Evaluation of the Treatment with Akkermansia muciniphila BAA-835 of Chemotherapy-induced Mucositis in Mice

Mucositis is a high-incidence side effect in cancer patients undergoing chemotherapy. Next-generation probiotics are emerging as new therapeutic tools for managing various disorders. Studies have demonstrated the potential of Akkermansia muciniphila to increase the efficiency of anticancer treatment and to mitigate mucositis. Due to the beneficial effect of A. muciniphila on the host, we evaluated the dose-response, the microorganism viability, and the treatment protocol of A. muciniphila BAA-835 in a murine model of chemotherapy-induced mucositis. Female Balb/c mice were divided into groups that received either sterile 0.9% saline or A. muciniphila by gavage. Mucositis was induced using a single intraperitoneal injection of 5-fluorouracil. The animals were euthanized three days after the induction of mucositis, and tissue and blood were collected for analysis. Prevention of weight loss and small intestine shortening and reduction of neutrophil and eosinophil influx were observed when animals were pretreated with viable A. muciniphila at 1010 colony-forming units per mL (CFU/mL). The A. muciniphila improved mucosal damage by preserving tissue architecture and increasing villus height and goblet cell number. It also improved the integrity of the epithelial barrier, decreasing intestinal permeability and bacterial translocation. In addition, the treatment prevented the expansion of Enterobacteriaceae. The immunological parameters were also improved by decreasing the expression of pro-inflammatory cytokines (IL6, IL1β, and TNF) and increasing IL10. In conclusion, pretreatment with 1010 CFU/mL of viable A. muciniphila effectively controlled inflammation, protected the intestinal mucosa and the epithelial barrier, and prevented Enterobacteriaceae expansion in treated mice.

Effect of high-refined carbohydrate diet on intestinal integrity

OBJECTIVES

One of the leading causes of obesity is the consumption of excess nutrients. Obesity is characterized by adipose tissue expansion, chronic low-grade inflammation, and metabolic alterations. Although consumption of a high-fat diet has been demonstrated to be a diet-induced obesity model associated with gut disorders, the same effect is not well explored in a mild-obesity model induced by high-refined carbohydrate (HC) diet intake. The intestinal tract barrier comprises mucus, epithelial cells, tight junctions, immune cells, and gut microbiota. This system is susceptible to dysfunction by excess dietary components that could increase intestinal permeability and bacterial translocation. The aim of this study was to evaluate whether an HC diet and the alterations resulting from its intake are linked to small intestine changes.

METHODS

Male BALB/c mice were fed a chow or an HC diet for 8 wk.

RESULTS

Although differences in body weight gain were not observed between the groups, mice fed the HC diet showed increased adiposity associated with metabolic alterations. The interferon-γ expression and myeloperoxidase levels were increased in the small intestine in mice fed an HC diet. However, the intestinal villi length, the expression of tight junctions (zonula occludens-1 and claudin-4) and tumor necrosis factor-α cytokine, and the percentage of intraepithelial lymphocytes did not differ in the jejunum or ileum between the groups. We did not observe differences in intestinal permeability and bacterial translocation.

CONCLUSION

Metabolic alterations caused by consumption of an HC diet lead to a mild obesity state that does not necessarily involve significant changes in intestinal integrity.

Association of Fructo-oligosaccharides and Arginine Improves Severity of Mucositis and Modulate the Intestinal Microbiota

Mucositis is defined as inflammatory and ulcerative lesions along of the gastrointestinal tract that leads to the imbalance of the intestinal microbiota. The use of compounds with action on the integrity of the intestinal epithelium and their microbiota may be a beneficial alternative for the prevention and/or treatment of mucositis. So, the aim of this study was to evaluate the effectiveness of the association of fructo-oligosaccharides (FOS) and arginine on intestinal damage in experimental mucositis. BALB/c mice were randomized into five groups: CTL (without mucositis + saline), MUC (mucositis + saline), MUC + FOS (mucositis + supplementation with FOS-1st until 10th day), MUC + ARG (mucositis + supplementation with arginine-1st until 10th day), and MUC + FOS + ARG (mucositis + supplementation with FOS and arginine-1st until 10th day). On the 7th day, mucositis was induced with an intraperitoneal injection of 300 mg/kg 5-fluorouracil (5-FU), and after 72 h, the animals were euthanized. The results showed that association of FOS and arginine reduced weight loss and oxidative stress (P < 0.05) and maintained intestinal permeability and histological score at physiological levels. The supplementation with FOS and arginine also increased the number of goblet cells, collagen area, and GPR41 and GPR43 gene expression (P < 0.05). Besides these, the association of FOS and arginine modulated intestinal microbiota, leading to an increase in the abundance of the genera Bacteroides, Anaerostipes, and Lactobacillus (P < 0.05) in relation to increased concentration of propionate and acetate. In conclusion, the present results show that the association of FOS and arginine could be important adjuvants in the prevention of intestinal mucositis probably due to modulated intestinal microbiota.

Pivotal Role of Intestinal Microbiota and Intraluminal Metabolites for the Maintenance of Gut-Bone Physiology

Intestinal microbiota, and their mutual interactions with host tissues, are pivotal for the maintenance of organ physiology. Indeed, intraluminal signals influence adjacent and even distal tissues. Consequently, disruptions in the composition or functions of microbiota and subsequent altered host-microbiota interactions disturb the homeostasis of multiple organ systems, including the bone. Thus, gut microbiota can influence bone mass and physiology, as well as postnatal skeletal evolution. Alterations in nutrient or electrolyte absorption, metabolism, or immune functions, due to the translocation of microbial antigens or metabolites across intestinal barriers, affect bone tissues, as well. Intestinal microbiota can directly and indirectly alter bone density and bone remodeling. Intestinal dysbiosis and a subsequently disturbed gut-bone axis are characteristic for patients with inflammatory bowel disease (IBD) who suffer from various intestinal symptoms and multiple bone-related complications, such as arthritis or osteoporosis. Immune cells affecting the joints are presumably even primed in the gut. Furthermore, intestinal dysbiosis impairs hormone metabolism and electrolyte balance. On the other hand, less is known about the impact of bone metabolism on gut physiology. In this review, we summarized current knowledge of gut microbiota, metabolites and microbiota-primed immune cells in IBD and bone-related complications.

Bovine milk-derived extracellular vesicles prevent gut inflammation by regulating lipid and amino acid metabolism

Inflammatory bowel disease (IBD) is a global health problem in which metabolite alteration plays an important pathogenic role. Bovine milk-derived extracellular vesicles (mEVs) have been shown to regulate nutrient metabolism in healthy animal models. This study investigated the effect of oral mEVs on metabolite changes in DSS-induced murine colitis. We performed metabolomic profiling on plasma samples and measured the concentrations of lipids and amino acids in both fecal samples and colonic tissues. Plasma metabolome analysis found that mEVs significantly upregulated 148 metabolite levels and downregulated 44 metabolite concentrations (VIP > 1, and p < 0.05). In the fecal samples, mEVs significantly increased the contents of acetate and butyrate and decreased the levels of tridecanoic acid (C13:0), methyl cis-10-pentadecenoate (C15:1) and cis-11-eicosenoic acid (C20:1). Moreover, the concentrations of eicosadienoic acid (C20:2), eicosapentaenoic acid (C20:5), and docosahexaenoic acid (C22:6) were decreased in colonic tissues with mEV supplementation. In addition, compared with the DSS group, mEVs significantly increased the content of L-arginine, decreased the level of L-valine in the fecal samples, and also decreased the levels of L-serine and L-glutamate in the colonic tissues. Collectively, our findings demonstrated that mEVs could recover the metabolic abnormalities caused by inflammation and provided novel insights into mEVs as a potential modulator for metabolites to prevent and treat IBD.

Bifidobacterium longum subsp. longum 51A Attenuates Signs of Inflammation in a Murine Model of Food Allergy

Food allergy is a pathological condition that can lead to hives, swelling, gastrointestinal distress, cardiovascular and respiratory compromise, and even anaphylaxis. The lack of treatment resources emphasizes the necessity for new therapeutic strategies, and in this way, probiotics has been pointed out as an alternative, especially because of its immunomodulatory properties. The goal of this study was to evaluate the probiotic effect of Bifidobacterium longum subsp. longum 5^1A (BL5^1A) in a murine model of ovalbumin (OVA) food allergy, as well as to investigate the effect of the dose and viability of the bacteria on the proposed model. For this purpose, the probiotic effect was assessed by clinical, immunological, and histological parameters in mice treated or not with the BL5^1A and sensitized or not with OVA. Oral administration of BL5^1A prevented weight loss and reduced serum levels of IgE anti-OVA and of sIgA in the intestinal fluid. Also, it reduced the intestinal permeability, proximal jejunum damage, recruitment of eosinophils and neutrophils, and levels of eotaxin-1, CXCL1/KC, IL4, IL5, IL6, IL13, and TNF. Furthermore, the treatment was able to increase the levels of IL10. Investigating different doses administered, the level of 10⁸ CFU showed the best results in terms of protective effect. In addition, the administration of the inactivated bacteria did not present any beneficial effect. Results demonstrate that BL5^1A promotes a systemic immunomodulatory protective effect in a murine model of food allergy that depends on the dose and viability of the bacteria, suggesting its use as probiotic in such disease.

Chemical Characterization and Metabolic Profiling of the Compounds in the Chinese Herbal Formula Li Chang Decoction by UPLC-QTOF/MS

Background

Li Chang decoction (LCD), a Chinese medicine formula, is commonly used to treat ulcerative colitis (UC) in clinics.

Purpose

This study aimed to identify the major components in LCD and its prototype and metabolic components in rat biological samples.

Methods

The chemical constituents in LCD were identified by establishing a reliable ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF/MS) method. Afterwards, the rats were orally administered with LCD, and the biological samples (plasma, urine, and feces) were collected for further analyzing the effective compounds in the treatment of UC.

Result

A total of 104 compounds were discriminated in LCD, including 26 flavonoids, 20 organic acids, 20 saponins, 8 amino acids, 5 oligosaccharides, 5 tannins, 3 lignans, 2 alkaloids, and 15 others (nucleosides, glycosides, esters, etc.). About 50 prototype and 94 metabolic components of LCD were identified in biological samples. In total, 29 prototype components and 22 metabolic types were detected in plasma. About 27 prototypes and 96 metabolites were discriminated in urine, and 34 prototypes and 18 metabolites were identified in feces.

Conclusion

The flavonoids, organic acids, and saponins were the major compounds of LCD, and this study promotes the further pharmacokinetic and pharmacological evaluation of LCD.

Gut microbial metabolome in inflammatory bowel disease: From association to therapeutic perspectives

Inflammatory bowel disease (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), is a set of clinically chronic, relapsing gastrointestinal inflammatory disease and lacks of an absolute cure. Although the precise etiology is unknown, developments in high-throughput microbial genomic sequencing significantly illuminate the changes in the intestinal microbial structure and functions in patients with IBD. The application of microbial metabolomics suggests that the microbiota can influence IBD pathogenesis by producing metabolites, which are implicated as crucial mediators of host-microbial crosstalk. This review aims to elaborate the current knowledge of perturbations of the microbiome-metabolome interface in IBD with description of altered composition and metabolite profiles of gut microbiota. We emphasized and elaborated recent findings of several potentially protective metabolite classes in IBD, including fatty acids, amino acids and derivatives and bile acids. This article will facilitate a deeper understanding of the new therapeutic approach for IBD by applying metabolome-based adjunctive treatment.

Effect of dexamethasone on experimental enteritis produced by Giardia lamblia in a Meriones unguiculatus model

Our aim was to evaluate the impact of immunosuppression on the development of giardiasis. Thirty-six gerbils (4-6 weeks old) were distributed in four groups containing nine animals each: Control (CT); Control-Infected by Giardia lamblia (CTIn), Immunosuppressed (IS), and Immunosuppressed-Infected by G. lamblia (ISIn). Animals in the IS and ISIn groups received intramuscular dexamethasone solution for 25 days. On the 11th day, the animals in the CTIn and ISIn groups were inoculated with G. lamblia. After 14 days of infection, the 25th day of the experiment, all groups were euthanized. Four hours after euthanasia, the intestinal permeability was evaluated and sections of the duodenum and spleen were harvested for morphometric and histopathological analyses. Immunosuppressed groups showed a significant increase in intestinal permeability compared to control and infected groups. Considering that the infection can become chronic in immunosuppressed groups, we should be alert to the possibilities of chronic inflammatory changes, both locally and systemically, due to the loss of the intestinal barrier. Lesions were observed in the duodenal mucosa of the gerbils of the CTIn group, with reduced villi size, crypt hyperplasia, edema, and the presence of inflammatory infiltrate in the lamina propria. In the ISIn group, we observed no inflammation, long and intact villi, and a significant increase in the area of intestinal mucins, despite the large number of trophozoites identified. Our results suggest that exacerbation of the immune response has a direct relationship with the appearance of lesions during enteritis produced by G. lamblia in the assessed model.

Antarctic Strain of Rhodotorula mucilaginosa UFMGCB 18,377 Attenuates Mucositis Induced by 5-Fluorouracil in Mice

Mucositis is one of the most strenuous side effects caused by chemotherapy drugs, such as 5-fluorouracil (5-FU), during the treatment of several types of cancers. The disease is so prevalent and aggressive that many patients cannot resist such symptoms. However, despite its frequency and clinical significance, there is no effective treatment to prevent or treat mucositis. Thus, the use of probiotics as an adjuvant for the treatment has gained prominence. In the present study, we evaluated the effectiveness of oral administration of the Antarctic strain of Rhodotorula mucilaginosa UFMGCB 18,377 as an alternative to minimize side effects of 5-FU-induced mucositis in mice. Body weight, food consumption, stool consistency, and presence of blood in the feces were assessed daily in mice orally treated or not with the yeast and submitted or not to experimental mucositis. Blood, bones, and intestinal tissues and fluid were used to determine intestinal permeability and immunological, microbiological, and histopathological parameters. Treatment with R. mucilaginosa UFMGCB 18,377 was able to decrease clinical signs of the disease, such as reduction of food intake and body weight loss, and also decreased the number of intestinal enterobacteria and intestinal length shortening. Additionally, treatment was able to decrease the levels of MPO and EPO activities and inflammatory infiltrates, as well as the histopathological lesions characteristic of mucositis in the jejunum and ileum. Results of the present study showed that the oral administration of R. mucilaginosa UFMGCB 18,377 protected mice against mucositis induced by 5-FU.

Fish Sidestream-Derived Protein Hydrolysates Suppress DSS-Induced Colitis by Modulating Intestinal Inflammation in Mice

Inflammatory bowel disease is characterized by extensive intestinal inflammation, and therapies against the disease target suppression of the inflammatory cascade. Nutrition has been closely linked to the development and suppression of inflammatory bowel disease, which to a large extent is attributed to the complex immunomodulatory properties of nutrients. Diets containing fish have been suggested to promote health and suppress inflammatory diseases. Even though most of the health-promoting properties of fish-derived nutrients are attributed to fish oil, the potential health-promoting properties of fish protein have not been investigated. Fish sidestreams contain large amounts of proteins, currently unexploited, with potential anti-inflammatory properties, and may possess additional benefits through bioactive peptides and free amino acids. In this project, we utilized fish protein hydrolysates, based on mackerel and salmon heads and backbones, as well as flounder skin collagen. Mice fed with a diet supplemented with different fish sidestream-derived protein hydrolysates (5% w/w) were exposed to the model of DSS-induced colitis. The results show that dietary supplements containing protein hydrolysates from salmon heads suppressed chemically-induced colitis development as determined by colon length and pro-inflammatory cytokine production. To evaluate colitis severity, we measured the expression of different pro-inflammatory cytokines and chemokines and found that the same supplement suppressed the pro-inflammatory cytokines IL-6 and TNFα and the chemokines Cxcl1 and Ccl3. We also assessed the levels of the anti-inflammatory cytokines IL-10 and Tgfb and found that selected protein hydrolysates induced their expression. Our findings demonstrate that protein hydrolysates derived from fish sidestreams possess anti-inflammatory properties in the model of DSS-induced colitis, providing a novel underexplored source of health-promoting dietary supplements.

Ultraperformance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry-Based Metabolomics and Lipidomics Identify Biomarkers for Efficacy Evaluation of Mesalazine in a Dextran Sulfate Sodium-Induced Ulcerative Colitis Mouse Model

This study aims to identify biomarkers for evaluating the therapeutic efficacy of mesalazine on ulcerative colitis by metabolomics and lipidomics. A dextran sulfate sodium-induced mouse model was used. The disease status was assessed by a disease activity index, the TNF-α level of colon was measured by an enzyme-linked immunosorbent assay, and the pathological changes of colon tissue was examined by hematoxylin-eosin staining. Serum metabolomics and lipidomics analysis based on ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry were applied to decipher the metabolic profile changes. Multivariate analysis was applied to differentiate the metabolites of controls, models, and mesalazine-treated mice. By the receiver operating characteristic (ROC) analysis, 40 differential metabolites with an area under curve (AUC) >0.80 were screened out between control and model groups. Among them, four potential biomarkers (palmitoyl glucuronide, isobutyrylglycine, PC (20:3 (5Z, 8Z, 11Z)/15:0) and L-arginine) had a signficantly reversed level of peak areas in the mesalazine group, and three of them were closely correlated with mesalazine efficacy by linear regression analysis. Furthermore, metabolic pathway analysis revealed several dysregulated pathways in colitis mice, including glycerophospholipid metabolism, pyrimidine metabolism, linoleic acid metabolism, arginine biosynthesis, etc. This study indicates that serum metabolomics is a useful approach that can noninvasively evaluate the therapeutic effect and provide unique insights into the underlying mechanism of mesalazine.

The alleviation of skin wound-induced intestinal barrier dysfunction via modulation of TLR signalling using arginine in gilthead seabream (Sparus aurata L)

The present study sought to investigate the effect of arginine on the involvement of toll-like receptors (TLRs) in skin wound-induced intestinal barrier dysfunction in gilthead seabream (Sparus aurata L.). Two replicates of fish (n = 8) were fed a commercial diet (CON, total 2.75% arginine), CON diet enriched with 1% arginine (ARG1, total 3.65% arginine) and 2% arginine (ARG2, total 4.53% arginine) for 30 days. Half of the fish were sampled, whereas the others were injured and sampled 7 days post-wounding. The intestinal histology results showed that a more intense infiltration of mixed leucocytes was evident in the wounded fish, which was remarkably reduced in fish that were fed the ARG1 diet. Serum IgM levels were significantly higher in the ARG1 group than levels in the CON group at 7 days post-wounding. Compared with the fish in the CON group after wounding, dietary administration of 1% arginine markedly downregulated the gene expression of TLRs (TLR2 and TLR5), MyD88, and proinflammatory cytokines (CSF1R, IL-1β, and TNFα), but significantly enhanced the gene expression of IκBα, the anti-inflammatory cytokine TGF-β1, and tight junction proteins (tricellulin and occludin) in wounded fish. Furthermore, the ARG2 diet demonstrated no additional benefits on intestinal cells, compared to both the ARG1 and the CON diets, and it even appeared to induce negative effects. In summary, dietary administration of 1% arginine significantly inhibited intestinal inflammatory response and tight junction disruption in skin-wounded gilthead seabream by modulating TLR signalling in the intestine.

Effects of dietary components on intestinal permeability in health and disease

Altered intestinal permeability plays a role in many pathological conditions. Intestinal permeability is a component of the intestinal barrier. This barrier is a dynamic interface between the body and the food and pathogens that enter the gastrointestinal tract. Therefore, dietary components can directly affect this interface, and many metabolites produced by the host enzymes or the gut microbiota can act as signaling molecules or exert direct effects on this barrier. Our aim was to examine the effects of diet components on the intestinal barrier in health and disease states. Herein, we conducted an in-depth PubMed search based on specific key words (diet, permeability, barrier, health, disease, and disorder), as well as cross references from those articles. The normal intestinal barrier consists of multiple components in the lumen, epithelial cell layer and the lamina propria. Diverse methods are available to measure intestinal permeability. We focus predominantly on human in vivo studies, and the literature is reviewed to identify dietary factors that decrease (e.g., emulsifiers, surfactants, and alcohol) or increase (e.g., fiber, short-chain fatty acids, glutamine, and vitamin D) barrier integrity. Effects of these dietary items in disease states, such as metabolic syndrome, liver disease, or colitis are documented as examples of barrier dysfunction in the multifactorial diseases. Effects of diet on intestinal barrier function are associated with precise mechanisms in some instances; further research of those mechanisms has potential to clarify the role of dietary interventions in treating diverse pathologic states.

Weissella paramesenteroides WpK4 plays an immunobiotic role in gut-brain axis, reducing gut permeability, anxiety-like and depressive-like behaviors in murine models of colitis and chronic stress

The relationship between inflammatory bowel disease (IBD) and mood disorders is complex and involves overlapping metabolic pathways, which may determine comorbidity. Several studies have been shown that this comorbidity could worsen IBD clinical course. The treatment of ulcerative colitis is complex, and involves traditional therapy to promote the function of epithelial barrier, reducing exacerbated inflammatory responses. Recently, it has been shown that some probiotic strains could modulate gut-brain axis, reducing depressive and anxiety scores in humans, including IBD patients. Accordingly, this study aimed to evaluate the role of Weissella paramesenteroides WpK4 in murine models of ulcerative colitis and chronic stress. It was observed that bacterium ingestion improved health of colitis mice, reducing intestinal permeability, besides improving colon histopathological appearance. In stressed mice, bacterial consumption was associated with a reduced anxiety-like and depressive-like behaviors. In both assays, the beneficial role of W. paramesenteroides WpK4 was related to its immunomodulatory feature. It is possible to state that W. paramesenteroides WpK4 exerted their beneficial roles in gut-brain axis through their immunomodulatory effects with consequences in several metabolic pathways related to intestinal permeability and hippocampal physiology.

Supplementation with L-Arginine Decreases Jejunal Lesions and Micronucleus Formation Induced by 5-Fluorouracil in Rats

The objective of this study was to evaluate the effect of L-arginine supplementation on the formation of jejunal lesions and micronuclei in Wistar rats following 5-fluorouracil (5-FU) treatment. Fifty rats were separated into five groups: CG served as the control group, G_Arg was supplemented L-arginine, G_5-FU was administered 5-FU, G_Arg+5-FU was supplemented L-arginine/day and administered 5-FU, and G_ciclo served as a positive control group for micronuclei formation. Jejunal lesions were assessed by histopathological analysis using a scoring system with a maximum of 39 points, based on the following lesions: lymph vessel dilatation, cubic enterocytes, villous flattening, villus fusion, interstitial edema, and apical necrosis of the villi. Micronuclei were counted in polychromatic erythrocytes from the femur bone marrow. The control and G_Arg rats had the lowest number of jejunal lesions (6.4 ± 2.8 and 5.3 ± 2.4, respectively) and micronuclei (1.9 ± 0.6 and 1.1 ± 0.3, respectively) while the G_5-FU rats had the highest number of jejunal lesions (24.2 ± 4.9) and micronuclei (36.0 ± 8.5). The G_Arg+5-FU rats showed significantly reduced (P < 0.05) jejunal lesions (10.2 ± 4.9) and micronuclei (15.4 ± 5.9). In conclusion L-arginine supplementation potentially reduces the jejunal lesions and DNA damage caused by 5-FU.

Selective deletion of MyD88 signaling in α-SMA positive cells ameliorates experimental intestinal fibrosis via post-transcriptional regulation

Intestinal fibrosis leading to strictures remains a significant clinical problem in inflammatory bowel diseases (IBD). The role of bacterial components in activating intestinal mesenchymal cells and driving fibrogenesis is largely unexplored. Tamoxifen-inducible α-SMA promoter Cre mice crossed with floxed MyD88 mice were subjected to chronic dextran sodium sulfate colitis. MyD88 was deleted prior to or after induction of colitis. Human intestinal myofibroblasts (HIMF) were exposed to various bacterial components and assessed for fibronectin (FN) and collagen I (Col1) production. RNA sequencing was performed. Post-transcriptional regulation was assessed by polysome profiling assay. Selective deletion of MyD88 in α-SMA-positive cells prior to, but not after induction of, experimental colitis decreased the degree of intestinal fibrosis. HIMF selectively responded to flagellin with enhanced FN or Col1 protein production in a MyD88-dependent manner. RNA sequencing suggested minimal transcriptional changes induced by flagellin in HIMF. Polysome profiling revealed higher proportions of FN and Col1 mRNA in the actively translated fractions of flagellin exposed HIMF, which was mediated by eIF2 alpha and 4EBP1. In conclusion, selectivity of flagellin-induced ECM secretion in HIMF is post-transcriptionally regulated. The results may represent a novel and targetable link between the gut microbiota and intestinal fibrogenesis.

Wheat gluten intake increases the severity of experimental colitis and bacterial translocation by weakening of the proteins of the junctional complex

Gluten is only partially digested by intestinal enzymes and can generate peptides that can alter intestinal permeability, facilitating bacterial translocation, thus affecting the immune system. Few studies addressed the role of diet with gluten in the development of colitis. Therefore, we investigate the effects of wheat gluten-containing diet on the evolution of sodium dextran sulphate (DSS)-induced colitis. Mice were fed a standard diet without (colitis group) or with 4·5 % wheat gluten (colitis + gluten) for 15 d and received DSS solution (1·5 %, w/v) instead of water during the last 7 d. Compared with the colitis group, colitis + gluten mice presented a worse clinical score, a larger extension of colonic injury area, and increased mucosal inflammation. Both intestinal permeability and bacterial translocation were increased, propitiating bacteria migration for peripheral organs. The mechanism by which diet with gluten exacerbates colitis appears to be related to changes in protein production and organisation in adhesion junctions and desmosomes. The protein α-E-catenin was especially reduced in mice fed gluten, which compromised the localisation of E-cadherin and β-catenin proteins, weakening the structure of desmosomes. The epithelial damage caused by gluten included shortening of microvilli, a high number of digestive vacuoles, and changes in the endosome/lysosome system. In conclusion, our results show that wheat gluten-containing diet exacerbates the mucosal damage caused by colitis, reducing intestinal barrier function and increasing bacterial translocation. These effects are related to the induction of weakness and disorganisation of adhesion junctions and desmosomes as well as shortening of microvilli and modification of the endocytic vesicle route.

Treatment with selenium-enriched Saccharomyces cerevisiae UFMG A-905 partially ameliorates mucositis induced by 5-fluorouracil in mice

PURPOSE

Gastrointestinal mucositis is a major problem associated with cancer therapy. To minimize these deleterious effects, simultaneous administration of antioxidant components, such as selenium, can be considered. There is a growing interest in the use of yeasts because they are able to convert inorganic selenium into selenomethionine. In the present study, oral administration of Saccharomyces cerevisiae UFMG A-905 enriched with selenium was evaluated as an alternative in minimizing the side effects of 5FU-induced mucositis in mice.

METHODS

Mice body weight, food consumption, faeces consistency and the presence of blood in faeces were assessed daily during experimental mucositis induced by 5-fluorouracil (5FU). Blood was used for intestinal permeability determination, and small intestine for oxidative stress, immunological and histopathological examination.

RESULTS

The increased intestinal permeability observed with mucositis induction was partially reverted by S. cerevisiae and selenium-enriched yeast. Both treatments were able to reduce myeloperoxidase activity, but only selenium-enriched yeast reduced eosinophil peroxidase activity. CXCL1/KC levels, histopathological tissue damage and oxidative stress (lipid peroxidation and nitrite production) in the small intestine were reduced by both treatments; however, this reduction was always higher when treatment with selenium-enriched yeast was evaluated.

CONCLUSIONS

Results of the present study showed that the oral administration of S. cerevisiae UFMG A-905 protected mice against mucositis induced by 5-FU, and that this effect was potentiated when the yeast was enriched with selenium.

Dietary Arginine Regulates Severity of Experimental Colitis and Affects the Colonic Microbiome

There is great interest in safe and effective alternative therapies that could benefit patients with inflammatory bowel diseases (IBD). L-arginine (Arg) is a semi-essential amino acid with a variety of physiological effects. In this context, our aim was to investigate the role of dietary Arg in experimental colitis. We used two models of colitis in C57BL/6 mice, the dextran sulfate sodium (DSS) model of injury and repair, and Citrobacter rodentium infection. Animals were given diets containing (1) no Arg (Arg0), 6.4 g/kg (ArgNL), or 24.6 g/kg Arg (ArgHIGH); or (2) the amino acids downstream of Arg: 28 g/kg L-ornithine (OrnHIGH) or 72 g/kg L-proline (ProHIGH). Mice with DSS colitis receiving the ArgHIGH diet had increased levels of Arg, Orn, and Pro in the colon and improved body weight loss, colon length shortening, and histological injury compared to ArgNL and Arg0 diets. Histology was improved in the ArgNL vs. Arg0 group. OrnHIGH or ProHIGH diets did not provide protection. Reduction in colitis with ArgHIGH diet also occurred in C. rodentium-infected mice. Diversity of the intestinal microbiota was significantly enhanced in mice on the ArgHIGH diet compared to the ArgNL or Arg0 diets, with increased abundance of Bacteroidetes and decreased Verrucomicrobia. In conclusion, dietary supplementation of Arg is protective in colitis models. This may occur by restoring overall microbial diversity and Bacteroidetes prevalence. Our data provide a rationale for Arg as an adjunctive therapy in IBD.

Role of soybean-derived bioactive compounds in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, inflammatory condition of the gastrointestinal tract. Patients with IBD present with debilitating symptoms that alter the quality of life and can develop into severe complications requiring surgery. Epidemiological evidence indicates Westernized societies have an elevated IBD burden when compared with Asian societies. Considering the stark contrast between the typical Western and Eastern dietary patterns, it is postulated that differences in food and lifestyle contribute to lower IBD incidence in Asian countries. Soybeans (Glycine max), which are consumed in high quantities and as various preparations in Eastern societies, contain a wealth of natural, biologically active compounds that include isoflavones, bioactive peptides, protease inhibitors, and phytosterols, among many others. These compounds have been shown to improve human health, and preclinical evidence suggests they have potential to improve the prognosis of IBD. This review summarizes the current state of evidence regarding the effects and the mechanisms of action of these soybean-derived bioactive compounds in experimental models of IBD.

Effect of immunonutrition on colorectal cancer patients undergoing surgery: a meta-analysis

PURPOSE

Immunonutrition has been used to prevent the complications after colorectal elective surgery. This systematic review aimed to analyze and assess the effect of immunonutrition on colorectal cancer patients who received elective surgery.

METHODS

Three electronic databases (Medline, Embase, Cochrane) were used to search the latent studies which investigated the effects of enteral immunonutrition (EIN) compared with standard enteral nutrition (EN) or parenteral immunonutrition (PIN) compared with standard parenteral nutrition (PN) on colorectal cancer patients who are undergoing surgery until 21st of April, 2017. Meta-analysis was conducted to calculate odd risk (OR), mean difference (MD), or standard mean difference (SMD) with 95% confidence interval (CI), and heterogeneity was tested by Q test.

RESULTS

Nine publications were included. The meta-analysis results presented that EIN improved the length of hospital stay (pooled MD, 2.53; 95% CI, 1.29-3.41), infectious complications (pooled OR, 0.33; 95% CI, 0.21-0.53) which contains the Surgical Site Infections (pooled OR, 0.25; 95% CI, 0.22-0.58) and Superficial/Deep incisional infections (pooled OR, 0.27; 95% CI, 0.12-0.64); meanwhile, PIN improved the length of hospital stay (pooled MD, 2.66; 95% CI, 0.62-4.76), IL-6 (pooled MD, - 6.09; 95% CI, - 10.11 to - 2.07), CD3 (pooled MD, 7.50; 95% CI, 3.57-11.43), CD4 (pooled MD, 5.47; 95% CI, 2.54-8.40), and CD4/CD8 (pooled MD, 0.50; 95% CI, 0.22-0.78); the level of CD8 was lower (pooled MD, - 4.32; 95% CI, - 7.09 to - 1.55) in PIN.

CONCLUSION

Immunonutrition could be an effective approach to enhance the immune function of colorectal cancer patients undergoing elective surgery and to improve the clinical and laboratory outcomes.

Dietary Protein and Amino Acid Supplementation in Inflammatory Bowel Disease Course: What Impact on the Colonic Mucosa?

Inflammatory bowel diseases (IBD), after disease onset, typically progress in two cyclically repeated phases, namely inflammatory flare and remission, with possible nutritional status impairment. Some evidence, either from epidemiological, clinical, and experimental studies indicate that the quantity and the quality of dietary protein consumption and amino acid supplementation may differently influence the IBD course according to the disease phases. For instance, although the dietary protein needs for mucosal healing after an inflammatory episode remain undetermined, there is evidence that amino acids derived from dietary proteins display beneficial effects on this process, serving as building blocks for macromolecule synthesis in the wounded mucosal area, energy substrates, and/or precursors of bioactive metabolites. However, an excessive amount of dietary proteins may result in an increased intestinal production of potentially deleterious bacterial metabolites. This could possibly affect epithelial repair as several of these bacterial metabolites are known to inhibit colonic epithelial cell respiration, cell proliferation, and/or to affect barrier function. In this review, we present the available evidence about the impact of the amount of dietary proteins and supplementary amino acids on IBD onset and progression, with a focus on the effects reported in the colon.