Partial replacement of dietary linoleic acid with long chain n-3 polyunsaturated fatty acids protects against dextran sulfate sodium-induced colitis in rats

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.

Integrated Analysis Reveals the Targets and Mechanisms in Immunosuppressive Effect of Mesalazine on Ulcerative Colitis

Background

Ulcerative colitis (UC) is an inflammatory bowel disease that causes inflammation and ulcers in the digestive tract. Approximately 3 million US adults suffer from this disease. Mesalazine, an anti-inflammatory agent, is commonly used for the treatment of UC. However, some studies have demonstrated side effects of mesalazine, such as acute pancreatitis and hypereosinophilia. Therefore, a better understanding of the anti-inflammatory mechanism of mesalazine in UC could help improve the effectiveness of the drug and reduce its side effects. In this study, we used a dextran sodium sulfate-induced UC mouse model, and applied network pharmacology and omics bioinformatics approaches to uncover the potential pharmaceutical targets and the anti-inflammatory mechanism of mesalazine.

Results

Network pharmacology analysis identified the core targets of mesalazine, biological processes, and cell signaling related to immunity and inflammatory responses mediated by mesalazine. Molecular docking analysis then indicated possible binding motifs on the core targets (including TNF-α, PTGS2, IL-1β, and EGFR). Metabolomics and 16S metagenomic analyses highlighted the correlation between gut microbiota and metabolite changes caused by mesalazine in the UC model.

Conclusions

Collectively, the omics and bioinformatics approaches and the experimental data unveiled the detailed molecular mechanisms of mesalazine in UC treatment, functional regulation of the gut immune system, and reduction of intestinal inflammation. More importantly, the identified core targets could be targeted for the treatment of UC.

Neurodevelopment, nutrition and genetics. A contemporary retrospective on neurocognitive health on the occasion of the 100th anniversary of the National Institute of Nutrition, Hyderabad, India

In celebration of the centenary of the National Institute of Nutrition (NIN), Hyderabad, India (1918-2018), a symposium highlighted the progress in nutrition knowledge made over the century, as well as major gaps in implementation of that knowledge. Brain famine caused by a shortage of nutrients required for perinatal brain development has unfortunately become a global reality, even as protein-calorie famine was largely averted by the development of high yield crops. While malnutrition remains widespread, the neglect of global food policies that support brain development and maintenance are most alarming. Brain disorders now top the list of the global burden of disease, even with obesity rising throughout the world. Neurocognitive health, remarkably, is seldom listed among the non-communicable diseases (NCDs) and is therefore seldom considered as a component of food policy. Most notably, the health of mothers before conception and through pregnancy as mediated by proper nutrition has been neglected by the current focus on early death in non-neurocognitive NCDs, thereby compromising intellectual development of the ensuing generations. Foods with balanced essential fatty acids and ample absorbable micronutrients are plentiful for populations with access to shore-based foods, but deficient only a few kilometres away from the sea. Sustained access to brain supportive foods is a priority for India and throughout the world to enable each child to develop to their intellectual potential, and support a prosperous, just, and peaceful world. Nutrition education and food policy should place the nutritional requirements for the brain on top of the list of priorities.

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.

Regulation of Intestinal Inflammation by Dietary Fats

With the epidemic of human obesity, dietary fats have increasingly become a focal point of biomedical research. Epidemiological studies indicate that high-fat diets (HFDs), especially those rich in long-chain saturated fatty acids (e.g., Western Diet, National Health Examination survey; NHANES 'What We Eat in America' report) have multi-organ pro-inflammatory effects. Experimental studies have confirmed some of these disease associations, and have begun to elaborate mechanisms of disease induction. However, many of the observed effects from epidemiological studies appear to be an over-simplification of the mechanistic complexity that depends on dynamic interactions between the host, the particular fatty acid, and the rather personalized genetics and variability of the gut microbiota. Of interest, experimental studies have shown that certain saturated fats (e.g., lauric and myristic fatty acid-rich coconut oil) could exert the opposite effect; that is, desirable anti-inflammatory and protective mechanisms promoting gut health by unanticipated pathways. Owing to the experimental advantages of laboratory animals for the study of mechanisms under well-controlled dietary settings, we focus this review on the current understanding of how dietary fatty acids impact intestinal biology. We center this discussion on studies from mice and rats, with validation in cell culture systems or human studies. We provide a scoping overview of the most studied diseases mechanisms associated with the induction or prevention of Inflammatory Bowel Disease in rodent models relevant to Crohn's Disease and Ulcerative Colitis after feeding either high-fat diet (HFD) or feed containing specific fatty acid or other target dietary molecule. Finally, we provide a general outlook on areas that have been largely or scarcely studied, and assess the effects of HFDs on acute and chronic forms of intestinal inflammation.

Diets with low n-6:n-3 PUFA ratio protects rats from fructose-induced dyslipidemia and associated hepatic changes: Comparison between 18:3 n-3 and long-chain n-3 PUFA

In the present study, we investigated the impact of substituting alpha-linolenic acid (ALA) or long-chain n-3 PUFA (eicosapentaenoic acid and docosahexaenoic acid) for linoleic acid and hence decreasing n-6:n-3 PUFA ratio on high-fructose diet-induced hypertriglyceridemia and associated hepatic changes. Weanling male Wistar rats were divided into four groups and fed with starch-diet (n-6:n-3 PUFA ratio 215:1) and high-fructose diets with different n-6:n-3 PUFA ratio (215:1, 2:1 with ALA and 5:1 with long-chain n-3 PUFA) for twenty-four weeks. Substitution of linoleic acid with ALA (n-6:n-3 PUFA ratio of 2) or long-chain n-3 PUFA (n-6:n-3 PUFA ratio of 5) protected the rats from fructose-induced dyslipidemia, hepatic oxidative stress and corrected lipogenic and proinflammatory gene expression. Both ALA and long-chain n-3 PUFA supplementation also reversed the fructose-induced upregulation of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) gene, which is involved in the generation of active glucocorticoids in tissues. Although both ALA and LC n-3 PUFA prevented fructose-induced dyslipidemia to a similar extent, compared to ALA, LC n-3 PUFA is more effective in preventing hepatic oxidative stress and inflammation.

Nutritional approach as therapeutic manipulation in inflammatory bowel disease

Malnutrition is observed more frequently in patients with inflammatory bowel disease (IBD) than in the general population and associated with adverse clinical outcomes. This study aimed to review the current knowledge regarding the efficacy of dietary and nutritional intervention in IBD patients. Exclusive enteral nutrition might be inferior to corticosteroid treatment in adults with active Crohn’s disease (CD) but might even be superior considering the adverse effects of corticosteroid treatment in children. Total parenteral nutrition has no advantage over enteral nutrition, which is considered a more physiologic modality in organ function. Current guidelines do not yet recommend ω3-polyunsaturated fatty acid supplementation for the prevention and maintenance of remission in IBD patients. Dietary fiber supplementation could be effective in the relief of symptoms and maintenance of remission in ulcerative colitis (UC). Although vitamin D may be favorable to clinical course of IBD and bone density. Probiotic supplementation has proven to be effective in preventing and treating pouchitis for UC but is less effective in treating CD. Nutritional interventions not only correct nutritional deficiencies but also improve symptoms and clinical courses of the disease. Hence, nutritional approaches need to be developed to significantly evaluate the effectiveness of dietary interventions used to treat IBD.

iTRAQ-based pharmacoproteomics reveals potential targets of berberine, a promising therapy for ulcerative colitis

Previous studies by us and others have indicated that berberine is a promising therapy for ulcerative colitis (UC). However, the mechanisms of UC and the therapeutic targets of berberine are poorly understood. iTRAQ-based proteomics was utilized to characterize the proteins and pathways associated with the development of colitis and its improvement after berberine treatment. By using a modified dextran sodium sulfate (DSS) colitis as the UC model, confirmed that berberine significantly attenuated clinical symptoms and colon shorting of the colitis mice. Proteomics identified 140 and 391 proteins that were differentially expressed in the colons of DSS- or DSS plus berberine-treated mice, respectively. Subsequent verification of 15 selected differentially expressed proteins (DEPs) by multiple reaction monitoring confirmed the reliability of the iTRAQ data. Further comparisons and bioinformatics analysis demonstrated that among the identified DEPs, 26, including Hist2h2be, Tubb3, and five immunoglobulins, were oppositely regulated by DSS and DSS plus berberine treatments. In addition, five commonly dysregulated pathways, including natural killer cell-mediated cytotoxicity and RRAR signaling were identified. Network analysis revealed that proteins involved in 7 and 11 pathways in DSS and DSS plus berberine treated mice, respectively, engaged in protein-protein interactions. Our study provides the first pharmacoproteomics profiling of colitis and its recovery after berberine treatment. The proteins, pathways and networks identified provide novel insights into the pathogenesis of colitis and the action mechanism of berberine, demonstrating their values for validation in human UC which could serve as targets for the development of novel therapies for UC.

Dietary Fatty Acids and Other Nutrients in Relation to Inflammation and Particularly to Oral Mucosa Inflammation. A Literature Review

Oral mucosa is site of inflammatory process development. When they are chronic, they provide a microenvironment based on cytokines and inflammatory mediators that contribute to cancer initiation, progression, invasion, and metastasis. Certain dietary fatty acids (FAs) have immunomodulatory, inflammatory, and antiinflammatory effects. This review examined the literature on inflammation, mainly referred to the oral mucosa, and its association with dietary FAs and other nutrients. A Pubmed search of studies published in English until June 2018 was carried out. N-3 FAs have shown immunomodulatory and antiinflammatory activity in certain human diseases. These FAs and their mediators may inhibit inflammation, angiogenesis, and cancer via multiple mechanisms. Studies on cellular models of murine and human intestinal mucosa indicate association between dietary n-3 FA intake and the inflammatory state of mucosa membranes. Nevertheless scarce information on the association between dietary FAs and oral inflammation could be found. Based on the evidence, we hypothesize that n-3 FAs reduce the oral mucosa inflammation thus decreasing the risk of developing precancerous lesions and cancer. Molecular and clinical studies referred to this topic should be carried out as a contribution to the oral cancer prevention.

Diet as a Trigger or Therapy for Inflammatory Bowel Diseases

The most common question asked by patients with inflammatory bowel disease (IBD) is, "Doctor, what should I eat?" Findings from epidemiology studies have indicated that diets high in animal fat and low in fruits and vegetables are the most common pattern associated with an increased risk of IBD. Low levels of vitamin D also appear to be a risk factor for IBD. In murine models, diets high in fat, especially saturated animal fats, also increase inflammation, whereas supplementation with omega 3 long-chain fatty acids protect against intestinal inflammation. Unfortunately, omega 3 supplements have not been shown to decrease the risk of relapse in patients with Crohn's disease. Dietary intervention studies have shown that enteral therapy, with defined formula diets, helps children with Crohn's disease and reduces inflammation and dysbiosis. Although fiber supplements have not been shown definitively to benefit patients with IBD, soluble fiber is the best way to generate short-chain fatty acids such as butyrate, which has anti-inflammatory effects. Addition of vitamin D and curcumin has been shown to increase the efficacy of IBD therapy. There is compelling evidence from animal models that emulsifiers in processed foods increase risk for IBD. We discuss current knowledge about popular diets, including the specific carbohydrate diet and diet low in fermentable oligo-, di-, and monosaccharides and polyols. We present findings from clinical and basic science studies to help gastroenterologists navigate diet as it relates to the management of IBD.

Mucosal Interactions between Genetics, Diet, and Microbiome in Inflammatory Bowel Disease

Numerous reviews have discussed gut microbiota composition changes during inflammatory bowel diseases (IBD), particularly Crohn’s disease (CD). However, most studies address the observed effects by focusing on studying the univariate connection between disease and dietary-induced alterations to gut microbiota composition. The possibility that these effects may reflect a number of other interconnected (i.e., pantropic) mechanisms, activated in parallel, particularly concerning various bacterial metabolites, is in the process of being elucidated. Progress seems, however, hampered by various difficult-to-study factors interacting at the mucosal level. Here, we highlight some of such factors that merit consideration, namely: (1) the contribution of host genetics and diet in altering gut microbiome, and in turn, the crosstalk among secondary metabolic pathways; (2) the interdependence between the amount of dietary fat, the fatty acid composition, the effects of timing and route of administration on gut microbiota community, and the impact of microbiota-derived fatty acids; (3) the effect of diet on bile acid composition, and the modulator role of bile acids on the gut microbiota; (4) the impact of endogenous and exogenous intestinal micronutrients and metabolites; and (5) the need to consider food associated toxins and chemicals, which can introduce confounding immune modulating elements (e.g., antioxidant and phytochemicals in oils and proteins). These concepts, which are not mutually exclusive, are herein illustrated paying special emphasis on physiologically inter-related processes.

Treatment with Mesna and n-3 polyunsaturated fatty acids ameliorates experimental ulcerative colitis in rats

Oxidative damage is a central feature of ulcerative colitis. Here, we tested whether the antioxidant Mesna, when administered alone or in combination with n-3 polyunsaturated fatty acids (n-3 PUFAs), affects the outcome of dextran sodium sulphate (DSS)-induced ulcerative colitis in rats. After the induction of colitis, DSS-treated rats were further treated orally (p.o), intraperitoneally (i.p) or intrarectally (i.r) for either 7 or 14 days with Mesna, n-3 PUFAs or both. Rats were euthanized at the end of each treatment period. Clinical disease activity index was recorded throughout the experiment. At necropsy colorectal gross lesions were scored. Colitis was scored histologically, and the expression of myeloperoxidase (MPO), caspase-3, inducible nitric oxide synthase (iNOS) and nuclear factor κB (NF-κΒ) in colonic tissue was assessed by immunohistochemistry. Mesna alone was sufficient to significantly reduce colorectal tissue damage when administered orally or intraperitoneally. Orally coadministered n-3 PUFAs enhanced this effect, resulting in the significant suppression of DSS colitis after 7 days, and a remarkable recovery of colorectal mucosa was evident after 14 days of treatment. The amelioration of colon pathology co-existed with a significant decrease in MPO expression, overexpression of iNOS and reduction of nuclear NF-κB p65 in inflammatory cells, and the suppression of apoptosis in colonic epithelial cells. The simultaneous administration of Mesna and n-3 PUFAs is particularly effective in ameliorating DSS colitis in rats, by reducing oxidative stress, inflammation and apoptosis, probably through a mechanism that involves the inhibition of NF-κB and overexpression of iNOS.