Effect of Senecio scandens ethanol extract on gut microbiota composition in mice.

The gut microbiota inhabits the animal intestinal tract, and dysbiosis of the gut microbiota may result in disease. Senecio scandens has pharmaceutical antibacterial activities and is regarded as a broad-spectrum antibiotic in traditional Chinese medicine. Extracts of S. scandens are reported to show strong antimicrobial activity, and quercetin significantly decreases some species in the caecal microflora. However, the bactericidal effects of the extracts on the gut microbiota remain obscure. Here, we supplied ethanol extract of S. scandens, which might possibly be used as an alternative for chemical antibiotics, to mice to investigate the state of the intestinal microbiota. Our studies included a control group, low-, moderate-, and high-dose ethanol extract groups, and cefixime capsule group. The ethanol extract groups did not present reduced diversity or differences in the gut microbiota balance. There were significant differences between the ethanol extract and cefixime capsule groups in terms of the gut microbiota. The control and ethanol extract groups contained similar bacteria, which suggested that the ethanol extract has no inhibitory effect on the gut microbiota in vivo. Bifidobacteriales and Lactobacillus acidophilus were significantly increased in the high-dose group. Both secretory immunoglobulin A and mucin 2 concentrations increased as the dose of ethanol extract increased. The functional prediction differences between the control and ethanol extract groups decreased with increasing extract doses, which indicated that the low-dose and high-dose extract treatments might regulate different pathways and functions of the gut microbiota. The results also highlighted the prevention of bacterial drug resistance in the ethanol extract groups.

Influence of Lacto-Immuno-Vital on growth performance and gene expression of IgA, MUC-2, and growth factor IGF-2 in the jejunum of broiler chickens.

The effects of Lacto-Immuno-Vital synbiotic preparation on gene expression of IgA, MUC-2, and growth factor IGF-2 in the jejunum and on BW gain in broiler chickens were studied. A flock of 64,400 1-day-old Hybrid ROSS 308 chickens was inducted in the 42-day experiment. The chickens were divided into 2 equally size groups in separate halls. The chickens in the experimental (E) group received 500 g of Lacto-Immuno-Vital in 1,000 L of drinking water. The preparation was administered daily from the first day (day 1) to day 7 of the experiment. From day 7 to day 22, it was given in pulsed manner (every third day) at a dose of 300 g in 1,000 L of drinking water. The broiler chickens in the E group gained more weight (P < 0.001) compared with control from day 10 to day 42. Death of animals during feeding period was 1,078 chickens in the E group compared with 1,115 dead chickens in the control group. Feed conversion ratio was 1.61 kg of supplemented diet/kg of BW in the E group compare with 1.67 kg of nonsupplemented diet/kg of BW in control. The relative expression of IgA gene in the jejunum was upregulated on day 22 in the E group compared with control (P < 0.05), whereas relative expression of MUC-2 gene was upregulated in the E group compared with control on day 8 and day 22 (P < 0.05; P < 0.001). Similarly, relative expression of IGF-2 gene was upregulated in the E group compared with control on both samplings (P < 0.01). The composition of Lacto-Immuno-Vital synbiotic preparation showed beneficial effects on growth performance, feed conversion ratio, morbidity, mortality, and selected parameters of mucosal immunity in the chicken jejunum.

p-Cymene and Rosmarinic Acid Ameliorate TNBS-Induced Intestinal Inflammation Upkeeping ZO-1 and MUC-2: Role of Antioxidant System and Immunomodulation.

p-Cymene (p-C) and rosmarinic acid (RA) are secondary metabolites that are present in medicinal herbs and Mediterranean spices that have promising anti-inflammatory properties. This study aimed to evaluate their intestinal anti-inflammatory activity in the trinitrobenzene sulphonic acid (TNBS)-induced colitis model in rats. p-C and RA (25-200 mg/kg) oral administration reduced the macroscopic lesion score, ulcerative area, intestinal weight/length ratio, and diarrheal index in TNBS-treated animals. Both compounds (200 mg/kg) decreased malondialdehyde (MDA) and myeloperoxidase (MPO), restored glutathione (GSH) levels, and enhanced fluorescence intensity of superoxide dismutase (SOD). They also decreased interleukin (IL)-1ß and tumor necrosis factor (TNF)-α, and maintained IL-10 basal levels. Furthermore, they modulated T cell populations (cluster of differentiation (CD)4+, CD8+, or CD3+CD4+CD25+) analyzed from the spleen, mesenteric lymph nodes, and colon samples, and also decreased cyclooxigenase 2 (COX-2), interferon (IFN)-γ, inducible nitric oxide synthase (iNOS), and nuclear transcription factor kappa B subunit p65 (NFκB-p65) mRNA transcription, but only p-C interfered in the suppressor of cytokine signaling 3 (SOCS3) expression in inflamed colons. An increase in gene expression and positive cells immunostained for mucin type 2 (MUC-2) and zonula occludens 1 (ZO-1) was observed. Altogether, these results indicate intestinal anti-inflammatory activity of p-C and RA involving the cytoprotection of the intestinal barrier, maintaining the mucus layer, and preserving communicating junctions, as well as through modulation of the antioxidant and immunomodulatory systems.

Enhanced therapeutic efficacy of a novel colon-specific nanosystem loading emodin on DSS-induced experimental colitis.

BACKGROUND: Ulcerative colitis (UC) is an intricate enteric disease with a rising incidence that is closely related to mucosa-barrier destruction, gut dysbacteriosis, and immune disorders. Emodin (1,3,8-trihydroxy-6-methyl-9,10-anthraquinone, EMO) is a natural anthraquinone derivative that occurs in many Polygonaceae plants. Its multiple pharmacological effects, including antioxidant, immune-suppressive, and anti-bacteria activities, make it a promising treatment option for UC. However, its poor solubility, extensive absorption, and metabolism in the upper gastrointestinal tract may compromise its anti-colitis effects. PURPOSE: EMO was loaded in a colon-targeted delivery system using multifunctional biomedical materials and the enhanced anti-colitis effect involving mucosa reconstruction was investigated in this study. METHODS: EMO-loaded Poly (DL-lactide-co-glycolide)/EudragitⓇ S100/montmorillonite nanoparticles (EMO/PSM NPs) were prepared by a versatile single-step assembly approach. The colon-specific release behavior was characterized in vitro and in vivo, and the anti-colitis effect was evaluated in dextran sulfate sodium (DSS)-induced acute colitis in mice by weight loss, disease activity index (DAI) score, colon length, histological changes, and colitis biomarkers. The integrity of the intestinal mucosal barrier was evaluated through transwell co-culture model in vitro and serum zonulin-related tight junctions and mucin2 (MUC2) in vivo. RESULTS: EMO/PSM NPs with a desirable hydrodynamic diameter (~ 235 nm) and negative zeta potential (~ -31 mV) could prevent the premature drug release (< 4% in the first 6 h in vitro) in the upper gastrointestinal tract (GIT) and boost retention in the lower GIT and inflamed colon mucosa in vivo. Compared to free EMO-treatment of different doses in UC mice, the NPs could enhance the remedial efficacy of EMO in DAI decline, histological remission, and regulation of colitis indicators, such as myeloperoxidase (MPO), nitric oxide (NO), and glutathione (GSH). The inflammatory factors including induced nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α, and IL-1ß were suppressed by EMO/PSM NPs at both mRNA and protein levels. The obtained NPs could also promote the regeneration of the mucosal barrier via reduced fluorescein isothiocyanate (FITC)-dextran leakage in the transwell co-culture model and decreased serum zonulin levels, which was demonstrated to be associated with the upregulated tight junctions (TJs)-related proteins (claudin-2, occludin, and zo-1) and MUC2 at mRNA level. Moreover, the NPs could contribute to attenuating the liver injury caused by free EMO under excessive immune inflammation. CONCLUSION: Our results demonstrated that EMO/PSM NPs could specifically release EMO in the diseased colon, and effectively enhance the anti-colitis effects of EMO related to intestinal barrier improvement. It can be considered as a novel potential alternative for oral colon-targeted UC therapy by increasing therapeutic efficacy and reducing side-effects.

Electroacupuncture relieves irritable bowel syndrome by increasing expression of nucleotide-binding oligomerization domain protein-like receptor family pyrin domain containing 6 in water-avoidance stress mice.

OBJECTIVE: To investigate the effect of electroacupuncture (EA) on irritable bowel syndrome (IBS) in mice through regulating nucleotide-binding oligomerization domain protein-like receptor family pyrin domain containing 6 (NLRP6). METHODS: Water-avoidance stress (WAS) mice model was used to investigate the effects and the mechanism of EA. Abdominal withdrawal reflex test, open field test, and intestinal motility test were used to evaluate visceral sensitivity, anxiety, and intestinal motility in mice. The expressions of NLRP6, Mucin-2 (MUC2) and E-cadherin were determined using immunofluorescence and Western blotting assays. RESULTS: EA significantly upregulated the expression of NLRP6 in the intestine of mice. Moreover, EA increased the expressions of MUC2 and E-cadherin in WAS mice. CONCLUSION: Our study found that the relief of IBS symptoms by EA may involve the increase in the expression of NLRP6 in WAS mice.

Effects of supplementation with ß-carotene on the growth performance and intestinal mucosal barriers in layer-type cockerels.

ß-carotene is a robust modulator of mucosal barriers, and it can amplify the immunoglobulin A (IgA) response via the retinoic acid (RA)-mediated pathway. We investigated the influence of ß-carotene on intestinal barriers in layer-type cockerels. In this study, ß-carotene has a positive influence on growth performance and intestinal morphology. ß-carotene remarkably enhanced serum secretory immunoglobulin A (sIgA) levels, jejunal mucosal sIgA, and IgA concentrations. ß-Carotene significantly enhanced mRNA expression levels of IgA, CC chemokine receptor-9 (CCR9), polymeric immunoglobulin receptor (pIgR), and retinoic acid receptor α (RARα) in the ileal tissues and pIgR in the jejunal tissues. ß-Carotene improves mRNA expression of intestinal barrier-related proteins including: mucin-2 (MUC-2), zonula occludens-2 (ZO-2), occludins (OCLN), and zonula occludens-1 (ZO-1) in the ileal tissues. Moreover, ß-carotene decreased the levels of Escherichia coli and elevates the levels of Lactobacillus. The results indicate that ß-carotene can promote growth performance and contribute to the gradual development of intestinal barriers in Hyline Brown chicks. This study enriches our knowledge about the effects of ß-carotene on intestinal barrier and highlights a theoretical basis of ß-carotene application in the poultry industry.

Phytase dosing affects phytate degradation and Muc2 transporter gene expression in broiler starters.

This study was conducted to determine effects of high phytase use on growth performance, amino acid (AA) digestibility, intestinal phytate breakdown, and nutrient transporter expression in starter broiler chickens. Male Ross 308 chicks were allocated to 24 pens, at 15 birds/pen and assigned to one of 4 dietary treatments. Treatments were: a control diet (PCa+) that contained adequate levels of calcium (Ca) and phosphorus (P) for growing broiler chicks; a reduced Ca and P diet (PCa-:-1.5 g P/kg and -1.6 g Ca/kg), and 2 additional diets in which phytase was supplemented in the PCa- diet at 1,500 (PCa-Phy1500) and 3,000 (PCa-Phy3000) FTU/kg feed. A common starter diet was fed from day 1 to 8. From day 8 to 22, birds were fed the 4 experimental diets. On day 22, birds were killed for sample collection. From day 8 to 15, average daily gain and average daily feed intake were not different across treatments (P < 0.05) but gain-to-feed ratio (G:F) was reduced (P < 0.006) in the PCa- treatment compared with other treatments. There were no further performance differences, but a tendency of phytase treatments improving the overall G:F (P = 0.079; day 8-22). Up to both the duodenum-jejunum and ileum, phytate, P, and Ca disappearance were increased (P < 0.05) in the PCa-Phy1500 and PCa-Phy3000 treatments compared with PCa- treatment. Phytase dose dependently increased myoinositol (MI) concentration in the digesta from both the duodenum-jejunum and ileum (P < 0.001). The highest concentration of MI was found in the PCa-Phy3000 treatment. Plasma MI concentration was increased by phytase supplementation (P < 0.001). Prececal disappearance of Cys was lower (P < 0.05) in the PCa- treatment than in PCa1and PCa-Phy3000 treatment. Expression of MUC2 in the duodenum-jejunum was higher (P < 0.05) in the PCa-Phy3000 treatment than in other treatments. Phytase-induced hydrolysis of phytate led to elevated digesta and plasma MI concentrations and reduced digesta concentrations of phytate breakdown intermediates.

Trifostigmanoside I, an Active Compound from Sweet Potato, Restores the Activity of MUC2 and Protects the Tight Junctions through PKCα/ß to Maintain Intestinal Barrier Function.

Sweet potato (Ipomoea batata) is considered a superfood among vegetables and has been consumed for centuries. Traditionally, sweet potato is used to treat several illnesses, including diarrhea and stomach disorders. This study aimed to explore the protective effect of sweet potato on intestinal barrier function, and to identify the active compounds of sweet potato and their underlying mechanism of action. To this purpose, bioactivity-guided isolation, Western blotting, and immunostaining assays were applied. Interestingly, our bioactivity-guided approach enabled the first isolation and identification of trifostigmanoside I (TS I) from sweet potato. TS I induced mucin production and promoted the phosphorylation of PKCα/ß in LS174T human colon cancer cells. In addition, it protected the function of tight junctions in the Caco-2 cell line. These findings suggest that TS I rescued the impaired abilities of MUC2, and protected the tight junctions through PKCα/ß, to maintain intestinal barrier function.

Intestinal anti-inflammatory activity of xique-xique (Pilosocereus gounellei A. Weber ex K. Schum. Bly. Ex Rowl) juice on acetic acid-induced colitis in rats.

Inflammatory bowel disease (IBD) is characterized by severe mucosal damage in the intestine and a deregulated immune response. Natural products derived from plants that are rich in bioactive compounds are used by many patients with IBD. Xique-xique (Pilosocereus gounellei) is a cactus of the Caatinga family that has been used by the local population for food and medicinal purposes. The intestinal anti-inflammatory effect of xique-xique cladode juice was evaluated in the present study. A dose of 5 mL kg-1 had a protective effect on intestinal inflammation, with an improvement in macroscopic damage, and a decrease in pro-inflammatory markers and oxidative stress, in addition to preserving the colonic tissue. Immunohistochemical analysis revealed the downregulation of IL-17, NF-κB, and iNOS, and upregulation of SOCs-1, ZO-1, and MUC-2. These protective effects could be attributed to the phenolic compounds as well as the fibers present in xique-xique juice. Further studies are needed before suggesting the use of xique-xique juice as a new alternative for treating IBD.

Deletion of the Casp8 gene in mice results in ileocolitis, gut barrier dysfunction, and malassimilation, which can be partially attenuated by inulin or sodium butyrate.

Genetically modified mice have been successfully used as models for inflammatory bowel diseases; however, dietary effects were poorly examined. Here, we studied the impact of particular nutrients and supplements on gut functions related to the knockout of the epithelial caspase-8 gene. Caspase-8 knockout (Casp8∆IEC) and control (Casp8fl) mice were fed for 4 wk a control diet (CD) enriched with 10% inulin (CD-Inu) or 5% sodium butyrate (CD-But) while having free access to plain water or water supplemented with 30% fructose (+F). Body weight changes, intestinal inflammation, and selected markers for barrier function and of liver steatosis were assessed. Casp8∆IEC mice developed ileocolitis accompanied by changes in intestinal barrier morphology and reduced expression of barrier-related genes such as mucin-2 (Muc2) and defensins in the ileum and Muc2 in the colon. Casp8∆IEC mice fed a CD also showed impaired body weight gain compared with Casp8fl mice, which was even more pronounced in mice receiving water supplemented with fructose. Furthermore, we observed a marked liver steatosis and inflammation in some but not all Casp8∆IEC mice under a CD, which was on average similar to that observed in control mice under a fructose-rich diet. Hepatic lipid accumulation, as well as markers of ileal barrier function, but not intestinal pathohistology or body weight loss, were attenuated by diets enriched with inulin or butyrate, especially in the absence of fructose supplementation. Our data show that ileocolitis, barrier dysfunction, and malassimilation in Caspase-8 knockout mice can be partially attenuated by oral inulin or butyrate supplementation.NEW & NOTEWORTHY Genetic mouse models for ileocolitis are important to understand inflammatory bowel disease in humans. We examined dietetic factors that might aggravate or attenuate ileocolitis and related pathologies in such a model. Deletion of the caspase-8 gene results not only in ileocolitis but also in gut barrier dysfunction, liver steatosis, and malassimilation, which can be partially attenuated by oral inulin or sodium butyrate. Our data indicate that diet modifications can contribute to disease variability and therapy.

Synergic Laxative Effects of an Herbal Mixture of Liriope platyphylla, Glycyrrhiza uralensis, and Cinnamomum cassia in Loperamide-Induced Constipation of Sprague Dawley Rats.

Constipation is an acute or chronic illness attributed to various causes, ranging from lifestyle habits to side effects of a disease. To improve the laxative effects of some traditional medicines, herbal mixtures of Liriope platyphylla, Glycyrrhiza uralensis, and Cinnamomum cassia (LGC) were evaluated for their mechanism of action and therapeutic effects in loperamide (Lop)-induced constipated Sprague Dawley rats by examining alterations in excretion parameters, histological structure, mucin secretion, and related protein levels. Food intake and water consumption were constant for all animals. We observed that the Lop+LGC-treated group had significantly greater excretion of stool and urine than was observed in the Lop+Vehicle-treated group. Administration of LGC in the constipation model restored the intestinal transit ratio to normal levels, and increased the number of goblet cells, mucosal layer, and muscle thickness. Mucin secretion was greater in the Lop+LGC-treated group than in the Lop+Vehicle-treated group, and the expression of MUC2 and AQP8 genes were also increased. In addition, reverse transcription polymerase chain reaction and Western blot revealed an increase in the muscarinic acetylcholine receptors (mAChRs) in the Lop+LGC-treated group compared to the Lop+Vehicle-treated group. Furthermore, compared with the Lop+Vehicle-treated group, treatment with LGC reduced the phosphorylation of PKC and PI3K, and expression of Gα protein, but increased levels of IP3. Our results suggest that the traditional herbal mixture of LGC induces a potent laxative effect in Lop-induced constipation through mucosal tissue changes and mucin production. We also demonstrated that the laxative effect of LGC is closely related to the expression of mAChR and its downstream signals, suggesting the possibility of developing a constipation-laxative agent using LGC.

Dietary fiber sources and non-starch polysaccharide-degrading enzymes modify mucin expression and the immune profile of the swine ileum.

Due to their complex chemical and physical properties, the effects and mechanisms of action of natural sources of dietary fiber on the intestine are unclear. Pigs are commonly fed high-fiber diets to reduce production costs and non-starch polysaccharide (NSP)-degrading enzymes have been used to increase fiber digestibility. We evaluated the expression of mucin 2 (MUC2), presence of goblet cells, and ileal immune profile of pigs housed individually for 28 days and fed either a low fiber diet based on corn-soybean meal (CSB, n = 9), or two high fiber diets formulated adding 40% corn distillers' dried grains with solubles (DDGS, n = 9) or 30% wheat middlings (WM, n = 9) to CSB-based diet. Pigs were also fed those diets supplemented with a NSP enzymes mix (E) of xylanase, ß-glucanase, mannanase, and galactosidase (n = 8, 10, and 9 for CSB+E, DDGS+E and WM+E, respectively). Feeding DDGS and WM diets increased ileal MUC2 expression compared with CSB diet, and this effect was reversed by the addition of enzymes. There were no differences in abundance of goblet cells among treatments. In general, enzyme supplementation increased gene expression and concentrations of IL-1ß, and reduced the concentrations of IL-4, IL-17A and IL-11. The effects of diet-induced cytokines on modulating intestinal MUC2 were assessed in vitro by treating mouse and swine enteroids with 1 ng/ml of IL-4 and IL-1ß. In accordance with previous studies, treatment with Il-4 induced Muc2 and expansion of goblet cells in mouse enteroids. However, swine enteroids did not change MUC2 expression or number of goblet cells when treated with IL-4 or IL-1ß. Our results suggest that mucin and immune profile are regulated by diet in the swine intestine, but by mechanisms different to mouse, emphasizing the need for using appropriate models to study responses to dietary fiber in swine.

Nanoselenium prevents eimeriosis-induced inflammation and regulates mucin gene expression in mice jejunum.

BACKGROUND: Although elemental selenium has been found to be effective against Eimeria, no study has yet investigated the effects of selenium nanoparticles (SeNPs) on the Eimeria parasite. The aim of this study, therefore, was to evaluate the ameliorative effect of SeNPs compared with elemental selenium on mice jejunum infected with sporulated oocysts of Eimeria papillata. METHODS: The mice were divided into 4 groups, with the first being the non-infected, control group, and the second, third, and fourth groups being orally inoculated with 1,000 sporulated oocysts of E. papillata. The third and fourth groups also received, respectively, an oral dose of 0.1 mg/kg sodium selenite and 0.5 mg/kg SeNPs daily for 5 consecutive days. RESULTS: The infection induced severe histopathological jejunal damage, reflected in the form of destroyed jejunal mucosa, increased jejunal oxidative damage, a reduction in the number of jejunal goblet cells, and increased production of pro-inflammatory cytokines, quantified by real-time polymerase chain reaction. Treatment of mice with SeNPs significantly decreased the oocyst output in the feces by ~80%. Furthermore, the number of parasitic stages counted in stained jejunal paraffin sections was significantly decreased after the mice were treated with SeNPs. In addition, the number of goblet cells increased from 42.6±7.3 to 95.3±8.5 cells/10 villus-crypt units after treatment. By day 5 post-infection with E. papillata, SeNPs could be seen to have significantly increased the activity of glutathione peroxidase from 263±10 to 402.4±9 mU/mL. Finally, SeNPs were able to regulate the gene expression of mucin 2, interleukin 1ß, interleukin 6, interferon-γ, and tumor necrosis factor α in the jejunum of mice infected with E. papillata. CONCLUSION: The results collectively showed that SeNPs are more effective than sodium selenite with regard to their anti-coccidial, anti-oxidant, and anti-inflammatory role against eimeriosis induced in the jejunum of mice.

Effects of dietary threonine and immune stress on growth performance, carcass trait, serum immune parameters, and intestinal muc2 and NF-κb gene expression in Pekin ducks from hatch to 21 days.

An experiment was conducted to investigate the effects of different dietary threonine (Thr) levels and immune stress on Pekin ducklings' growth performance, carcass traits, serum immune parameters, and intestinal mucin 2 (MUC2) and nuclear factor kB (NF-κB) gene expressions. A total of 320 Pekin ducklings was randomly assigned to a 5 × 2 factorial arrangement of treatments. Each treatment group consisted of 4 replicate pens with 8 ducks per pen. Ducklings were fed 5 graded levels of Thr: 0.49, 0.56, 0.60, 0.65, and 0.76% from hatch to 21 d of age. At 11 d of age, ducks in the stressed groups were challenged with bovine serum albumin (BSA), and ducks in the unstressed groups were injected with normal saline water. The results showed that increasing Thr supplementation from 0.49 to 0.56% in the diet can improve BWG; feed consumption; weight and relative weight of breast and leg; weight of liver, bursa of Fabricius, spleen, and thymus; serum natural immune globulin A (IgA) concentration; and MUC2 gene expression in the ileum of 21-day-old Pekin ducks, significantly (P < 0.05). Immune stress with BSA had a significant effect on 21-day-old Pekin ducklings' BWG, feed consumption, and weight and relative weight of breast and thymus (P < 0.05), but no interaction between BSA and dietary Thr content was noticed in our experiment in 21-day-old Pekin ducks (P < 0.05). Dietary Thr requirements of the unstressed groups and stressed groups based on broken-line model analyses for ducks' BWG were 0.705 and 0.603%, respectively, and for ducks' feed consumption were 0.724 and 0.705%, respectively.

Effects of dietary threonine supplementation on intestinal barrier function and gut microbiota of laying hens.

The effects of supplemental dietary threonine (Thr) on laying performance, expression of intestinal mucin 2 (MUC2) and secretory IgA (sIgA), and intestinal microbiota of laying hens fed a low CP diet were investigated. A total of 240 Lohmann Brown laying hens, 28 wk of age, was allocated to 3 dietary treatments, each of which included 5 replicates of 16 hens. Hens were fed a control diet (16% CP), a low CP diet (14% CP), or a low CP diet supplemented with 0.3% L-Thr for 12 weeks. Chemical analyses of the diets for Thr are 0.49, 0.45, and 0.69%, respectively. Lowering dietary CP impaired egg production and egg mass of laying hens. Dietary Thr supplementation to the low CP diet increased (P < 0.05) egg production and egg mass. In addition, ileal sIgA contents and MUC2 and sIgA mRNA expression were increased (P < 0.05) by dietary Thr addition. Dietary CP reduction reduced (P < 0.05) intestinal bacterial diversity, whereas dietary Thr supplementation to the low CP diet recovered the bacteria diversity and significantly increased the abundance of potential beneficial bacteria. In conclusion, dietary Thr supplementation to a low CP diet could affect intestinal health and hence productivity via regulating intestinal mucin and sIgA expression, and microbial population of laying hens.

The effect of aspartate supplementation on the microbial composition and innate immunity on mice.

The study was conducted to investigate the changes of intestinal microbiota composition and innate immunity with different dietary dosages of aspartate (Asp) supplementation. Thirty-six female ICR mice were divided randomly to four groups and thereafter fed the basal diets (controls) or those supplemented with additional 0.5, 1.0 and 2.0% aspartate. After 2 week feeding, microbial composition in ileum and feces, gene expression of pro-inflammatory cytokine, and innate immune factors in ileum were determined. The ratio of Firmicutes: Bacteroidetes in ileum and feces decreased in 0.5 and 1.0% Asp-supplemented groups, whereas this ratio increased in feces in 2.0% Asp-supplemented group. Meanwhile, the gene expression of IL-17 and IFN-γ in ileum decreased in 1.0% Asp-supplemented group; the gene expression in ileum of Muc2 decreased in 0.5 and 1.0% Asp-supplemented groups. Dietary supplementation with 2.0% Asp enhanced the expression of pIgR and Crp1 as compared to the other three groups. The results indicated that dietary 1.0% Asp supplementation lowers the ratio of Firmicutes:Bacteroidetes, which affects the innate immunity by decreasing the gene expression of IL-17, IFN-γ, and Muc2 in ileum.

Saturated and Unsaturated Fatty Acids Differently Modulate Colonic Goblet Cells In Vitro and in Rat Pups.

BACKGROUND: High-fat diets induce intestinal barrier alterations and promote intestinal diseases. Little is known about the effects of long-chain fatty acids (LCFAs) on mucin 2 (MUC2) production by goblet cells, which are crucial for intestinal protection. OBJECTIVE: We investigated the effects of LCFAs on the differentiation of colonic goblet cells, MUC2 expression, and colonic barrier function. METHODS: Upon reaching confluence, human colonic mucus-secreting HT29-MTX cells were stimulated (21 d) with a saturated LCFA (palmitic or stearic acid), a monounsaturated LCFA (oleic acid), or a polyunsaturated LCFA (linoleic, γ-linolenic, α-linolenic, or eicosapentaenoic acid). In addition, rat pups underwent oral administration of oil (palm, rapeseed, or sunflower oil) or water (10 µL/g body weight, postnatal days 10-15). Subsequently, colon goblet cells were studied by Western blotting, reverse transcriptase-quantitative polymerase chain reaction, and immunohistochemistry and colonic transmucosal electrical resistance was measured by using Ussing chambers. RESULTS: In vitro, palmitic acid enhanced MUC2 production (140% of control) and hepatocyte nuclear factor 4α expression, whereas oleic, linoleic, γ-linolenic, α-linolenic, and eicosapentaenoic acids reduced MUC2 expression (at least -50% of control). All unsaturated LCFAs decreased the expression of human atonal homolog 1, a transcription factor controlling goblet cell differentiation (at least -31% vs. control). In vivo, rats fed palm oil had higher palmitic acid concentrations (3-fold) in their colonic contents and increased mucus granule surfaces in their goblet cells (>2-fold) than did all other groups. Palm oil also increased colonic transmucosal electrical resistance (245% of control), yet had no effect on occludin and zonula occludens-1 expression. In contrast, sunflower and rapeseed oils decreased goblet cell number when compared with control (at least -10%) and palm oil (at least -14%) groups. CONCLUSIONS: Palm oil in rat pups and palmitic acid in HT29-MTX cells increase the production of MUC2 and strengthen the intestinal barrier. In contrast, unsaturated LCFAs decrease MUC2 expression. These data should be taken into account in the context of preventive or therapeutic nutritional programs.

Favourable effects of grape seed extract on intestinal epithelial differentiation and barrier function in IL10-deficient mice.

The impairment in the rate of cell proliferation and differentiation leads to a negative consequence on the renewal of the intestinal epithelium, which is the aetiological factor of a number of digestive diseases. Grape seed extract (GSE), a rich source of proanthocyanidins, is known for its beneficial health effects. The present study evaluated the beneficial effects of GSE on colonic cell differentiation and barrier function in IL10-deficient mice. Female mice aged 6 weeks were randomised into two groups and given drinking-water containing 0 or 0.1 % GSE (w/v) for 12 weeks. GSE supplementation decreased serum TNF-α level and intestinal permeability, and increased the colonic goblet cell density that was associated with increased mRNA expression of mucin (Muc)-2. Immunohistochemical analyses showed lower accumulation of ß-catenin in the crypts of colon tissues of the GSE-supplemented mice, which was associated with a decreased mRNA expression of two downstream effectors of Wingless and Int (Wnt)/catenin signalling, myelocytomatosis oncogene protein (Myc) and cyclin D1 (Ccnd1). Consistently, GSE supplementation decreased the number of colonic proliferating cell nuclear antigen-positive cells, a well-known cell proliferation marker, and a weakened extracellular signal-regulated kinases 1 and 2 (ERK1/2) signalling. In summary, these data indicate that supplementation of 0.1 % GSE for 12 weeks improved gut barrier function and colonic cell differentiation in the IL10-deficient mice probably via inhibiting Wnt/ß-catenin pathway.

Dietary squid ink polysaccharide induces goblet cells to protect small intestine from chemotherapy induced injury.

Gastrointestinal mucositis induced by chemotherapy is associated with alterations of intestinal barrier function due to the potential damage induced by anti-cancer drugs on the epithelial cells. Goblet cells, an important epithelial lining in the intestine, contribute to innate immunity by secreting mucin glycoproteins. Employing a mouse model of chemotherapy induced intestinal mucosal immunity injury by cyclophosphamide, we demonstrated for the first time that polysaccharide from the ink of Ommastrephes bartramii (OBP) enhanced Cyto18, which is a mucin expression in goblet cells. The up-regulation of mucins by OBP relied on the augmented quantity of goblet cells, but not on the changes in the ultrastructure of endoplasmic reticulum (ER). Our results may have important implications for enhanced immunopotentiation function of functional OBP on intestinal mucosal immunity against intestinal disorders involving inflammation and infection.

Glutamine Improves Innate Immunity and Prevents Bacterial Enteroinvasion During Parenteral Nutrition.

BACKGROUND: Patients receiving parenteral nutrition (PN) are at increased risk of infectious complications compared with enteral feeding, which is in part explained by impaired mucosal immune function during PN. Adding glutamine (GLN) to PN has improved outcome in some clinical patient groups. Although GLN improves acquired mucosal immunity, its effect on innate mucosal immunity (defensins, mucus, lysozymes) has not been investigated. METHODS: Forty-eight hours following venous cannulation, male Institute of Cancer Research mice were randomized to chow (n = 10), PN (n = 12), or PN + GLN (n = 13) for 5 days. Small intestine tissue and luminal fluid were collected for mucin 2 (MUC2), lysozyme, cryptdin 4 analysis, and luminal interleukin (IL)-4, IL-10, and IL-13 level measurement. Tissue was also harvested for ex vivo intestinal segment culture to assess tissue susceptibility to enteroinvasive Escherichia coli. RESULTS: In both luminal and tissue samples, PN reduced MUC2 and lysozyme (P < .0001, respectively) compared with chow, whereas GLN addition increased MUC2 and lysozyme (luminal, P < .05; tissue, P < .0001, respectively) compared with PN alone. PN significantly suppressed cryptdin 4 expression, while GLN supplementation significantly enhanced expression. IL-4, IL-10, and IL-13 decreased significantly with PN compared with chow, whereas GLN significantly increased these cytokines compared with PN. Functionally, bacterial invasion increased with PN compared with chow (P < .05), while GLN significantly decreased enteroinvasion to chow levels (P < .05). CONCLUSIONS: GLN-supplemented PN improves innate immunity and resistance to bacterial mucosal invasion lost with PN alone. This work confirms a clinical rationale for providing glutamine for the protection of the intestinal mucosa.