. To further investigate the effect of GPs on the gut barrier and A. muciniphila, male C57BL/6 mice were fed a high-fat diet (HFD) or low-fat diet (LFD) with or without 1% GPs (HFD-GP, LFD-GP) for 12 weeks. Compared to the mice fed unsupplemented diets, GP-supplemented mice showed increased relative abundance of fecal and cecal A. muciniphila, a reduction in total bacteria, a diminished colon mucus layer and increased fecal mucus content. GP supplementation also reduced the presence of goblet cells regardless of dietary fat. Compared to the HFD group, ileal gene expression of lipopolysaccharide (LPS)-binding protein (Lbp), an acute-phase protein that promotes pro-inflammatory cytokine expression, was reduced in the HFD-GP group, suggesting reduced LPS in circulation. Despite depletion of the colonic mucus layer, markers of inflammation (Ifng, Il1b, Tnfa, and Nos2) were similar among the four groups, with the exception that ileal Il6 mRNA levels were lower in the LFD-GP group compared to the LFD group. Our findings suggest that the GP-induced increase in A. muciniphila promotes redistribution of the intestinal mucus layer to the intestinal lumen, and that the GP-induced decrease in total bacteria results in a less inflammatory intestinal milieu.

An Elemental Diet Enriched in Amino Acids Alters the Gut Microbial Community and Prevents Colonic Mucus Degradation in Mice with Colitis

The role of dietary amino acids or intact proteins in the progression of colitis remains controversial, and the mechanism involving gut microbes is unclear. Here, we investigated the effects of an elemental diet (ED) enriched in amino acids and a polymeric diet enriched in intact protein on the pathogenesis of dextran sulfate sodium (DSS)-induced colitis in mice. Our results showed that the ED induced remission of colitis in mice. Notably, ED treatment reduced the abundance of the mucolytic bacteria Akkermansia and Bacteroides, which was attributed to decreased colonic protein fermentation. Consistently, the activities of mucolytic enzymes were decreased, leading to protection against mucus layer degradation and microbial invasion. Fecal microbiota transplantation from ED-fed mice reshaped microbial ecology and alleviated intestinal inflammation in recipient mice. The ED failed to induce remission of colitis in pseudogermfree mice. Together, our results demonstrate the critical role of the gut microbiota in the prevention of colitis by an ED. IMPORTANCE The prevalence of inflammatory bowel disease is rapidly increasing and has become a global burden. Several specific amino acids have been shown to benefit mucosal healing and colitis remission. However, the role of amino acids or intact proteins in diets and enteral nutrition formulas is controversial, and the mechanisms involving gut microbes remain unclear. In this study, we investigated the effects of an elemental diet (ED) enriched in amino acids and a polymeric diet enriched in intact protein on the pathogenesis of colitis in mice. The underlying mechanisms were explored by utilizing fecal microbiota transplantation and pseudogermfree mice. ED treatment reduced the abundance of mucolytic bacteria, thereby protecting the mucus layer from microbial invasion and degradation. For the first time, we convincingly demonstrated the critical role of gut microbiota in the effects of the ED. This study may provide new insights into the gut microbiota-diet interaction and its role in human health.

Dark-purple rice extract modulates gut microbiota composition in acetic acid– and indomethacin-induced inflammatory bowel disease in rats

Ulcerative colitis (UC) and Crohn's disease (CD) are two major forms of inflammatory bowel disease (IBD). The disease has been linked with gut microbiota dysbiosis in which the balance of commensal communities is disrupted. Accumulating evidence demonstrates that treatment with biologically active compounds can modulate gut microbiota composition in animal models. Our previous work has also shown the beneficial effect of Luem Pua (LP) rice extract, which is rich in anthocyanins, on inflammation. However, its effect on gut microbiota is yet to be explored. In this study, we profiled fecal microbiota of acetic acid (AA)-induced UC and indomethacin (ID)-induced CD rat models with and without pretreatment with LP rice extract by 16S rRNA gene sequencing. The results showed that gut microbiota communities of rats were altered by both AA-induced UC and ID-induced CD. The relative abundances of beneficial bacteria, especially the Lachnospiraceae NK4A136 group and Lactobacillus, were decreased in the AA-induced UC model, while some opportunistic pathogens (Bacteroides, Escherichia/Shigella, Fusobacterium, and Veillonella) were raised by ID-induced CD. Interestingly, pretreatment with LP rice extract before AA-inducing UC in rats increased the proportion of the butyrate-producing bacteria (Lachnospiraceae NK4A136 group). The abundances of these beneficial bacteria and other SCFA-producing bacteria were unaffected by the indomethacin treatment with LP. Overall, our study revealed different impacts of AA-induced UC and ID-induced CD on changes in community composition and hinted at how LP may protect against UC by modifying the gut microbiota.

Dietary Turmeric Consumption Alleviates Ulcerative Colitis via Restoring Tryptophan Metabolism and Alleviating Gut Microbiota Dysbiosis in Mice

This study was designed to first verify the protective capacity of turmeric powder (TP) as a traditional cooking spice against dextran sulfate sodium (DSS)-induced intestinal inflammation and intestine microbiota imbalance. The DSS-induced mice were fed a standard rodent chow supplemented with or without TP (8%) for 37 days. The results indicated that the pathological phenotype, gut barrier disruption, and colon inflammation of DSS-induced mice were significantly improved through supplementation of TP. In addition, 16S rRNA-based microbiota or targeted metabolomics analysis indicated that TP ameliorated intestinal microbiota dysbiosis caused by DSS and particularly enhanced the abundances of probiotics correlated with tryptophan metabolism, such as Lactobacillus and Bifidobacterium, where the cecal tryptophan was metabolized to indole-3-propionic acid and indole-3-acetic acid. Consumption of TP markedly enhanced the expression levels of colonic aromatic hydrocarbon receptors and further increased the expressions of intestinal tight junction proteins and interleukin-22 in the colitis mice. Collectively, these findings manifest the protective actions of dietary TP consumption against ulcerative colitis via restoring the intestinal microbiota disorders, promoting microbial metabolism, and improving intestinal barrier damage.

Huoxiang Zhengqi alleviates azoxymethane/dextran sulfate sodium-induced colitis-associated cancer by regulating Nrf2/NF-κB/NLRP3 signaling

Colitis-associated cancer (CAC) is a subtype of inflammatory bowel disease (IBD)-associated colorectal cancer. Huoxiang Zhengqi (HXZQ) is a classical Chinese herbal medicine and has been used to treat intestinal disorders, however, anti-CAC effects and underlying mechanisms of HXZQ have not been reported. An azoxymethane/dextran sulfate sodium-induced CAC mice model was used to investigate the anti-CAC effect of HXZQ. HXZQ significantly reduced colonic inflammation, suppressed the size and number of tumors, and reduced the levels of pro-inflammatory cytokines (interleukin [IL]-1α, IL-1β, IL-6, IL-17A, IL-21, IL-23, granulocyte macrophage-colony stimulating factor, and tumor necrosis factor-α) and oxidative stress markers (reactive oxygen species and malondialdehyde), and increased the levels of anti-inflammatory cytokines (IL-10 and IL-27) in CAC mice. Intestinal microbiota and serum metabolomics analyses indicated that HXZQ altered the gut microbial composition and the abundance of 29 serum metabolites in CAC mice. Additionally, HXZQ activated the nuclear factor-erythroid factor 2-related factor 2 (Nrf2) signaling pathway and increased the levels of antioxidants such as catalase (CAT), heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductases-1 (NQO-1), and superoxide dismutase-1 (SOD-1). HXZQ inhibited the activation of the nuclear factor kappa-B (NF-κB) signaling pathway and decreased the expression of NLR family pyrin domain containing 3 (NLRP3) by inhibiting the phosphorylation of inhibitor of nuclear factor kappa-B (IκB), inhibitor of nuclear factor kappa-B kinase (IKK), and NF-κB. In conclusion, HXZQ alleviated CAC in mice by modulating the intestinal microbiota and metabolism, activating Nrf2-mediated antioxidant response, and inhibiting NF-κB-mediated NLRP3 inflammasome activation against inflammation. The present data provide a reference for the use of HXZQ as a therapeutic or combination agent for clinical CAC treatment.

Camel milk modulates the gut microbiota and has anti-inflammatory effects in a mouse model of colitis

Camel milk is a nutritionally rich food that shows anti-inflammatory, immune regulation, and gut microbiota maintenance properties. However, the relationship between camel milk and the intestinal microbiota during colitis is unclear. Herein, we evaluated the protective effect of camel milk in mice with colitis induced using dextran sodium sulfate. Our results showed that camel milk can prevent body weight loss and colon shortening, reduce the disease activity index, and attenuate colon tissue damage. Additionally, camel milk could reduce the overexpression of inflammatory factors, inhibit the apoptosis of intestinal epithelial cells, and promote the expression of claudin-1, occludin, and zonula occludens-1 proteins. Moreover, camel milk effectively regulated intestinal microbiota in mice with colitis by increasing the gut microbiota diversity, increasing the abundance of beneficial bacteria (such as g_norank_f_Muribaculaceae, and Lachnospiraceae_NK4A136_group), and reducing the number of harmful bacteria (Bacteroides, Escherichia-Shigella). In addition, camel milk increased the levels of intestinal short-chain fatty acids. The results of the present study demonstrated that via regulating the intestinal microbiota, maintaining intestinal barrier function, and inhibiting proinflammatory cytokines, camel milk can ameliorate dextran sodium sulfate-induced colitis.

Mitigation of DSS-Induced Colitis Potentially via Th1/Th2 Cytokine and Immunological Function Balance Induced by Phenolic-Enriched Buckwheat (Fagopyrum esculentum Moench) Bee Pollen Extract

Colitis is an inflammatory disease that results from the overactivation of effector immune cells, producing a high quantity of pro-inflammatory cytokines. Our study aimed to explore whether buckwheat (F. esculentum) bee pollen extract (FBPE) could inhibit the progression of dextran sulfate sodium (DSS)-induced colitis via regulating immune function. We isolated and identified six main phenolic compounds of FBPE such as luteolin (9.46 mg/g) by column chromatography, HPLC-DAD, ESI-MS and NMR spectroscopy, then assessed their effects on colonic mucosal injury by clinical symptoms, histomorphology and immunohistochemistry examinations. The results showed that FBPE at 25.2 g/kg body weight (g/kg BW) changed the clinical symptoms of colitis, the ICAM-1 expression in colon, the activity of related inflammatory mediators in colon tissue and helped restore the immune system. Compared with the model group (40.28%), the CD4 positivity was significantly reduced in the HD (High-dose group: 25.2 g FBPE/kg BW/day) group (20.45%). Administration of 25.2 g/kg BW of FBPE decreased the IFN-γ, TNF-α and IL-4 levels, while enhancing the IL-10 level, and significantly inhibited the abnormally decreased IgG (Model: 13.25 mg/mL, HD: 14.06 mg/mL), showing a reversal effect on the Th1/Th2 levels in colitis. These findings suggested that FBPE at 25.2 g/kg BW had the effects of alleviating colitis and immunomodulation, which can help in the development of safe and effective immune therapy.

Structural Characteristics of Inulin and Microcrystalline Cellulose and Their Effect on Ameliorating Colitis and Altering Colonic Microbiota in Dextran Sodium Sulfate-Induced Colitic Mice

Several studies have reported that dietary fibers (DFs) from plants may exert beneficial effects on inflammatory bowel disease. In the present study, we investigated the structural differences of soluble DF (inulin) and insoluble DF (microcrystalline cellulose, MCC) and their effects on the intestinal barrier integrity, gut microbiota community, and inflammation response in mice with dextran sodium sulfate (DSS)-induced colitis. Mice were fed for 21 days with diets containing inulin or MCC (2.5 g/kg body weight), and colitis was induced by administration of DSS (4% w/v) in drinking water during the last 8 days of experimentation. The results showed that inulin and MCC differ in morphology and structure. MCC exhibited a smaller particle size, a larger specific surface area, and higher thermal stability than inulin. In addition, both inulin and MCC restored various physical signs (body weight, colon weight and length, disease activity index score, and infiltration of inflammatory cells), gut barrier function (as evidenced by the increased expression of claudin-3, claudin-7, ZO-2, occludin, JAM-2, and MUC-3 and the decreased activity of myeloperoxidase activity), downregulation of mRNA expression of proinflammatory cytokines (caspase-1, NLPR3, TLR4, TNF-α, and IL-1β), and modulation of colon microbiota community. Taken together, the present study demonstrates that DFs differ in morphology and structure and ameliorate DSS-induced colitis in mice by blocking proinflammatory cytokines, reinforcing gut barrier integrity, and modulating gut microbiota. Therefore, DFs, especially inulin, are promising dietary supplements to alleviate intestinal inflammation.