Selenium deficiency increased duodenal permeability and decreased expression of antimicrobial peptides by activating ROS/NF-κB signal pathway in chickens.

Selenium (Se) is an essential trace element for the body. Various organs of the body, including the intestine, are affected by its deficiency. Se deficiency can induce oxidative stress and inflammatory responses in the intestine. It can also increase intestinal permeability and decrease intestinal immune function in mammals. However, the detailed studies, conducted on the intestinal molecular mechanisms of Se deficiency-induced injury in poultry, are limited. This study explored the adverse effects of Se deficiency on intestinal permeability and its mechanism. A Se-deficient chicken model was established, and the morphological changes in the chicken duodenum tissues were observed using a light microscope and transmission electron microscope (TEM). Western blotting, qRT-PCR, and other methods were used to detect the expression levels of selenoproteins, oxidative stress indicators, inflammatory factors, tight junction (TJ) proteins, antimicrobial peptides, and other related indicators in intestinal tissues. The results showed that Se deficiency could decrease the expression levels of selenoproteins and antioxidant capacity, activate the nuclear factor kappa-B (NF-κB) pathway, cause inflammation, and decrease the expression levels of TJ proteins and antimicrobial peptides in the duodenum tissues. The study also demonstrated that Se deficiency could increase intestinal permeability and decrease antimicrobial peptides via reactive oxygen species (ROS)/NF-κB. This study provided a theoretical basis for the scientific prevention and control of Se deficiency in poultry. Se deficiency decreased the expression levels of selenoproteins and increased ROS levels to activate the NF-κB pathway, resulting in the production of pro-inflammatory cytokines, reducing the expression levels of TJ protein, and weakening the expression of antimicrobial peptides, which contributed to the higher intestinal permeability. Oxidative stress weakened the expression of antimicrobial peptides.

[Effect of electroacupuncture at "Zusanli" (ST 36) on duodenal mast cells, NGF and NTRK1 in rats with functional dyspepsia].

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Zusanli" (ST 36) on duodenal mast cells, nerve growth factor (NGF) and neurotrophic tyrosine kinase receptor type 1 (NTRK1), and to explore the mechanism of electroacupuncture at Zusanli (ST 36) on functional dyspepsia (FD). METHODS: Sixty SPF-grade 10-day-old SD rats were randomly divided into a normal group, a model group, a ketotifen group and an EA group, 15 rats in each group. The FD model was prepared by iodoacetamide combined with rat tail clamping method in the model group, the ketotifen group and the EA group. The rats in the ketotifen group were injected intraperitoneally with ketotifen (1 mg•kg-1•d-1) for 7 days; the rats in the EA group were treated with EA at bilateral "Zusanli" (ST 36), with disperse-dense wave, frequency of 2 Hz/50 Hz and intensity of 0.5 mA, 20 min each time, once a day for 14 days. The gastric emptying rate and small intestinal propulsion rate in each group were observed; the morphology of duodenal mucosa was observed by HE staining; the toluidine blue staining was used to observe the number and degranulation of mast cells in duodenal mucosa; the protein and mRNA expressions of NGF, NTRK1 in duodenum were detected by Western blot and real-time PCR; the level of interleukin-1ß (IL-1ß) in duodenum was measured by ELISA. RESULTS: Compared with the normal group, the gastric emptying rate and small intestinal propulsion rate in the model group were decreased (P<0.01); compared with the model group, the gastric emptying rate and small intestinal propulsion rate in the ketotifen group and the EA group were increased (P<0.01); the small intestinal propulsion rate in the EA group was higher than that in the ketotifen group (P<0.01). In the model group, local defects in duodenal mucosa were observed with a small amount of inflammatory cell infiltration; no obvious abnormality was found in duodenal mucosa of the other groups. Compared with the normal group, the mast cells of duodenal mucosa in the model group were increased significantly with significant degranulation; compared with the model group, the mast cells of duodenal mucosa in the ketotifen group and the EA group were decreased significantly, and the degranulation was not obvious. Compared with the normal group, the protein and mRNA expressions of NGF, NTRK1 as well as the level of IL-1ß in duodenum in the model group were increased (P<0.01); compared with the model group, the protein and mRNA expressions of NGF, NTRK1 as well as the levels of IL-1ß in duodenum in the ketotifen group and the EA group were decreased (P<0.01, P<0.05); compared with the ketotifen group, the mRNA expression of NGF, as well as the protein and mRNA expressions of NTRK1 in duodenum in the EA group were decreased (P<0.05, P<0.01). CONCLUSION: EA at "Zusanli" (ST 36) could inhibit the activation of duodenal mast cells and regulate the expressions of NGF and its receptor to improve the low-grade inflammatory response of duodenum, resulting in treatment effect on FD.

Dietary methionine source alters the lipidome in the small intestinal epithelium of pigs.

Methionine (Met) as an essential amino acid has key importance in a variety of metabolic pathways. This study investigated the influence of three dietary Met supplements (0.21% L-Met, 0.21% DL-Met and 0.31% DL-2-hydroxy-4-(methylthio)butanoic acid (DL-HMTBA)) on the metabolome and inflammatory status in the small intestine of pigs. Epithelia from duodenum, proximal jejunum, middle jejunum and ileum were subjected to metabolomics analysis and qRT-PCR of caspase 1, NLR family pyrin domain containing 3 (NLRP3), interleukins IL1ß, IL8, IL18, and transforming growth factor TGFß. Principal component analysis of the intraepithelial metabolome revealed strong clustering of samples by intestinal segment but not by dietary treatment. However, pathway enrichment analysis revealed that after L-Met supplementation polyunsaturated fatty acids (PUFA) and tocopherol metabolites were lower across small intestinal segments, whereas monohydroxy fatty acids were increased in distal small intestine. Pigs supplemented with DL-HMTBA showed a pronounced shift of secondary bile acids (BA) and sphingosine metabolites from middle jejunum to ileum. In the amino acid super pathway, only histidine metabolism tended to be altered in DL-Met-supplemented pigs. Diet did not affect the expression of inflammation-related genes. These findings suggest that dietary supplementation of young pigs with different Met sources selectively alters lipid metabolism without consequences for inflammatory status.

Four AAs increase DMT1 abundance in duodenal brush-border membrane vesicles and enhance iron absorption in iron-deprived mice.

Iron-deficiency anemia is common worldwide and typically treated by oral iron supplementation. Excess enteral iron, however, may cause pathological outcomes. Developing new repletion approaches is thus warranted. Previous experimentation revealed that select amino acids (AAs) induce trafficking of transporters onto the enterocyte brush-border membrane (BBM) and enhance electrolyte absorption/secretion. Here, we hypothesized that certain AAs would increase the abundance of the main intestinal iron importer, divalent metal-ion transporter 1 (DMT1), on the BBM of duodenal enterocytes, thus stimulating iron absorption. Accordingly, all 20 AAs were screened using an ex vivo duodenal loop/DMT1 western blotting approach. Four AAs (Asp, Gln, Glu, and Gly) were selected for further experimentation and combined into a new formulation. The 4 AAs stimulated 59Fe transport in mouse duodenal epithelial sheets in Ussing chambers (∼4-fold; P < .05). In iron-deprived mice, oral intragastric administration of the 4 AA formulation increased DMT1 protein abundance on the enterocyte BBM by ∼1.5-fold (P < .05). The 4 AAs also enhanced in vivo 59Fe absorption by ∼2-fold (P < .05), even when ∼26 µg of cold iron was included in the transport solution (equal to a human dose of ∼73 mg). Further experimentation using DMT1int/int mice showed that intestinal DMT1 was required for induction of iron transport by the 4 AAs. Select AAs thus enhance iron absorption by inducing DMT1 trafficking onto the apical membrane of duodenal enterocytes. We speculate that further refinement of this new 4 AA formulation will ultimately allow iron repletion at lower effective doses (thus mitigating negative side effects of excess enteral iron).

Effects of different selenium sources on duodenum and jejunum tight junction network and growth performance of broilers in a model of fluorine-induced chronic oxidative stress.

The protective effects and underlying molecular mechanisms of sodium selenite (SS) and selenomethionine (SM) against chronic oxidative stress-induced duodenum and jejunum tight junction (TJ) network disturbance and growth inhibition of broilers were investigated in the current experiment. At the age of 1 d, 720 Lingnan Yellow broiler chicks were allocated to 4 experimental diets (with 6 replicates per diet and 30 birds per replicate) and offered either a control diet (fluorine [F] 23 mg/kg, control [CoN] group) or test diets (800 mg/kg F, high F [HF] group; 800 mg/kg F+0.15 mg selenium [Se]/kg as SS [SS group] or SM [SM group]) for 56 d. The results showed that HF group could induce chronic oxidative stress and subsequently increased (P < 0.05) proinflammatory cytokines levels of duodenum and jejunum in comparison with the CoN group. Increased proinflammatory cytokines levels of HF group promoted myosin light chain kinase (MLCK) transcription, thus leading to a decrease (P < 0.05) in TJ proteins expression of duodenum and jejunum when compared with the CoN group. A reduction of TJ proteins expression destroyed the TJ structures in the HF group, which in turn increased intestinal mucosal permeability of duodenum and jejunum and ultimately induced growth inhibition of broilers. Dietary Se supplementation could ameliorate HF-induced duodenum and jejunum TJ network impairment and growth retardation of broilers, potentially by increasing (P < 0.05) the glutathione peroxidase and thioredoxin reductase activities, reducing (P < 0.05) the reactive oxygen species and malondialdehyde levels, regulating the secretion of proinflammatory cytokines, and mediating the transcription level of MLCK in the duodenum and jejunum. Additionally, our data also suggested that the protective effects of SM were superior to those of SS. This study will provide a theoretical basis for developing SM into an efficient protective agent for intestinal mucosal barrier in poultry.

Gut HIF2α signaling is increased after VSG, and gut activation of HIF2α decreases weight, improves glucose, and increases GLP-1 secretion.

Gastric bypass and vertical sleeve gastrectomy (VSG) remain the most potent and durable treatments for obesity and type 2 diabetes but are also associated with iron deficiency. The transcription factor HIF2α, which regulates iron absorption in the duodenum, increases following these surgeries. Increasing iron levels by means of dietary supplementation or hepatic hepcidin knockdown does not undermine the effects of VSG, indicating that metabolic improvements following VSG are not secondary to lower iron levels. Gut-specific deletion of Vhl results in increased constitutive duodenal HIF2α signaling and produces a profound lean, glucose-tolerant phenotype that mimics key effects of VSG. Interestingly, intestinal Vhl deletion also results in increased intestinal secretion of GLP-1, which is essential for these metabolic benefits. These data demonstrate a role for increased duodenal HIF2α signaling in regulating crosstalk between iron-regulatory systems and other aspects of systemic physiology important for metabolic regulation.

Identification, tissue distribution, and anorexigenic effect of amylin in Siberian sturgeon (Acipenser baeri).

Amylin is a 37-amino acid polypeptide that has been found to be involved in feeding regulation in some mammals, birds, and goldfish. We cloned amylin of Siberian sturgeon and detected its distribution pattern in 15 tissues. The expression levels in the periprandial period (pre-and post-feeding), the changes in the food intake, and the expression levels of related appetite factors after the intraperitoneal injection of amylin were detected. The expression of amylin was found to be the highest in the hypothalamus. Compared with 1 h pre-feeding, the expression levels of amylin in the hypothalamus and duodenum were increased significantly 1 h post-feeding. Compared with the control group (saline), intraperitoneal injection of 50 ng/g, 100 ng/g, and 200 ng/g of amylin significantly inhibited food intake at 1 h post injection, but not at 3 h and 6 h. The injection of 50 ng/g, 100 ng/g, and 200 ng/g amylin significantly inhibited the cumulative feed. After 1 h of 50 ng/g amylin injection, the levels of MC4R and somatostatin in the hypothalamus increased significantly, while the levels of amylin and NPY decreased significantly. The levels of CCK in the valvular intestine were increased significantly. Insulin in the duodenum was also increased significantly, but there was no significant change in ghrelin in the duodenum. These results show that amylin inhibits feeding in Siberian sturgeon by down-regulating the appetite-stimulating factor NPY and up-regulating the appetite-suppressing factors somatostatin, MC4R, CCK, and insulin. This study provides a theoretical basis for studying the feeding function and action mechanisms of amylin in Siberian sturgeon.

L-Theanine Regulates the Abundance of Amino Acid Transporters in Mice Duodenum and Jejunum via the mTOR Signaling Pathway.

The intestine is a key organ for the absorption of amino acids. L-theanine (LTA) is a structural analog of glutamine and a characteristic non-protein amino acid found in tea (Camellia sinensis) that regulates lipid and protein metabolism. The present study explored the role of LTA in intestinal amino acid absorption, protein synthesis, and its mechanisms. Overall, our findings suggest that LTA supplementation not only affects serum alkaline phosphatase (AKP), total protein (TP), and urea nitrogen (BUN) levels, but it also upregulates the mRNA and protein expression of amino acid transporters (EAAT3, EAAT1, 4F2hc, y+LAT1, CAT1, ASCT2, and B0AT1), and activates the mTOR signaling pathway. The downstream S6 and S6K1 proteins are regulated, and the expression of amino acid transporters is regulated. These findings suggest that LTA increases intestinal AA absorption, promotes protein metabolism, and increases nitrogen utilization by upregulating AAT expression, activating the mTOR signaling pathway, and phosphorylating the mTOR downstream proteins S6 and S6K1.

Effect of electroacupuncture at "Zusanli" (ST 36) on duodenal mast cells, NGF and NTRK1 in rats with functional dyspepsia / 中国针灸

OBJECTIVE@#To observe the effect of electroacupuncture (EA) at "Zusanli" (ST 36) on duodenal mast cells, nerve growth factor (NGF) and neurotrophic tyrosine kinase receptor type 1 (NTRK1), and to explore the mechanism of electroacupuncture at Zusanli (ST 36) on functional dyspepsia (FD).@*METHODS@#Sixty SPF-grade 10-day-old SD rats were randomly divided into a normal group, a model group, a ketotifen group and an EA group, 15 rats in each group. The FD model was prepared by iodoacetamide combined with rat tail clamping method in the model group, the ketotifen group and the EA group. The rats in the ketotifen group were injected intraperitoneally with ketotifen (1 mg•kg-1•d-1) for 7 days; the rats in the EA group were treated with EA at bilateral "Zusanli" (ST 36), with disperse-dense wave, frequency of 2 Hz/50 Hz and intensity of 0.5 mA, 20 min each time, once a day for 14 days. The gastric emptying rate and small intestinal propulsion rate in each group were observed; the morphology of duodenal mucosa was observed by HE staining; the toluidine blue staining was used to observe the number and degranulation of mast cells in duodenal mucosa; the protein and mRNA expressions of NGF, NTRK1 in duodenum were detected by Western blot and real-time PCR; the level of interleukin-1β (IL-1β) in duodenum was measured by ELISA.@*RESULTS@#Compared with the normal group, the gastric emptying rate and small intestinal propulsion rate in the model group were decreased (P<0.01); compared with the model group, the gastric emptying rate and small intestinal propulsion rate in the ketotifen group and the EA group were increased (P<0.01); the small intestinal propulsion rate in the EA group was higher than that in the ketotifen group (P<0.01). In the model group, local defects in duodenal mucosa were observed with a small amount of inflammatory cell infiltration; no obvious abnormality was found in duodenal mucosa of the other groups. Compared with the normal group, the mast cells of duodenal mucosa in the model group were increased significantly with significant degranulation; compared with the model group, the mast cells of duodenal mucosa in the ketotifen group and the EA group were decreased significantly, and the degranulation was not obvious. Compared with the normal group, the protein and mRNA expressions of NGF, NTRK1 as well as the level of IL-1β in duodenum in the model group were increased (P<0.01); compared with the model group, the protein and mRNA expressions of NGF, NTRK1 as well as the levels of IL-1β in duodenum in the ketotifen group and the EA group were decreased (P<0.01, P<0.05); compared with the ketotifen group, the mRNA expression of NGF, as well as the protein and mRNA expressions of NTRK1 in duodenum in the EA group were decreased (P<0.05, P<0.01).@*CONCLUSION@#EA at "Zusanli" (ST 36) could inhibit the activation of duodenal mast cells and regulate the expressions of NGF and its receptor to improve the low-grade inflammatory response of duodenum, resulting in treatment effect on FD.

Zinc Status Index (ZSI) for Quantification of Zinc Physiological Status.

Zinc (Zn) deficiency is estimated to affect over one billion (17%) of the world's population. Zn plays a key role in various cellular processes such as differentiation, apoptosis, and proliferation, and is used for vital biochemical and structural processes in the body. Widely used biomarkers of Zn status include plasma, whole blood, and urine Zn, which decrease in severe Zn deficiency; however, accurate assessment of Zn status, especially in mild to moderate deficiency, is difficult, as studies with these biomarkers are often contradictory and inconsistent. Thus, sensitive and specific biological markers of Zn physiological status are still needed. In this communication, we provide the Zn status index (ZSI) concept, which consists of a three-pillar formula: (1) the LA:DGLA ratio, (2) mRNA gene expression of Zn-related proteins, and (3) gut microbiome profiling to provide a clear assessment of Zn physiological status and degree of Zn deficiency with respect to assessing dietary Zn manipulation. Analysis of five selected studies found that with lower dietary Zn intake, erythrocyte LA:DGLA ratio increased, mRNA gene expression of Zn-related proteins in duodenal and liver tissues was altered, and gut microbiota populations differed, where the ZSI, a statistical model trained on data from these studies, was built to give an accurate estimation of Zn physiological status. However, the ZSI needs to be tested and refined further to determine its full potential.

Olive oil cake extract stabilizes the physiological condition of lipopolysaccharide-challenged piglets by reducing oxidative stress and inflammatory responses and modulating the ileal microbiome.

Olives are a rich source of compounds with antioxidant and anti-inflammatory activities. This study was designed to investigate whether a standardized olive cake extract was able to alleviate oxidative stress, inflammation and intestinal villus damage in a model of lipopolysaccharide (LPS)-challenged piglets. Thirty weaned piglets (6.9 ± 0.9 kg) were assigned to five groups using a randomized complete block design. Piglets were fed a basal diet before intraperitoneal (i.p.) injection of physiological saline (C); fed a basal diet alone (CL) or fed a basal diet plus an olive cake extract (OL), antibiotics (AL), or olive cake extract plus antibiotics (OAL) before i.p. injection of LPS. The feeding period lasted for 2 weeks. Piglets were euthanized 4 h after the LPS injection. Systemic oxidative and inflammatory status and intestinal morphology were evaluated. LPS challenge significantly lowered the serum levels of GSH-Px, SOD and ALB and increased the serum concentration of MDA, NO, LDH, ALT, AST, TNF-α, IL-6, DAO and D-xylose (P < 0.05), as extracted from the comparison of piglets in the C and CL groups. Intestinal morphology was altered in the duodenum and ileum, displaying that the CL group had significantly lower villus height (VH), higher crypt depth (CD) and lower VH/CD compared with the control group (P < 0.05). Moreover, feed supplementation was able to partially mitigate the negative effects of LPS challenge in all groups (OL, AL, and OAL), as evidenced by the significantly increased serum levels of GSH-Px, SOD, ALB and IL-10 and decreased concentration of MDA, NO, LDH, ALT, AST, TNF-α, IL-6, DAO and D-xylose, compared with the CL group (P < 0.05). Alterations in intestinal morphology were also prevented and the OL, AL, and OAL groups had significantly lower CD and higher VH/CD compared with the CL group (P < 0.05), both in the ileum and duodenum. Furthermore, the positive effect in the relative abundance of intestinal Lactobacillus and Clostridium at the genus level was also observed for the OL group compared to the CL group. In summary, dietary supplementation with an olive cake extract stabilized the physiological condition of piglets subjected to an acute LPS challenge by reducing oxidative stress and the inflammatory status, improving intestinal morphology and increasing the abundance of beneficial intestinal bacteria. This trial was registered at Zhejiang University (http://www.lac.zju.edu.cn) as No. ZJU20170529.

Comparative Evaluation of Sucrosomial Iron and Iron Oxide Nanoparticles as Oral Supplements in Iron Deficiency Anemia in Piglets.

Iron deficiency is the most common mammalian nutritional disorder. However, among mammalian species iron deficiency anemia (IDA), occurs regularly only in pigs. To cure IDA, piglets are routinely injected with high amounts of iron dextran (FeDex), which can lead to perturbations in iron homeostasis. Here, we evaluate the therapeutic efficacy of non-invasive supplementation with Sucrosomial iron (SI), a highly bioavailable iron supplement preventing IDA in humans and mice and various iron oxide nanoparticles (IONPs). Analysis of red blood cell indices and plasma iron parameters shows that not all iron preparations used in the study efficiently counteracted IDA comparable to FeDex-based supplementation. We found no signs of iron toxicity of any tested iron compounds, as evaluated based on the measurement of several toxicological markers that could indicate the occurrence of oxidative stress or inflammation. Neither SI nor IONPs increased hepcidin expression with alterations in ferroportin (FPN) protein level. Finally, the analysis of the piglet gut microbiota indicates the individual pattern of bacterial diversity across taxonomic levels, independent of the type of supplementation. In light of our results, SI but not IONPs used in the experiment emerges as a promising nutritional iron supplement, with a high potential to correct IDA in piglets.

Hepcidin and Iron Deficiency in Women One Year after Sleeve Gastrectomy: A Prospective Cohort Study.

Iron deficiency with or without anemia, needing continuous iron supplementation, is very common in obese patients, particularly those requiring bariatric surgery. The aim of this study was to address the impact of weight loss on the rescue of iron balance in patients who underwent sleeve gastrectomy (SG), a procedure that preserves the duodenum, the main site of iron absorption. The cohort included 88 obese women; sampling of blood and duodenal biopsies of 35 patients were performed before and one year after SG. An analysis of the 35 patients consisted in evaluating iron homeostasis including hepcidin, markers of erythroid iron deficiency (soluble transferrin receptor (sTfR) and erythrocyte protoporphyrin (PPIX)), expression of duodenal iron transporters (DMT1 and ferroportin) and inflammatory markers. After surgery, sTfR and PPIX were decreased. Serum hepcidin levels were increased despite the significant reduction in inflammation. DMT1 abundance was negatively correlated with higher level of serum hepcidin. Ferroportin abundance was not modified. This study shed a new light in effective iron recovery pathways after SG involving suppression of inflammation, improvement of iron absorption, iron supply and efficiency of erythropoiesis, and finally beneficial control of iron homeostasis by hepcidin. Thus, recommendations for iron supplementation of patients after SG should take into account these new parameters of iron status assessment.

Plant origin prebiotics affect duodenal brush border membrane functionality and morphology, in vivo (Gallus Gallus).

The intra-amniotic administration approach has been used to evaluate the effects of plant origin prebiotics on intestinal health and on brush border membrane functionality and morphology. Prebiotics are fermentable dietary fibers, which can positively affect the host by selectively stimulating the growth and activity of colon bacteria, thus improving intestinal health. The consumption of prebiotics increases digestive tract motility, which leads to hyperplasia and/or hypertrophy of intestinal cells, increasing nutrient digestive and absorptive surface area. This review collates information about the effects and relationship between prebiotic consumption on small intestinal brush border membrane functionality and morphology by utilizing the intra-amniotic administration approach. To date, research has shown that the intra-amniotic administration of prebiotics affects the expression of key brush border membrane functional proteins, intestinal surface area (villi height/width), and goblet cell number/size. These effects may improve brush border membrane functionality and digestive/absorptive capabilities.

Dietary supplementation with Bacillus subtilis and xylo-oligosaccharides improves growth performance and intestinal morphology and alters intestinal microbiota and metabolites in weaned piglets.

The present study was conducted to investigate the effects of dietary supplementation with Bacillus subtilis (BS) and xylo-oligosaccharides (XOS) on growth performance, intestinal morphology, intestinal microbial community, and metabolites of weaned piglets. One hundred and twenty-eight piglets were randomly allocated to one of four groups, including a control group (basal diet), BS group (basal diet + 500 g t-1 BS), XOS group (basal diet + 250 g t-1 XOS), and BS + XOS group (basal diet + 500 g t-1 BS + 250 g t-1 XOS). Dietary BS and XOS were mixed with the basal diet. All groups had eight replicates with four piglets per replicate. The experiment lasted for 42 days. The results showed that dietary XOS supplementation increased the ADFI and ADG, while decreasing the F/G. Dietary BS or XOS supplementation improved the intestinal morphology of weaned piglets by increasing the villus height and the ratio of villus height to crypt depth in the ileum. In addition, dietary XOS supplementation increased the concentrations of butyrate in the ileum and tryptamine and spermidine in the colon, while decreasing the concentration of indole in the colon compared with the control group. Dietary BS supplementation increased the colonic concentrations of butyrate, tryptamine, and cadaverine, while decreasing the concentration of skatole compared with the control group. The LEfSe analysis identified 16 biomarkers in the ileum of the BS group. The intestinal microbiota alterations of weaned piglets indicated that dietary BS or XOS supplementation could improve intestinal health by increasing the gut microbial diversity and altering the relative abundances of different bacterial species. Moreover, Spearman's correlation analysis revealed the potential link between gut microbiota alterations and metabolite changes of weaned piglets. These findings suggest that dietary XOS supplementation could alone improve the growth performance, while dietary BS or XOS and BS with XOS supplementation could influence intestinal health by altering the intestinal morphology, microbial community, and metabolites of weaned piglets. Meanwhile, there were interactions between BS and XOS in intestinal metabolites.

Selenium enriched Bacillus subtilis yb-1114246 activated the TLR2-NF-κB1 signaling pathway to regulate chicken intestinal ß-defensin 1 expression.

The aim of this study was to investigate the effects and potential signaling pathway of selenium-enriched Bacillus subtilis (SEBS) on beta defensin 1 (BD1) expression in chicken intestine. Chinese Huainan Partridge chickens (500 individuals) were randomly allocated into five groups, including control, inorganic Se, B. subtilis, SEBS, and a mixture of Se and B. subtilis (Se-BS). After 56 d of feeding, chicken ileal mucous membranes were harvested to detect differences in expression of BD1. The results indicated that BD1 was produced in intestinal crypt cells and secreted into the lumen through the villi brush border. BD1 was up-regulated in distal ileum segments colonized by SEBS and B. subtilis. Chicken primary intestinal crypt cells were cultured and grouped into control, inorganic Se, B. subtilis, SEBS, and Se-BS treatments to identify the receptor of B. subtilis. Results indicated that B. subtilis and SEBS were recognized by toll-like receptor 2 (TLR2), stimulating the NF-κB1 signaling pathway to increase expression of BD-1, which was further enhanced when combined with Se. Pro-inflammatory cytokines TNF-α, IL-1ß, and IL-6 were up-regulated with B. subtilis supplementation, and inhibited under the action of Se. In conclusion, B. subtilis and SEBS were recognized by the TLR2 receptor in the ileal mucous membrane, which activated the TLR2-MyD88-NF-κB1 signaling pathway to upregulate BD1 expression. In addition, Se enhanced recognition of B. subtilis and reduced levels of pro-inflammatory factors caused by estrogenic B. subtilis supplementation.

Quantification of P-Glycoprotein in the Gastrointestinal Tract of Humans and Rodents: Methodology, Gut Region, Sex, and Species Matter.

Intestinal efflux transporters affect the gastrointestinal processing of many drugs but further data on their intestinal expression levels are required. Relative mRNA expression and relative and absolute protein expression data of transporters are commonly measured by real-time polymerase chain reaction (RT-PCR), Western blot and mass spectrometry-based targeted proteomics techniques. All of these methods, however, have their own strengths and limitations, and therefore, validation for optimized quantification methods is needed. As such, the identification of the most appropriate technique is necessary to effectively translate preclinical findings to first-in-human trials. In this study, the mRNA expression and protein levels of the efflux transporter P-glycoprotein (P-gp) in jejunal and ileal epithelia of 30 male and female human subjects, and the duodenal, jejunal, ileal and colonic tissues in 48 Wistar rats were quantified using RT-PCR, Western blot and liquid chromatography-tandem mass spectrometry (LC-MS/MS). A similar sex difference was observed in the expression of small intestinal P-gp in humans and Wistar rats where P-gp was higher in males than females with an increasing trend from the proximal to the distal parts in both species. A strong positive linear correlation was determined between the Western blot data and LC-MS/MS data in the small intestine of humans (R2 = 0.85). Conflicting results, however, were shown in rat small intestinal and colonic P-gp expression between the techniques (R2 = 0.29 and 0.05, respectively). In RT-PCR and Western blot, an internal reference protein is experimentally required; here, beta-actin was used which is innately variable along the intestinal tract. Quantification via LC-MS/MS can provide data on P-gp expression without the need for an internal reference protein and consequently, can give higher confidence on the expression levels of P-gp along the intestinal tract. Overall, these findings highlight similar trends between the species and suggest that the Wistar rat is an appropriate preclinical animal model to predict the oral drug absorption of P-gp substrates in the human small intestine.

Effects of corn grain endosperm type and fineness of grind on site of digestion, ruminal digestion kinetics, and flow of nitrogen fractions to the duodenum in lactating dairy cows.

Our objective was to evaluate effects of corn grain endosperm type and fineness of grind on feed intake, feeding behavior, and productive performance of lactating cows. Eight ruminally and duodenally cannulated Holstein cows in mid lactation (130 ± 42 d in milk; mean ± standard deviation) were used in a duplicated 4 × 4 Latin square design with 21-d periods. A 2 × 2 factorial arrangement of treatments was used with main effects of corn grain endosperm type (floury or vitreous) and fineness of grind (fine or medium). Rations included alfalfa silage, corn treatments, protein supplement, minerals, and vitamins and were formulated to contain 29% starch, 27% neutral detergent fiber, 18.2% forage neutral detergent fiber, and 18% crude protein. Corn grain treatments supplied 86.2% of dietary starch. Endosperm was 25% vitreous for the floury treatment and 66% vitreous for the vitreous treatment. The floury treatment increased rate of starch degradation by 94% (19.2 vs. 9.9%/h) and decreased rate of starch passage by 38% (16.1 vs. 25.8%/h), increasing apparent ruminal starch digestibility by 117% (53.7 vs. 24.7%). The floury treatment increased total-tract starch digestibility by 8% (92.2 vs. 85.1%) despite 37% lower postruminal starch digestion for the floury treatment compared with vitreous corn (38.4 vs. 60.7% of starch intake). Fine grind size increased apparent ruminal starch digestibility by 52% (47.2 vs. 31.1%) compared with medium grind size by increasing the rate of starch degradation by 105% (19.5 vs. 9.5%/h) with no effect on rate of starch passage. However, total-tract starch digestibility was not affected by fineness of grind because postruminal starch digestibility was 37% greater for medium compared with fine grind size (57.2 vs. 41.9% of starch intake). Endosperm type did not affect flow of nitrogen (N) fractions to the duodenum or microbial N efficiency, whereas fine grind size increased duodenal flow of nonammonia N by increasing duodenal flow of microbial N by 22% compared with medium grind size (438 vs. 359 g/d) but did not affect apparent total-tract N digestibility. No interactions were detected for any measure of starch digestion, ruminal N metabolism, or flow of N fractions to the duodenum. Endosperm type greatly affected ruminal and total-tract starch digestibility independent of the fineness of grind of corn grain with no effects on flow of N fractions.

In vivo bioavailability and in vitro toxicological evaluation of the new butyric acid releaser N-(1-carbamoyl-2-phenyl-ethyl) butyramide.

A large body of evidence suggests that supplementation of butyric acid exerts beneficial intestinal and extra-intestinal effects. Unfortunately, unpleasant sensorial properties and unfavourable physico-chemical properties strongly limit its use in food supplements and foods for medicinal purposes. N-(1-carbamoyl-2-phenyl-ethyl) butyramide (FBA) is a new butyric acid releaser in solid form with neutral sensorial properties. The aim of this investigation is to provide preliminary information on its pharmacokinetic and toxicological properties through the study of a) in vivo bioavailability of FBA administered by oral gavage to male and female Swiss CD1 mice in comparison with sodium butyrate, b) the influence of digestion on FBA stability through an in vitro simulated oro-gastro-duodenal digestion process, and c) in vitro toxicological profile by means of the Ames Test and Micronucleus Test. The results reveal that FBA is a good butyric acid releaser, being able to increase butyrate serum concentration in a dose and time dependent manner in both male and female mice with a pharmacokinetic profile similar to that obtained from sodium butyrate as such. These data are confirmed by investigating the influence of digestion on FBA, which undergoes extensive hydrolysis following oro-gastro-duodenal digestion, especially in duodenal conditions, with a residual concentration of less than 10% of the initial FBA concentration. Finally, in the Ames and Micronucleus Tests, FBA does not show any in vitro genotoxicity as it is non mutagenic in the Ames Test and results to be unable to induce chromosome breaks in the Micronucleus Test. In conclusion, FBA is a new butyric acid releaser that can overcome the disadvantages of butyric acid while maintaining the same pharmacokinetic properties and safety profile, as shown by the results of the preliminary in vitro toxicological studies performed in this investigation.

The potential of porcine ex vivo platform for intestinal permeability screening of FcRn-targeted drugs.

Conventionally, the intestinal permeability of drugs is evaluated using cell monolayer models that lack morphological, physiological and architectural features, as well as realistic neonatal Fc receptor (FcRn) expression. In addition, it is time-consuming, expensive and excessive to use a large number of mice for large-scale screening of FcRn-targeted candidates. For preclinical validation, it is critical to use suitable models that mimic the human intestine; the porcine ex vivo model is widely used for intestinal permeability studies, due to its physiological and anatomical similarities to humans. This study intended to analyze the potential to measure the intestinal permeability of FcRn-targeted substances using a porcine ex vivo platform, which is able to analyze 96 samples at the same time. In addition, the platform allows the screening of FcRn-targeting substances for transmucosal delivery, taking into consideration (cross-species) receptor-ligand binding kinetics. After analyzing the morphology of the porcine tissue, the FcRn expression across the gastrointestinal tract was verified. By studying the stomach, duodenum and jejunum, it was demonstrated that FcRn expression is maintained for up to 7 days. When evaluating the duodenum permeability of free engineered human albumin variants, it was shown that the variant with the mutation K573P (KP) is more efficiently transported. Given this, the porcine ex vivo platform was revealed to be a potential model for the screening of FcRn-targeted oral drug formulations.