Compound polysaccharides ameliorate experimental colitis by modulating gut microbiota composition and function

Updated Progress on Polysaccharides with Anti-Diabetic Effects through the Regulation of Gut Microbiota: Sources, Mechanisms, and Structure-Activity Relationships

Diabetes mellitus (DM) is a common chronic metabolic disease worldwide. The disturbance of the gut microbiota has a complex influence on the development of DM. Polysaccharides are one type of the most important natural components with anti-diabetic effects. Gut microbiota can participate in the fermentation of polysaccharides, and through this, polysaccharides regulate the gut microbiota and improve DM. This review begins by a summary of the sources, anti-diabetic effects and the gut microbiota regulation functions of natural polysaccharides. Then, the mechanisms of polysaccharides in regulating the gut microbiota to exert anti-diabetic effects and the structure-activity relationship are summarized. It is found that polysaccharides from plants, fungi, and marine organisms show great hypoglycemic activities and the gut microbiota regulation functions. The mechanisms mainly include repairing the gut burrier, reshaping gut microbiota composition, changing the metabolites, regulating anti-inflammatory activity and immune function, and regulating the signal pathways. Structural characteristics of polysaccharides, such as monosaccharide composition, molecular weight, and type of glycosidic linkage, show great influence on the anti-diabetic activity of polysaccharides. This review provides a reference for the exploration and development of the anti-diabetic effects of polysaccharides.

Effect of vinegar steaming on the composition and structure of Schisandra chinensis polysaccharide and its anti-colitis activity

In this study, infrared spectroscopy, high-performance liquid chromatography, and matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) technology were applied to systematically explain the Schisandra chinensis's polysaccharide transformation in configuration, molecular weight, monosaccharide composition, and anti-ulcerative colitis (UC) activity after vinegar processing. Scanning electron microscopic results showed that the appearance of S. chinensis polysaccharide changed significantly after steaming with vinegar. The MALDI-TOF-MS results showed that the mass spectra of raw S. chinensis polysaccharides (RSCP) were slightly lower than those of vinegar-processed S. chinensis polysaccharides (VSCP). The RSCP showed higher peaks at m/z 1350.790, 2016.796, and 2665.985, all with left-skewed distribution, and the molecular weights were concentrated in the range of 1300-3100, with no higher peak above m/z 5000. The VSCPs showed a whole band below m/z 3000, with m/z 1021.096 being the highest peak, and the intensity decreased with the increase of m/z. In addition, compared to RSCPs, VSCPs can significantly increase the content of intestinal short-chain fatty acids (SCFAs). This study showed that the apparent morphology and molecular weight of S. chinensis's polysaccharides significantly changed after steaming with vinegar. These changes directly affect its anti-UC effect significantly, and its mechanism is closely related to improving the structure and diversity of gut microbiota and SCFA metabolism.

Research progress on the structure, derivatives, pharmacological activity, and drug carrier capacity of Chinese yam polysaccharides: A review

Chinese yam is a traditional Chinese medicine that has a long history of medicinal and edible usage in China and is widely utilised in food, medicine, animal husbandry, and other industries. Chinese yam polysaccharides (CYPs) are among the main active components of Chinese yam. In recent decades, CYPs have received considerable attention because of their remarkable biological activities, such as immunomodulatory, antitumour, hypoglycaemic, hypolipidaemic, antioxidative, anti-inflammatory, and bacteriostatic effects. The structure and chemical alterations of polysaccharides are the main factors affecting their biological activities. CYPs are potential drug carriers owing to their excellent biodegradability and biocompatibility. There is a considerable amount of research on CYPs; however, a systematic summary is lacking. This review summarises the structural characteristics, derivative synthesis, biological activities, and their usage as drug carriers, providing a basis for future research, development, and application of CYPs.

Updating the Classification of Chronic Inflammatory Enteropathies in Dogs

Chronic inflammatory enteropathies (CIEs) in dogs are currently classified based on response to sequential treatment trials into food-responsive (FREs); antibiotic-responsive (AREs); immunosuppressant-responsive (IREs); and non-responsive enteropathies (NREs). Recent studies have reported that a proportion of NRE dogs ultimately respond to further dietary trials and are subsequently misclassified. The FRE subset among CIEs is therefore probably underestimated. Moreover, alterations in the gut microbiota composition and function (dysbiosis) have been shown to be involved in CIE pathogenesis in recent research on dogs. Metronidazole and other antibiotics that have been used for decades for dogs with AREs have been demonstrated to result in increased antimicrobial resistance and deleterious effects on the gut microbiota. As a consequence, the clinical approach to CIEs has evolved in recent years toward the gradual abandonment of the use of antibiotics and their replacement by other treatments with the aim of restoring a diverse and functional gut microbiota. We propose here to refine the classification of canine CIEs by replacing the AREs category with a microbiota-related modulation-responsive enteropathies (MrMREs) category.

Bergenin Alleviates Ulcerative Colitis By Decreasing Gut Commensal Bacteroides vulgatus-Mediated Elevated Branched-Chain Amino Acids

Ulcerative colitis is closely associated with the dysregulation of gut microbiota. There is growing evidence that natural products may improve ulcerative colitis by regulating the gut microbiota. In this research, we demonstrated that bergenin, a naturally occurring isocoumarin, significantly ameliorates colitis symptoms in dextran sulfate sodium (DSS)-induced mice. Transcriptomic analysis and Caco-2 cell assays revealed that bergenin could ameliorate ulcerative colitis by inhibiting TLR4 and regulating NF-κB and mTOR phosphorylation. 16S rRNA sequencing and metabolomics analyses revealed that bergenin could improve gut microbiota dysbiosis by decreasing branched-chain amino acid (BCAA) levels. BCAA intervention mediated the mTOR/p70S6K signaling pathway to exacerbate the symptoms of ulcerative colitis in mice. Notably, bergenin greatly decreased the symbiotic bacteria Bacteroides vulgatus (B. vulgatus), and the gavage of B. vulgatus increased BCAA concentrations and aggravated the symptoms of ulcerative colitis in mice. Our findings suggest that gut microbiota-mediated BCAA metabolism plays a vital role in the protective effect of bergenin on ulcerative colitis, providing novel insights for ulcerative colitis prevention through manipulation of the gut microbiota.

Research progress of natural plant polysaccharides inhibiting inflammatory signaling pathways and regulating intestinal flora and metabolism to protect inflammatory bowel disease

Natural plant polysaccharides are macromolecular substances with a wide range of biological activities. They have a wide range of biological activities, especially play an important role in the treatment of inflammatory bowel disease. The molecular weight of polysaccharides, the composition of monosaccharides and the connection of glycosidic bonds will affect the therapeutic effect on inflammatory bowel disease. Traditional Chinese medicine plant polysaccharides and various types of plant polysaccharides reduce the levels of inflammatory cytokines IL-1β, IL-6, IL-8 and IL-17, increase the level of anti-inflammatory factor IL-10, regulate NF-κB signaling pathway, and NLRP3 inflammasome to relieve colitis. At the same time, they can play a protective role by regulating the balance of intestinal flora in mice with colitis and increasing the abundance of probiotics to promote the metabolism of polysaccharide metabolites SCFAs. This review summarizes the research on the treatment of inflammatory bowel disease by many natural plant polysaccharides, and provides a theoretical basis for the later treatment of polysaccharides on inflammatory bowel disease.

Scytosiphon lomentaria fucoidan ameliorates DSS-induced colitis in dietary fiber-deficient mice via modulating the gut microbiota and inhibiting the TLR4/NF-κB/MLCK pathway

The prevalence of ulcerative colitis (UC) poses a serious threat to human health. This study showed that fiber-deficient diet (FD) increased the susceptibility of mice to low dosage of DSS-induced UC, and a UC model was established by feeding mice with DSS and FD to evaluate the effect of Scytosiphon lomentaria fucoidan (SLF) on UC. SLF ameliorated the symptoms of UC, as evidenced by increases in colon length, goblet cells and glycoprotein and reduction in inflammatory cell infiltration and intestinal epithelial injury. SLF alleviated oxidative stress and inhibited colonic inflammation by reducing the levels of lipopolysaccharides and pro-inflammatory cytokines and suppressing the activation of nuclear factor kappa B pathway. SLF protected tight junction integrity by reducing the level of myosin light chain kinase and increasing the levels of claudin, zonula occludens-1 and occludin. SLF improved serum metabolites profile and affected multiple metabolic pathways that are crucial to human health, e.g. butanoate metabolism. The underlying mechanism can be associated with modulation of the gut microbiota and metabolites, including increases in short chain fatty acids and reduction in Proteobacteria, Bacteroides and Romboutsia. It suggests that SLF could be developed as a prebiotic polysaccharide to benefit human health by improving intestinal microecology.

Preventive Effect of Ecklonia cava Extract on DSS-Induced Colitis by Elevating Intestinal Barrier Function and Improving Pathogenic Inflammation

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a complex gastrointestinal disorder with a multifactorial etiology, including environmental triggers, autoimmune mechanisms, and genetic predisposition. Despite advancements in therapeutic strategies for IBD, its associated mortality rate continues to rise, which is often attributed to unforeseen side effects of conventional treatments. In this context, we explored the potential of Ecklonia cava extract (ECE), derived from an edible marine alga known for its anti-inflammatory and antioxidant properties, in mitigating IBD. This study investigated the effectiveness of ECE as a preventive agent in a murine model of dextran sulfate sodium (DSS)-induced colitis. Our findings revealed that pretreatment with ECE significantly ameliorated colitis severity, as evidenced by increased colon length, reduced spleen weight, and histological improvements demonstrated by immunohistochemical analysis. Furthermore, ECE significantly attenuated the upregulation of inflammatory cytokines and mediators and the infiltration of immune cells known to be prominent features of colitis in mice. Notably, ECE alleviated dysbiosis of intestinal microflora and aided in the recovery of damaged intestinal mucosa. Mechanistically, ECE exhibited protective effects against pathogenic colitis by inhibiting the NLRP3/NF-κB pathways known to be pivotal regulators in the inflammatory signaling cascade. These compelling results suggest that ECE holds promise as a potential candidate for IBD prevention. It might be developed into a functional food for promoting gastrointestinal health. This research sheds light on the preventive potential of natural compounds like ECE in the management of IBD, offering a safer and more effective approach to combating this challenging disease.

Review article: The complex interplay between diet and Escherichia coli in inflammatory bowel disease

BACKGROUND

Although no causative microbe has been yet identified or successfully targeted in the treatment of inflammatory bowel disease (IBD), the role of Escherichia coli in the pathogenesis of Crohn's disease has attracted considerable interest.

AIM

In this review, we present a literature overview of the interactions between diet and E. coli and other Proteobacteria in the aetiology, outcomes and management of IBD and suggest future research directions.

METHODS

An extensive literature search was performed to identify in vitro studies and research in animal models that explored mechanisms by which dietary components can interact with E. coli or Proteobacteria to initiate or propagate gut inflammation. We also explored the effect diet and dietary therapies have on the levels of E. coli or Proteobacteria in patients with IBD.

RESULTS

Preclinical data suggest that the Western diet and its components influence the abundance, colonisation and phenotypic behaviour of E. coli in the gut, which may in turn initiate or contribute to gut inflammation. In contrast, the Mediterranean diet and specific dietary fibres may abrogate these effects and protect from inflammation. There are limited data from clinical trials, mostly from patients with Crohn's disease during treatment with exclusive enteral nutrition, with findings often challenging observations from preclinical research. Data from patients with ulcerative colitis are sparse.

CONCLUSIONS

Preclinical and some clinical trial data suggest that E. coli and other Proteobacteria interact with certain dietary components to promote gut inflammation. Well-designed clinical trials are required before dietary recommendations for disease management can be made.

CPW partially attenuates DSS-induced ulcerative colitis in mice

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) of the gastrointestinal tract. The etiology is not fully understood, but environmental, microbial, and immunologic factors, as well as a genetic predisposition, play a role. UC is characterized by episodes of abdominal pain, diarrhea, bloody stools, weight loss, severe colonic inflammation, and ulceration. Despite the increase in the frequency of UC and the deterioration of the quality of life, there are still patients who do not respond well to available treatment options. Against this background, natural products such as polysaccharides are becoming increasingly important as they protect the intestinal mucosa, promote wound healing, relieve inflammation and pain, and restore intestinal motility. In this study, we investigated the effect of a polysaccharide isolated from the biomass of Campomanesia adamantium and Campomanesia pubescens (here referred to as CPW) in an experimental model of acute and chronic ulcerative colitis induced by dextran sulfate sodium (DSS). CPW reversed weight loss, increased disease activity index (DAI), bloody diarrhea, and colon shortening. In addition, CPW reduced visceral mechanical hypersensitivity, controlled oxidative stress and inflammation, and protected the mucosal barrier. CPW is not absorbed in the intestine, does not inhibit cytochrome P450 proteins, and does not exhibit AMES toxicity. These results suggest that CPW attenuates DSS-induced acute and chronic colitis in mice and may be a potential alternative treatment for UC.

Selenium-enriched crude polysaccharide from Rosa roxburghii Tratt ameliorates cadmium-induced acute kidney injury in mice by modulating intestinal microorganisms

Cadmium is a toxic heavy metal that can cause serious damage to the body. It can trigger the oxidative stress response and damage various organs of the body (kidney, liver, brain, lung, testis, etc.). Selenium polysaccharides are considered to possess better antioxidant, immune regulation, and heavy metal removal activities than other polysaccharides, But few reports focused on Selenium Polysaccharides in Rosa roxburghii Tratt. The purpose of this study was to isolate crude polysaccharides (RRP), and crude Selenium polysaccharides (SeRRP) from Rosa roxburghii Tratt fruit and determine their structure, antioxidant activity, and protective effects on cadmium-exposed mice (PONY-2020-FL-62). Results showed that SeRRP had lower half-maximal inhibitory concentration (IC50) and higher superoxide dismutase (SOD) activity. The intake of food and body weight decreased, while the kidney index and liver index increased significantly after acute cadmium exposure. Most significantly, SeRRP ameliorates kidney injury by improving the kidney index. Furthermore, changes in the gut microbiota may be related to SeRRP or RRP. SeRRP and RRP decreased the Firmicutes/Bacteroidetes ratio, and increased the abundance of beneficial bacteria (Lachnospiraceae, Muribaculaceae, and Ruminococcaceae, etc.). These findings indicate that SeRRP and RRP have the potential to be functional food against oxidant and heavy metal exposure.

The gut microbes in inflammatory bowel disease: Future novel target option for pharmacotherapy

Gut microbes constitute the main microbiota in the human body, which can regulate biological processes such as immunity, cell proliferation, and differentiation, hence playing a specific function in intestinal diseases. In recent years, gut microbes have become a research hotspot in the pharmaceutical field. Because of their enormous number, diversity, and functional complexity, gut microbes have essential functions in the development of many digestive diseases. Inflammatory bowel disease (IBD) is a chronic non-specific inflammatory disease with a complex etiology, the exact cause and pathogenesis are unclear. There are no medicines that can cure IBD, and more research on therapeutic drugs is urgently needed. It has been reported that gut microbes play a critical role in pathogenesis, and there is a tight and complex association between gut microbes and IBD. The dysregulation of gut microbes may be a predisposing factor for IBD, and at the same time, IBD may exacerbate gut microbes' disorders, but the mechanism of interaction between the two is still not well defined. The study of the relationship between gut microbes and IBD is not only important to elucidate the pathogenesis but also has a positive effect on the treatment based on the regimen of regulating gut microbes. This review describes the latest research progress on the functions of gut microbes and their relationship with IBD, which can provide reference and assistance for further research. It may provide a theoretical basis for the application of probiotics, fecal microbiota transplantation, and other therapeutic methods to regulate gut microbes in IBD.

Recent progress in plant-derived polysaccharides with prebiotic potential for intestinal health by targeting gut microbiota: a review

Natural products of plant origin are of high interest and widely used, especially in the food industry, due to their low toxicity and wide range of bioactive properties. Compared to other plant components, the safety of polysaccharides has been generally recognized. As dietary fibers, plant-derived polysaccharides are mostly degraded in the intestine by polysaccharide-degrading enzymes secreted by gut microbiota, and have potential prebiotic activity in both non-disease and disease states, which should not be overlooked, especially in terms of their involvement in the treatment of intestinal diseases and the promotion of intestinal health. This review elucidates the regulatory effects of plant-derived polysaccharides on gut microbiota and summarizes the mechanisms involved in targeting gut microbiota for the treatment of intestinal diseases. Further, the structure-activity relationships between different structural types of plant-derived polysaccharides and the occurrence of their prebiotic activity are further explored. Finally, the practical applications of plant-derived polysaccharides in food production and food packaging are summarized and discussed, providing important references for expanding the application of plant-derived polysaccharides in the food industry or developing functional dietary supplements.

Terminalia bellirica Fruit Extract Alleviates DSS-Induced Ulcerative Colitis by Regulating Gut Microbiota, Inflammatory Mediators, and Cytokines

Ulcerative colitis (UC) is a chronic inflammatory disease significantly impacting patients' lives. This study aimed to elucidate the alleviating effect of ethyl acetate extract (TBEA) from Terminalia bellirica fruit on UC and to explore its mechanism. TBEA was the fraction with the best anti-inflammatory activity screened using in vitro anti-inflammatory assays, and HPLC initially characterized its composition. The mice model of ulcerative colitis was established after free drinking of 2.5% dextran sulfate sodium for six days, and the experimental group was treated with 50 mg/kg and 100 mg/kg TBEA for seven days. We found that TBEA significantly alleviated symptoms in UC mice, including a physiologically significant reduction in disease activity index and pathological damage to colonic tissue. TBEA dramatically slowed down oxidative stress and inflammatory process in UC mice, as evidenced by decreasing myeloperoxidase and malondialdehyde activities and increasing glutathione and catalase levels by reducing the concentrations of IL-6, IL-1β, TNF-α, and NO in UC mice, as well as by regulating key proteins in the IL-6/JAK2/STAT3 pathway. Meanwhile, TBEA maintained intestinal homeostasis by regulating intestinal flora structure. Our study provides new ideas for developing TBEA into a new drug to treat UC.

Dendrobium as a new natural source of bioactive for the prevention and treatment of digestive tract diseases: A comprehensive review with future perspectives

BACKGROUND

The incidence of diseases related to the digestive tract is on the rise, with many types of complex etiologies. Dendrobium nobile Lindl. is a famous Traditional Chinese Medicine (TCM) rich in many bioactives proven to be beneficial in several health diseases related to inflammation and oxidative stress.

PURPOSE

At present, despite the availability of various therapeutic clinical drugs used for the treatment of digestive tract diseases, resistance emergence and existence of several side effects warrant for the developing of novel drugs for improved effects on digestive tract diseases.

METHODS

"Orchidaceae", "Dendrobium", "inflammation", "digestive tract", and "polysaccharide" were used as search terms to screen the literature. The therapeutic use of Dendrobium related to digestive tract diseases relative to known polysaccharides and other bioactive compounds were derived from online databases, including Web of Science, PubMed, Elsevier, Science Direct, and China National Knowledge Infrastructure, as well as relevant information on the known pharmacological actions of the listed phytochemicals.

RESULTS

To better capitalize upon Dendrobium for preventing and treating diseases related to digestive tract, this review summarizes bioactives in Dendrobium reported of potential in digestive tract diseases management and their underlying action mechanisms. Studies revealed that Dendrobium encompasses diverse classes including polysaccharides, phenolics, alkaloids, bibenzyls, coumarins, phenanthrene and steroids, with polysaccharide as the major class. Dendrobium exerts various health effects on a variety of disease related to the digestive tract. Action mechanisms involve antioxidant, anti-inflammatory, anti-apoptotic, antioxidant, anticancer, alongside the regulation of some key signaling pathways.

CONCLUSION

Overall, Dendrobium appears as a promising TCM source of bioactives that has the potential to be further developed into nutraceuticals for digestive tract diseases compared to current drug treatments. This review highlights for Dendrobium potential effects with future perspectives for needed future research to maximize the use of bioactive compounds from Dendrobium for digestive tract disease treatment. A compile of Dendrobium bioactives is also presented alongside methods for their extraction and enrichment for potential incorporation in nutraceuticals.

A critical review on inflammatory bowel diseases risk factors, dietary nutrients regulation and protective pathways based on gut microbiota during recent 5 years

The treatment of inflammatory bowel diseases (IBDs) has become a worldwide problem. Intestinal flora plays an important role in the development and progression of IBDs. Various risk factors (psychology, living habits, dietary patterns, environment) influence the structure and composition of the gut microbiota and contribute to the susceptibility to IBDs. This review aims to provide a comprehensive overview on risk factors regulating intestinal microenvironment which was contributed to IBDs. Five protective pathways related to intestinal flora were also discussed. We hope to provide systemic and comprehensive insights of IBDs treatment and to offer theoretical guidance for personalized patients with precision nutrition.

Gut microbiota mediates the anti-colitis effects of polysaccharides derived from Rhopilema esculentum Kishinouye in mice

Ulcerative colitis (UC) is closely associated with the disturbance of gut microbiota. Crude polysaccharide-rich extract from Rhopilema esculentum Kishinouye has been proven to alleviate dextran sulfate sodium (DSS)-triggered colitis. However, it remains unclear whether the polysaccharides from Rhopilema esculentum (REP) in the extract play a predominant role in ameliorating colitis and whether gut microbiota mediates the beneficial effect of REP. Herein, we aimed to investigate the anti-colitis effects of REP and its mechanisms and to explore the role of REP-modulated gut microbiota in alleviating colitis in mice. Oral REP supplementation ameliorated the symptoms, inflammatory responses, colonic damage and gut microbial dysbiosis in colitic mice. REP significantly enriched SCFA-producing bacteria such as Roseburia and probiotics such as Bifidobacterium and restored the level of SCFAs especially butyric acid and propionic acid. Next, we found that transplantation of microbiota from REP-treated mice alleviated DSS-induced acute colitis, evidenced by improved gut barrier integrity and lower inflammation compared with mice receiving microbiota from control mice. Notably, dramatically enriched Bifidobacterium, Faecalibaculum and SCFA-producing bacteria including Butyricicoccus and Roseburia were found in mice receiving microbiota from the REP-treated donor mice. Lastly, the protective effect of REP supplementation on colitis was abolished in the antibiotic-treated mice. Overall, our findings suggest that REP could alleviate DSS-induced colitis in mice by regulating the imbalance of the microbiome. The polysaccharides of Rhopilema esculentum Kishinouye have the potential to be developed into promising prebiotic agents for rectifying dysbiosis of gut microbiota and preventing UC.

Inflammatory bowel disease therapeutic strategies by modulation of the microbiota: how and when to introduce pre-, pro-, syn-, or postbiotics?

Inflammatory bowel diseases (IBD), a heterogeneous group of inflammatory conditions that encompass both ulcerative colitis and Crohn's disease, represent a major public health concern. The etiology of IBD is not yet fully understood and no cure is available, with current treatments only showing long-term effectiveness in a minority of patients. A need to increase our knowledge on IBD pathophysiology is growing, to define preventive measures, to improve disease outcome, and to develop new effective and lasting treatments. IBD pathogenesis is sustained by aberrant immune responses, associated with alterations of the intestinal epithelial barrier (IEB), modifications of the enteric nervous system, and changes in microbiota composition. Currently, most of the treatments target the inflammation and the immune system, but holistic approaches targeting lifestyle and diet improvements are emerging. As dysbiosis is involved in IBD pathogenesis, pre-, pro-, syn-, and postbiotics are used/tested to reduce the inflammation or strengthen the IEB. The present review will resume these works, pointing out the stage of life, the duration, and the environmental conditions that should go along with microbiota or microbiota-derived treatments.

A Potential Role of Plant/Macrofungi/Algae-Derived Non-Starch Polysaccharide in Colitis Curing: Review of Possible Mechanisms of Action

Multiple in vitro and in vivo model investigations have suggested a broad spectrum of potential mechanisms by which plant/macrofungi-derived non-starch polysaccharides may play a role in the treatment of inflammatory bowel disease (IBD). This article reviews the in vivo and in vitro evidence of different plant-derived polysaccharides for IBD therapy. Their underlying mechanisms, particularly the molecular mechanisms associated with protective effects in the treatment and prevention of IDB, have been well summarized, including anti-inflammatory, epithelial barrier repair, and the regulation of intestinal flora. Emerging studies have observed the potent role of probiotics in IBD, particularly its ability to modulate gut microbiota, a well-known key factor for IBD. In summary, plant/macrofungi-derived polysaccharides have the potential to be a promising agent for the adjuvant treatment and prevention of IBD and will contribute to the design of well-designed clinical intervention trials that will ultimately improve the therapy of IBD.

The Role of the Human Gut Microbiome in Inflammatory Bowel Disease and Radiation Enteropathy

The human gut microbiome plays a key role in regulating host physiology. In a stable state, both the microbiota and the gut work synergistically. The overall homeostasis of the intestinal flora can be affected by multiple factors, including disease states and the treatments given for those diseases. In this review, we examine the relatively well-characterised abnormalities that develop in the microbiome in idiopathic inflammatory bowel disease, and compare and contrast them to those that are found in radiation enteropathy. We discuss how these changes may exert their effects at a molecular level, and the possible role of manipulating the microbiome through the use of a variety of therapies to reduce the severity of the underlying condition.

Novel Compound Polysaccharides from Chinese Herbal Medicines: Purification, Characterization, and Antioxidant Activities

The present study investigated physicochemical properties and antioxidant activities in vivo and in vitro of purified compound polysaccharides (CPs-1) from Chinese herbal medicines, composed of lotus leaf, hawthorn, Fagopyrum tataricum, Lycium barbarum, Semen cassiae, and Poria cocos with the mass ratio of 2 : 4 : 2 : 1 : 1.5 : 1. The HPGPC profile and FT-IR spectra indicated that the average molecular weight of CPs-1 was 38.7 kDa and possessed the α- and β-D-pyranose, respectively. The methylation analysis and NMR spectrum demonstrated that CPs-1 had a →6)-β-D-Glcp-(1→6)-β-D-Glcp(1→ backbone. Furthermore, the antioxidant assays in vitro revealed that CPs-1 displayed high scavenging abilities for DPPH, hydroxyl, and reducing power, as well as ABTS and superoxide scavenging capacity. The antioxidant experiments in vivo revealed that CPs-1 could significantly enhance CAT, SOD, and GSH-Px activities and dramatically reduce MDA levels in liver and serum of high-fat mice. Therefore, CPs-1 could be potentially incorporated into pharmaceutical products or functional foods as a natural antioxidant.

Polysaccharides from soybean residue fermented by Neurospora crassa alleviate DSS-induced gut barrier damage and microbiota disturbance in mice

Soluble polysaccharides derived from microbial fermentation of agricultural by-products were considered as potential functional ingredients, primarily having probiotic properties. Herein, soluble polysaccharides (FSRP) were isolated from soybean residue fermented by Neurospora crassa, and FSRP mainly contained rhamnose, arabinose, fucose, mannose, glucose, and galactose, according to GC-MS analysis. To further investigate the protective effect of FSRP against colitis, dextran sulfate sodium induction (DSS)-treated mice were orally gavaged with FSRP (200 mg kg-1 d-1) or inulin (400 mg kg-1 d-1, a positive control) for 7 d. The results showed that DSS-treated mice displayed symptoms of body weight loss, atrophy, and histopathological changes of colon, as well as gut barrier damage, which were recovered after FSRP supplementation (similar to inulin). Furthermore, the beneficial effects of FSRP were linked to a decreased inflammatory response and increased protein expression of E-cadherin, claudin-1 and ZO-1. Illumina-MiSeq sequencing analysis revealed that FSRP increased microbial diversity and altered community structure. Specifically, FSRP could modulate the abundance of inflammation-related bacteria (such as Tenericutes, Clostridia, and Bacilli) to ameliorate colitis symptoms. Therefore, FSRP can relieve DSS-induced colitis, which is closely associated with reduced levels of inflammatory factors, improved gut barrier function and gut microbiota homeostasis.

Dehydrocostus Lactone Suppresses Dextran Sulfate Sodium-Induced Colitis by Targeting the IKKα/β-NF-κB and Keap1-Nrf2 Signalling Pathways

Dehydrocostus lactone (DCL) is a major sesquiterpene lactone isolated from Aucklandia lappa Decne, a traditional Chinese herbal medicine that used to treat gastrointestinal diseases. This study aimed to examine the therapeutic effects of DCL on dextran sulfate sodium (DSS)-induced colitis with a focus on identifying the molecular mechanisms involved in DCL-mediated anti-inflammatory activity in macrophages. First, oral administration of DCL (5–15 mg/kg) not only ameliorated symptoms of colitis and colonic barrier injury, but also inhibited the expression of proinflammatory cytokines and myeloperoxidase in colon tissues in DSS-challenged mice. Furthermore, DCL also exhibited significant anti-inflammatory activity in LPS/IFNγ-stimulated RAW264.7 macrophages. Importantly, DCL significantly suppressed the phosphorylation and degradation of IκBα and subsequent NF-κB nuclear translocation, and enhanced the nuclear accumulation of Nrf2 in LPS/IFNγ-treated RAW264.7 cells. Mechanistically, DCL could directly interact with IKKα/β and Keap1, thereby leading to the inhibition of NF-κB signalling and the activation of Nrf2 pathway. Furthermore, DCL-mediated actions were abolished by dithiothreitol, suggesting a thiol-mediated covalent linkage between DCL and IKKα/β or Keap1. These findings demonstrated that DCL ameliorates colitis by targeting NF-κB and Nrf2 signalling, suggesting that DCL may be a promising candidate in the clinical treatment of colitis.

Current advances in the anti-inflammatory effects and mechanisms of natural polysaccharides

Inflammatory bowel disease (IBD) is a chronic, multifactorial and inflammatory disease occurring in the colon tract. Bioactive polysaccharides from natural resources have attracted extensive attention due to their safety, accessibility and good bioactivities. In recent years, a variety of natural bioactive polysaccharides have been proven to possess anti-inflammatory effects on treating acute colitis. The objective of this review was to give an up-to-date review on the anti-inflammatory effects and mechanisms of natural polysaccharides on acute colitis. The anti-inflammatory effects of natural polysaccharides on acute colitis concerning clinical symptoms amelioration, colon tissue repairment, anti-oxidative stress alleviation, anti-inflammation, immune regulation, and gut microbiota modulation were comprehensively summarized. In addition, inducible murine models for assessing the anti-inflammatory effects of natural polysaccharides on acute colitis were also concluded. This review will offer the comprehensive understanding of anti-inflammatory mechanisms of natural polysaccharides in acute colitis, and render theoretical basis for the development and application of natural polysaccharides in drug and functional food.

Cereus sinensis Polysaccharide Alleviates Antibiotic-Associated Diarrhea Based on Modulating the Gut Microbiota in C57BL/6 Mice

The present study investigated whether the purified polysaccharide from Cereus sinensis (CSP-1) had beneficial effects on mice with antibiotic-associated diarrhea (AAD). The effects of CSP-1 on gut microbiota were evaluated by 16S rRNA high-throughput sequencing. Results showed that CSP-1 increased the diversity and richness of gut microbiota. CSP-1 enriched Phasecolarctobacterium, Bifidobacterium and reduced the abundance of Parabacteroides, Sutterella, Coprobacillus to near normal levels, modifying the gut microbial community. Microbial metabolites were further analyzed by gas chromatography-mass spectrometry (GC-MS). Results indicated CSP-1 promoted the production of various short-chain fatty acids (SCFAs) and significantly improved intestinal microflora dysfunction in AAD mice. In addition, enzyme linked immunosorbent assay and hematoxylin-eosin staining were used to assess the effects of CSP-1 on cytokine levels and intestinal tissue in AAD mice. Results demonstrated that CSP-1 inhibited the secretion of interleukin-2 (IL-2), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) and improved the intestinal barrier. Correspondingly, the daily records also showed that CSP-1 promoted recovery of diarrhea status score, water intake and body weight in mice with AAD. In short, CSP-1 helped alleviate AAD by regulating the inflammatory cytokines, altering the composition and richness of intestinal flora, promoting the production of SCFAs, improving the intestinal barrier as well as reversing the dysregulated microbiota function.

Structure Characterization of Polysaccharide from Chinese Yam (Dioscorea opposite Thunb.) and Its Growth-Promoting Effects on Streptococcus thermophilus

To clarify the mechanisms underlying the growth-promoting effects of yam polysaccharide on Streptococcus thermophilus (S. thermophilus), the yam polysaccharide was extracted using a deep eutectic solvents (DESs) method and separated into four fractions by DEAE-cellulose 52. These fractions were used as the alternative carbon source to substitute lactose to compare their growth-promoting effects on S. thermophilus. Furthermore, their molecular weight, monosaccharide and functional groups' composition, microscopic forms and other basic structure characterizations were analyzed. The results showed that all the fractions could significantly promote S. thermophilus growth, and fractions exhibited significantly different growth-promoting effects, whose viable count increased by 6.14, 6.03, 11.48 and 11.29%, respectively, relative to those in the M17 broth medium. Structure-activity relationship analysis revealed that the high growth-promoting activity of yam polysaccharide might be more dependent on the higher molecular weight, the higher galacturonic acid content and its complex spatial configuration, and the existence of β-glycosides would make the yam polysaccharide have a better growth-promoting effect on S. thermophilus.

Effects of ShenLing BaiZhu San Supplementation on Gut Microbiota and Oxidative Stress in Rats with Ulcerative Colitis

The aim of this study was to evaluate the effect of gut microbiota and antioxidation of Shenling Baizhu San (SLBZS) as a supplement in a rat model of ulcerative colitis (UC) induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS). Acute intestinal inflammation was induced in 40 male SD rats aged 4 weeks with 100 mg/kg TNBS, and then three dosages of SLBZS (0.5 g/kg, 1 g/kg, and 1.5 g/kg) were administered for eight days, respectively. Faecal microbiome composition was assessed by 16S rRNA high-throughput sequencing. The result indicated that SLBZS could reduce the diversity of gut microbiota and increased its abundance. At the genus level, the relative abundance of SCFAs producing bacteria including Prevotella and Oscillospira increased, while the relative abundance of opportunistic pathogens including Desulfovibrio and Bilophila decreased. Meanwhile, SLBZS could improve the lesions of colon and significantly reduce the level of MPO, increase the levels of SOD and CAT in rats' serum. These findings revealed that SLBZS was effective and possessed anticolitic activities in a rat model of UC by reducing macroscopical and microscopical colon injury, enhancing antioxidant capacity, and regulating gut microbiota.

Ruminiclostridium 5, Parabacteroides distasonis, and bile acid profile are modulated by prebiotic diet and associate with facilitated sleep/clock realignment after chronic disruption of rhythms

Chronic disruption of rhythms (CDR) impacts sleep and can result in circadian misalignment of physiological systems which, in turn, is associated with increased disease risk. Exposure to repeated or severe stressors also disturbs sleep and diurnal rhythms. Prebiotic nutrients produce favorable changes in gut microbial ecology, the gut metabolome, and reduce several negative impacts of acute severe stressor exposure, including disturbed sleep, core body temperature rhythmicity, and gut microbial dysbiosis. In light of previous compelling evidence that prebiotic diet broadly reduces negative impacts of acute, severe stressors, we hypothesize that prebiotic diet will also effectively mitigate the negative impacts of chronic disruption of circadian rhythms on physiology and sleep/wake behavior. Male, Sprague Dawley rats were fed diets enriched in prebiotic substrates or calorically matched control chow. After 5 weeks on diet, rats were exposed to CDR (12 h light/dark reversal, weekly for 8 weeks) or remained on undisturbed normal light/dark cycles (NLD). Sleep EEG, core body temperature, and locomotor activity were recorded via biotelemetry in freely moving rats. Fecal samples were collected on experimental days -33, 0 (day of onset of CDR), and 42. Taxonomic identification and relative abundances of gut microbes were measured in fecal samples using 16S rRNA gene sequencing and shotgun metagenomics. Fecal primary, bacterially modified secondary, and conjugated bile acids were measured using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Prebiotic diet produced rapid and stable increases in the relative abundances of Parabacteroides distasonis and Ruminiclostridium 5. Shotgun metagenomics analyses confirmed reliable increases in relative abundances of Parabacteroides distasonis and Clostridium leptum, a member of the Ruminiclostridium genus. Prebiotic diet also modified fecal bile acid profiles; and based on correlational and step-wise regression analyses, Parabacteroides distasonis and Ruminiclostridium 5 were positively associated with each other and negatively associated with secondary and conjugated bile acids. Prebiotic diet, but not CDR, impacted beta diversity. Measures of alpha diversity evenness were decreased by CDR and prebiotic diet prevented that effect. Rats exposed to CDR while eating prebiotic, compared to control diet, more quickly realigned NREM sleep and core body temperature (ClockLab) diurnal rhythms to the altered light/dark cycle. Finally, both cholic acid and Ruminiclostridium 5 prior to CDR were associated with time to realign CBT rhythms to the new light/dark cycle after CDR; whereas both Ruminiclostridium 5 and taurocholic acid prior to CDR were associated with NREM sleep recovery after CDR. These results support our hypothesis and suggest that ingestion of prebiotic substrates is an effective strategy to increase the relative abundance of health promoting microbes, alter the fecal bile acid profile, and facilitate the recovery and realignment of sleep and diurnal rhythms after circadian disruption.

Pu-erh tea extraction alleviates intestinal inflammation in mice with flora disorder by regulating gut microbiota

Pu-erh tea is very popular in Southwestern China and South Asian countries and is now becoming increasingly popular in Europe due to its well-documented beneficial effects on human health. Pu-erh tea aqueous extracts can maintain intestinal homeostasis. However, the mechanism of its beneficial effects on intestinal flora disorder is not clear. In this study, we focused on the effects of ripe Pu-erh tea aqueous extracts on the intestinal microbiota in an intestinal flora disorder mouse model. Physiological indexes and the tissue section staining results showed that feeding Pu-erh tea extract could help mice regain weight and alleviate intestinal inflammation. Further assessment of the intestinal microflora found that Pu-erh tea extract could promote the growth of intestinal probiotics and inhibit pathogenic bacteria, thereby achieving a treatment effect for enteritis. This study provides new evidence for the therapeutic effect of Pu-erh tea.

2,4,6-trinitrobenzenesulfonic acid-induced colitis in Rattus norgevicus: a categorization proposal

Reproducibility in animal research is crucial for its reliance and translational relevance. The 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced model of inflammatory bowel disease (IBD) is widely used but inconsistently and incompletely characterized throughout the literature. This hinders comparisons between studies and influences the low rate of translation of effective preclinical molecules. The purpose of this study was to categorize TNBS-induced colitis, based on macroscopic and microscopic scoring systems, and to identify basic routine parameters that could anticipate those categories. We retrospectively analysed male Wistar Rattus norvegicus (n=28 for the control group and n=87 for the TNBS group) and categorized TNBS-induced colitis in three phenotypes: Mild, Moderate and Severe colitis, as for human IBD. Also, we showed that the time course of food intake and fecal excretion (but not body weight, fluid intake or welfare scores) could foresee those categories. So, routine evaluation of food intake and fecal excretion may guide researchers in planning their experiments, selecting the animals with the severity of colitis that better matches their aims, or applying early humane endpoints to animals that will not be used in the experiments. In conclusion, categorizing TNBS-induced colitis enhances the reproducibility of data gathered with this experimental model and strengths its translational relevance.

The dietary supplement Rhodiola crenulata extract alleviates dextran sulfate sodium-induced colitis in mice through anti-inflammation, mediating gut barrier integrity and reshaping the gut microbiome

Rhodiola species are edible medicinal plants, which have been traditionally used in both Asia and Europe as an adaptogen, a tonic, an anti-depressant and anti-inflammatory supplement. However, whether it presents a therapeutic effect on colitis or not remains unknown. The aim of this study is to investigate the protective effect of a Rhodiola crenulata extract (RCE) on mice with DSS-induced colitis. RCE significantly alleviated the pathological abnormalities in colitic mice, including the correspondingly increased colon length, ameliorated colonic injury and reduced pro-inflammatory factors. The protective effect was similar to that of the positive control, 5-aminosalicylic acid. The DSS-induced epithelial apoptosis and maintained intestinal barrier function were attenuated by RCE through the upregulation of the level of tight junction proteins such as ZO-1 and occludin. Notably, RCE prevented gut dysbiosis in colitic mice by restoring the microbial richness and diversity, and decreasing the abundance of Proteobacteria phylum and opportunistic pathogenic Parasutterella and Staphylococcus, as well as increasing the abundance of beneficial microbes in Lactobacillus and Bifidobacterium, which were closely correlated with its protective effect against colitis. Meanwhile, chemical characterization of RCE was performed by UPLC-HR-MS to explain its material basis. A total of 63 compounds were identified, while the content of two bioactive ingredients (salidroside, 1.81%; rosavin, 0.034%) was determined.

Strategies for inflammatory bowel disease drug research by targeting gut microbiota

The pathogenesis of inflammatory bowel disease (IBD) is complex, which may be associated with genetic factors, environmental factors, intestinal mucosal barrier function, immune response, and gut microbiota. At present, there is no cure for IBD, and therefore there is an urgent need to develop therapeutic drugs. Gut microbiota is considered an important factor in the pathogenesis of IBD and is thus an important target for IBD drug research, with the function of regulating the vital activities of host, modulating the immune response, and protecting against intestinal flora disorders. This paper briefly discusses the strategies for IBD drug research by targeting gut microbiota. Fecal transplantation and human microbiota-associated model are effective ways to elucidate the mechanism of IBD therapeutic drugs. Drugs that can enrich probiotics or inhibit harmful bacteria have great potential for the treatment of IBD. Exploring the causal relationship between the changes in gut microbiota and IBD therapeutic drugs through multiple molecular techniques is the focus of IBD drug research in the future.

Polysaccharides from natural resources exhibit great potential in the treatment of ulcerative colitis: A review

The incidence of ulcerative colitis (UC) is high. Despite the availability of various therapeutic agents for the treatment of UC, the routine treatment has limitations and serious side effects. Therefore, a new drug that safely and effectively treats UC is urgently needed. Polysaccharides from natural resources have recently become a hot topic of study for their therapeutic effects on UC. These effects are associated with the regulation of inflammatory cytokines, intestinal flora, and immune system and protection of the intestinal mucosa. This review focuses on the recent advances of polysaccharides from natural resources in the treatment of UC. The mechanisms and practicability of polysaccharides, including pectin, guar gum, rhamnogalacturonan, chitosan, fructan, psyllium, glycosaminoglycan, algal polysaccharides, polysaccharides from fungi and traditional Chinese medicine, and polysaccharide derivatives, are discussed in detail. The good efficacy and safety of polysaccharides make them promising drugs for treating UC.

The Anti-colitis Effect of Schisandra chinensis Polysaccharide Is Associated With the Regulation of the Composition and Metabolism of Gut Microbiota

Background: The pathogenesis of inflammatory bowel disease (IBD) is linked to an intricate association of environmental, microbial, and host-related factors. Polysaccharide affects host immunity by regulating the composition and metabolism of gut microbiota is the common mechanism of disease resistance. However, the efficacy and mechanism of Schisandra chinensis polysaccharide (SCP) in the treatment of inflammatory bowel disease have not been studied.

Objective: To explore the effect and mechanism of SCP on dextran sodium sulfate (DSS) - induced ulcerative colitis (UC) in mice.

Materials/Methods: In this study, we established a mouse model of UC, and used SCP for treatment intervention. The biochemical indexes related to inflammation were determined by ELISA kit, and the therapeutic effect of SCP on UC was clarified. Then, 16S rDNA sequencing was used to study the effect of SCP on the composition and diversity of gut microbiota. At the same time, GC-MS was used to determine the content of short chain fatty acids in intestinal contents. Finally, the relationship among gut microbiota, short chain fatty acids and inflammatory factors was analyzed, and to comprehensively explain the effect and mechanism of SCP on UC.

Results: The results showed that SCP could significantly improve the physiological state of UC mice and regulate the level of inflammatory factors to normal levels. Meanwhile, SCP could significantly regulate the imbalance of gut microbiota and increase the content of SCFAs. In addition, the results of the correlation between gut microbiota and SCFAs showed that butyric acid, isobutyric acid and valeric acid had the highest correlation with gut microbiota.

Conclusion: In conclusion, this research showed that SCP can inhibit inflammatory bowel disease by regulating the composition and metabolism of gut microbiota, and indicating that SCP may be used as adjuvant therapy for IBD patients.

Regulation of the intestinal microbiota: An emerging therapeutic strategy for inflammatory bowel disease

The rapid development of metagenomics, metabolomics, and metatranscriptomics provides novel insights into the intestinal microbiota factors linked to inflammatory bowel disease (IBD). Multiple microorganisms play a role in intestinal health; these include bacteria, fungi, and viruses that exist in a dynamic balance to maintain mucosal homeostasis. Perturbations in the intestinal microbiota disrupt mucosal homeostasis and are closely related to IBD in humans and colitis in mice. Therefore, preventing or correcting the imbalance of microbiota may serve as a novel prevention or treatment strategy for IBD. We review the most recent evidence for direct or indirect interventions targeting intestinal microbiota for treatment of IBD in order to overcome the current limitations of IBD therapies and shed light on personalized treatment options.

Integrated metabolomics and 16S rRNA sequencing to investigate the regulation of Chinese yam on antibiotic-induced intestinal dysbiosis in rats

Objective: Antibiotics have saved hundreds of millions of patient's lives, but there are also many side effects. This paper mainly studies the regulation of Chinese yam on antibiotic-induced gut dysbiosis in rats. Methods: Male Wistar rats were divided into three groups, normal control group, antibiotic group, and Chinese yam group. In the antibiotic group and the yam group, a rat model of intestinal dysfunction was established by intragastric administration of imipenem/cilastatin sodium (antibiotic) for 21 days. The yam group was also given yam decoction for intervention. The fecal samples of each group of rats were analyzed using an ultra-performance liquid chromatography quadrupole/time-of-flight mass spectrometry (UPLC-Q-TOF/MS) method to find potential biomarkers. The DNA in the feces was extracted, and analyzed using 16S rDNA method to find the differential flora. Spearman correlation analysis was performed on differential flora and differential metabolites to determine the main metabolic pathways of the host after intestinal flora dysregulation. Results: The administration of antibiotics can lead to disorders of intestinal flora, decreased microbial diversity, and changes in host metabolic phenotype. Chinese yam can significantly improve the intestinal flora, making the host's metabolic phenotype tend toward normal. Conclusion: Long-term use of Imipenem/cilastatin sodium can cause disturbance of intestinal flora in normal rats. Chinese yam may regulate intestinal flora disorder and have potential prebiotic effects.