New prebiotics from rice bran ameliorate inflammation in murine colitis models through the modulation of intestinal homeostasis and the mucosal immune system

Antimicrobial Effects of Plant-Based Supplements on Gut Microbial Diversity in Small Ruminants

Every year in the United States, approximately 48 million people are affected by bacterial illnesses that are transmitted through food, leading to 3000 fatalities. These illnesses typically stem from food animals and their by-products, which may harbor dangerous pathogens like Salmonella enterica, Listeria monocytogenes, enterohemorrhagic Escherichia coli O157:H7, and Campylobacter jejuni. Factors that contribute to contamination include manure used as a soil amendment, exposure to polluted irrigation water, and contact with animals. To improve food safety, researchers are studying pre-slaughter intervention methods to eliminate bacterial contamination in live animals. While small ruminants are vital to global agriculture and income generation for small farms, traditional feeding practices involve supplements and antibiotics to boost performance, which contributes to antibiotic resistance. Hence, researchers are looking for friendly bacterial strains that enhance both animal and human health without impacting livestock productivity. The global trend is to minimize the use of antibiotics as feed supplements, with many countries prohibiting or limiting their use. The aim of this review is to provide a comprehensive insight on the antioxidant capabilities, therapeutic attributes, and applications of bioactive compounds derived from sweet potato tops (SPTs), rice bran (RB) and radish tops (RTs). This overview provides an insight on plant parts that are abundant in antioxidant and prebiotic effects and could be used as value-added products in animal feed and pharmaceutical applications. This review was based on previous findings that supplementation of basal diets with natural supplements represents a multifaceted intervention that will become highly important over time. By remarkably reducing the burden of foodborne pathogens, they apply to multiple species, are cheap, do not require withdrawal periods, and can be applied at any time in food animal production.

Integrated Microbiota and Metabolite Changes following Rice Bran Intake during Murine Inflammatory Colitis-Associated Colon Cancer and in Colorectal Cancer Survivors

Dietary rice bran-mediated inhibition of colon carcinogenesis was demonstrated previously for carcinogen-induced rodent models via multiple anti-cancer mechanisms. This study investigated the role of dietary rice bran-mediated changes to fecal microbiota and metabolites over the time course of colon carcinogenesis and compared murine fecal metabolites to human stool metabolic profiles following rice bran consumption by colorectal cancer survivors (NCT01929122). Forty adult male BALB/c mice were subjected to azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colitis-associated colon carcinogenesis and randomized to control AIN93M (n = 20) or diets containing 10% w/w heat-stabilized rice bran (n = 20). Feces were serially collected for 16S rRNA amplicon sequencing and non-targeted metabolomics. Fecal microbiota richness and diversity was increased in mice and humans with dietary rice bran treatment. Key drivers of differential bacterial abundances from rice bran intake in mice included Akkermansia, Lactococcus, Lachnospiraceae, and Eubacterium xylanophilum. Murine fecal metabolomics revealed 592 biochemical identities with notable changes to fatty acids, phenolics, and vitamins. Monoacylglycerols, dihydroferulate, 2-hydroxyhippurate (salicylurate), ferulic acid 4-sulfate, and vitamin B6 and E isomers significantly differed between rice bran- and control-fed mice. The kinetics of murine metabolic changes by the host and gut microbiome following rice bran consumption complemented changes observed in humans for apigenin, N-acetylhistamine, and ethylmalonate in feces. Increased enterolactone abundance is a novel diet-driven microbial metabolite fecal biomarker following rice bran consumption in mice and humans from this study. Dietary rice bran bioactivity via gut microbiome metabolism in mice and humans contributes to protection against colorectal cancer. The findings from this study provide compelling support for rice bran in clinical and public health guidelines for colorectal cancer prevention and control.

Role of Dietary Defatted Rice Bran in the Modulation of Gut Microbiota in AOM/DSS-Induced Colitis-Associated Colorectal Cancer Rat Model

Defatted rice bran (DRB) is a by-product of rice bran derived after the oil extraction. DRB contains several bioactive compounds, including dietary fiber and phytochemicals. The supplementation with DRB manifests chemopreventive effects in terms of anti-chronic inflammation, anti-cell proliferation, and anti-tumorigenesis in the azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced colitis-associated colorectal cancer (CRC) model in rats. However, little is known about its effect on gut microbiota. Herein, we investigated the effect of DRB on gut microbiota and short chain fatty acid (SCFA) production, colonic goblet cell loss, and mucus layer thickness in the AOM/DSS-induced colitis-associated CRC rat model. The results suggested that DRB enhanced the production of beneficial bacteria (Alloprevotella, Prevotellaceae UCG-001, Ruminococcus, Roseburia, Butyricicoccus) and lessened the production of harmful bacteria (Turicibacter, Clostridium sensu stricto 1, Escherichia-Shigella, Citrobacter) present in colonic feces, mucosa, and tumors. In addition, DRB also assisted the cecal SCFAs (acetate, propionate, butyrate) production. Furthermore, DRB restored goblet cell loss and improved the thickness of the mucus layer in colonic tissue. These findings suggested that DRB could be used as a prebiotic supplement to modulate gut microbiota dysbiosis, which decreases the risks of CRC, therefore encouraging further research on the utilization of DRB in various nutritional health products to promote the health-beneficial bacteria in the colon.

Effect of Massa Medicata Fermentata on the intestinal flora of rats with functional dyspepsia

BACKGROUND

Massa Medicata Fermentata (MMF) is one of the most commonly used traditional fermented Chinese medicines. MMF is widely used for the treatment of digestive diseases such as dyspepsia and flatulence in traditional Chinese medicine (TCM). However, the therapeutic mechanism of MMF is not well understood.

METHOD

In this study, SD rats received 0.1% iodoacetamide either alone or in combination with water platform sleep deprivation to induce functional dyspepsia and were administered MMF (1 or 3 g/kg/d, ig), mosapride citrate (Mosa., 2 mg/kg/d, ig) or saline for 21 days. After treatment, the sucrose preferences and gastric emptying rates of the rats were assessed; HE staining was used to detect the pathological changes in the rat duodenum; ELISA kits were used to detect motilin (MTL) in the rat duodenum and the serum contents of Interferon-λ (IFN-λ), Interleukin 6 (IL-6), and Tumor Necrosis Factor-α (TNF-α). An approach based on 16S rDNA amplicon sequencing was utilized to explore the intestinal microflora in the colon contents of rats and the metabolism of the microflora to assess the potential mechanisms of MMF in ameliorating functional dyspepsia (FD). In addition, gas chromatography-mass spectrometry (GC/MS) was used to detect changes in short fatty acids (SCFAs) in the colon contents of rats.

RESULTS

MMF reduced the serum levels of TNF-α, and IFN-λ, improved the morphology of duodenal intestinal villi and ameliorated intestinal mucosal lamina propria injury in FD rats, and the sucrose preference increased and the gastric emptying rate decreased in FD rats. MMF alleviated intestinal microflora disturbance and exerted a regulatory effect on Bacteroidetes, Proteobacteria, and Firmicutes, reduced total SCAFs, Butyric Acid, Propionic acid-2-methyl, Butanoic Acid-3-methyl, and Hexanoic acid.

CONCLUSIONS

These results showed that the effect of MMF on the intestinal flora and its metabolites may provide a new treatment strategy for FD.

Immobilization of Lactobacillus plantarum NCIMB 8826 ameliorates Citrobacter rodentium induced lesions and enhances the gut inflammatory response in C57BL/6 weanling mice

Infectious diarrhea is a major cause of infant mortality in most developing countries. In this research, we evaluated the potential of immobilized Lactobacillus plantarum NCIMB 8826 on weanimix infant cereal and its effectiveness in reducing the severity of Citrobacter rodentium-induced diarrhea in weanling mice. Thirty-six C57BL/6 weanling mice were placed into four groups (n = 9 each; negative, positive, prevention and cure). Mice received either L. plantarum (109 CFU/g) immobilized on weanimix infant cereal 3 days before C. rodentium (109 CFU/ ml) infection (Prevention) or 3 days after C. rodentium infection (Cure). A positive control group was infected with C. rodentium only, while a negative control group received neither L. plantarum nor C. rodentium. Positive control mice showed colonic mucosal and submucosal inflammation, erosion, and mucosal epithelia hyperplasia with the C. rodentium infection. Mice in the prevention and cure groups had less severe histologic alterations in the colon. Some beneficial effect of L. plantarum was observed in cecal short-chain fatty acid concentrations, which stimulates water and electrolytes absorption to reduce diarrhea. Our findings demonstrated that L. plantarum NCIMB 8826 could be immobilized on weanimix infant cereal to help reduce diarrhea during weaning.

Graphical Abstract

Looking inside Mexican Traditional Food as Sources of Synbiotics for Developing Novel Functional Products

Currently, emerging alimentary alternatives are growing, leading to the consumption of natural products including bio, fermented, and traditional foods. The studies over functional properties of food matrices and their derived compounds have resulted in the development of new functional alimentary items. However, most of the population still has limited access to, and information about, suitable foods. Analyzing traditional fermented products, we found fermented food matrices containing beneficial bacteria, with the possibility of exerting effects on different substrates enhancing the bioavailability of short-chain fatty acids (SFCAs), antioxidants, among other food-derived products. Maize (Zea mays L.), agave varieties, nopal (Opuntia ficus-indica), and beans (Phaseolus vulgaris L.) were key foods for the agricultural and nutritional development of Mesoamerica. We believe that the traditional Mexican diet has relevant ingredients with these functionalities and their association will allow us to develop functional food suitable for each population and their current needs. In this review, the functional properties of maize, agave, nopal, and frijol are detailed, and the functional food innovation and development opportunities for these food matrices are analyzed, which may be an important precedent for future basic and applied research.

Biological Functions and Activities of Rice Bran as a Functional Ingredient: A Review

Rice bran (RB) is a nutrient-rich by-product of the rice milling process. It consists of pericarp, seed coat, nucellus, and aleurone layer. RB is a rich source of a protein, fat, dietary fibers, vitamins, minerals, and phytochemicals (mainly oryzanols and tocopherols), and is currently mostly used as animal feed. Various studies have revealed the beneficial health effects of RB, which result from its functional components including dietary fiber, rice bran protein, and gamma-oryzanol. The health effects of RB including antidiabetic, lipid-lowering, hypotensive, antioxidant, and anti-inflammatory effects, while its consumption also improves bowel function. These health benefits have drawn increasing attention to RB in food applications and as a nutraceutical product to mitigate metabolic risk factors in humans. This review therefore focuses on RB and its health benefits.

Growth Performance, Antioxidant Activity, Immune Status, Meat Quality, Liver Fat Content, and Liver Histomorphology of Broiler Chickens Fed Rice Bran Oil

Simple Summary

There are numerous approaches for enrichment of broiler’s meat with valuable nutrients, for instance the enrichment with polyunsaturated fatty acids (PUFA). The addition of vegetable oils in the diets of broilers is an appropriate strategy to enrich the chicken meat with beneficial FA, however, this enrichment is accompanied by a lipid peroxidation with a resultant decrease in the nutritional value, quality, and shelf-life of the meat, and for that reason, the dietary supplementation with antioxidants becomes necessary. What places rice bran oil (RBO) on top of other vegetable oils is its antioxidant components and unique fatty acid profile and it is reported to induce substantial lipid-reducing effects and antioxidant properties. Therefore, this study was performed to determine the influence of RBO inclusion in the diets of broiler chickens on performance, carcass characteristics, blood parameters, meat quality, antioxidant activity, liver lipid content, and liver histological structure. RBO inclusion had a positive effect on the growing performance, dressing percentage, and immune status. Furthermore, RBO supplementation decreased the abdominal fat yield and EE content in the meat, while it increased the content of PUFA in the meat, which may be beneficial for consumers. RBO improved the antioxidant capacity of the meat and the liver, whereas it reduced the concentration of cholesterol and triglycerides in the blood, meat and liver. RBO could be used as an efficient ingredient in broiler chickens’ diets to improve performance, immune status, antioxidant activity, blood lipid profile, and the nutritive value of meat.

Abstract

This trial was performed to determine the effect of rice bran oil (RBO) inclusion in diets of broiler chickens on performance, carcass characteristics, blood parameters, meat quality, antioxidant activity, liver lipid content, and liver histological structure. The 35-day feeding trial was conducted on 240 one-day-old Ross 308 broiler chickens, allocated to four treatment groups with six replicates each. RBO was examined at different inclusion levels, 0% (control), 1% (RBO_1%), 1.5% (RBO_1.5%), and 2% (RBO_2%) in a completely randomized design. The results showed that at the end of the trial (35 days) the RBO supplementation had positive effects (p < 0.001) on the productivity parameters, but the feed intake was linearly decreased due to RBO inclusion. In addition, RBO supplementation linearly improved (p < 0.05) the dressing percentage, breast yield, immune organs relative weights, and meat glutathione concentration, while it decreased (p < 0.01) the abdominal fat yield and meat crude fat, triglycerides, cholesterol, and Malondialdehyde (MDA) contents in broiler’s meat. Moreover, serum total protein, globulin, and high-density lipoprotein contents improved noticeably (p < 0.01) due to offering an RBO-supplemented diet, but serum total lipids, total cholesterol, triglyceride, low-density lipoprotein, and aspartate aminotransferase concentrations linearly reduced (p < 0.01). The RBO supplementation augmented (p < 0.05) the phagocytic index, phagocytic activity, and antibody titer compared to control. On the other hand, RBO inclusion had no effect on the breast, thigh, or abdominal fat color parameters. Moreover, RBO supplementation reduced (p < 0.01) the content of total saturated FA (SFA), but increased (p < 0.01) the content of total monounsaturated FA (MUFA), and polyunsaturated FA in both breast and thigh meat. Chemical analysis of the liver tissue samples revealed that the inclusion of RBO linearly reduced (p < 0.05) hepatic cholesterol, triglyceride, and MDA contents. Histologically, the lipid percentage and number of lipid droplets (p < 0.01) were markedly lessened in the RBO-supplemented groups. The histological structure of the liver asses by light and electron microscope were normal in all groups without any pathological lesions. It is concluded that RBO could be used as a valuable ingredient in broiler chickens’ diets to stimulate the growing performance and immune status, enhance the antioxidant activity and blood lipid profile, augment liver function, and improve the nutritive value of the meat.

The Study on the Active Ingredients and Potential Targets of Rice Bran Petroleum Ether Extracts for Treating Diabetes Based on Network Pharmacology

AIM AND OBJECTIVE

In ancient China, rice bran was used to treat diabetes and hyperlipidemia. The aim of this paper is to explore the active compounds and underlying mechanism of Rice Bran Petroleum Ether extracts (RBPE) against diabetes using network pharmacology.

MATERIALS AND METHODS

Gas chromatography-mass spectrometer analysis was performed to identify the chemical composition in RBPE. Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform, Swiss Target Prediction database, BATMAN-TCM, comprehensive database of human genes and gene phenotypes, therapeutic target database, DurgBank and GeneCards database were used to screen targets. The "component-target-disease" interactive network was constructed by Cytoscape software. Gene ontology and pathways related to the targets were analyzed by ClueGO, and core targets were screened by the MCODE, and Autodock vina was used for molecular docking.

RESULTS

The compounds with a percentage greater than 1.0% were selected for subsequent analysis. The RBPE contains oleic acid, (E)-9-Octadecenoic acid ethyl ester, and other chemical components that can regulate insulin, mitogen-activated protein kinase 3, epidermal growth factor receptor, mitogen-activated protein kinase 1, and other genes, which were mainly related to Pathways in cancer, Human cytomegalovirus infection and AGE-RAGE signaling pathway in diabetic complications, etc. The affinity of the core compounds and the corresponding protein of the gene targets was good.

CONCLUSION

The results of network pharmacology analysis indicate that the RBPE has multiple anti- diabetic ingredients, and RBPE exert anti-diabetic activity through multiple targets and signaling pathways. The present study can provide a scientific basis for further elucidating the mechanism of RBPE against diabetes.

The effects of resistant starches on inflammatory bowel disease in preclinical and clinical settings: a systematic review and meta-analysis

Background

Inflammatory bowel disease (IBD) is a debilitating chronic disease with limited treatment options. Resistant starches may represent a novel treatment for IBD. However, its efficacy and safety remain unclear. Our objective was to perform a systematic review to summarize the preclinical and clinical effects of resistant starch, which may help guide future studies.

Methods

Medline, EMBASE, and the Cochrane Central Register were searched. Included studies investigated the use of resistant starch therapy in in vivo animal models of IBD or human patients with IBD. Articles were screened, and data extracted, independently and in duplicate. The primary outcomes were clinical remission (clinical) and bowel mucosal damage (preclinical).

Results

21 preclinical (n = 989 animals) and seven clinical (n = 164 patients) studies met eligibility. Preclinically, resistant starch was associated with a significant reduction in bowel mucosal damage compared to placebo (standardized mean difference − 1.83, 95% CI − 2.45 to − 1.20). Clinically, five studies reported data on clinical remission but clinical and methodological heterogeneity precluded pooling. In all five, a positive effect was seen in patients who consumed resistant starch supplemented diets. The majority of studies in both the preclinical and clinical settings were at a high or unclear risk of bias due to poor methodological reporting.

Conclusions

Our review demonstrates that resistant starch is associated with reduced histology damage in animal studies, and improvements in clinical remission in IBD patients. These results need to be tempered by the risk of bias of included studies. Rigorously designed preclinical and clinical studies are warranted.

Trial registration

The review protocols were registered on PROSPERO (preclinical: CRD42019130896; clinical: CRD42019129513).

Protective effects of fermented rice extract on ulcerative colitis induced by dextran sodium sulfate in mice

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD), characterized by the gut mucosal ulceration. Growing evidence indicates that dysregulation of immune response to the commensal microbiota involves the pathogenesis of IBD. Previous studies have demonstrated the favorable probiotic effects of fermented rice extracts through triple fermentation with Saccharomyces cerevisiae and Weissella cibaria (FRe). Thus, the therapeutic potential of FRe for UC was examined. Dextran sodium sulfate UC mice model was orally administered distilled water as a control, sulfasalazine, or FRe at 300, 200, and 100 mg/kg, once a day for a week. The UC control exhibited body weight loss, bloody stools, and colonic shortening. However, the FRe, especially at 300 mg/kg, led to a reduction in weight loss, disease activity index scores, and colon weight, and an increase in colorectal length. The histopathological analyses revealed mild changes involved in the colonic crypt and mucosal damages in the FRe groups, along with inhibited inflammation. Indeed, the FRe reduced neutrophil infiltration and production of proinflammatory cytokines (i.e., tumor necrosis factor-α, interleukin-6/-8). This was accompanied by the down-regulation of nuclear factor-kappa B. The gene expression responsible for the intestinal barrier integrity (i.e., Zonna occludens-1/-2, Claudin-1, Occludin, Mucin-1/-2) was up-regulated in the FRe groups. In addition, the FRe reduced lipid peroxidation and enhanced antioxidant activity. Interestingly, the microbiota dysbiosis was attenuated in the FRe groups, and the number of beneficial bacteria, Lactobacilli and Bifidobacteria, was increased. It suggests that the FRe potently ameliorate UC as a functional food.

Rice Components with Immunomodulatory Function

Rice (Oryza sativa) is one of the most important food crops in the world, and the effect of its consumption on human health is of great concern. Evidence has accumulated that rice contains several components, such as γ-oryzanol and rice bran fibers, which modulate the immune system. In addition, rice has other immunologically beneficial characteristics. It has a low allergenic potential and is gluten-free, reducing the risk of development of food allergies and diseases related to gluten sensitivity such as coeliac disease. This review presents the recent advances in our understanding of the immunomodulatory function of rice components.

Antioxidant and antimicrobial evaluation of rice bran (Oryza sativa L.) extracts in a mayonnaise-type emulsion

The objective of this study was to evaluate the in vitro antimicrobial and antioxidant activities of different bran extracts and concentrations, and their influence on the parameters of a mayonnaise-type emulsion. To that end, first ethanol and then water were used to extract two rice bran extracts (RBE) from rice bran. Both these extracts were then added at two different concentrations (0.5 and 2%) to the emulsions that were subsequently analysed after seven days under two different storage temperatures, 4 °C and 20 °C. The antioxidant and antimicrobial ability of the extracts were evaluated, along with a control and a synthetic antioxidant. Results indicate the positive effect of rice bran extracts as additives in the food matrix. Ethanolic rice bran extract (EE) at 2% decreased the oxidation as well as mould and yeast proliferation and preserved the emulsion structure, while the other treatments acted in a similar way although their effect was less pronounced.

Extraction of Lipophilic Fraction from Polished Rice Improves Its Ameliorative Effect on Intestinal Impairment

Glucosylceramide (GlcCer), a major sphingolipid in plants and fungi, is known to have food functions such as preventing intestinal impairment and enhancing the moisture content of skin. However, there is little information about functions of GlcCer in food sources as most of the studies on GlcCer functions are done using purified GlcCer. This study was performed to investigate the effects of GlcCer contained in food on intestinal impairment; polished rice flour (RF) and this ethanol extract (RE) were used as sources of GlcCer, and these were evaluated by studying the formation of aberrant crypt foci (ACF) in 1,2-dimethylhydrazine (DMH)-treated mice, which is a model of colon cancer. Mice were fed with either a control diet, a RF diet where RF replaces cornstarch (150 g/kg), or a plus RE diet (0.5 g/kg; RE was extracted from the same amount of RF present in the RF diet). The amount of GlcCer was similar in both the RF and RE diets (3.0 and 2.7 mg/kg, respectively). DMH treatment induced the formation of ACF and the production of inflammation-related cytokines. Both dietary RF and RE suppressed ACF formation and RE, in particular, showed a significant suppressive effect. Dietary RE inhibited the production of almost all of the inflammation-related cytokines studied, while RF suppressed only a few of these cytokines. The present study suggests that the lipophilic fraction including GlcCer, present in polished rice has protective effects against intestinal impairment, but it requires extraction since digestion alone is not enough to elicit its complete protective action.

Implications of butyrate and its derivatives for gut health and animal production

Butyrate is produced by microbial fermentation in the large intestine of humans and animals. It serves as not only a primary nutrient that provides energy to colonocytes, but also a cellular mediator regulating multiple functions of gut cells and beyond, including gene expression, cell differentiation, gut tissue development, immune modulation, oxidative stress reduction, and diarrhea control. Although there are a large number of studies in human medicine using butyrate to treat intestinal disease, the importance of butyrate in maintaining gut health has also attracted significant research attention to its application for animal production, particularly as an alternative to in-feed antibiotics. Due to the difficulties of using butyrate in practice (i.e., offensive odor and absorption in the upper gut), different forms of butyrate, such as sodium butyrate and butyrate glycerides, have been developed and examined for their effects on gut health and growth performance across different species. Butyrate and its derivatives generally demonstrate positive effects on animal production, including enhancement of gut development, control of enteric pathogens, reduction of inflammation, improvement of growth performance (including carcass composition), and modulation of gut microbiota. These benefits are more evident in young animals, and variations in the results have been reported. The present article has critically reviewed recent findings in animal research on butyrate and its derivatives in regard to their effects and mechanisms behind and discussed the implications of these findings for improving animal gut health and production. In addition, significant findings of medical research in humans that are relevant to animal production have been cited.

Gamma-aminobutyric Acid Enriched Rice Bran Diet Attenuates Insulin Resistance and Balances Energy Expenditure via Modification of Gut Microbiota and Short-Chain Fatty Acids

In this study, gamma-aminobutyric acid (GABA) enriched rice bran (ERB) was supplemented to obese rats to investigate the attenuation of metabolic syndromes induced by high-fat diet. ERB-containing diet stimulated butyrate and propionate production by promoting Anaerostipes, Anaerostipes sp., and associated synthesizing enzymes. This altered short-chain fatty acid (SCFA) distribution further enhanced circulatory levels of leptin and glucagon-like peptide-1, controlling food intake by downregulating orexigenic factors. Together with the enhanced fatty acid β-oxidation highlighted by Prkaa2, Ppara, and Scd1 expression via AMPK signaling pathway and nonalcoholic fatty liver disease pathway, energy expenditure was positively modulated. Serum lipid compositions showed ERB supplement exhibited a more efficient effect on lowering serum sphingolipids, which was closely associated with the status of insulin resistance. Consistently, genes of Ppp2r3b and Prkcg, involved in the function of ceramides in blocking insulin action, were also downregulated following ERB intervention. Enriched GABA and phenolic acids were supposed to be responsible for the health-beneficial effects.

Role of short-chain fatty acids in colonic inflammation, carcinogenesis, and mucosal protection and healing

Short-chain fatty acids (SCFAs), mainly acetate, propionate, and butyrate, produced by microbial fermentation of undigested food substances are believed to play a beneficial role in human gut health. Short-chain fatty acids influence colonic health through various mechanisms. In vitro and ex vivo studies show that SCFAs have anti-inflammatory and anticarcinogenic effects, play an important role in maintaining metabolic homeostasis in colonocytes, and protect colonocytes from external harm. Animal studies have found substantial positive effects of SCFAs or dietary fiber on colonic disease, but convincing evidence in humans is lacking. Most human intervention trials have been conducted in the context of inflammatory bowel disease. Only a limited number of those trials are of high quality, showing little or no favorable effect of SCFA treatment over placebo. Opportunities for future research include exploring the use of combination therapies with anti-inflammatory drugs, prebiotics, or probiotics; the use of prodrugs in the setting of carcinogenesis; or the direct application of SCFAs to improve mucosal healing after colonic surgery.

Effect of dietary supplementation with <i>Rhizopus oryzae</i> or <i>Chrysonilia crassa</i> on growth performance, blood profile, intestinal microbial population, and carcass traits in broilers exposed to heat stress

Abstract. Dietary supplementation of additives has recently been part of strategies to deal with the detrimental effects of heat stress (HS) on the performance and carcass traits in broiler chicks. This study aimed to investigate the effect of dietary supplementation with the fungi Rhizopus oryzae or Chrysonilia crassa on growth, blood profile, intestinal microbial population and carcass traits in broiler chicks subjected to HS. R. oryzae and C. crassa are filamentous fungi isolated from the ileum of indigenous Indonesian chickens which exhibited probiotic and antioxidant properties. Two hundred and forty 21-day-old male broiler chicks were randomly allotted into six groups, including birds reared under normal temperature (28 ± 2 °C) (CONT), birds reared under HS conditions (35 ± 2 °C) (HS-CONT), birds reared under HS and provided with commercial anti-stress formula (HS-VIT), birds reared under HS and provided with R. oryzae (HS-RO), birds reared under HS and provided with C. crassa (HS-CC) and birds reared under HS and provided with rice bran (HS-RB). Body weight gain was highest (P < 0. 01) and lowest (P < 0. 01) in CONT and HS-CONT birds, respectively. The heart was heavier (P < 0. 05) in CONT than in HS-CONT and HS-VIT birds. CONT birds had heavier duodenum (P < 0. 05) and jejunum (P < 0. 01) than other birds. Eosinophils was higher (P < 0. 05) in HS-CC than in other birds. Low-density lipoprotein (LDL) was higher (P < 0. 05) in HS-CONT than in CONT, HS-VIT and HS-CC birds. Total triglyceride was highest (P < 0. 05) and lowest (P < 0. 05) in HS-RB and HS-RO birds, respectively. Alanine aminotransferase (ALT) was higher (P < 0. 05) in HS-CONT than in other HS birds. Total protein was lowest and highest (P < 0. 05) in CONT and HS-CONT birds, respectively. Albumin was higher (P < 0. 05) in HS-CONT and HS-VIT than in HS-RO birds. Globulin was lower (P < 0. 05) in CONT than in HS-CONT, HS-VIT and HS-RB birds. Uric acid was lower (P < 0. 05) in CONT than in HS-CONT and HS-VIT birds. The 2,2′-azino-bis(3-ethyl-benzthiazolin-6-sulfonic acid) (ABTS) percentage inhibition values of the serum were higher (P < 0. 01) in CONT, HS-CONT and HS-VIT than those in HS-RO, HS-CC and HS-RB birds. In conclusion, dietary supplementation of C. crassa decreased serum LDL concentration and ALT activity and improved antioxidant status of broiler subjected to HS. Supplementation with C. crassa seemed beneficial in improving physiological conditions of HS birds.

Heat-stabilised rice bran consumption by colorectal cancer survivors modulates stool metabolite profiles and metabolic networks: a randomised controlled trial

Rice bran (RB) consumption has been shown to reduce colorectal cancer (CRC) growth in mice and modify the human stool microbiome. Changes in host and microbial metabolism induced by RB consumption was hypothesised to modulate the stool metabolite profile in favour of promoting gut health and inhibiting CRC growth. The objective was to integrate gut microbial metabolite profiles and identify metabolic pathway networks for CRC chemoprevention using non-targeted metabolomics. In all, nineteen CRC survivors participated in a parallel randomised controlled dietary intervention trial that included daily consumption of study-provided foods with heat-stabilised RB (30 g/d) or no additional ingredient (control). Stool samples were collected at baseline and 4 weeks and analysed using GC-MS and ultra-performance liquid chromatography-MS. Stool metabolomics revealed 93 significantly different metabolites in individuals consuming RB. A 264-fold increase in β-hydroxyisovaleroylcarnitine and 18-fold increase in β-hydroxyisovalerate exemplified changes in leucine, isoleucine and valine metabolism in the RB group. A total of thirty-nine stool metabolites were significantly different between RB and control groups, including increased hesperidin (28-fold) and narirutin (14-fold). Metabolic pathways impacted in the RB group over time included advanced glycation end products, steroids and bile acids. Fatty acid, leucine/valine and vitamin B₆ metabolic pathways were increased in RB compared with control. There were 453 metabolites identified in the RB food metabolome, thirty-nine of which were identified in stool from RB consumers. RB consumption favourably modulated the stool metabolome of CRC survivors and these findings suggest the need for continued dietary CRC chemoprevention efforts.

Dietary Supplementation of Fermented Rice Bran Effectively Alleviates Dextran Sodium Sulfate-Induced Colitis in Mice

Rice bran (RB) is a major by-product of rice polishing and a rich source of bioactive compounds. Here, we investigated the anti-colitis effect of diet supplementation with fermented rice bran (FRB) in a murine model of ulcerative colitis. FRB was prepared by dual fermentation of RB using fungi and lactic acid bacteria. Colitis was induced in C57Bl/6N male mice (n = 8/group) by dextran sodium sulfate (DSS). Body weight change, disease activity index (DAI), histopathology score, tissue myeloperoxidase (MPO) activity, cytokine and chemokine transcript levels, and the production of short-chain fatty acids (SCFAs) and mucin in the colonic tissue were monitored. Based on histopathology scores, DSS induced severe mucosal inflammation, with an increased loss of crypts, and inflammatory cell infiltration in the control and RB groups, but not in the FRB group. MPO activity, thiobarbituric acid-reactive substance levels, and pro-inflammatory cytokine transcript (Tnf-α, Il-1β, Il-6, and Il-17) levels were significantly higher in the control and RB groups than in the FRB group. Thus, dietary FRB attenuated intestinal inflammation owing to elevated SCFAs and tryptamine production, which might regulate tight junction barrier integrity and intestinal homeostasis. These results suggest that FRB could comprise an effective potential preventive agent for ulcerative colitis.

Dietary interventions that reduce mTOR activity rescue autistic-like behavioral deficits in mice

Enhanced mammalian target of rapamycin (mTOR) signaling in the brain has been implicated in the pathogenesis of autism spectrum disorder (ASD). Inhibition of the mTOR pathway improves behavior and neuropathology in mouse models of ASD containing mTOR-associated single gene mutations. The current study demonstrated that the amino acids histidine, lysine, threonine inhibited mTOR signaling and IgE-mediated mast cell activation, while the amino acids leucine, isoleucine, valine had no effect on mTOR signaling in BMMCs. Based on these results, we designed an mTOR-targeting amino acid diet (Active 1 diet) and assessed the effects of dietary interventions with the amino acid diet or a multi-nutrient supplementation diet (Active 2 diet) on autistic-like behavior and mTOR signaling in food allergic mice and in inbred BTBR T+Itpr3tf/J mice. Cow's milk allergic (CMA) or BTBR male mice were fed a Control, Active 1, or Active 2 diet for 7 consecutive weeks. CMA mice showed reduced social interaction and increased self-grooming behavior. Both diets reversed behavioral impairments and inhibited the mTOR activity in the prefrontal cortex and amygdala of CMA mice. In BTBR mice, only Active 1 diet reduced repetitive self-grooming behavior and attenuated the mTOR activity in the prefrontal and somatosensory cortices. The current results suggest that activated mTOR signaling pathway in the brain may be a convergent pathway in the pathogenesis of ASD bridging genetic background and environmental triggers (food allergy) and that mTOR over-activation could serve as a potential therapeutic target for the treatment of ASD.

Local Treatment with Lactate Prevents Intestinal Inflammation in the TNBS-Induced Colitis Model

Lactate has long been considered as a metabolic by-product of cells. Recently, this view has been changed by the observation that lactate can act as a signaling molecule and regulates critical functions of the immune system. We previously identified lactate as the component responsible for the modulation of innate immune epithelial response of fermented milk supernatants in vitro. We have also shown that lactate downregulates proinflammatory responses of macrophages and dendritic cells. So far, in vivo effects of lactate on intestinal inflammation have not been reported. We evaluated the effect of intrarectal administration of lactate in a murine model of colitis induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS). The increase in lactate concentration in colon promoted protective effects against TNBS-induced colitis preventing histopathological damage, as well as bacterial translocation and rise of IL-6 levels in serum. Using intestinal epithelial reporter cells, we found that flagellin treatment induced reporter gene expression, which was abrogated by lactate treatment as well as by glycolysis inhibitors. Furthermore, lactate treatment modulated glucose uptake, indicating that high levels of extracellular lactate can impair metabolic reprograming induced by proinflammatory activation. These results suggest that lactate could be a potential beneficial microbiota metabolite and may constitute an overlooked effector with modulatory properties.

Effects of extracted rice bran supplementation on growth performance, nutrient digestibility, diarrhea score, blood profiles, and fecal microbial shedding in comparison with apramycin (antibiotic growth promoter) in weanling pigs

This study evaluated the efficacy of extracted rice bran (ERB) in weanling piglets. One hundred forty weanling pigs [(Yorkshire × Landrace) × Duroc] with an average BW of 5.70 ± 1.41 kg (21 d of age) were fed in two phases in a 6-wk experiment. Weanling pigs were allotted to diets containing 0 or 0.1 g kg−1 of ERB, and 0 or 165 mg kg−1 of apramycin according to a 2 × 2 factorial arrangement of treatments. Both apramycin and ERB supplementation increased growth efficiency (G:F) during phase 1 and overall, respectively (P < 0.05). The apparent total tract digestibility (ATTD) of dry matter (DM) was increased in response to either ERB or apramycin at wk 2 and 6 (P < 0.05). Supplementation of ERB decreased total cholesterol (TC) and increased high-density lipoprotein cholesterol (HDL-C) in diets lacking ERB at wk 6 (P < 0.05). Pigs receiving diets supplemented with apramycin reduced Escherichia coli at wk 2 and 6, and Salmonella counts at wk 6 (P < 0.05). Supplementation of ERB increased fecal Lactobacillus and reduced Salmonella counts at wk 6 (P < 0.05). In conclusion, results indicated that dietary supplementation of ERB improved performance in weanling pigs.

Current Hypothesis for the Relationship between Dietary Rice Bran Intake, the Intestinal Microbiota and Colorectal Cancer Prevention

Globally, colorectal cancer (CRC) is the third most common form of cancer. The development of effective chemopreventive strategies to reduce CRC incidence is therefore of paramount importance. Over the past decade, research has indicated the potential of rice bran, a byproduct of rice milling, in CRC chemoprevention. This was recently suggested to be partly attributable to modification in the composition of intestinal microbiota when rice bran was ingested. Indeed, previous studies have reported changes in the population size of certain bacterial species, or microbial dysbiosis, in the intestines of CRC patients and animal models. Rice bran intake was shown to reverse such changes through the manipulation of the population of health-promoting bacteria in the intestine. The present review first provides an overview of evidence on the link between microbial dysbiosis and CRC carcinogenesis and describes the molecular events associated with that link. Thereafter, there is a summary of current data on the effect of rice bran intake on the composition of intestinal microbiota in human and animal models. The article also highlights the need for further studies on the inter-relationship between rice bran intake, the composition of intestinal microbiota and CRC prevention.

High purity galacto-oligosaccharides enhance specific Bifidobacterium species and their metabolic activity in the mouse gut microbiome

Prebiotics are selectively fermented ingredients that result in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon the host health. The aim of this study was to evaluate the influence of a β(1-4)galacto-oligosaccharides (GOS) formulation consisting of 90% pure GOS (GOS90), on the composition and activity of the mouse gut microbiota. Germ-free mice were colonised with microbiota from four pathogen-free wt 129 mice donors (SPF), and stools were collected during a feeding trial in which GOS90 was delivered orally for 14 days. Pyrosequencing of 16S rDNA amplicons showed that Bifidobacterium and specific Lactobacillus, Bacteroides and Clostridiales were more prevalent in GOS90-fed mice after 14 days, although the prebiotic impact on Bifidobacterium varied among individual mice. Prebiotic feeding also resulted in decreased abundance of Bacteroidales, Helicobacter and Clostridium. High-throughput quantitative PCR showed an increased abundance of Bifidobacterium adolescentis, Bifidobacterium pseudocatenulatum, Bifidobacterium lactis and Bifidobacterium gallicum in the prebiotic-fed mice. Control female mice showed a higher diversity (phylogenetic diversity (PD) = 15.1 ± 3.4 in stools and PD = 13.0 ± 0.6 in intestinal contents) than control males (PD = 7.8 ± 1.6 in stool samples and PD = 9.5 ± 1.0 in intestinal contents). GOS90 did not modify inflammatory biomarkers (interleukin (IL)-6, IL-12, IL-1β, interferon gamma and tumour necrosis factor alpha). Decreased butyrate, acetate and lactate concentrations in stools of prebiotic fed mice suggested an increase in colonic absorption and reduced excretion. Overall, our results demonstrate that GOS90 is capable of modulating the intestinal microbiome resulting in expansion of the probiome (autochtonous commensal intestinal bacteria considered to have a beneficial influence on health).

Moderately Fermentable Potato Fiber Attenuates Signs and Inflammation Associated with Experimental Colitis in Mice

BACKGROUND

Dietary fiber intake leading to short-chain fatty acid (SCFA) production could be a strategy to combat intermittent bouts of inflammation during ulcerative colitis.

OBJECTIVE

Our objective was to evaluate dietary potato fiber (PF) in attenuating inflammation using a dextran sodium sulfate (DSS)-induced colitis mouse model. We hypothesized that PF would show anti-inflammatory effects compared with cellulose due in part to SCFA production.

METHODS

Male C57Bl/6J mice were fed diets containing either 8% cellulose or 14.5% PF for a 22-d feeding study. Starting on study day 14, mice were provided either distilled water (control) or 2% (wt:vol) DSS in drinking water for 5 d (cellulose+control, n = 17; PF+control, n = 16; cellulose+DSS, n = 17; and PF+DSS, n = 16). Body weights and food and water intakes were collected daily from day 14 through day 22. Distal colon tissue was analyzed for histologic outcomes and changes in gene expression, and cecal contents were analyzed for SCFA concentrations. Data were analyzed by ANOVA, with repeated measures applied where necessary.

RESULTS

At day 5 post-DSS induction, cellulose+DSS mice exhibited a 2% reduction (P < 0.05) in body weight compared with PF+DSS and PF+ and cellulose+control mice. PF+DSS mice had greater (P < 0.05) cecal butyrate concentrations [24.5 μmol/g dry matter (DM)] than did cellulose+DSS mice (4.93 μmol/g DM). Mice fed PF+DSS had lower (P < 0.05) infiltration of leukocytes in the distal colon than did mice fed cellulose+DSS (mean histology scores of 1.22 and 2.30, respectively). Furthermore, mice fed cellulose+DSS exhibited 1.42, 11.5, 8.48, and 35.5 times greater (P < 0.05) colon mRNA expression of tumor necrosis factor α (Tnfa) and interleukin (Il) 1b, Il6, and Il17a, respectively, and 7.10 times greater (P < 0.05) expression of C-X-C motif ligand 1 (Cxc1) compared with mice fed PF+DSS.

CONCLUSIONS

These results suggest that PF fed to mice before and during DSS colitis attenuates inflammation, potentially through SCFA production; however, future studies are needed to understand the role of dietary fiber intake and immune activation.

High protective efficacy of rice bran against human rotavirus diarrhea via enhancing probiotic growth, gut barrier function, and innate immunity

Previously, we showed that rice bran (RB) was able to reduce human rotavirus (HRV) diarrhea in gnotobiotic pigs. Here, we investigated its effect on the growth of diarrhea-reducing probiotic Lactobacillus rhamnosus GG (LGG) and Escherichia coli Nissle (EcN), and the resulting effects on HRV diarrhea, gut epithelial health, permeability and innate immune responses during virulent HRV challenge. On 3, 5, and 7 days of age pigs were inoculated with 2 × 10⁴ colony-forming-units LGG+EcN to initiate colonization. Daily RB supplementation (replacing 10% calorie intake) was started at 5 days of age and continued until euthanasia. A subset of pigs in each group was challenged orally with 10⁵ focus-forming-units of virulent HRV at 33 days of age. RB completely prevented HRV diarrhea in LGG+EcN colonized pigs. RB significantly promoted the growth of both probiotic strains in the gut (~5 logs) and increased the body-weight-gain at 4–5 weeks of age compared to non-RB group. After HRV challenge, RB-fed pigs had significantly lower ileal mitotic index and villus width, and significantly increased intestinal IFN-γ and total IgA levels compared to non-RB group. Therefore, RB plus LGG+EcN colonization may represent a highly effective therapeutic approach against HRV and potentially a variety of other diarrhea-inducing enteric pathogens.

Lactate and short chain fatty acids produced by microbial fermentation downregulate proinflammatory responses in intestinal epithelial cells and myeloid cells

The use of short chain fatty acids to modulate gastrointestinal inflammatory conditions such as ulcerative colitis has produced encouraging results either in animal models or also in clinical trials. Identifying the key cellular and molecular targets of this activity will contribute to establish the appropriate combinations/targeting strategies to maximize the efficacy of anti-inflammatory interventions. In the present work, we evaluated in vitro the interaction of lactate, acetate, propionate and butyrate on cells relevant for innate immune response of the gastrointestinal tract. All molecules tested regulate the production of proinflammatory cytokines by TLR-4 and TLR-5 activated intestinal epithelial cells in a dose response manner. Furthermore SCFAs and lactate modulate cytokine secretion of TLR-activated bone marrow derived macrophages and also TLR-dependent CD40 upregulation in bone marrow derived dendritic in a dose-dependent manner. Butyrate and propionate have been effective at concentrations of 1 to 5mM whereas acetate and lactate produced modulatory effects at concentrations higher than 20-50mM in different assays. Our results indicate that in concentrations similar to found in large bowel lumen, all SCFAs tested and lactate can modulate activity of relevant sentinel cell types activated by TLR signals. Modulatory activity was not inhibited by pertussis toxin treatment indicating that the effects are not related to Gi signaling. The use of these molecules in combined or separately as intervention strategy in conditions where epithelial or myeloid cells are main triggers of the inflammatory situation seems appropriate.

Mast Cell Serotonin Immunoregulatory Effects Impacting on Neuronal Function: Implications for Neurodegenerative and Psychiatric Disorders

Mast cells (MCs) are derived from hemopoietic precursor cells, undergo their maturation in peripheral tissues, and play a significant role in both the innate and adaptive immune response. Cross-linking of the FcεRI on MCs initiates activation of several cytoplasmic protein tyrosine kinases which rapidly lead to phosphorylation and recruitment of adaptor molecules. These effects trigger the release of preformed mediators stored in the cytoplasmic granules, including histamine, serotonin and tryptase, as well as newly synthesized mediators, such as cytokines/chemokines, prostaglandins, leukotrienes, and growth factors. Serotonin (5-HT) is a bioactive monoamine, which has seven specific cell surface membrane bound receptors which are coupled to G-proteins, plays an important role in the central and peripheral nervous system, and is one of the key mediators in signaling between nervous and immune systems. Serotonin is not stored in all MC types but is implicated in MC adhesion, chemotaxis, tumorigenesis, and tissue regeneration through smooth muscle differentiation of stromal cells. Recent evidence indicates that serotonin has immunoregulatory actions that may be important in neuropsychiatric conditions. Chemokines, RANTES/CCL5, MCP-1/CCL2, and related molecules, constitute the C-C class of chemokine supergene family, play a role in regulating T helper-cell cytokine production and MC trafficking, and are involved in histamine and serotonin generation and MC functions. Pro-inflammatory cytokines such as interleukin-1-β and tumor necrosis factor which mediate MC response, are capable of activating p38 MAPK, and might increase serotonin generation through p38 MAPK activation. Here, we review the relationship between MCs and serotonin and its role in inflammatory diseases and neuroimmune interactions.

Pilot dietary intervention with heat-stabilized rice bran modulates stool microbiota and metabolites in healthy adults

Heat-stabilized rice bran (SRB) has been shown to regulate blood lipids and glucose, modulate gut mucosal immunity and inhibit colorectal cancer in animal and human studies. However, SRB’s effects on gut microbial composition and metabolism and the resulting implications for health remain largely unknown. A pilot, randomized-controlled trial was developed to investigate the effects of eating 30 g/day SRB on the stool microbiome and metabolome. Seven healthy participants consumed a study meal and snack daily for 28 days. The microbiome and metabolome were characterized using 454 pyrosequencing and gas chromatography-mass spectrometry (GC-MS) at baseline, two and four weeks post-intervention. Increases in eight operational taxonomic units (OTUs), including three from Bifidobacterium and Ruminococcus genera, were observed after two and four weeks of SRB consumption (p < 0.01). Branched chain fatty acids, secondary bile acids and eleven other putative microbial metabolites were significantly elevated in the SRB group after four weeks. The largest metabolite change was a rice bran component, indole-2-carboxylic acid, which showed a mean 12% increase with SRB consumption. These data support the feasibility of dietary SRB intervention in adults and support that SRB consumption can affect gut microbial metabolism. These findings warrant future investigations of larger cohorts evaluating SRB’s effects on intestinal health.

Rice prolamin extract ameliorates acute murine colitis by inhibiting nuclear factor-kappa B and modulating intestinal apoptosis and cell proliferation

We investigated the impact of rice prolamin extract (RPE) on lipopolysaccharide (LPS)-induced nuclear factor (NF)-κB signalling in intestinal epithelial cells and macrophages, and determined the therapeutic efficacy of RPE in acute murine colitis. The effect of RPE on LPS-induced NF-κB signalling and proinflammatory gene expression was evaluated by reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, immunofluorescence and electrophoretic mobility shift assay (EMSA). The in-vivo efficacy of RPE was assessed in mice with 3% dextran sulphate sodium (DSS)-induced colitis. Apoptotic and cellular proliferative activities were evaluated by immunostaining with cleaved caspase-3 and proliferating cell nuclear antigen (PCNA) antibodies. RPE inhibited LPS-induced expression of monocyte chemotactic protein (MCP)-1, interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha and LPS-induced NF-κB signalling in intestinal epithelial cells and macrophages. RPE-fed, DSS-exposed mice showed less weight loss, longer colon length and lower histological score compared to control diet-fed, DSS-exposed mice. Immunostaining analysis revealed a significant decrease of cleaved caspase-3 positive cells in RPE-fed, DSS-exposed mice compared to DSS-exposed mice. Also, the number of PCNA-positive cells within intact colonic crypts decreased significantly in RPE-fed, DSS-exposed mice compared to control diet-fed, DSS-exposed mice. DSS-induced NF-κB signalling was inhibited by RPE. RPE ameliorates intestinal inflammation by inhibiting NF-κB activation and modulating intestinal apoptosis and cell proliferation in an acute murine colitis.

Functional impacts of the intestinal microbiome in the pathogenesis of inflammatory bowel disease

: The human intestinal microbiome plays a critical role in human health and disease, including the pathogenesis of inflammatory bowel disease (IBD). Numerous studies have identified altered bacterial diversity and abundance at varying taxonomic levels through biopsies and fecal samples of patients with IBD and diseased model animals. However, inconsistent observations regarding the microbial compositions of such patients have hindered the efforts in assessing the etiological role of specific bacterial species in the pathophysiology of IBD. These observations highlight the importance of minimizing the confounding factors associated with IBD and the need for a standardized methodology to analyze well-defined microbial sampling sources in early IBD diagnosis. Furthermore, establishing the linkage between microbiota compositions with their function within the host system can provide new insights on the pathogenesis of IBD. Such research has been greatly facilitated by technological advances that include functional metagenomics coupled with proteomic and metabolomic profiling. This review provides updates on the composition of the microbiome in IBD and emphasizes microbiota dysbiosis-involved mechanisms. We highlight functional roles of specific bacterial groups in the development and management of IBD. Functional analyses of the microbiome may be the key to understanding the role of microbiota in the development and chronicity of IBD and reveal new strategies for therapeutic intervention.

Passiflora edulis peel intake and ulcerative colitis: approaches for prevention and treatment

Inflammatory bowel disease is a chronic relapsing disease that affects millions of people worldwide; its pathogenesis is influenced by genetic, environmental, microbiological, and immunological factors. The aim of this study was to evaluate the effects of short- and long-term Passiflora edulis peel intake on the antioxidant status, microbiota, and short-chain fatty acids formation in rats with 2,4,6-trinitrobenzenesulphonic acid-induced colitis using two "in vivo" experiments: chronic (prevention) and acute (treatment). The colitis damage score was determined using macroscopic and microscopic analyses. In addition, the antioxidant activity in serum and other tissues (liver and colon) was evaluated. Bifidobacteria, lactobacilli, aerobic bacteria and enterobacteria, and the amount of short-chain fatty acids (acetic, butyric, and propionic acids) in cecum content were counted. Differences in the colon damage scores were observed; P. edulis peel intake improved serum antioxidant status. In the treatment protocol, decreased colon lipid peroxidation, a decreased number of aerobic bacteria and enterobacteria, and an improvement in acetic and butyric acid levels in the feces were observed. An improvement in the bifidobacteria and lactobacilli was observed in the prevention protocol. These results suggested that P. edulis peel can modulate microbiota and could be used as source of fiber and polyphenols in the prevention of oxidative stress through the improvement of serum and tissue antioxidant status.

Rice brans, rice bran oils, and rice hulls: composition, food and industrial uses, and bioactivities in humans, animals, and cells

Rice plants produce bioactive rice brans and hulls that have been reported to have numerous health-promoting effects in cells, animals, and humans. The main objective of this review is to consolidate and integrate the widely scattered information on the composition and the antioxidative, anti-inflammatory, and immunostimulating effects of rice brans from different rice cultivars, rice bran oils derived from rice brans, rice hulls, liquid rice hull smoke derived from rice hulls, and some of their bioactive compounds. As part of this effort, this paper also presents brief summaries on the preparation of health-promoting foods including bread, corn flakes, frankfurters, ice cream, noodles, pasta, tortillas, and zero-trans-fat shortening as well as industrial products such bioethanol and biodiesel fuels. Also covered are antibiotic, antiallergic, anticarcinogenic, antidiabetic, cardiovascular, allelochemical, and other beneficial effects and the mechanisms of the bioactivities. The results show that food-compatible and safe formulations with desirable nutritional and biological properties can be used to develop new multifunctional foods as well as bioethanol and biodiesel fuel. The overlapping aspects are expected to contribute to a better understanding of the potential impact of the described health-promoting potential of the rice-derived brans, oils, and hulls in food and medicine. Such an understanding will enhance nutrition and health and benefit the agricultural and industrial economies.

Effects of the modulation of microbiota on the gastrointestinal immune system and bowel function

The gastrointestinal tract harbors a tremendous number and variety of commensal microbiota. The intestinal mucosa simultaneously absorbs essential nutrients and protects against detrimental antigens or pathogenic microbiota as the first line of defense. Beneficial interactions between the host and microbiota are key requirements for host health. Although the gut microbiota has been previously studied in the context of inflammatory diseases, it has recently become clear that this microbial environment has a beneficial role during normal homeostasis, by modulating the immune system or bowel motor function. Recent studies revealed that microbiota, including their metabolites, modulate key signaling pathways involved in the inflammation of the mucosa or the neurotransmitter system in the gut-brain axis. The underlying molecular mechanisms of host-microbiota interactions are still unclear; however, manipulation of microbiota by probiotics or prebiotics is becoming increasingly recognized as an important therapeutic option, especially for the treatment of the dysfunction or inflammation of the intestinal tract.

Pathobiology and potential therapeutic value of intestinal short-chain fatty acids in gut inflammation and obesity

BACKGROUND

The lumen of the gastrointestinal tract contains many substances produced from the breakdown of foodstuffs, from salivary, esophageal, intestinal, hepatic, and pancreatic secretions, and from sloughed cells present in the gastrointestinal lumen. Although these substances were traditionally regarded as waste products, there is increasing realization that many can be biologically active, either as signalling compounds or as nutrients. For example, proteins are broken down into amino acids, which are then sensed by nutrient receptors. The gut microbiome, which is at highest abundance in the ileocecum, has powerful metabolic activity, digesting and breaking down unabsorbed carbohydrates, proteins, and other ingested nutrients into phenols, amines, volatile organic compounds, methane, carbon dioxide, hydrogen, and hydrogen sulfide into volatile fatty acids, also called short-chain fatty acids (SCFAs).

CONCLUSION

These latter substances are the topic of this review. In this review, we will briefly discuss recent advances in the understanding SCFA production, signalling, and absorption, followed by a detailed description and discussion of trials of SCFAs, probiotics, and prebiotics in the treatment of gastrointestinal disease, in particular ulcerative colitis (UC), pouchitis, short bowel syndrome, and obesity.

Cellulose supplementation early in life ameliorates colitis in adult mice

Decreased consumption of dietary fibers, such as cellulose, has been proposed to promote the emergence of inflammatory bowel diseases (IBD: Crohn disease [CD] and ulcerative colitis [UC]) where intestinal microbes are recognized to play an etiologic role. However, it is not known if transient fiber consumption during critical developmental periods may prevent consecutive intestinal inflammation. The incidence of IBD peaks in young adulthood indicating that pediatric environmental exposures may be important in the etiology of this disease group. We studied the effects of transient dietary cellulose supplementation on dextran sulfate sodium (DSS) colitis susceptibility during the pediatric period in mice. Cellulose supplementation stimulated substantial shifts in the colonic mucosal microbiome. Several bacterial taxa decreased in relative abundance (e.g., Coriobacteriaceae [p = 0.001]), and other taxa increased in abundance (e.g., Peptostreptococcaceae [p = 0.008] and Clostridiaceae [p = 0.048]). Some of these shifts persisted for 10 days following the cessation of cellulose supplementation. The changes in the gut microbiome were associated with transient trophic and anticolitic effects 10 days following the cessation of a cellulose-enriched diet, but these changes diminished by 40 days following reversal to a low cellulose diet. These findings emphasize the transient protective effect of dietary cellulose in the mammalian large bowel and highlight the potential role of dietary fibers in amelioration of intestinal inflammation.

Stabilized rice bran improves weaning pig performance via a prebiotic mechanism

Stabilized rice bran (SRB) is classified as a "functional food" because of its prebiotic characteristics. With increasing grain prices and the pressure to remove antibiotics from swine diets because of concern over antibiotic resistance, SRB was investigated as a nursery diet ingredient with and without the addition of antibiotics (ANT). Two hundred pigs were weaned at 21 d of age, blocked by BW, and allotted to diets containing 0 or 10% SRB ± ANT according to a 2 × 2 factorial arrangement of treatments. Five animals were housed per pen throughout a 28-d growth period. At the end of the trial, 1 pig from each pen was euthanized for measurement of intestinal morphology. Antibiotic supplementation improved ADG by 6.4% during Phase 2 (d 14 to 28; P = 0.02), but other production variables were unaffected by ANT. During Phase 2 and cumulatively (d 0 to 28), the supplementation of SRB improved G:F by 10% in ANT-free pigs but not in pigs fed ANT (ANT × SRB, P < 0.03). Ileal histology revealed an increase in crypt depth of pigs fed the diet containing ANT plus SRB and corresponding decreases in villi:crypt associated with both ANT and SRB supplementation (P < 0.05). Intraepithelial lymphocytes were increased by 15% in pigs fed SRB without ANT, but were unaffected by SRB in pigs fed ANT (ANT x SRB, P = 0.003). Colonic bifidobacteria tended to increase with SRB supplementation (P < 0.10). Differences in ileal and cecal digesta short-chain fatty acid concentrations were not detected. In summary, SRB improved the efficiency of nutrient utilization in nursery diets lacking antibiotics and tended to increase intestinal bifidobacteria concentrations, indicating that SRB may exert beneficial prebiotic effects in weanling pigs.

The interplay between fiber and the intestinal microbiome in the inflammatory response

Fiber intake is critical for optimal health. This review covers the anti-inflammatory roles of fibers using results from human epidemiological observations, clinical trials, and animal studies. Fiber has body weight-related anti-inflammatory activity. With its lower energy density, a diet high in fiber has been linked to lower body weight, alleviating obesity-induced chronic inflammation evidenced by reduced amounts of inflammatory markers in human and animal studies. Body weight-unrelated anti-inflammatory activity of fiber has also been extensively studied in animal models in which the type and amount of fiber intake can be closely monitored. Fermentable fructose-, glucose-, and galactose-based fibers as well as mixed fibers have shown systemic and local intestinal anti-inflammatory activities when plasma inflammatory markers and tissue inflammation were examined. Similar anti-inflammatory activities have also been demonstrated in some human studies that controlled total fiber intake. The anti-inflammatory activities of synbiotics (probiotics plus fiber) were reviewed as well, but there was no convincing evidence indicating higher efficacy of synbiotics compared with that of fiber alone. Adverse effects have not been observed with the amount of fiber intake or supplementation used in studies, although patients with Crohn's disease may be more sensitive to inulin intake. Several possible mechanisms that may mediate the body weight-unrelated anti-inflammatory activity of fibers are discussed based on the in vitro and in vivo evidence. Fermentable fibers are known to affect the intestinal microbiome. The immunomodulatory role of the intestinal microbiome and/or microbial metabolites could contribute to the systemic and local anti-inflammatory activities of fibers.

Nutritional and probiotic supplementation in colitis models

In vitro and animals models have long been used to study human diseases and identify novel therapeutic approaches that can be applied to combat these conditions. Ulcerative colitis and Crohn's disease are the two main entities of inflammatory bowel disease (IBD). There is an intricate relationship between IBD features in human patients, in vitro and animal colitis models, mechanisms and possible therapeutic approaches in these models, and strategies that can be extrapolated and applied in humans. Malnutrition, particularly protein-energy malnutrition and vitamin and micronutrient deficiencies, as well as dysregulation of the intestinal microbiota, are common features of IBD. Based on these observations, dietary supplementation with essential nutrients known to be in short supply in the diet in IBD patients and with other molecules believed to provide beneficial anti-inflammatory effects, as well as with probiotic organisms that stimulate immune functions and resistance to infection has been tested in colitis models. Here we review current knowledge on nutritional and probiotic supplementation in in vitro and animal colitis models. While some of these strategies require further fine-tuning before they can be applied in human IBD patients, their intended purpose is to prevent, delay or treat disease symptoms in a non-pharmaceutical manner.

Review of natural products actions on cytokines in inflammatory bowel disease

The purpose of this review is to provide an overview of the effects that natural products have on inflammatory bowel disease (IBD) and to provide insight into the relationship between these natural products and cytokines modulation. More than 100 studies from the past 10 years were reviewed herein on the therapeutic approaches for treating IBD. The natural products having anti-IBD actions included phytochemicals, antioxidants, microorganisms, dietary fibers, and lipids. The literature revealed that many of these natural products exert anti-IBD activity by altering cytokine production. Specifically, phytochemicals such as polyphenols or flavonoids are the most abundant, naturally occurring anti-IBD substances. The anti-IBD effects of lipids were primarily related to the n-3 polyunsaturated fatty acids. The anti-IBD effects of phytochemicals were associated with modulating the levels of tumor necrosis factor α (TNF-α), interleukin (IL)-1, IL-6, inducible nitric oxide synthase, and myeloperoxide. The anti-IBD effects of dietary fiber were mainly mediated via peroxisome proliferator-activated receptor-γ, TNF-α, nitric oxide, and IL-2, whereas the anti-IBD effects of lactic acid bacteria were reported to influence interferon-γ, IL-6, IL-12, TNF-α, and nuclear factor-κ light-chain enhancer of activated B cells. These results suggest that the anti-IBD effects exhibited by natural products are mainly caused by their ability to modulate cytokine production. However, the exact mechanism of action of natural products for IBD therapy is still unclear. Thus, future research is needed to examine the effect of these natural products on IBD and to determine which factors are most strongly correlated with reducing IBD or controlling the symptoms of IBD.

Chemopreventive properties of dietary rice bran: current status and future prospects

Emerging evidence suggests that dietary rice bran may exert beneficial effects against several types of cancer, such as breast, lung, liver, and colorectal cancer. The chemopreventive potential has been related to the bioactive phytochemicals present in the bran portion of the rice such as ferulic acid, tricin, β-sitosterol, γ-oryzanol, tocotrienols/tocopherols, and phytic acid. Studies have shown that the anticancer effects of the rice bran-derived bioactive components are mediated through their ability to induce apoptosis, inhibit cell proliferation, and alter cell cycle progression in malignant cells. Rice bran bioactive components protect against tissue damage through the scavenging of free radicals and the blocking of chronic inflammatory responses. Rice bran phytochemicals have also been shown to activate anticancer immune responses as well as affecting the colonic tumor microenvironment in favor of enhanced colorectal cancer chemoprevention. This is accomplished through the modulation of gut microflora communities and the regulation of carcinogen-metabolizing enzymes. In addition, the low cost of rice production and the accessibility of rice bran make it an appealing candidate for global dietary chemoprevention. Therefore, the establishment of dietary rice bran as a practical food-derived chemopreventive agent has the potential to have a significant impact on cancer prevention for the global population.

Butyrate: implications for intestinal function

PURPOSE OF REVIEW

Butyrate is physiologically produced by the microbial fermentation of dietary fibers and plays a plurifunctional role in intestinal cells. This review examines the recent findings regarding the role and mechanisms by which butyrate regulates intestinal metabolism and discusses how these findings could improve the treatment of several gastrointestinal disorders.

RECENT FINDINGS

Butyrate is more than a primary nutrient that provides energy to colonocytes and acts as a cellular mediator in those cells through several mechanisms. One remarkable property of butyrate is its ability to inhibit histone deacetylases, which is associated with the direct effects of butyrate and results in gene regulation, immune modulation, cancer suppression, cell differentiation, intestinal barrier regulation, oxidative stress reduction, diarrhea control, visceral sensitivity and intestinal motility modulation. All of these actions make butyrate an important factor for the maintenance of gut health.

SUMMARY

From studies published over 30 years, there is no doubt of the important role that butyrate plays in maintaining intestinal homeostasis. However, despite these effects, clinical studies are still required to validate the routine use of butyrate in clinical practice and, specifically, in the treatment of intestinal diseases.

Dietary rice bran promotes resistance to Salmonella enterica serovar Typhimurium colonization in mice

Background

Dietary rice bran consists of many bioactive components with disease fighting properties; including the capacity to modulate the gut microbiota. Studies point to the important roles of the gut microbiota and the mucosal epithelium in the establishment of protection against enteric pathogens, such as Salmonella. The ability of rice bran to reduce the susceptibility of mice to a Salmonella infection has not been previously investigated. Therefore, we hypothesized that the incorporation of rice bran into the diet would inhibit the colonization of Salmonella in mice through the induction of protective mucosal responses.

Results

Mice were fed diets containing 0%, 10% and 20% rice bran for one week prior to being orally infected with Salmonella enterica serovar Typhimurium. We found that mice consuming the 10 and 20% rice bran diets exhibited a reduction in Salmonella fecal shedding for up to nine days post-infection as compared to control diet fed animals (p < 0.05). In addition, we observed decreased concentrations of the pro-inflammatory cytokines, TNF-alpha, IFN-gamma, and IL-12 (p < 0.05) as well as increased colonization of native Lactobacillus spp. in rice bran fed mice (p < 0.05). Furthermore, in vitro experiments revealed the ability of rice bran extracts to reduce Salmonella entry into mouse small intestinal epithelial cells.

Conclusions

Increasing rice bran consumption represents a novel dietary means for reducing susceptibility to enteric infection with Salmonella and potentially via induction of native Lactobacillus spp.

Consumption of rice bran increases mucosal immunoglobulin A concentrations and numbers of intestinal Lactobacillus spp

Gut-associated lymphoid tissue maintains mucosal homeostasis by combating pathogens and inducing a state of hyporesponsiveness to food antigens and commensal bacteria. Dietary modulation of the intestinal immune environment represents a novel approach for enhancing protective responses against pathogens and inflammatory diseases. Dietary rice bran consists of bioactive components with disease-fighting properties. Therefore, we conducted a study to determine the effects of whole dietary rice bran intake on mucosal immune responses and beneficial gut microbes. Mice were fed a 10% rice bran diet for 28 days. Serum and fecal samples were collected throughout the study to assess total immunoglobulin A (IgA) concentrations. Tissue samples were collected for cellular immune phenotype analysis, and concentrations of native gut Lactobacillus spp. were enumerated in the fecal samples. We found that dietary rice bran induced an increase in total IgA locally and systemically. In addition, B lymphocytes in the Peyer's patches of mice fed rice bran displayed increased surface IgA expression compared with lymphocytes from control mice. Antigen-presenting cells were also influenced by rice bran, with a significant increase in myeloid dendritic cells residing in the lamina propria and mesenteric lymph nodes. Increased colonization of native Lactobacillus was observed in rice bran-fed mice compared with control mice. These findings suggest that rice bran-induced microbial changes may contribute to enhanced mucosal IgA responses, and we conclude that increased rice bran consumption represents a promising dietary intervention to modulate mucosal immunity for protection against enteric infections and induction of beneficial gut bacteria.

Stress-induced visceral analgesia assessed non-invasively in rats is enhanced by prebiotic diet

AIM

To investigate the influence of repeated water avoidance stress (rWAS) on the visceromotor response (VMR) to colorectal distension (CRD) and the modulation of the response by a prebiotic diet in rats using a novel surgery-free method of solid-state manometry.

METHODS

Male Wistar rats fed a standard diet with or without 4% enzyme-treated rice fiber (ERF) for 5 wk were subjected to rWAS (1 h daily x 10 d) or no stress. The VMR to graded phasic CRD was assessed by intraluminal colonic pressure recording on days 0 (baseline), 1 and 10 (45 min) and 11 (24 h) after rWAS and expressed as percentage change from baseline. Cecal content of short chain fatty acids and distal colonic histology were assessed on day 11.

RESULTS

WAS on day 1 reduced the VMR to CRD at 40 and 60 mmHg similarly by 28.9% ± 6.6% in both diet groups. On day 10, rWAS-induced reduction of VMR occurred only at 40 mmHg in the standard diet group (36.2% ± 17.8%) while in the ERF group VMR was lowered at 20, 40 and 60 mmHg by 64.9% ± 20.9%, 49.3% ± 11.6% and 38.9% ± 7.3% respectively. The visceral analgesia was still observed on day 11 in ERF- but not in standard diet-fed rats. By contrast the non-stressed groups (standard or ERF diet) exhibited no changes in VMR to CRD. In standard diet-fed rats, rWAS induced mild colonic histological changes that were absent in ERF-fed rats exposed to stress compared to non-stressed rats. The reduction of cecal content of isobutyrate and total butyrate, but not butyrate alone, was correlated with lower visceral pain response. Additionally, ERF diet increased rWAS-induced defecation by 26% and 75% during the first 0-15 min and last 15-60 min, respectively, compared to standard diet, and reduced rats' body weight gain by 1.3 fold independently of their stress status.

CONCLUSION

These data provide the first evidence of psychological stress-related visceral analgesia in rats that was enhanced by chronic intake of ERF prebiotic.