Microarchitecture and Spatial Relationship Between Bacteria and Ileal, Cecal, and Colonic Epithelium in Chicks Fed a Direct-Fed Microbial, PrimaLac, and Salinomycin

Effect of feeding soybean meal and differently processed peas on intestinal morphology and functional glucose transport in the small intestine of broilers

Peas are locally grown legumes being rich in protein and starch. However, the broad usage of peas as a feed component in poultry nutrition is limited to anti-nutritional factors, which might impair gut morphology and function. This study investigated the effect of feeding raw or differently processed peas compared with feeding a soybean meal-based control diet (C) on intestinal morphology and nutrient transport in broilers. A total of 360 day-old broiler chicks were fed with one of the following diets: The C diet, and 3 diets containing raw peas (RP), fermented peas (FP) and enzymatically pre-digested peas (EP), each supplying 30% of dietary crude protein. After 35 d, jejunal samples of broilers were taken for analyzing histomorphological parameters, active glucose transport in Ussing chambers and the expression of genes related to glucose absorption, intestinal permeability and cell maturation. Villus length (P = 0.017) and crypt depth (P = 0.009) of EP-fed broilers were shorter compared to birds received C. The villus surface area was larger in broilers fed C compared to those fed with the pea-containing feed (P = 0.005). Glucose transport was higher for broilers fed C in comparison to birds fed with the EP diet (P = 0.044). The sodium-dependent glucose co-transporter 1 (SGLT-1) expression was down-regulated in RP (P = 0.028) and FP (P = 0.015) fed broilers. Correlation analyses show that jejunal villus length negatively correlates with the previously published number of jejunal intraepithelial T cells (P = 0.014) and that jejunal glucose transport was negatively correlated with the occurrence of jejunal intraepithelial leukocytes (P = 0.041). To conclude, the feeding of raw and processed pea containing diets compared to a soybean based diet reduced the jejunal mucosal surface area of broilers, which on average was accompanied by lower glucose transport capacities. These morphological and functional alterations were associated with observed mucosal immune reactions. Further studies are required elucidating the specific components in peas provoking such effects and whether these effects have a beneficial or detrimental impact on gut function and animal health.

Gut-Associated Lymphoid Tissue: A Key Tissue Inside the Mucosal Immune System of Hens Immunized with Escherichia coli F4

Immunoglobulin Y (IgY) is the predominant antibody found in hen's (Gallus domesticus) egg yolk. This antibody, developed against several microorganisms in hen egg yolk, has been successfully used as an alternative to immunoglobulins from mammals for use in immunodiagnostics and immunotherapy. Enteropathogenic Escherichia coli (E.coli) F4 is the main etiological agent associated with swine neonatal diarrhea, and it causes notable economic losses in swine production. The aim of the present study was to evaluate the relationship between humoral immune response and the activation of gut-associated lymphoid tissue (GALT) in laying hens intramuscularly immunized with E. coli F4. Adult laying Shaver hens were immunized with a bacterin based on an inactivated lysate E. coli F4 strain that was originally isolated from neonatal piglet diarrhea, following a recommended schedule. The percentage of B lymphocytes in blood and spleen homogenates was determined by flow cytometry. Villi histomorphometry and the size of germinal centers (GC) activated in GALT and the spleen were measured in histological samples either stained with hematoxylin/eosin or through immunofluorescence. Antibody and isotype-specific antibodies in serum and egg yolk were measured using indirect enzyme-linked immunosorbent assay (ELISA). Secretory and serum immunoglobulin A (IgA) were measured by ELISA tests. Laying hen with intramuscular immunization with E. coli F4 lysate, activated both mucosal and systemic protection. Mucosal protection was provided through B lymphocytes, and most of them were activated on Peyer's patches and esophageal tonsils, in GALT. Furthermore, increased B lymphocyte number in the lamina propria of the gut, and increased intraepithelial plasmatic cell number, produced high levels of mucosal IgA. Activated B lymphocytes interacted with absorptive cells, immune cells, and microbiota in the gut, producing signals that were translated into a powerful physical defense by producing a greater volume of mucin from an increased number of goblet cells. Systemic protection was provided through B lymphocyte activation of spleen GC, which produced hugely specific IgY serum levels. One week later, this specific IgY was deposited in the yolk. This suggests that GALT is a key immunologic tissue inside the mucosal immune system, acting as the "command center" for humoral reaction.

Efficacy of protein, symbiotic and probiotic supplementation on production performance and egg quality characteristics in molted layers

Two hundred white leg horn layers at 70 weeks of age were induced to molt with high dietary zinc (3 g/kg of feed); thereafter, birds were equally and randomly divided (n = 50 each) into four groups keeping G1 as control (CP 16 % diet, no other supplement), G2 (CP 18 % diet), G3 (CP 16 % diet + symbiotic; Perfectin® at 85 mg/L in drinking water daily), and G4 (CP 16 % diet + probiotic; Protexin® at 85 mg/L in drinking water daily). The egg production record was maintained throughout the experiment period, and egg quality parameters were performed at 5 %, peak, and end of post molt production stage. The overall egg production was highest in G2 (74.51 %) followed by G3 (64.95 %) and G4 (65.03 %) and lowest in G1 (58.51 %). The overall egg weight, length, diameter, weight and diameter of albumin and yolk, egg shell thickness as well as egg shell breaking strength increased (P ≤ 0.01) in G2 and G3 as compared to G1. The albumin height, yolk height, yolk index, and haugh unit score decreased (P ≤ 0.01) in G2 and G3 as compared to G1. FCR/12 eggs improved in all the supplemented groups as compared to control (G1). The bacterial contamination of eggs was seen in G1. Conclusively, it was observed in the current experiment that the supplementation with protein, probiotic, and symbiotic did improve the production quality and potential in molted layers.

Environmental cues and symbiont microbe-associated molecular patterns function in concert to drive the daily remodelling of the crypt-cell brush border of the Euprymna scolopes light organ

Recent research has shown that the microbiota affects the biology of associated host epithelial tissues, including their circadian rhythms, although few data are available on how such influences shape the microarchitecture of the brush border. The squid-vibrio system exhibits two modifications of the brush border that supports the symbionts: effacement and repolarization. Together these occur on a daily rhythm in adult animals, at the dawn expulsion of symbionts into the environment, and symbiont colonization of the juvenile host induces an increase in microvillar density. Here we sought to define how these processes are related and the roles of both symbiont colonization and environmental cues. Ultrastructural analyses showed that the juvenile-organ brush borders also efface concomitantly with daily dawn-cued expulsion of symbionts. Manipulation of the environmental light cue and juvenile symbiotic state demonstrated that this behaviour requires the light cue, but not colonization. In contrast, symbionts were required for the observed increase in microvillar density that accompanies post dawn brush-border repolarization; this increase was induced solely by host exposure to phosphorylated lipid A of symbiont cells. These data demonstrate that a partnering of environmental and symbiont cues shapes the brush border and that microbe-associated molecular patterns play a role in the regulation of brush-border microarchitecture.

Dietary β-galactomannans have beneficial effects on the intestinal morphology of chickens challenged with Salmonella enterica serovar Enteritidis

Salmonella enterica serovar Enteritidis is one of the leading causes of food-borne salmonellosis in humans. Poultry is the single largest reservoir, and the consumption of incorrectly processed chicken meat and egg products is the major source of infection. Since 2006, the use of antibiotics as growth promoters has been banned in the European Union, and the dietary inclusion of β-galactomannans (βGM) has become a promising strategy to control and prevent intestinal infections. The aim of this study was to investigate the effect of various βGM-rich products on intestinal morphology in chickens challenged with Salmonella Enteritidis. To assess this effect, a total of 280 male Ross 308 chickens were studied (40 animals per treatment housed in 5 cages). There were 7 treatments, including controls: uninoculated birds fed the basal diet (negative control) and inoculated birds fed the basal diet (positive control) or the basal diet supplemented with Salmosan (1 g/kg), Duraió gum (1 g/kg), Cassia gum (1 g/kg), the cell walls of Saccharomyces cerevisiae (0.5 g/kg), or the antibiotic colistine (0.8 g/kg). The birds were fed these diets from the d 1 to 23, except the animals in the colistine group, which were fed the diet containing the antibiotic only from d 5 to 11. The inoculated animals were orally infected on d 7 with 10(8) cfu of Salmonella Enteritidis. Bird performance per replicate was determined for the whole study period (23 d), and the distal ileum and cecal tonsil of 5 animals per treatment (1 animal per replicate) were observed at different magnification levels (scanning electron, light, and laser confocal microscopy). In the images corresponding to the treatments containing βGM we observed more mucus, an effect that can be associated with the observation of more goblet cells. Moreover, the images also show fewer M cells, which are characteristic of infected animals. Regarding the morphometric parameters, the animals that received Duraió and Cassia gums show greater (P = 0.001 and P = 0.016, respectively) villus length compared with the animals in the positive control, thus indicating the capacity of these products to increase epithelial surface area. However, no effect (P > 0.05) on microvillus dimensions was detected. In conclusion, the results obtained indicating the beneficial effects of these βGM on intestinal morphology give more evidence of the positive effects of these supplements in poultry nutrition.

Effect of Dietary Exogenous Enzyme Supplementation on Enteric Mucosal Morphological Development and Adherent Mucin Thickness in Turkeys

Anti-nutritional factors (ANFs) in feed ingredients can challenge gut health and reduce nutrient utilization. Birds typically activate their innate immune system as a protective response against the adverse effects of ANF, which often involves the secretion of mucin. Although dietary supplementation of exogenous enzymes are commonly used to alleviate the adverse effects of ANF on apparent nutrient digestibility, little is known about how they affect gut health, particularly in relation to the morphological development and mucin secretion of enteric mucosa. We carried out two trials to examine the effect of dietary supplementation of different types of exogenous enzymes on gut health of by accessing the effect of jejunum morphological development and ileal enteric adherent mucin thickness layer in turkeys. Dietary β-mannanase supplementation reduced ileal adherent mucin thickness layer (804 vs 823 μg/g; p < 0.05), while a commercial blend of xylanase, amylase, and protease (XAP) reduced ileal adherent mucin layer thickness (589 vs 740 μg/g; p < 0.05); thus reducing the apparent endogenous loss of nutrients. Both enzyme supplements also affected gut morphological characteristics. In comparison to the control treatment, dietary β-mannanase supplementation improved the jejunum tip width (219 vs 161; p < 0.05), base width (367 vs 300; p < 0.05), surface area (509,870 vs 380, 157; p < 0.05) and villi height/crypt depth ratio (7.49 vs 5.70; p < 0.05), and XAP improved the crypt depth (p < 0.05). In conclusion, dietary supplementation of exogenous enzymes may help alleviate the adverse effects of ANF on nutrient utilization by directly or indirectly removing the mucosal irritation that stimulates enteric mucin secretion.

Metagenomic Analysis of Chicken Gut Microbiota for Improving Metabolism and Health of Chickens - A Review

Chicken is a major food source for humans, hence it is important to understand the mechanisms involved in nutrient absorption in chicken. In the gastrointestinal tract (GIT), the microbiota plays a central role in enhancing nutrient absorption and strengthening the immune system, thereby affecting both growth and health of chicken. There is little information on the diversity and functions of chicken GIT microbiota, its impact on the host, and the interactions between the microbiota and host. Here, we review the recent metagenomic strategies to analyze the chicken GIT microbiota composition and its functions related to improving metabolism and health. We summarize methodology of metagenomics in order to obtain bacterial taxonomy and functional inferences of the GIT microbiota and suggest a set of indicator genes for monitoring and manipulating the microbiota to promote host health in future.

Evaluation of the efficacy of sequential or continuous administration of probiotics and phytogenics in broiler diets

Three dietary combinations of probiotics and phytogenics administered sequentially or continuously were assessed for their effects on broiler performance, nutrient digestibility, caecal microbiota composition, volatile fatty acid (VFA) pattern and plasma total antioxidant capacity (TAC). One-day-old Cobb male broilers (n = 525) were allocated to five experimental treatments for 42 days. Each treatment had three replicates of 35 broilers each. Depending on the time-frame of sequential or continuous addition in the basal diet (BD) of the probiotics (108 CFU/kg BD) and phytogenics (125 mg/kg BD), experimental treatments were: control (no additions, Days 1–42); PE1, probiotic Days 1–14 and phytogenic Days 15–42; PE2, probiotic Days 1–28 and phytogenic Days 29–42; PE3, probiotic and phytogenic continuously (Days 1–42); and A (2.5 mg avilamycin/kg diet, Days 1–42). There was no loss of probiotic viability upon mixing with the phytogenic for up to 7 days. Overall bodyweight gain was higher (P = 0.025) in the control and PE1 than PE2 and PE3, whereas Treatment A was intermediate and not different from the rest. Overall feed intake in the control was the highest (P = 0.003). Treatments PE1, PE2 and PE3 had better (P = 0.004) overall feed conversion ratio (FCR) than the control. The FCR in PE1 and PE3 did not differ from A, which had the best FCR. Mortality did not differ among treatments. Nutrient digestibility and caecal microbiota composition did not differ among treatments. However, differences (P ≤ 0.05) in caecal VFA pattern were noted, with the control having the lowest acetate molar ratio as well as the highest sum of valeric, hexanoic and heptanoic acids. Plasma TAC in the control was lower than in PE3, PE1 and PE2 at Day 14 (P < 0.001) and PE1 (P = 0.003) at Day 42. The concept of sequential or throughout probiotic and phytogenic administration showed promising results regarding feed efficiency and plasma TAC.

Effect of dietary inclusion level of a multi-species probiotic on broiler performance and two biomarkers of their caecal ecology

The effect of the dietary inclusion level of a three-species probiotic on broiler performance, nutrient digestibility, caecal microbiota composition and volatile fatty acid (VFA) pattern was evaluated. Day-old Cobb broilers (n = 448) were allocated in four treatments for 6 weeks. Each treatment had four replicates (two per gender) of 28 broilers each. Depending on the type of addition per kg basal diet, treatments were C (no other addition), PL (108 colony forming units of probiotic), PH (109 colony forming units of probiotic) and A (2.5 mg avilamycin). Overall bodyweight gain was better (P = 0.002) in PL and PH than in the control (2082 g) by 8.7% and 7.5%, respectively, while treatment PL did not differ from A (2341 g), which showed the highest bodyweight gain. The ileal and total-tract apparent digestibility of DM and the apparent metabolisable energy content corrected for N improved linearly (P ≤ 0.05) with the probiotic level. Fluorescent in situ hybridisation analysis showed caecal Bifidobacterium levels to increase linearly (P = 0.006) with the probiotic level. Probiotic administration resulted in altered caecal VFA patterns compared with the control. Gender effects (P ≤ 0.05) were noted for caecal levels of C. histolyticum group, Bacteroides fragilis group and Streptococcus spp., while interactions (P ≤ 0.05) of treatment with gender were seen for Bifidobacterium and all VFA components, except for acetate. In conclusion, beneficial effects on bodyweight gain, DM digestibility, apparent metabolisable energy content corrected for N, caecal Bifidobacterium levels and VFA patterns were noted with both probiotic inclusion levels.

Bacteria, phages and pigs: the effects of in-feed antibiotics on the microbiome at different gut locations

Disturbance of the beneficial gut microbial community is a potential collateral effect of antibiotics, which have many uses in animal agriculture (disease treatment or prevention and feed efficiency improvement). Understanding antibiotic effects on bacterial communities at different intestinal locations is essential to realize the full benefits and consequences of in-feed antibiotics. In this study, we defined the lumenal and mucosal bacterial communities from the small intestine (ileum) and large intestine (cecum and colon) plus feces, and characterized the effects of in-feed antibiotics (chlortetracycline, sulfamethazine and penicillin (ASP250)) on these communities. 16S rRNA gene sequence and metagenomic analyses of bacterial membership and functions revealed dramatic differences between small and large intestinal locations, including enrichment of Firmicutes and phage-encoding genes in the ileum. The large intestinal microbiota encoded numerous genes to degrade plant cell wall components, and these genes were lacking in the ileum. The mucosa-associated ileal microbiota harbored greater bacterial diversity than the lumen but similar membership to the mucosa of the large intestine, suggesting that most gut microbes can associate with the mucosa and might serve as an inoculum for the lumen. The collateral effects on the microbiota of antibiotic-fed animals caused divergence from that of control animals, with notable changes being increases in Escherichia coli populations in the ileum, Lachnobacterium spp. in all gut locations, and resistance genes to antibiotics not administered. Characterizing the differential metabolic capacities and response to perturbation at distinct intestinal locations will inform strategies to improve gut health and food safety.

The Bacillus subtilis and Lactic Acid Bacteria Probiotics Influences Intestinal Mucin Gene Expression, Histomorphology and Growth Performance in Broilers

The aim of the present study was to evaluate the effect of commercial monostrain and multistrain probiotics in diets on growth performance, intestinal morphology and mucin gene (MUC2) expression in broiler chicks. Three hundred seventy-eight 1-d-old male Arian broiler chicks were allocated in 3 experimental groups for 6 wk. The birds were fed on a corn-soybean based diet and depending on the addition were labeled as follows: control-unsupplemented (C), birds supplemented with Bacillus subtilis (BS) and lactic acid bacteria (LAB) based probiotics. Each treatment had 6 replicates of 21 broilers each. Treatment effects on body weight, feed intake, feed conversion ratio and biomarkers such as intestinal goblet cell density, villus length, villus width, and mucin gene expression were determined. Total feed intake did not differ significantly between control birds and those fed a diet with probiotics (p>0.05). However, significant differences in growth performance were found. Final body weight at 42 d of age was higher in birds fed a diet with probiotics compared to those fed a diet without probiotic (p<0.05). Inclusion of Bacillus subtilis based probiotic in the diets also significantly affected feed conversion rate (FCR) compared with control birds (p<0.05). No differences in growth performance were observed in birds fed different types of probiotic supplemented diets. Inclusion of lactic acid bacteria based probiotic in the diets significantly increased goblet cell number and villus length (p<0.05). Furthermore, diets with Bacillus subtilis based probiotics significantly increased gene expression (p<0.05), with higher intestinal MUC2 mRNA in birds fed diet with probiotics compared to those fed the control diet. In BS and LAB probiotic fed chicks, higher growth performance may be related to higher expression of the MUC2 gene in goblet cells and/or morphological change of small intestinal tract. The higher synthesis of the mucin gene after probiotic administration may positively affect bacterial interactions in the intestinal digestive tract, intestinal mucosal cell proliferation and consequently efficient nutrient absorption.

Effects of a probiotic, Enterococcus faecium, on growth performance, intestinal morphology, immune response, and cecal microflora in broiler chickens challenged with Escherichia coli K88

The effects of feeding dehydrated Enterococcus faecium on growth performance, immune response, and cecal microflora in broiler chickens challenged with Escherichia coli K88 were investigated. Two hundred eighty-eight 1-d-old birds were randomly assigned to 4 treatments: negative control birds (N-con) fed a basal diet and not challenged with E. coli K88; positive control birds (P-con) fed a basal diet and challenged with E. coli K88; birds fed a basal diet including dehydrated E. faecium (Ef) at 1 × 10(9) cfu/kg of feed and challenged with E. coli K88; and birds fed a basal diet including the antibiotic colistine sulfate (Anti) at 10 mg/kg of feed and challenged with E. coli K88. Birds fed E. faecium had greater (P < 0.05) BW on d 14, 21, and 28 and greater (P < 0.05) jejunal villus height on d 21 and 28 compared with birds on the other treatments. Jejunal crypt depth was decreased (P < 0.05) in birds fed either E. faecium or antibiotic compared with P-con treatment birds on d 10, 21, and 28. Birds fed E. faecium had a greater (P < 0.05) concentration of IL-4 in their jejunal mucosa than did those in the N-con treatment group on d 10, 14, and 21. Infected birds, with or without E. faecium feeding, had a higher (P < 0.05) tumor necrosis factor-α and secreted IgA in their jejunal mucosa than did those in the N-con treatment group on d 10 and 14. Birds fed E. faecium had lower (P < 0.05) concentrations of E. coli on d 14 and 28, less (P < 0.05) Clostridium perfringens on d 28, greater Lactobacillus counts on d 14 and 21, and greater (P < 0.05) Bifidobacterium in their cecal contents on d 21 than did the P-con birds. These results suggest that E. faecium can promote growth performance, improve intestinal morphology, and beneficially manipulate the cecal microflora in broilers challenged with E. coli K88.

Dietary supplementation of Bifidobacterium longum strain AH1206 increases its cecal abundance and elevates intestinal interleukin-10 expression in the neonatal piglet

Intestinal microbiota of infants differ in response to gestational age, delivery mode and feeding regimen. Dietary supplementation of probiotic bacteria is one method of promoting healthy populations. We examined the impact of a novel probiotic strain of Bifidobacterium longum (AH1206) on the health, growth and development of neonatal pigs as a model for infants. Day-old pigs were fed milk-based formula containing AH1206 at 0, 10⁹, or 10¹¹ CFU/d for 18 d (n=10/treatment). Differences were not detected in growth, organ weights or body temperatures (P>0.1); however pigs fed the high dose showed a small (2%) reduction in feed intake. Bacterial translocation was not affected as indicated by total anaerobic and aerobic counts (CFU) in samples of spleen, liver and mesenteric lymph nodes (P>0.1). Feeding AH1206 had no effects on fecal consistency, but increased the density of B. longum in the cecum. Ileal TNF expression tended to increase (P=0.08) while IL-10 expression increased linearly (P=0.01) with supplementation. Based upon findings in the suckling piglet model, we suggest that dietary supplementation with B. longum (AH1206) may be safe for human infants based on a lack of growth, development or deleterious immune-related effects observed in piglets.

Effect of Saccharomyces boulardii and Bacillus subtilis B10 on intestinal ultrastructure modulation and mucosal immunity development mechanism in broiler chickens

The recent ban on the use of antibiotics as a feed additive has led to the search for alternative sources of antibiotics in the feed industry. Presently, probiotics are considered as a potential substitute for antibiotic as a live biotherapeutic agent to improve animal health and performance. Accordingly, study was focused on evaluating the effect of Saccharomyces boulardii (Sb) and Bacillus subtilis B10 (Bs) on ultrastructure modulation and mucosal immunity development in broiler chickens. A total of three hundred 1-d-old Sanhuang broilers (a Chinese cross breed) were randomized into 3 groups, each group with 5 replications (n = 20). The control group (Ctr) was fed a basal diet containing an antibiotic (virginiamycin, 20 mg/kg). Meanwhile, broilers in experimental groups received Sb and Bs (1 × 10(8) cfu/kg of feed) in addition to the basal diet for 72 d. The results of the experimental groups revealed a significant improvement in live BW and relative weight of bursa of Fabricius and thymus. Also, intestinal villus height, width, and number of goblet cells increased in the Sb and Bs groups. Meanwhile, modulation in the intestinal ultrastructure and increased mRNA expression levels of occluding, cloudin2, and cloudin3 (P < 0.05) were observed in the Sb and Bs groups. Moreover, IgA-positive cells significantly increased in the jejunum of Sb- and Bs-supplemented groups (P < 0.05). Intestinal cytokines interleukin-6, tumor necrosis factor-α, interleukin-10, transforming growth factor-β, and secretory IgA concentrations were (P < 0.05) improved in the probiotic groups; however, Sb induced inflammatory and antiinflammatory cytokines (P < 0.05) in comparison with the Ctr group. The present findings conclusively revealed that Sb and Bs increased IgA-positive cells in the lumen of the intestinal villus and revealed that Sb and Bs could modulate intestinal ultrastructure through increasing occluding, cloudin2, and cloudin3 mRNA expression levels in broiler intestine.

Effects of probiotic, Clostridium butyricum, on growth performance, immune function, and cecal microflora in broiler chickens

Four hundred and fifty 1-d-old male Lingnan Yellow broiler chickens were used to investigate the effects of Clostridium butyricum on growth performance, immune function, and cecal microflora. The birds were randomly assigned to 5 treatments and offered the same antibiotic-free basal diets for 42 d. The treatments were as follows: no addition (control), 1 × 10(7) cfu C. butyricum/kg of diet (CB1), 2 × 10(7) cfu C. butyricum/kg of diet (CB2), 3 × 10(7) cfu C. butyricum/kg of diet (CB3), and 10 mg of colistine sulfate/kg of diet (antibiotic). Birds fed either CB2 or antibiotic had greater overall BW than those in the control group. During d 1 to 7, d 21 to 42, and d 1 to 42, birds fed either CB2 or CB3 or the antibiotic diet had greater ADG compared with those in the control group. No significant differences were observed in BW or ADG among the CB2, CB3, and antibiotic groups. Birds fed the CB2 or CB3 diet had greater concentrations of IgA and IgG in the serum from d 14 to 42 and greater IgM in the serum from d 21 to 42 than those in the control group. Birds fed the CB3 diet had a greater concentration of complement component 3 in the serum than those in the control group from d 7 to 42. Dietary C. butyricum decreased (P < 0.05) Escherichia coli in cecal contents on d 14 and 42, and both CB2 and CB3 decreased (P < 0.05) cecal Salmonella and Clostridium perfringen from d 14 to 42 compared with the control. Broilers fed either CB2 or CB3 had greater cecal Lactobacillus and Bifidobacterium counts from d 21 to 42, and birds fed C. butyricum had greater cecal C. butyricum counts during the whole period compared with those in the control group. The results indicate that C. butyricum promotes growth performance and immune function and benefits the balance of the intestinal microflora in broiler chickens.

Direct fed microbial supplementation repartitions host energy to the immune system

Direct fed microbials and probiotics are used to promote health in livestock and poultry; however, their mechanism of action is still poorly understood. We previously reported that direct fed microbial supplementation in young broilers reduced ileal respiration without changing whole-body energy expenditure. The current studies were conducted to further investigate the effects of a direct fed microbial on energy metabolism in different tissues of broilers. One hundred ninety-two 1-d-old broiler chicks (16 chicks/pen) were randomly assigned to 2 dietary groups: standard control starter diet (CSD) and CSD plus direct fed microbial (DFMD; 0.3%) with 6 pens/treatment. Body weight, feed consumption, whole-body energy expenditure, organ mass, tissue respiration rates, and peripheral blood mononuclear cell (PBMC) ATP concentrations were measured to estimate changes in energy metabolism. No differences in whole body energy expenditure or BW gain were observed; however, decreased ileal O(2) respiration (P < 0.05) was measured in DFMD fed broilers. In contrast, the respiration rate of the thymus in those broilers was increased (P < 0.05). The PBMC from DFMD fed broilers had increased ATP concentrations and exhibited increased ATP turnover (P < 0.01). To determine if the increased energy consumption by PBMC corresponded with an altered immune response, broilers were immunized with sheep red blood cells (SRBC) and assayed for differences in their humoral response. The DFMD-fed broilers had a faster rate of antigen specific IgG production (P < 0.05) and an increase in total IgA (P < 0.05). Collectively, these data indicate that supplementation with the direct fed microbial used in this study resulted in energy re-partitioning to the immune system and an increase in antibody production independent of changes in whole body metabolism or growth performance.

Effect of enteral nutrition on dextran sulfate sodium-induced colitis in rats

OBJECTIVE

To study the effect of enteral nutrition (EN) on dextran sulfate sodium (DSS)-induced colitis in rats.

METHODS

Eighty-four Sprague-Dawley rats were divided into 7 groups (12 rats in each group). The blank control group was given ordinary laboratory feed and drinking water. The experimental groups received 5% DSS as drinking water for 7 days. Of the experimental groups, the model control group received ordinary laboratory feed, protein based enteral nutrition (PEN) was fed in the PEN group, while other groups received ordinary laboratory feed plus 5-aminosalicylic acid (5-ASA), methyl-prednisolone, Lactobacillus or glutamine, respectively. On the 8th day, all the rats were sacrificed. Inflammatory scores were assessed from colonic mucosa. Blood culture from inferior vena cava, fecal culture and secretary immunoglobulin-A (S-IgA) levels from colonic contents were determined.

RESULTS

Colon inflammatory scores of Lactobacillus, PEN, glutamine and drug-treated groups were lower than that of the model control group (P < 0.01). The ratios of bacteria translocation in the EN (PEN, Lactobacillus and glutamine) groups were lower than that in the model control group (P < 0.0083). Fecal Lactobacilli in the Lactobacillus and glutamine groups were higher than that in the model control group (P < 0.05). S-IgA levels in colonic contents of the PEN and 5-ASA group were lower than that in the model control group (P < 0.05).

CONCLUSIONS

EN is an effective therapy for treating DDS-induced colitis. EN could alleviate damage, promote the repair of colonic epithelial cells and inhibit bacterial translocation. Lactobacillus and glutamine could also increase the Lactobacilli in colon.

Ultrastructural development of the small intestinal mucosa in the embryo and turkey poult: A light and electron microscopy study

The potential for growth and feed efficiency in turkey poults directly correlates with the early development of the intestinal epithelium. Although the metabolic aspects of enteric maturation have been studied, little is known about the ultrastructural development of the enteric epithelium in the turkey embryo and poult. Hence, the objective of this study was to document the morphological and ultrastructural development of the jejunum mucosa in turkeys, from 15 d of incubation (embryonic day; E) to 12 d posthatch. Intestinal samples from 4 embryos or poults were collected and analyzed by light and electron microscopy (transmission and scanning). In addition, amniotic fluid volume was determined in 6 eggs from E15 to E25. Longitudinal previllus ridges at E15 gradually formed zigzag patterns that led to the formation of 2 parallel lines of mature villi by E25. The volume of amniotic fluid was rapidly depleted as the embryo swallowed it between E19 and E25. During this period, a major increase occurs in villus height, the apical end of epithelial cells is gradually tightened by the junctional complex, and mature goblet cells are visible at the apical end of villi. Villus height steadily increases until reaching a plateau at 8 d. Villi morphology shifts gradually from finger-like projections before hatch to leaf-like projections by 12 d. At this age, the enteric epithelium is in intimate association with microbes such as segmented filamentous bacteria. The profound morphological adaptations of the turkey gut epithelium in response to amniotic fluid swallowing before hatch, and dietary factors and bacteria after hatch, demonstrate the plasticity of the enteric epithelium at this time. Hence, the supplementation of enteric modulators before hatch (in ovo feeding) and after hatch has the potential to shape gut maturation and enhance the growth performance of turkey poults.

Evaluation of the chicory inulin efficacy on ameliorating the intestinal morphology and modulating the intestinal electrophysiological properties in broiler chickens

Chicory (Cichorium intybus) belongs to plants of the Compositae family accumulating energy in the form of inulin fructan. Chicory, a prebiotic, is a fermentable oligosaccharide and oligofructose that may affect the intestinal mucosal architecture and the electrophysiological parameters. Therefore, this study was conducted to evaluate the effectiveness of adding chicory fructans in feed on the intestinal morphology and electrogenic transport of glucose in broilers. Four hundred, 1-day-old broiler chicks were randomly divided into two groups (200 birds per group) for 5 weeks. The dietary treatments were (i) control, (ii) basal diets supplemented with the dried, ground chicory pulp containing inulin (1 kg of chicory/ton of the starter and grower diets). In duodenum, dietary chicory increased the villus height and villus width and villus height to crypt depth ratio (p< 0.05), but the duodenal crypt depth remained unaffected (p > 0.05). However, in jejunum, the villus height, crypt depth and villus height to crypt depth ratio were decreased by dietary chicory compared with control birds (p < 0.05). In ileum, the villus height and villus crypt depth was decreased by dietary chicory supplementation compared with control (p< 0.05), but, the villus height to crypt depth ratio was increased (p< 0.05). Moreover, dietary chicory relatively affected the electrophysiological parameters of the intestine but did not reach significance. The amount of ΔIsc after d-glucose addition to the jejunal mucosa was numerically higher for chicory fed birds (19 μA/cm(2) ) than control birds (10 μA/cm(2) ). The percentage of increase in the Isc after d-glucose addition (ΔIsc %) was higher for chicory group upto (90%) of the control group. In colon, the actual Isc value and Isc after d-glucose addition was numerically higher for chicory fed birds than control birds (p> 0.05). Moreover, the conductance of jejunal and colonic tissues after d-glucose addition remained unaffected by the dietary chicory. In conclusion, addition of chicory to broilers diet increased the duodenal villus height, villus width and villus height to crypt depth ratio and decreased the villus height and crypt depth in both jejenum and ileum. Furthermore, dietary chicory relatively modified the small intestinal electrogenic transport of glucose in broilers.

Inulin and probiotics in newly weaned piglets: effects on intestinal morphology, mRNA expression levels of inflammatory marker genes and haematology

The study aimed at determining the effect of inulin and/or a multispecies probiotic formulation on gastrointestinal tract (GIT) morphology, immunological and haematological parameters. Forty-eight newly weaned piglets were assigned to four feeding groups, receiving a standard basal diet (control), supplemented with 0.4% inulin, probiotics (1 x 10(9) CFU/kg as fed, enterococci, lactobacilli, bifidobacteria) or a combination of both (synbiotic). After four weeks of ad libitum feeding piglets were slaughtered and intestinal tissue samples were obtained for histometry. Additional tissue samples of the GIT, mesenteric lymph nodes, blood, liver and spleen were taken for mRNA expression analysis of cell turnover (CDK4, caspase3, IGF I), transcription factor NFkappaB and inflammatory marker genes (TNFalpha, TGFbeta). Changes in histometry occurred predominantly in the small intestine, showing higher jejunal villi when probiotics were administered alone (p < 0.10). Inulin decreased the number of acidic goblet cells in jejunal villi (p < 0.05), whereas probiotics increased neutral goblet cells in ileal villi (p < 0.05). Though inflammatory marker genes were uninfluenced by treatment in the proximal GIT, the colon showed downregulations induced by inulin (TNFalpha: p < 0.10, TGFbeta: p < 0.05). Gene expression of CDK4 was upregulated in the jejunum and of TGFbeta in the mesenteric lymph nodes in the probiotic groups. Interestingly, the probiotic group alone exhibited upregulations in cell turnover marker genes in the colon and blood. Furthermore, for numerous parameters, inulin and probiotics led to no synergistic but antagonistic interactions.

The role of probiotics in the poultry industry

The increase of productivity in the poultry industry has been accompanied by various impacts, including emergence of a large variety of pathogens and bacterial resistance. These impacts are in part due to the indiscriminate use of chemotherapeutic agents as a result of management practices in rearing cycles. This review provides a summary of the use of probiotics for prevention of bacterial diseases in poultry, as well as demonstrating the potential role of probiotics in the growth performance and immune response of poultry, safety and wholesomeness of dressed poultry meat evidencing consumer's protection, with a critical evaluation of results obtained to date.

Effect of dietary antibiotic, probiotic and prebiotic as growth promoters, on growth performance, carcass characteristics and hematological indices of broiler chickens

This experiment was conducted for comparison the effects of antibiotic (flavomycin), probiotic (primalac), prebiotic (Biolex-MB) and mixture ofprobiotic and prebiotic (primalac plus Biolex-MB) as dietary growth promoter on growth performance, carcass characteristics and hematological indices of broiler chickens. Three hundred day old Ross 308 broilers were equally distributed into 30 floor pens and reared for 42 day. A basal diet was formulated covering the recommendations of NRC (1994) for starter (0-21 days) and grower (22-42 days) periods and considered as control diet. Four tested diets were formulated by supplemented the basal control diet with antibiotic (flavomycin), probiotic (primalac), prebiotic (Biolex-MB) and mixture ofprimalac plus Biolex-MB, respectively. Six replicates were used for each treatment. The results of present study showed that all growth promoters used was improved growth indices of Ross 308 broilers. The highest significant (p<0.05) values of carcass and thigh were recorded for broilers fed diet supplemented with flavomycin. The highest (p>0.05) value of breast was recorded for broilers fed the diet supplemented with primalac, meanwhile the lower value were showed for birds fed either diet or diet supplemented with Biolex-MB. The percent of carcass and cuts followed the same trend. Hematological parameter including cholesterol was recorded the highest (p>0.05) values groups fed the diets either control or supplemented with flavomycin, meanwhile the lower value was showed for bird fed diet supplemented primalac plus Biolex-MB. Triglycerides and very low density lipoprotein cholesterol (VLDL) were recorded the highest concentration for bird fed both control and diet supplemented with flavomycin groups while least concentration was found for bird fed diet supplemented with primalac. The results of present study revealed that probiotic and prebiotic as growth promoters can use as alternatives non-antibiotic feed additives to their free harmful side effects on the consumers and to improve broiler chickens growth indices.

Bacterial-mucosal interactions in inflammatory bowel disease: an alliance gone bad

The complex interaction of genetic, microbial, and environmental factors may result in continuous activation of the mucosal immune system leading to inflammatory bowel disease (IBD). Most present treatments for IBD involve altering or suppressing the aberrant immune response; however, the role of the intestinal microbiota in the pathophysiology of IBD is becoming more evident. The epithelial layer is essential for the proper functioning of the gastrointestinal tract, and its increased permeability to the luminal antigens may lead to the inflammatory processes and mucosal damage observed in IBD. Factors affecting the efficacy of the epithelial barrier include presence of pathogenic bacteria (e.g., Helicobacter spp.), presence of probiotic bacteria, availability of selected nutrients, and others. Defective function of the mucosal barrier might facilitate the contact of bacterial antigens and adjuvants with innate and adaptive immune cells to generate prolonged inflammatory responses. This review will briefly describe the complex structure of the epithelial barrier in the context of bacterial-mucosal interactions observed in human IBD and mouse models of colitis.

Intestinal structure and function of broiler chickens on diets supplemented with a synbiotic containing Enterococcus faecium and oligosaccharides

A feeding trial was conducted on broiler chickens to study the effects of the synbiotic BIOMIN IMBO [a combination of Enterococcus faecium, a prebiotic (derived from chicory) and immune modulating substances (derived from sea algae)], with a dose of 1 kg/ton of the starter diets and 0.5 kg/ton of the grower diets on the intestinal morphometry and nutrient absorption. The general performance was improved (P < 0.05) by the dietary inclusion of synbiotic compared with the controls. Furthermore, the addition of synbiotic increased (P < 0.001) the villus height/crypt depth ratio and villus height in ileum. However, the ileal crypt depth was decreased by dietary supplementation of synbiotic compared with control. The addition of glucose in Ussing chamber produced a significant increase (P ≤ 0.001) in short-circuit current (Isc) in jejunum and colon relative to the basal values in both synbiotic and control groups. However, in jejunum the percentage of Isc increase after glucose addition was higher for synbiotic group (333 %) than control group (45 %). In conclusion, dietary inclusion of synbiotic BIOMIN IMBO increased the growth performance and improved intestinal morphology and nutrient absorption.

Direct-Fed Microbial PrimaLac and Salinomycin Modulate Whole-Body and Intestinal Oxygen Consumption and Intestinal Mucosal Cytokine Production in the Broiler Chick

The current study investigated whole-body O2 consumption, intestinal O2 consumption, and intestinal inflammation status through mucosal cytokine production on broiler chicks fed the direct-fed microbial PrimaLac. One hundred twenty 1-d-old broiler chicks were randomly assigned to 1 of 3 experimental diets: standard starter diet (control), standard starter diet with added salinomycin (SAL), and standard starter diet with added PrimaLac (DFM). Birds were housed in 2 separate rooms, the control and SAL treatments in one room and the DFM in another. Intact ileal and cecal samples were collected on d 19, 20, and 21 after measuring whole-body O2 consumption using indirect calorimetry. The O2 up-take of ileal tissue was measured using an in vitro O2 monitor. Analysis of intestinal immune status of broilers was measured by the relative differences in mRNA of both pro- and antiinflammatory cytokines: interleukin-(IL) 1beta, IL-6, and IL-10 using real-time reverse transcription-PCR. Broilers exhibited a 6 to 16% decrease in whole-body energy expenditures and up to a 47% decrease (P<0.05) in ileal energy expenditures in the DFM group compared with other treatments. The reverse transcription-PCR data demonstrated that DFM consortium numerically altered both pro- and antiinflammatory cytokines within the ileum of 19-d posthatch broilers. These data suggest that direct-fed microbials like PrimaLac increase metabolic efficiency via changes in intestinal physiology and metabolism.