Supplementing the early diet of broilers with soy protein concentrate can improve intestinal development and enhance short-chain fatty acid-producing microbes and short-chain fatty acids,especially butyric acid

Background:Research on nutrition in early-life commonly focuses on the maturation of the intestine because the intestinal system is crucial for ensuring continued growth.To explore the importance of early nutrition regulation in animals,soy protein concentrate(SPC)was added to the early diet of broilers to investigate its effects on amino acid digestibility,intestinal development,especially intestinal microorganisms,and broiler metabolites.A total of 192 oneday-old Arbor Acres(AA)male broilers were randomly assigned to two experimental treatments with 8 replicates of 12 birds.The control group was fed a basal diet(control),and the treatment group was fed a basal diet supplemented with 12%SPC(SPC12)during the first 10 d(starter phase).From d 11 to 21(grower phase)and d 22 to 42(finisher phase),a basal diet was fed to both treatment groups.Results:SPC reduced the pH value and acid-binding capacity of the starter diet(P<0.05,d 10);SPC in the early diet enhanced the gizzard weight(P<0.05,d 10 and d 42)and the ileum weight(P<0.05,d 10)and decreased the weight and length of the jejunum(P<0.05,d 10)and the relative length of the duodenum and jejunum(P<0.05,d 10).At the same time,SPC enhanced villus height(P<0.05,d 10)and muscle thickness in the jejunum and ileum(P<0.05,d 10)and increased the number of goblet cells in the duodenum(P<0.05,d 10).Meanwhile,SPC increased the Chao1 index and the ACE index(P<0.05,d 10)and altered the composition of caecal microflora at d 10.SPC also increased the relative abundance of Alistipes,Anaerotruncus,Erysipelatoclostridium,Intestinimonas and Flavonifractor bacteria(P<0.05,d 10).At the same time,the concentrations of caecal butyric acid and total short-chain fatty acids(SCFAs)were also increased in the SPC12 group(P<0.05,d 10).Conclusions:In summary,the results showed that supplementing the starter diet of broilers with SPC has a significant effect on the early development of the intestine and the microflora.

Effects of different forms of yeast Saccharomyces cerevisiae on growth performance,intestinal development,and systemic immunity in early-weaned piglets

The present study was conducted to determine effects of different forms of yeast （Saccharomyces cerevisiae, strain Y200007） on the growth performance, intestinal development, and systemic immunity in early-weaned piglets. A total of 96 piglets （14-d old, initial average body weight of 4.5 kg） were assigned to 4 dietary treatments： （1） basa diet without yeast （Control）; （2） basal diet supplemented with 3.00 g/kg live yeast （LY）; （3） basal diet supplemented with 2.66 g/kg heat-killed whole yeast （HKY）; and （4） basal diet supplemented with 3.00 g/kg superfine yeast powders （SFY）. Diets and water were provided ad libitum to the piglets during 3-week experiment. Growth performance of piglets was measured weekly. Samples of blood and small intestine were collected at days 7 and 21 of experiment. Dietary supplementation with LY and SFY improved G：F of piglets at days ]-21 of the experiment （P 〈 0.05） compared to Control group. Serum concentrations of growth hormone （GH）, triiodothyronine （T3）, tetraiodothyronine （T4）, and insulin growth factor 1 （iGF-1） in piglets at day 21 of the experiment were higher when fed diets supplemented with LY and SFY than those in Control group （P 〈 0.05）. Compared to Control group, contents of serum urea nitrogen of piglets were reduced by the 3 yeast-supplemented diets （P 〈 0.05）. Diets supplemented with LY increased villus height and villus-to-crypt ratio in duodenum and jejunum of piglets （P 〈 0.05） compared to other two groups at day 7 of the experiment. Feeding diets supplemented with LY and SFY increased （P 〈 0.05） serum concentrations of IgA, IL-2, and IL-6 levels in piglets compared to Control. The CD4＋/CD8＋ ratio and proliferation of T-lymphocytes in piglets fed diets supplemented with LY were increased compared to that of Control group at day 7 of the experiment （P 〈 0.05）. In conclusion, dietary supplementation with both LY and SFY enhanced feed conversion, small intestinal development, and systemic immunity in early-weaned piglets, with better improvement in feed conversion by dietary supplementation with LY, while dietary supplementation with SFY was more effective in increasing systemic immune functions in early-weaned piglets.

Methionine sources and genotype affect embryonic intestinal development,antioxidants,tight junctions,and growth-related gene expression in chickens

Methionine(Met)is an essential and first limiting amino acid in the poultry diet that plays a significant role in chicken embryonic development and growth.The present study examined the effect of in ovo injection of DL-Met and L-Met sources and genotypes on chicken embryonic-intestinal development and health.Fertilized eggs of the two genotypes,TETRA-SL layer hybrid(TSL)—commercial layer hybrid and Hungarian Partridge colored hen breed(HPC)—a native genotype,were randomly distributed into four treatments for each genotype.The treatment groups include the following:1)control non-injected eggs(NoIn);2)saline-injected(SaIn);3)DL-Met injected(DLM);and 4)L-Met injected(LM).The in ovo injection was carried out on 17.5 d of embryonic development;after hatching,eight chicks per group were sacrificed,and the jejunum was extracted for analysis.The results showed that both DLM and LM groups had enhanced intestinal development as evidenced by increased villus width,villus height,and villus area(P<0.05)compared to the control.The DLM group had significantly reduced crypt depth,glutathione(GSH)content,glutathione S-transferase 3 alpha(GST3),occludin(OCLN)gene expression and increased villus height to crypt depth ratio in the TSL genotype than the LM group(P<0.05).The HPC genotype has overexpressed insulin-like growth factor 1(IGF1)gene,tricellulin(MD2),occludin(OCLN),superoxide dismutase 1(SOD1),and GST3 genes than the TSL genotype(P<0.05).In conclusion,these findings showed that in ovo injection of Met enhanced intestinal development,and function,with genotypes responding differently under normal conditions.Genotypes also influenced the expression of intestinal antioxidants,tight junction,and growth-related genes.

Microencapsulated Lactobacillus plantarum promotes intestinal development through gut colonization of layer chicks

The effects of Lactobacillus plantarum in microencapsulation(LPM)on intestinal development in layer chicks were investigated in this study,as well as the colonization of L.plantarum in the gut.A total of 480 healthy Hy-Line Brown layer chicks at 0 d old were randomly divided into 4 groups(8 replicates each treatment),and the diets of these birds were supplemented with nothing(control),L.plantarum(0.02 g/kg feed;109 CFU/kg feed),LPM(1.0 g/kg feed;109 CFU/kg feed)and wall material of LPM(WM;0.98 g/kg feed),respectively.Compared to control,LPM improved growth performance and intestinal development of layer chicks,evidenced by significantly increased body weight,average daily gain,average daily feed intake,villus height,villus height/crypt depth,as well as weight and length of the duodenum,jejunum and ileum(P<0.05).These results could be attributed to the increased colonization of L.plantarum in the gut,which was verified by significant increases in lactic acid content,viable counts in chyme and mucosa(P<0.05),as well as a visible rise in number of strains labeled with fluorescein isothiocyanate.Meanwhile,the relative abundances of Lactobacillus and Bifidobacterium significantly increased in response to microencapsulated L.plantarum supplementation(P<0.05),accompanied by the significant up-regulation of colonization related genes(P<0.05),encoding solute carrier family,monocarboxylate transporter,activin A receptor,succinate receptor and secretogranin II.To sum up,microencapsulated L.plantarum supplementation promoted intestinal development,which could be attributed to the enhancement of L.plantarum colonization in the intestine through the mutual assistance of Bifidobacterium and interactions with colonization related transmembrane proteins.

Effects ofβ-alanine on intestinal development and immune performance of weaned piglets

Beta-alanine is an important amino acid involved in several metabolic reactions in the body.The study aimed to investigate the effect ofβ-alanine supplementation on intestinal development and the immune performance of weaned piglets.Thirty-two 21-day-old healthy weaned piglets(half female and half male;Duroc×Landrace×Yorkshire)with an initial body weight of 8.11±0.21 kg were randomly divided into 4 groups with 8 replicates of 1 pig each.The control group was fed a basal diet and the three experimental treatment groups were fed diets supplemented with 300,600 and 1,200 mg/kgβ-alanine,respectively.The trial lasted 28 days and the diets fed were divided into 2 phases:the late lactation period(day 1 to 14)and the nursery period(day 15 to 28),during which the weaned piglets had free access to food and water.The regulatory effects ofβ-alanine were further investigated in vitro using organoids obtained from the jejunum of piglets.In vivo,the addition ofβ-alanine to the diet had no significant effect on the growth performance of weaned piglets(P>0.05),but significantly reduced serum levels of immunoglobulin G(IgG)(P<0.01),immunoglobulin M(IgM)(P=0.005),and complement 3(C3)(P=0.017).The serum interleukin-6(IL-6)levels(P<0.01)were significantly reduced in the 1,200 mg/kg treatment group.The addition ofβ-alanine increased ileal villus height,with the most significant effect at a concentration of 300 mg/kg(P=0.041).The addition of 600 mg/kgβ-alanine significantly up-regulated the expression of superoxide dismutase(SOD)activity(P=0.020)and the zonula occludens-1(ZO-1)gene(P=0.049)in the jejunum.Diets supplemented with 300 mg/kgβ-alanine significantly increased the number of Ki67 positive cells in the jejunal crypts(P<0.01).In vitro,β-alanine increased the organoid budding rates(P=0.001)and the budding height of the crypt significantly(P=0.004).In conclusion,β-alanine can improve intestinal morphology and barrier function,reduce inflammatory responses and alleviate the adverse effects of weaning stress on piglet intestinal health.

Effects of dietary leucine supplementation on the gene expression of mammalian target of rapamycin signaling pathway and intestinal development of broilers

This experiment was to investigate the effects of dietary leucine supplementation on the gene expression of mammalian target of rapamycin(mTOR) signaling pathway and intestinal development of broilers. A total of 384 one-day-old broilers were randomly assigned into 4 treatments with 6 replicates(16 broilers per replicate). Broilers in these treatment groups were offered the following diets with 1.37,1.77,2.17 and2.57% of leucine. These diet treatments were named 1.37 TM, 1.77 TM, 2.17 TM, and 2.57 TM. The experiment lasted 21 days and all birds had free access to feed and water. Results indicated that there was no significant difference in body weight, average daily gain and average feed intake among all treatments(P > 0.05). The broiler duodenal villus height in 2.57 TM was the lowest, but the highest occurred in1.37 TM on d 7 and 14(P < 0.05). The villus height in the jejunum and ileum increased along with leucine level from 1.37 to 2.17%. The villus height of jejunum was significantly higher in 2.17 TM than in 1.37 TM on d 7 and 14, and the ratio of villus height to crypt depth(V:C) in the duodenum, jejunum and ileum increased significantly(P < 0.05) on d 21. The gene expression level of mTOR in the duodenum decreased with increasing leucine level and was higher in 1.37 TM than in 2.57 TM on d 7 and 14(P < 0.05). On d 14 and 21 of the trial, the expression of S6 K1 in the duodenum was higher in 1.37 TM than in 2.57 TM(P < 0.05), and the expression of mTOR, S6 K1 in the jejunum and ileum increased with increasing leucine level form 1.37 to 2.17%, whereas a significant difference occurred between 1.37 TM and 2.17 TM(P< 0.05).In conclusion, the addition of leucine fails to enhance the growth performance of broilers. However,leucine can improve intestinal development by enhancing villus height and V:C ratio in the jejunum and ileum. Moreover, the expression of mTOR, S6 K1 increased as the level of dietary leucine was elevated from 1.37 to 2.17%.

Effects of dietary tributyrin on intestinal mucosa development,mitochondrial function and AMPK-mTOR pathway in weaned pigs

Background:The objective of this experiment was to investigate the influence of dietary tributyrin on intestinal mucosa development,oxidative stress,mitochondrial function and AMPK-mTOR signaling pathway.Methods:Seventy-two pigs were divided into two treatments and received either a basal diet or the same diet supplemented with 750 mg/kg tributyrin.Each treatment has six replicates of six pigs.After 14 days,6 pigs from each treatment were selected and the jejunal samples were collected.Results:Results showed that supplemental tributyrin increased(P<0.05)villus height and villus height:crypt depth of weaned pigs.Pigs fed tributyrin had greater(P<0.05)RNA/DNA and protein/DNA ratios than pigs on the control group.The mRNA levels of sodium glucose transport protein-1 and glucose transporter-2 in the jejunum were upregulated(P<0.05)in pigs fed the tributyrin diet.Dietary tributyrin supplementation lowered(P<0.05)the malondialdehyde and hydrogen peroxide(H2O2)content in jejunum,enhanced(P<0.05)the mitochondrial function,as demonstrated by decreased(P<0.05)reactive oxygen species level and increased(P<0.05)mitochondrial membrane potential.Furthermore,tributyrin increased(P<0.05)mitochondrial DNA content and the mRNA abundance of genes related to mitochondrial functions,including peroxisomal proliferator-activated receptor-γcoactivator-1α,mitochondrial transcription factor A,nuclear respiratory factor-1 in the jejunum.Supplementation with tributyrin elevated(P<0.05)the phosphorylation level of AMPK and inhibited(P<0.05)the phosphorylation level of mTOR in jejunum compared with the control group.Conclusions:These findings suggest that dietary supplementation with tributyrin promotes intestinal mucosa growth,extenuates oxidative stress,improves mitochondrial function and modulates the AMPK-mTOR signal pathway of weaned pigs.

Effect of probiotics on growth performance, development of small intestinal tract and microbial populations in broilers

The experiment was conducted using a total of 1392 one-day-old, Cobb commercial male broilers to investigate the effects of a commercial probiotic addition in diet on growth, the development of the small intestine and microbial populations of broilers. Broilers were randomly allotted by BW to 1 of 6 replicate cages （29 chicks per cage） for each of 8 treatments in a randomized block design involving one factorial arrangement of treatments. Dietary treatments included the basal diet （including corn, soybean, rapeseed, cottonseed meal） added with 100 mg/kg antibiotic, 0%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25% or 0.3%. The experiment last 42 d and divided into the starter period （1-21 d） and the finisher period （22-42 d）. The results showed that there were significant differences in broiler body weight （BW） （P〈0.001）, average daily feed intake （ADFI） （P=0.033）, relative length of the duodenum （P〈0.001）, jejunum （P=0.008）, ileum （P〈0.001） and the populations of lactobacillus （P〈0.001） and coliform （P〈0.001） in the rectum between the probiotics treatments and the control treatment only in the starter period of the trails. No significant differences were observed in intestinal morphology parameters in two periods of the experiment. Our results indicated that the probiotic was able to improve the performance of broiler chickens, and it was better in the starter period to be used than in the finisher period.

Effect of Active Dried Yeast on Intestine Development,Intestinal Flora and Serum Cholesterol Mass Concentration of Quails

[ Objective] The experiments aimed to investigate the effect of dietary active dried yeast on intestine development, intestinal flora and serum cholesterol mass concentration of quails. [ Method] One-day-old 180 quails were randomly divided into 4 groups, 3 repetitions, each with 15 quails. Control group was fed with basic dietary, while experimental groups were added with 0.6, 1,2 g/kg active dried yeast respectively in basic dietary, [ Result] Addition of active dried yeast had little effect on quails＇ intestine development（ P 〉0.05）. With the increasing adding amount active dried yeast, the number of colibacillus decreased significantly （P 〈0.05） while lactobacillus content increasing sharply （P 〈 0.05）. Dietary with 1 and 2 g/kg active dried yeast can significantly decrease the mass concentration of cholesterol in serum （ P 〈 0.05）. [ Conclusion ] Adding active dried yeast in feed can decrease the number of colibacillus while increasing lactobacillus content in intestinal tract of quails, also can low serum cholesterol mass concentration.

Ontogeny,growth and development of the small intestine:Understanding pediatric gastroenterology

Throughout our lifetime,the intestine changes.Some alterations in its form and function may be genetically determined,and some are the result of adaptation to diet,temperature,or stress.The critical period programming of the intestine can be modified,such as from subtle differences in the types and ratios of n3:m6 fatty acids in the diet of the pregnant mother,or in the diet of the weanlings.This early forced adaptation may persist in later life,such as the unwanted increased intestinal absorption of sugars,fatty acids and cholesterol.Thus,the ontogeny,early growth and development of the intestine is important for the adult gastroenterologist to appreciate,because of the potential for these early life events to affect the responsiveness of the intestine to physiological or pathological challenges in later life.

Morphology and ontogeny of dendritic cells in rats at different development periods

AIM： To study the morphology and ontogeny of dendritic cells of Peyer＇s patches in rats at different development periods. METHODS： The morphometric and flow cytometric analyses were performed to detect all the parameters of villous-crypts axis and the number of OX62＋DC, OX62＋CD4＋SIRP＋DC, and OX62＋CD4-SIRP-DC in the small intestine in different groups of rats. The relationship between the parameters of villous-axis and the number of DC and DC subtype were analyzed. RESULTS： All morphometric parameters changed significantly with the development of pups in the different age groups （F = 10.751, 12.374, 16.527, 5.291, 3.486; P = 0.000, 0.000, 0.000, 0.001, 0.015）. Villous height levels were unstable and increased from 115.24μm to 140.43 μm as early as 3 wk postpartum. Villous area increased significantly between 5 and 7 wk postpartum, peeked up to 13817.60 tam2 at 7 wk postpartum. Villous height and crypt depth ratios were relatively stable and increased significantly from 2.80 ＋ 1.01 to 4.54 =1= 1.56, 9-11 wk postpartum. The expression of OX62＋DC increased from 33.30%±5.80% to 80%± 17.30%, 3-11 wk postpartum （F =5.536, P = 0.0013）. OX62＋CD4＋SIRP＋DC subset levels detected in single-cell suspensions of rat total Peyer＇s patch dendritic cells （PP-DCs） increased significantly from 30.73% ± 5.16% to 35.50% ± 4.08%, 5-7 wk postpartum and from 34.20% ±1.35% to 43.60% ± 2.07% 9-11 wk postpartum （F = 7.216, P = 0.005）. CONCLUSION： This study confirms the agerelated changes in villous-crypt axis differentiation in the small intestine. Simultaneously, there are also development and maturation in rat PP-DCs phenotypic expression. Furthermore, the morphological changes of intestinal mucosa and the development of immune cells （especially DC） peaked at 9-11 wk postpartum, indicating that the intestinal mucosae reached a relatively mature state at 11 wk postpartum.

Effect of early nutrition on intestine development of intrauterine growth retardation in rats and its correlation to leptin

AIM：To investigate the intestine and body development of intrauterine growth retardation（IUGR）rats under early different protein diet and to analyze the correlation between leptin and intestine and body development．METHODS：An IUGR rat model was established by food restriction of pregnant female rats．Fifty-six neonatal IUGR rats and 24 neonatal normal rats were randomly divided into normal control group（Cgroup），IUGR model group （scgroup），low protein diet IUGR group（SL group），and high protein diet IUGR group（SH group）．Eight rats were killed per group at wk 0，4，and 12．Serum leptin，body weight（BW），body length（BL），intestinal weight（IW），intestinal length（IL），andintestinal disaccharidase（including lactase，maltase，and saccharase） were detected．RESULTS：BW（4．50±0．41g），BL（5．96±0．40cm），IW（0．05±0．01g），and IL（15.9±2．8cm）in neonatal IUGR rats were much lower than those in Cgroup（6．01±0．55g，6．26±0．44cm，0．10±0．02g，21.8±2．7cm，P〈0．05），while intestinal lactase and maltase activities were higher than those in Cgroup．SH group showed the fastest catch up growth and their BW，BL，IW，and IL reached the Cgroup level at wk 4．SC group showed relatively slower catch up growth than SH group，and their BW，BL，IW did not reach the Cgroup level at wk 4．SL group did not show intestine and body catch up growth．Intestinal maltase [344±33μmol／（min·q）]and saccharase activities[138±32μmol／（min·g）]in SL group were both markedly lower than nose in C group [751±102，258±271μmol／（min·g），P〈0．05]．There were no significant difierences in lactase activities at wk 4 and disaccharidase activities at wk 12 among all groups（P〈0．05）．The leptin level in SL group（0．58±0．12ng／mL） was the highest in all groups，and much lower in SH group（0．21±0．03ng／mL） than that in any other IUGR groups at wk 4（P〈0．05）．Leptin was negatively related to BW （r=-0．556，P=0．001），IW（r=-0．692，P=0．001） and IL（r=-0．738，P=0．000）at wk 4，while no correlation was found at wk 12．CONCLUSION：High protein diet is a reasonable early nutritional mode to IUGR rats in promoting intestine and body catch up growth．

The development and role of microbialhost interactions in gut mucosal immune development

At birth the piglet＇s immune system is immature and it is dependent upon passive maternal protection until weaning.The piglet＇s mucosal immune system develops over the first few weeks but has not reached maturity at weaning ages which are common on commercial farms. At weaning piglets are presented with a vast and diverse range of microbial and dietary/environmental antigens. Their ability to distinguish between antigens and mount a protective response to potential pathogens and to develop tolerance to dietary antigens is critical to their survival and failure to do so is reflected in the high incidence of morbidity and mortality in the post-weaning period. A growing recognition that the widespread use of antibiotics to control infection during this critical period should be controlled has led to detailed studies of those factors which drive the development of the mucosal immune system, the role of gut microbiota in driving this process, the origin of the bacteria that colonise the young piglet＇s intestine and the impact of rearing environment. This review briefly describes how the mucosal immune system is equipped to respond ＂appropriately＂ to antigenic challenge and the programmed sequence by which it develops. The results of studies on the critical interplay between the host immune system and gut microbiota are discussed along with the effects of rearing environment. By comparing these with results from human studies on the development of allergies in children, an approach to promote an earlier maturation of the piglet immune system to resist the challenges of weaning are outlined.

The Development of Early Life Microbiota in Human Health and Disease

The colonization of the human microbiota in early life has long-lasting health implications.The status of the initial intestinal microbiota determines human growth and development from infancy to adulthood,and thus represents a crucial window in our long-term development.This review aims to summarize the latest findings on the symbiotic gut microbiota early in life and its vital role in metabolic-,allergic-,and auto-immune-disorder-related diseases,including obesity,diabetes,allergy,autism,inflammatory bowel disease,and stunting.It discusses the development process and various factors shaping the gut micro-biota,as well as the crosstalk between the gut microbiota and the host’s physiological systems(especially intestinal immune development and homeostasis,and the central nervous system in the course of neu-rodevelopment),during the early life establishment of the gut microbiota,in order to decipher the mech-anisms of diseases associated with the intestinal microbiome of early life.In addition,it examines microbiota-targeted therapeutic methods that show promising effects in treating these diseases.The true process of gut microbiome maturation,which depends on genetics,nutrition,and environmental factors,must be scrutinized in order to monitor healthy gut microbiome development and potentially correct unwanted courses by means of intervention via methods such as novel probiotics or fecal microbiota transplantation.

Mechanism of iron on the intestinal epithelium development in suckling piglets

This study aimed to investigate the mechanism of iron on intestinal epithelium development of suckling piglets. Compared with newborn piglets, 7-day-old and 21-day-old piglets showed changes in the morphology of the jejunum, increased proliferation,differentiated epithelial cells, and expanded enteroids. Intestinal epithelium maturation markers and iron metabolism genes were significantly changed. These results suggest that lactation is a critical stage in intestinal epithelial development, accompanied by changes in iron metabolism. In addition, deferoxamine(DFO) treatment inhibited the activity of intestinal organoids at passage 4(P4) of 0-day-old piglets, but no significant difference was observed in epithelial maturation markers at passage 1(P1) and P4,and only argininosuccinate synthetase 1(Ass1) and β-galactosidase(Gleb) were up-regulated at passage 7(P7). These results in vitro show that iron deficiency may not directly affect intestinal epithelium development through intestinal stem cells(ISCs). The iron supplementation significantly down-regulated the m RNA expression of interleukin-22 receptor subunit alpha-2(IL-22RA2)in the jejunum of piglets. Furthermore, the m RNA expression of IL-22 in 7-day-old piglets was significantly higher than that in0-day-old piglets. Adult epithelial markers were significantly up-regulated in organoids treated with recombinant murine cytokine IL-22. Thus, IL-22 may play a key role in iron-affecting intestinal epithelium development.

Effects of dietary yeast β-glucan on nutrient digestibility and serum profiles in pre-ruminant Holstein calves

This study aimed to investigate the effects of dietary supplementation of yeast 13-glucan on the nutrient digestibility and serum profiles in pre-ruminant Holstein calves. Forty-two neonatal Holstein calves （（39.6＋4.2） kg） were randomly allotted to six groups, and each was offered one of the following diets： a basal diet （control） or the basal diet supplemented with 25, 50, 75, 100 or 200 mg of yeast 13-glucan kg-~ feed （dry matter basis）. The basal diet consisted of a milk replacer and a starter feed. The trial lasted for 56 d. Two digestibility trials were conducted from d 14 to 20 and from d 42 to 48. Blood samples were collected on d 0, 14, 28 and 42 for serum profile analyses. On d 56, three calves from each group were slaughtered, and intestinal samples were collected to assess the villous height, crypt depth and mucosal thickness. Although feed intake was not affected by dietary treatment （P〉0.05）, the average daily gain （ADG） and gain-to-feed ratios were higher （P〈0.05） for the calves fed 75 mg of yeast β-glucan kg^-1 feed than those in the other groups. The supplementation of yeast β-glucan at 75 mg kg^-1 feed increased the apparent digestibility of dry matter （DM）, crude protein （CP）, ether extract （EE）, and phosphorus （P） （P〈0.05） and the ratio of intestinal villous height to crypt depth （V/C） （P〈0.05） when compared with the control group. No effects of yeast β-glucan on the serum concentrations of total protein （TP）, albumin （ALB）, serum urea nitrogen （SUN） and glucose （GLU） were observed （P〉0.05）. Compared with the control group, supplementation of yeast β-glucan decreased （P〈0.05） the serum concentrations of triglycerides （TG） and total cholesterol （TC）. The serum concentration of immunoglobulin G （IgG） and immunoglobulin M （IgM） increased quadratically （P〈0.05）, whereas the serum concentration of immunoglobulin A （IgA） was unaffected by dietary treatments （P〉0.05）. The supplementation of yeast β-glucan stimu- lated the enzymatic activity of alkaline phosphatase （ALP） （P〈0.05） compared with the control group. The lysozyme （LYZ） concentration increased quadratically （P〈0.05） with increasing yeast β-glucan levels. The results suggested that dietary supplementation of yeast 13-glucan at 75 mg kg^-1 feed improved nutrient digestibility, enhanced immunity by increasing the immunoglobulin concentration and stimulating ALP, and exerted no adverse effects on metabolism in pre-ruminant calves.

Recent advances in small bowel diseases:Part Ⅰ

As is the case in all parts of gastroenterology and hepatology,there have been many advances in our knowledge and understanding of small intestinal diseases.Over 1000 publications were reviewed for 2008 and 2009,and the important advances in basic science as well as clinical applications were considered.In Part Ⅰ of this Editorial Review,seven topics are considered:intestinal development;proliferation and repair;intestinal permeability;microbiotica,infectious diarrhea and probiotics;diarrhea;salt and water absorption;necrotizing enterocolitis;and immunology/allergy.These topics were chosen because of their importance to the practicing physician.

Nutritional stimulation by in-ovo feeding modulates cellular proliferation and differentiation in the small intestinal epithelium of chicks

Nutritional stimulation of the developing small intestine of chick embryos can be conducted by in-ovo feeding(IOF).We hypothesized that IOF of glutamine and leucine can enhance small intestinal development by promoting proliferation and differentiation of multipotent small intestinal epithelial cells.Broiler embryos(n=128)were subject to IOF of glutamine(IOF-Gln),leucine(IOF-Leu),NaCl(IOF-NaCl)or no injection(control)at embryonic d 17(E 17).Multipotent,progenitor and differentiated cells were located and quantified in the small intestinal epithelium between E 17 and d 7 after hatch(D 7)in all treatment groups by immunofluorescence of SRY-box transcription factor 9(Sox9)and proliferating cell nuclear antigen(PCNA),in-situ hybridization of leucine-rich repeat containing G-protein coupled receptor 5(Lgr5)and peptide transporter 1(PepT1)and histochemical goblet cell staining.The effects of IOF treatments at E 19(48 h post-IOF),in comparison to control embryos,were as follows:total cell counts increased by 40%,33%and 19%,and multipotent cell counts increased by 52%,50%and 38%,in IOF-Gln,IOF-Leu and IOF-NaCl embryos,respectively.Only IOF-Gln embryos exhibited a significance,36%increase in progenitor cell counts.All IOF treatments shifted Lgr5+ stem cell localizations to villus bottoms.The differentiated,PepT1+region of the villi was 1.9 and 1.3-fold longer in IOF-Gln and IOF-Leu embryos,respectively,while goblet cell densities decreased by 20%in IOF-Gln embryos.Postehatch,crypt and villi epithelial cell counts were significantly higher IOF-Gln chicks,compared to control chicks(P<0.05).We conclude IOF of glutamine stimulates small intestinal maturation and functionality during the peri-hatch period by promoting multipotent cell proliferation and differentiation,resulting in enhanced compartmentalization of multipotent and differentiated cell niches and expansions of the absorptive surface area.

Cdx1b protects intestinal cell fate by repressing signaling networks for liver specification

In mammals,the expression of the homeobox family member Cdx2/CDX2 is restricted within the intestine.Conditional ablation of the mouse Cdx2 in the endodermal cells causes a homeotic transformation of the intestine towards the esophagus or gastric fate.In this report,we show that null mutants of zebrafish cdx1b,encoding the counterpart of mammalian CDX2,could survive more than 10 days post fertilization,a stage when the zebrafish digestive system has been well developed.Through RNA sequencing(RNA-seq)and single-cell sequencing(sc RNA-seq)of the dissected intestine from the mutant embryos,we demonstrate that the loss-of-function of the zebrafish cdx1b yields hepatocyte-like intestinal cells,a phenotype never observed in the mouse model.Further RNA-seq data analysis,and genetic double mutants and signaling inhibitor studies reveal that Cdx1b functions to guard the intestinal fate by repressing,directly or indirectly,a range of transcriptional factors and signaling pathways for liver specification.Finally,we demonstrate that heat shock-induced overexpression of cdx1b in a transgenic fish abolishes the liver formation.Therefore,we demonstrate that Cdx1b is a key repressor of hepatic fate during the intestine specification in zebrafish.

Enteromorpha polysaccharide-zinc replacing prophylactic antibiotics contributes to improving gut health of weaned piglets

This research aimed to study whether Enteromorpha polysaccharide-zinc(EP-Zn)can act as an alternative to antibiotics in weaned piglet feeds.Two hundred and twenty-four weaned piglets from 14 pens were randomly assigned into 1 of 2 groups according to their body weight and litter size(7 pens/group).The piglets in the antibiotics group were fed with olaquindox at 400 mg/kg and enduracidin at 800 mg/kg basal diet,and piglets in the EP-Zn group were fed with EP-Zn at 800 mg/kg basal diet.One piglet per pen was selected to collect samples after 14 d of feeding.Results showed that EP-Zn supplementation significantly increased the plasma anti-oxidants level compared with the antibiotics group.However,a nonsignificant difference was observed in growth performance between treatment groups.Additionally,the intestinal tight junction(TJ)protein expression and the histopathologic evaluation data showed that EP-Zn contributed to improving intestinal development.Further,piglets in the EP-Zn group had a lower level of intestinal inflammation-related cytokines including IL-6(P<0.001),IL-8(P<0.05),IL-12(P<0.05)and tumor necrosis factor-α(TNF-α)(P<0.001),and showed an inhibition of the phosphor-ylation nuclear transcription factor-kappa B(p-NF-kB)(P<0.05)and total NF-kB(P<0.001)level in the jejunal mucosa.Taken together,it is supposed that EP-Zn,to some extent,would be a potent alternative to prophylactic antibiotics in improving the health status of weaned piglets.