Protective effect of Broussonetia papyrifera leaf polysaccharides on intestinal integrity in a rat model of diet-induced oxidative stress.

This study aimed to investigate the effect of Broussonetia papyrifera polysaccharides (BPP) on the jejunal intestinal integrity of rats ingesting oxidized fish oil (OFO) induced oxidative stress. Polysaccharides (Mw 16,956 Da) containing carboxyl groups were extracted from Broussonetia papyrifera leaves. In vitro antioxidant assays showed that this polysaccharide possessed antioxidant capabilities. Thirty-two male weaned rats were allocated into two groups orally infused BPP solution and PBS for 26 days, respectively. From day 9 to day 26, half of the rats in each group were fed food containing OFO, where the lipid peroxidation can induce intestinal oxidative stress. OFO administration resulted in diarrhea, decreased growth performance (p < 0.01), impaired jejunal morphology (p < 0.05) and antioxidant capacity (p < 0.01), increased the levels of ROS and its related products, IL-1ß and IL-17 (p < 0.01) of jejunum, as well as down-regulated Bcl-2/Bax (p < 0.01) and Nrf2 signaling (p < 0.01) of jejunum in rats. BPP gavage effectively alleviated the negative effects of OFO on growth performance, morphology, enterocyte apoptosis, antioxidant capacity and inflammation of jejunum (p < 0.05) in rats. In the oxidative stress model cell assay, the use of receptor inhibitors inhibited the enhancement of antioxidant capacity by BPP. These results suggested that BPP protected intestinal morphology, thus improving growth performance and reducing diarrhea in rats ingesting OFO. This protective effect may be attributed to scavenging free radicals and activating the Nrf2 pathway, which enhances antioxidant capacity, consequently reducing inflammation and mitigating intestinal cell death.

Yucca schidigera purpurea-sourced arabinogalactan polysaccharides augments antioxidant capacity facilitating intestinal antioxidant functions.

This study isolated and purified a novel homogeneous arabinogalactan polysaccharide from Yucca schidigera extract (YSE), unveiled its unique structure and explored its antioxidant function. Firstly, the antioxidant potential of YSE was demonstrated in piglet trials. A homogeneous polysaccharide with a molecular weight of 24.2 kDa, designated as Yucca schidigera polysaccharide B (YPB), was isolated and purified from YSE. The monosaccharide composition of YPB was Rha, Araf, Galp, and Glcp, whose molar percentages were 2.8 %, 11.6 %, 45.5 %, and 40.0 %, respectively. Methylation analysis combined with 1D and 2D nuclear magnetic resonance showed that YPB was a complex polysaccharide with a main glycosidic linkage pattern of →2)-α-ʟ-Rha-(1 â†’ 3)-ß-ᴅ-Galp-(1→3)-ß-ᴅ-Galp-(1 â†’ 3)-ß-ᴅ-Galp-(1 â†’ 3)-ß-ᴅ-Glcp-(1→, and branched Araf and Galp fragments were connected with the main chain through →3,6)-ß-ᴅ-Galp-(1→, →3,4)-ß-ᴅ-Glcp-(1→, and →2,4)-α-ʟ-Rha-(1→ linkages. Following the in vitro biochemical assays of bioactive components, YPB should be the contributor to the antioxidant activity in YSE. Based on the establishment of oxidative stress model, YPB exhibited strong antioxidant capacity and activated NRF2 pathway, and then provided protection against the damage induced oxidative stress in IPEC-J2 cells and rats. Further analysis with inhibitors found that this antioxidant effect was attributed to its interaction with epidermal growth factor receptor and mannose receptor, and stimulating PI3K/AKT pathway.

Iron overload induces colitis by modulating ferroptosis and interfering gut microbiota in mice.

BACKGROUND: Iron plays a pivotal role in various physiological processes, including intestinal inflammation, ferroptosis, and the modulation of the gut microbiome. However, the way these factors interact with each other is unclear. METHODS: Mice models were fed with low, normal and high iron diets to assess their impacts on colitis, ferroptosis and gut microbiota. Untargeted fecal metabolomics analysis, 16S rRNA sequencing, histopathology analysis, real-time quantitative PCR and western blot were performed to analyze the differences in the intestinal inflammatory response and understanding its regulatory mechanisms between low, normal and high iron groups. RESULTS: The iron overload changed the serum iron, colon iron and fecal iron. In addition, the iron overload induced the colitis, induced the ferroptosis and altered the microbiome composition in the fecal of mice. By using untargeted fecal metabolomics analysis to screen of metabolites in the fecal, we found that different metabolomics profiles in the fecal samples between iron deficiency, normal iron and iron overload groups. The correlation analysis showed that both of iron deficiency and overload were closely related to Dubosiella. The relationship between microbial communities (e.g., Akkermansia, Alistipes, and Dubosiella) and colitis-related parameters was highly significant. Additionally, Alistipes and Bacteroides microbial communities displayed a close association with ferroptosis-related parameters. Iron overload reduced the concentration of metabolites, which exert the anti-inflammatory effects (e.g., (+)-.alpha.-tocopherol) in mice. The nucleotide metabolism, enzyme metabolism and metabolic diseases were decreased and the lipid metabolism was increased in iron deficiency and iron overload groups compared with normal iron group. CONCLUSION: Iron overload exacerbated colitis in mice by modulating ferroptosis and perturbing the gut microbiota. Iron overload-induced ferroptosis was associated with NRF2/GPX-4 signaling pathway. Specific microbial taxa and their associated metabolites were closely intertwined with both colitis and ferroptosis markers.

The effect of dietary Yucca schidigera extract supplementation on productive performance, egg quality, and gut health in laying hens with Clostridium perfringens and coccidia challenge.

Yucca schidigera extract (YSE) is a green feed additive that is known to reduce toxic gas emissions and promote intestinal health in animal production. This study investigated the potential of dietary YSE supplementation to mitigate the negative effect of Clostridium perfringens and coccidia infection on productive performance and gut health in laying hens. A total of 48 Lohmann gray laying hens (35 wk of age) were randomly allotted to 1 of 2 groups (n = 24) fed with either a basal diet or a YSE-supplemented diet for 45 d. From d 36 to 45, half of the hens in each group were orally administrated with Clostridium perfringens type A and coccidia. This challenge impaired productive performance and egg quality (P < 0.05), destroyed jejunal morphology and functions (P < 0.05), induced jejunal epithelial cell apoptosis (P < 0.05), and downregulated the antioxidant capacity and Nrf2 pathway expression of jejunal mucosa (P < 0.05) in laying hens. Supplementing YSE in the laying hen diet, to some extents, improved productive performance and egg quality (P < 0.05), and alleviated the effect of challenge on morphology, functions, cell apoptosis, and antioxidant capacity in the jejunum (P < 0.05). Overall, the results suggested that dietary YSE supplementation might mitigate the negative effects of Clostridium perfringens and coccidia infection on gut health, and thereby improve the productive performance and egg quality of laying hens, possibly through enhancing the antioxidant capacity of the jejunum.

Effect of Dietary Lactose Supplementation on Growth Performance and Intestinal Epithelium Functions in Weaned Pigs Challenged by Rotavirus.

The purpose of this study was to investigate whether dietary lactose supplementation relieves rotavirus (RV)-induced diarrhea and gut dysfunction. Thirty-six crossbred weaned piglets were randomly allocated into three groups and fed diets containing 0, 4%, and 6% lactose for 20 days. On Day 15, half of the piglets in each group were orally infused with RV. RV infection impaired growth performance; induced severe diarrhea; decreased serum D-xylose concentration and morphology and sIgA level of jejunal mucosa; downregulated MUC1, MUC2, occludin, Bcl-2, IL-4, pBD3, pBD2, and pBD1 mRNA expression of jejunal mucosa and/or mesenteric lymph nodes; upregulated Bax, caspase-3, IL-2, IFN-γ, and IFN-ß mRNA expression of jejunal mucosa and/or mesenteric lymph nodes; and damaged microbiota and metabolites of cecal digesta in weaned piglets (p < 0.05). Dietary lactose supplementation improved nutrient digestibility and growth performance and relieved the negative influence of RV challenge on intestinal barrier function, mRNA expression of cytokines, and host defense peptides of jejunal mucosa and/or mesenteric lymph nodes in weaned piglets (p < 0.05). Dietary administration of 6% lactose tended to relieve diarrhea (p = 0.07). These results suggest that lactose in feed increases growth performance and has a tendency to alleviate RV-induced diarrhea, derived from the improvement of nutrient utilization, gut barrier function, and immunity.

Effects of dietary plant essential oil supplementation on growth performance, nutrient digestibility and meat quality in finishing pigs.

This study was aimed to explore the effects of dietary plant essential oil (PEO) supplementation on growth performance and meat quality in finishing pigs. A total of eighteen Duroc × Landrace × Yorkshire finishing barrows with an average initial body weight of 79.86 ± 1.94 kg were randomly assigned to CON group (fed with a basal diet) and PEO group (fed with the basal diet containing 200 mg/kg PEO) with 9 replicates per treatment. The trial lasted for 42 days. The results showed that dietary PEO supplementation significantly increased ADG during phase I (1-21 days) and the overall experimental period (p < 0.05), tended to increase ADFI in phase II (22-42 days) and the overall experimental period (p = 0.09), decreased F/G in phase I (p < 0.05) and tended to decrease F/G during the overall experimental period (p = 0.08). Meanwhile, compared to the CON group, the digestibility of DM, GE and EE in the PEO group was improved remarkably (p < 0.05). PEO supplementation also significantly improved T-AOC and lowered MDA content in longissimus dorsi (p < 0.05), tended to increase the activity of T-SOD (p = 0.06). A higher IMF content (p = 0.09) and a lower shear force (p = 0.08) of longissimus dorsi were found in the PEO group than that in CON group (p = 0.09). Furthermore, pigs fed the PEO diet showed higher mRNA abundances of GLUT4, LPL, CPT-1, CD36, FABP and LDL-R in the liver, and GLUT4 and FAS in the longissimus dorsi (p < 0.05). In conclusion, PEO fed to finishing pigs improved the growth performance and nutrient digestibility. Furthermore, PEO supplementation had the potential role to improve pork quality by increasing the antioxidant capacity and IMF content, and decreasing the shear force of longissimus dorsi to a certain extent.

Tannic acid extracted from gallnut prevents post-weaning diarrhea and improves intestinal health of weaned piglets.

This experiment was conducted to evaluate the effects of different levels of tannic acid (TA) on growth performance, diarrhea rate, nutrient digestibility and intestinal health in weaned piglets. A total of 180 weaned piglets (Duroc × Landrace × Yorkshire, 24 d of age, initial average BW = 7.77 ± 0.17 kg) were allotted to 5 groups (6 pigs/pen and 6 replicates/group) in a randomized complete block design according to their gender and body weight. Piglets were fed a basal diet, or the basal diet supplemented with 0.05%, 0.1%, 0.2% or 0.4% TA for 28 d. The supplementary levels of TA in the diets were obtained by adding tannalbin containing 51% TA and 40.17% protein. The results showed that, compared with the CON group, dietary TA did not affect ADFI, ADG or F:G, and linearly reduced (P < 0.01) the diarrhea rate and diarrhea index of piglets. There were no significant effects on apparent total tract digestibility (ATTD) in the 0.05%, 0.1% and 0.2% TA groups, while negative effects (P < 0.05) on apparent digestibility of crude protein and gross energy were observed in the 0.4% TA group. In addition, the nutrient digestibility of dry matter, crude protein and gross energy linearly decreased (P < 0.01) with the increase of TA dosage. Supplementation of TA increased (P < 0.05) the villus height of the duodenum and jejunum, as well as increased (P < 0.05) catalase (CAT) activity in serum. Dietary TA improved (P < 0.05) the Bacillus counts in cecal digesta. Further, TA significantly improved (P < 0.05) Bacillus counts and reduced (P < 0.05) the Escherichia coli counts in colonic digesta. The concentration of acetic acid, propionic acid, butyric acid and isovaleric acid in cecal digesta were significantly increased (P < 0.05). The mRNA expression level of zonula occludens-1 (ZO-1), zonula occludens-2 (ZO-2), and claudin-2 (CLDN-2) in the jejunum were greater (P < 0.05) in TA supplemented groups. The study showed that, compared to the control, TA prevented post-weaning diarrhea and improved intestinal health of weaned piglets, and the appropriate level of TA supplementation would be from 0.1% to 0.2%.

Fermented Diet Liquid Feeding Improves Growth Performance and Intestinal Function of Pigs.

Accumulating evidences demonstrate that fermented feed and liquid feeding exerted a great beneficial influence on growth performance and health in the pig industry. This experiment was conducted to evaluate the effects of fermented liquid feeding on the growth performance and intestinal function of pigs. Two hundred and eighty-eight 27-day-old weaned piglets (8.21 ± 0.27 kg) were randomly allocated to a control group (basal diet (CON)), an antibiotic group (basal diet supplemented with antibiotics (AB)) and a fermented liquid feeding group (basal diet with fermented liquid feeding (FLF)), with 6 replicates per treatment and 16 weaned piglets per replicate. The experiment lasted for 160 days. Fresh fecal samples were collected to evaluate the apparent total tract digestibility (ATTD) of nutrients from the last 4 days of each stage. The results are shown as follows: (1) Compared with the CON group, in the whole stage, the FLF diet significantly increased the final body weight (BW) and ADG of pigs (P < 0.05), and had a tendency to increase ADFI (P = 0.086), but had no effect on F/G. (2) The ATTD of dry matter (DM), crude protein (CP), ether extract (EE), crude ash (CA), crude fiber (CF), gross energy (GE), calcium (Ca) and total phosphorus (TP) in the FLF group was significantly elevated compared with those of the CON group at 8-20 kg stage (P < 0.05). Meanwhile, the ATTD of EE in the FLF group was significantly increased compared with that of the CON group at the 50-75 kg and 100-125 kg stages (P < 0.05), and the ATTD of Ca was higher than that of CON group at the 100-125 kg stage (P < 0.05). (3) Compared with that of the CON group, the level of serum leptin in the FLF group had a tendency to decrease (P = 0.054), the level of serum ghrelin in the FLF group was significantly elevated (P < 0.05) and the level of serum peptide YY in the FLF group was significantly decreased (P < 0.05). (4) The abundance of Lactobacillus in cecal and colonic digesta was observably enhanced in FLF group. Meanwhile, the abundance of Escherichia coli in cecal and colonic digesta were dramatically reduced in the FLF group compared with that in the CON and AB groups (P < 0.05). (5) The levels of acetic acid in colonic digesta were significantly increased in the FLF group (P < 0.05), and an increasing trend was observed in total VFA in colonic digesta compared with CON (P < 0.1). The levels of acetic acid in colonic digesta were significantly promoted in the FLF group compared with that of the AB group (P < 0.05). In conclusion, these results indicate that fermented liquid feeding improved the growth performance of pigs, which might be associated with gastrointestinal hormone and intestinal functions.

Infusion of short chain fatty acids in the ileum improves the carcass traits, meat quality and lipid metabolism of growing pigs.

Short chain fatty acids (SCFA) are the main products of indigestible carbohydrates undergoing bacterial fermentation in the hindgut, which are related to some physiological functions. This study was designed to investigate the effects of SCFA infusion by ileum on the carcass traits, meat quality and lipid metabolism of growing pigs. In a 28-day study, 24 growing barrows fitted with a T-cannula in distal ileum were divided into 4 treatments: 1) Control, 2) antibiotics (AB), 3) AB + 300 mL of SCFA1 solution (ABS1), 4) AB + 300 mL of SCFA2 solution (ABS2). The concentrations of acetate, propionate and butyrate in SCFA1 solution were respectively 61.84, 18.62 and 12.55 mmol/L, and in SCFA2 were respectively 40.08, 15.41 and 9.78 mmol/L. The results showed that the SCFA infusion increased the average daily feed intake and average daily gain of pigs (P < 0.05). Meanwhile, the SCFA treatments increased longissimus dorsi area (P < 0.05) and carcass weight (P = 0.058), decreased the drip loss of longissimus dorsi (P = 0.059), and reduced serum concentrations of triglyceride, total cholesterol and urea nitrogen (P < 0.05). Besides, the SCFA administration inhibited the mRNA expressions of fatty acid synthase (FAS) and acetyl-CoA carboxylase in longissimus dorsi (P < 0.05), the mRNA expression of FAS in the liver (P < 0.05), and the mRNA expression of hormone-sensitive lipase in abdominal fat (P < 0.05). Short chain fatty acid infusion also enhanced the mRNA expression of carnitine palmitoyltransferase-1α in the liver (P < 0.05), the mRNA expressions of peroxisome proliferator activated receptor gamma and lipoprotein lipase in abdominal fat (P < 0.05), and the mRNA expressions of free fatty acid receptor 2, glucose-6-phosphatase and phosphoenolpyruvate carboxykinase 1 in the colon (P < 0.05). These results suggested that SCFA administration in the ileum could improve the carcass traits and meat quality of growing pigs, which was possibly due to the fact that SCFA modulated lipid metabolism.

Sodium acetate, propionate, and butyrate reduce fat accumulation in mice via modulating appetite and relevant genes.

OBJECTIVES: Acetate, propionate, and butyrate, three of the most common short-chain fatty acids (SCFAs), can be produced when some non-digestible carbohydrates enter the large intestine and undergo bacterial fermentation. The aim of this study was to investigate the effects of these three SCFAs on appetite regulation and lipid metabolism and to determine the extent that appetite contributes to the beneficial influences of SCFAs. METHODS: In a 35-d study, 48 C57BL/6J male mice were randomly allocated to six groups: control; 5% sodium acetate; 5% sodium propionate; 5% sodium butyrate; pair fed 1; and pair fed 2. RESULTS: The study showed that dietary supplementation of sodium acetate reduced serum triacylglycerol, free fatty acids, glucose, and interleukin (IL)-6 levels (P < 0.05), increased serum glucagon-like peptide 1, and leptin levels (P < 0.05), downregulated the mRNA expressions of fatty acid synthase, peroxisome proliferator-activated receptor, and lipoprotein lipase (P < 0.05), and upregulated the mRNA expressions of fasting-induced adipose factor, nuclear respiratory factor 1, mitochondrial transcription factor A, tumor necrosis factor receptor superfamily member 9, cytochrome-C oxidase IV and free fatty acid receptor 2 (P < 0.05). Sodium propionate also reduced serum IL-1ß level (P < 0.05), increased serum peptide YY level (P < 0.05), downregulated the mRNA expressions of acetyl-coenzyme A carboxylase and sterol regulatory element-binding protein 1c (P < 0.05), and upregulated the mRNA expression of transmembrane protein 26 (P < 0.05). Additionally, sodium butyrate decreased average daily feed intake (P < 0.05) downregulated the mRNA expression of myosin heavy-chain (MyHc) Ⅱb (P < 0.05), and upregulated the mRNA expressions of lipase hormone-sensitive, MyHC Ⅱa and carnitine palmitoyltransferase-1α (P < 0.05). Moreover, the metabolic benefits of SCFAs were partly attributed to the reduction of feed intake. CONCLUSION: Taken together, SCFAs could reduce appetite and fat accumulation via modulating relevant genes and hormones, which might further illustrate the potential mechanisms that underlay the effects of SCFAs on lipid homeostasis and control of body weight.

Wheat bran fermented by mixed fungal strains improves the digestibility of crude fiber and may benefit the gut health without impacting the growth performance in weaned pigs.

This study was conducted to compare the effect of raw (WB) or mixed fungi-fermented wheat bran (FWB) on the growth, nutrient digestibility and intestinal health in weaned piglets. After the preparation of FWB, twenty-one cross-bred weaned piglets (7.20 ± 0.5 kg) were separated into three groups for a 40-day trial. The pigs in the control group were fed a basal corn-soybean meal diet. For the other two groups, 8% of expanded corn in the basal diet was replaced by equivalent WB or FWB. Results showed that the content of main nutrients and the composition of dietary fiber in FWB improved compared to that for WB. The digestibility of fiber in pigs fed FWB improved (P < 0.05) compared to the control and/or WB without affecting their growth performance. Both WB and FWB decreased the conditional pathogen (Streptococcus) or/and E. coli virulence factor (STb) in the colon compared to control (P < 0.05), and the ratio of villus height to crypt depth (VCR) in jejunum increased (P < 0.05). The number of goblet cells, the expression of MUC-1 and pBD1 in jejunal mucosa, and the proportion of blood CD4+ T lymphocyte subset improved (P < 0.05) by FWB rather than WB. Furthermore, although only WB elevated (P < 0.05) the concentration of butyrate in the colon, both WB and FWB increased the number of butyrate-producing bacteria (P < 0.05) compared to the control. Thus, the main advantage of FWB over WB in weaned pigs is its improvement in fiber digestibility.

The Nutritional Significance of Intestinal Fungi: Alteration of Dietary Carbohydrate Composition Triggers Colonic Fungal Community Shifts in a Pig Model.

Carbohydrates represent the most important energy source in the diet of humans and animals. A large number of studies have shown that dietary carbohydrates (DCHO) are related to the bacterial community in the gut, but their relationship with the composition of intestinal fungi is still unknown. Here, we report the response of the colonic fungal community to different compositions of DCHO in a pig model. Three factors, ratio (2:1, 1:1, and 1:2) of amylose to amylopectin (AM/AP), level of nonstarch polysaccharides (NSP; 1%, 2%, and 3%), and mannan-oligosaccharide (MOS; 400, 800, and 1,200 mg/kg body weight), were considered according to an L9 (34) orthogonal design to form nine diets with different carbohydrate compositions. Sequencing based on an Illumina HiSeq 2500 platform targeting the internal transcribed spacer 1 region showed that the fungal community in the colon of the pigs responded to DCHO in the order of MOS, AM/AP, and NSP. A large part of some low-abundance fungal genera correlated with the composition of DCHO, represented by Saccharomycopsis, Mrakia, Wallemia, Cantharellus, Eurotium, Solicoccozyma, and Penicillium, were also associated with the concentration of glucose and fructose, as well as the activity of ß-d-glucosidase in the colonic digesta, suggesting a role of these fungi in the degradation of DCHO in the colon of pigs. Our study provides direct evidence for the relationship between the composition of DCHO and the fungal community in the colon of pigs, which is helpful to understand the function of gut microorganisms in pigs.IMPORTANCE Although fungi are a large group of microorganisms along with bacteria and archaea in the gut of monogastric animals, the nutritional significance of fungi has been ignored for a long time. Our previous studies revealed a distinct fungal community in the gut of grazing Tibetan pigs (J. Li, D. Chen, B. Yu, J. He, et al., Microb Biotechnol 13:509-521, 2020, https://doi.org/10.1111/1751-7915.13507) and a close correlation between fungal species and short-chain fatty acids, the main microbial metabolites of carbohydrates in the hindgut of pigs (J. Li, Y. Luo, D. Chen, B. Yu, et al., J Anim Physiol Anim Nutr 104:616-628, 2020, https://doi.org/10.1111/jpn.13300). These groundbreaking findings indicate a potential relationship between intestinal fungi and the utilization of DCHO. However, no evidence directly proves the response of intestinal fungi to changes in DCHO. Here, we show a clear alteration of the colonic fungal community in pigs triggered by different compositions of DCHO simulated by varied concentrations of starch, nonstarch polysaccharides (NSP), and oligosaccharides. Our results highlight the potential involvement of intestinal fungi in the utilization of nutrients in monogastric animals.

Active or Autoclaved Akkermansia muciniphila Relieves TNF-α-Induced Inflammation in Intestinal Epithelial Cells Through Distinct Pathways.

Intestinal inflammation is a major threat to the health and growth of young animals such as piglets. As a next-generation probiotics, limited studies have shown that Akkermansia muciniphila could alleviate inflammation of intestinal epithelial cells (IECs). In this study, a TNF-α-induced inflammatory model of IPEC-J2 cells, the intestinal porcine enterocytes, was built to evaluate the effects of active or inactive A. muciniphila on the inflammation of IECs. The viability of IPEC-J2 cells was the highest when treated with active (108 copies/mL) or inactive (109 copies/mL) A. muciniphila for 7.5 h (P < 0.01). Treated with 20 ng/mL of TNF-α and followed by a treatment of A. muciniphila, the mRNA level of proinflammatory cytokines (IL-8, IL-1ß, IL-6 and TNF-α) was remarkably reduced (P < 0.05) along with the increased mRNA level of tight junction proteins (ZO-1 and Occludin, P < 0.05). Flow cytometry analysis showed that active or inactive A. muciniphila significantly suppressed the rate of the early and total apoptotic of the inflammatory IPEC-J2 cells (P < 0.05). According to results of transcriptome sequencing, active and inactive A. muciniphila may decline cell apoptosis by down-regulating the expression of key genes in calcium signaling pathway, or up-regulating the expression of key genes in cell cycle signaling pathway. And the bacterium may alleviate the inflammation of IECs by down-regulating the expression of PI3K upstream receptor genes. Our results indicate that A. muciniphila may be a promising NGP targeting intestinal inflammation.

l-Isoleucine Administration Alleviates DSS-Induced Colitis by Regulating TLR4/MyD88/NF-κB Pathway in Rats.

Inflammatory bowel disease (namely, colitis) severely impairs human health. Isoleucine is reported to regulate immune function (such as the production of immunoreactive substances). The aim of this study was to investigate whether l-isoleucine administration might alleviate dextran sulfate sodium (DSS)-induced colitis in rats. In the in vitro trial, IEC-18 cells were treated by 4 mmol/L l-isoleucine for 12 h, which relieved the decrease of cell viability that was induced by TNF-α (10 ng/ml) challenge for 24 h (P <0.05). Then, in the in vivo experiment, a total of 44 Wistar rats were allotted into 2 groups that were fed l-isoleucine-supplemented diet and control diet for 35 d. From 15 to 35 d, half of the rats in the 2 groups drank the 4% DSS-adding water. Average daily gain, average daily feed intake and feed conversion of rats were impaired by DSS challenge (P <0.05). Drinking the DSS-supplementing water also increased disease activity index (DAI) and serum urea nitrogen level (P <0.05), shortened colonic length (P <0.05), impaired colonic enterocyte apoptosis, cell cycle, and the ZO-1 mRNA expression (P <0.05), increased the ratio of CD11c-, CD64-, and CD169-positive cells in colon (P <0.05), and induced extensive ulcer, infiltration of inflammatory cells, and collagenous fiber hyperplasia in colon. However, dietary l-isoleucine supplementation attenuated the negative effect of DSS challenge on growth performance (P <0.05), DAI (P <0.05), colonic length and enterocyte apoptosis (P <0.05), and dysfunction of colonic histology, and downregulated the ratio of CD11c-, CD64-, and CD169-positive cells, pro-inflammation cytokines and the mRNA expression of TLR4, MyD88, and NF-κB in the colon of rats (P <0.05). These results suggest that supplementing l-isoleucine in diet improved the DSS-induced growth stunting and colonic damage in rats, which could be associated with the downregulation of inflammation via regulating TLR4/MyD88/NF-κB pathway in colon.

Tannic acid prevents post-weaning diarrhea by improving intestinal barrier integrity and function in weaned piglets.

BACKGROUND: Tannic acid (TA) is potential to reduce diarrhea in weaning pigs, but knowledge about the influence of TA on intestinal barrier integrity and function is still scarce. This experiment was conducted to investigate the effects of dietary TA supplementation on growth performance, diarrhea rate, intestinal barrier integrity and function of weaned pigs. METHODS: A total of 108 crossbred (Duroc × Landrace × Yorkshire) piglets, with an initial average body weight of 6.60 ± 0.27 kg, were allotted to 3 groups (6 pigs/pen and 6 replicates/group) in a randomized complete block design according to their gender and body weight. Piglets were fed the basal diet with 0 (control, CON), 0.2% and 1.0% TA, respectively. The trial lasted for 28 d. RESULTS: Compared with the CON group, dietary 0.2% and 1.0% TA supplementation didn't affect ADFI, ADG and F:G (P > 0.05), but reduced diarrhea rate, diarrhea index and diarrhea score of piglets (P < 0.05), reduced diamine oxidase (DAO) activity and D-lactic acid concentration in serum (P < 0.01). The higher occludin expression and localization were observed in the duodenum, jejunum and ileum after supplementation with 0.2% or 1.0% TA (P < 0.05). Adding 0.2% TA to diet significantly decreased crypt depth, increased villus height/crypt depth ratio in the duodenum (P < 0.05), and dietary 1.0% TA tended to decrease crypt depth (P < 0.10) and significantly decreased villus height (P < 0.05) of the ileum. Moreover, lower malondialdehyde content in the ileum was detected in the pigs fed 1.0% TA (P < 0.05). In the duodenum, both 0.2% and 1.0% TA groups had higher occludin (OCLN) mRNA and 0.2% TA group had higher zonula occludens-2 (ZO-2) level (P < 0.05). Meanwhile, dietary 1.0% TA supplementation tended to up-regulate OCLN mRNA levels in the jejunum (P < 0.10) and 0.2% TA supplementation tended to up-regulate zonula occludens-1 (ZO-1) mRNA levels in the ileum (P < 0.10). CONCLUSION: In conclusion, dietary supplementation of 0.2% or 1.0% TA could effectively alleviate post-weaning diarrhea without altering growth performance in weaned piglets, which might be achieved by improving intestinal barrier integrity and function.

Dietary pectic oligosaccharide supplementation improves rat reproductive performance via regulating intestinal volatile fatty acids during middle gestation.

As a kind of green additive, pectic oligosaccharide (POS) may regulate some physiological functions of animals, such as gut health, antioxidant capacity, immunity and lipid metabolism. This study aimed to identify whether POS administration can improve maternal reproduction, and to determine the possible metabolism. A total of 48 pregnant Wistar rats randomly allotted into 2 groups, and each group was fed a diet supplemented with 0 or 800 mg/kg of POS. Pectic oligosaccharide administration increased rat born number (P < 0.05), did not affect rat embryo number on d 7 of gestation, but increased rat fetus number on d 14 of gestation (P < 0.05). On d 14 of gestation, POS treatment improved Lactobacillus and Bifidobacterium populations and volatile fatty acid concentrations of cecal digesta (P < 0.05), hormone (progesterone and nitric oxide) and cytokine (interleukin 2) concentrations of serum (P < 0.05), and antioxidant capacity of serum (increased total antioxidant capacity and decreased malondialdehyde) and placenta (increased total superoxide dismutase, decreased malondialdehyde) (P < 0.05) in pregnant rats. These results suggest that POS administration improved rat reproduction via decreasing fetus loss in middle gestation. This was due to the increased volatile fatty acid concentrations in rat gut improving hormone and inflammatory-cytokine productions, and antioxidant capacity.

Capsulized faecal microbiota transplantation ameliorates post-weaning diarrhoea by modulating the gut microbiota in piglets.

Early weaning-induced stress causes diarrhoea, thereby reducing the growth performance of piglets. Gut bacterial dysbiosis has emerged as a leading cause of post-weaning diarrhoea. The present study aimed to investigate the effect of capsulized faecal microbiota transplantation (FMT) on the gut bacterial community, immune response and gut barrier function of piglets. Thirty-two weaned barrows were randomly divided into two groups. The recipient group was inoculated orally with capsulized faecal microbiota of healthy Tibetan pigs during the whole period of the trial, while the control group was given an empty capsule. The feed-to-gain ratio, diarrhoea ratio, and histological damage score of recipient piglets were significantly decreased. FMT treatment significantly increased the colon length of piglets. Furthermore, the relative abundances of Firmicutes, Euryarchaeota, Tenericutes, Lactobacillus, and Methanobrevibacter in the colon of recipient piglets were increased, and the relative abundances of Campylobacter and Proteobacteria were significantly decreased compared with those in the control group. CD4+ lymphocytes and CD4+/CD8+ ratio in the peripheral blood of recipient piglets were significantly increased. FMT treatment increased the IL-4 and IL-10 levels and decreased the TNF-α and INF-γ levels in the colonic tissue of piglets. The recipient piglets' mRNA expression of TLR2, TLR8, NF-κB, and iNOS was significantly regulated. In addition, FMT significantly enhanced the gene expression of ZO-1. Overall, treatment with capsulized FMT ameliorated diarrhoea in piglets, with significant effects on limiting colon inflammatory responses, downregulating the TLR signalling pathway and the gene expression of iNOS, and strengthening intestinal barrier function by modulating the constituents of the gut microbiota.

The fungal community and its interaction with the concentration of short-chain fatty acids in the caecum and colon of weaned piglets.

In sharp contrast to the numerous studies on bacteria, very little is known about the fungal community in mammalian gut. Recent studies on human and mice highlighted the importance of "mycobiota" in the metabolism and gut health of host, but our knowledge on the fungal composition and distribution in swine gut is very limited. In the current study, the fungal community in the caecal and colonic digesta from five weaned piglets was analysed based on an Illumina HiSeq 2500 platform targeting the internal transcribed spacer 1 region, and its relationship with the concentration of short-chain fatty acids was also investigated. Results revealed that the fungal profile in the caecal and colonic digesta of the piglets was distinct, and the caecal fungal diversity was significantly higher (p < .05). Basidiomycota and Ascomycota were the two predominant fungal phyla in the caecum and colon of the piglets. Comparing with that in colon, the abundance of Saccharomycopsis, Wallemia and Mrakia showed significantly higher (p < .05), and the abundance of Scheffersomyces, Aspergillus, Penicillium and Mucor was significantly lower in the caecum (p < .05). Canonical correspondence analysis showed a correlation between the fungal community and the concentration of isobutyrate, isovalerate, propionate and acetate in the digesta samples. Spearman's correlation indicated that the low-abundance genera, Fusarium, Plectosphaerella and Metarhizium, were positively correlated with of isobutyrate (p < .05), while Xeromyces were negatively correlated with acetate (p < .05), and Cornuvesica was negatively correlated with both acetate and propionate (p < .05). Results illuminated a probable interaction between the fungal composition and the bacterial degradation of protein and complex carbohydrates in the diet. These findings would be helpful to enhance our understanding of fungi in swine gut and provide a foundation for future work on the function of mycobiota in pigs.

COX-2 inhibition by celecoxib in epithelial ovarian cancer attenuates E-cadherin suppression through reduced Snail nuclear translocation.

Elevated cyclooxygenase-2 (COX-2) closely associates with tumor progression and distant metastasis in various human cancers. However, the role of COX-2 in epithelial ovarian cancer (EOC), and its mechanistic details, remain poorly understood. In the present study, we tested hypothesis that COX-2 induces loss of expression of E-cadherin, with resulting promotion of cancer cells' invasiveness in ovarian cancer. First, we observed an inverse relationship between COX-2 and E-cadherin expression as COX-2 was enhanced but E-cadherin was decreased in surgically-resected specimens of EOC. Depletion of COX-2, by celecoxib treatment, resulted in attenuated nuclear translocation of Snail, and, in turn, significantly increased E-cadherin in EOC cell line SKOV3, which was established to be due to the reduced binding of Snail onto E-cadherin promoter. Such COX-2 inhibition resulted in reduced invasion of EOC cells, similar to what was achieved through Snail silencing in SKOV as well as ES-2 EOC cells. These results suggest that COX-2-Snail signaling plays a critical role in regulation of E-cadherin and might provide insights into mechanisms for paracrine inflammation-mediated aggressiveness in EOC.