Intraepithelial lymphocyte numbers and histomorphological parameters in the porcine gut after Enterococcus faecium NCIMB 10415 feeding in a Salmonella Typhimurium challenge

Evaluation of Enterococcal Probiotic Usage and Review of Potential Health Benefits, Safety, and Risk of Antibiotic-Resistant Strain Emergence

Enterococci are often used in probiotics but can also cause nosocomial infections. As such, enterococcal consumption may have beneficial health effects, but a thorough evaluation of virulence absence and risk of antibiotic resistance spread is needed at the strain level. This article reviewed ten online health product shopping websites in the US. On these websites, 23 probiotic products using enterococci were found across 12 companies. In addition, this article reviewed studies that demonstrated the probiotic potential of enterococcal consumption (e.g., gastrointestinal and respiratory disease, hyperlipidemia alleviation, as well as infection prevention). To investigate the safety aspects of enterococci, the present work examined studies evaluating virulence factors and antibiotic resistance. Furthermore, this article assessed research that explored these virulent factors, specifically in probiotics containing enterococci, as well as the potential transfer mechanism of their antibiotic resistance. Based on reviewed data, enterococcal probiotic consumption has been proven beneficial for conditions or symptoms of multiple diseases without any apparent adverse effects. However, due to the plasmid- or transposon-mediated gene transfer ability of enterococci, surveillance monitoring and further studies regarding enterococcal consumption are warranted. Future studies that identify enterococcal strains safe to use in probiotics without virulence factors and antibiotic resistance are imperative for evidence-based decisions by health organizations and government agencies.

Immuno-modulatory Effects of Inactivated Dietzia Maris on the Selected Aspects of Cellular and Humoral Immune Responses in Mice

Background

The current study is an attempt to register the alterations in the immunological and histological parameters in mice arising from the administration of Dietza maris (D. maris) in order to confirm its protective properties.

Materials and Methods

Mice underwent 7 days of treatment with three doses of D. maris. Then, animals were scrutinized in terms of body weight, relative weight of organs, delayed type of hypersensitivity (DTH) response, and hemagglutination titer (HT). The determination of villus height, villus width, crypt depth, villus/crypt ratio (V/C), Goblet cells, and intestinal epithelial lymphocyte (IEL) density in villi was carried out.

Results

A boosted DTH response was observed as a result of bacteria at medium dose. A variation was noted between the hemagglutinin titer of the control group and that of the high-dose group. Crypt depth, villus width, and villus height manifested alterations. High-dose-treated mice demonstrated proliferation of Goblet cells in the villi, whereas both in medium- and high-dose-treated mice, a distribution of IELs in the villus epithelium was noted. Overall, D. maris showed a stimulatory effect on immune functions in mice. Thus, thanks to improved cellular and humoral immunity and the increased quality of intestine function, we believe that D. maris promises novel therapeutic applications in the future.

Conclusion

The attained findings lend credence to immuno-stimulatory effects arising from the capacity of D. maris to function as immunological adjuvants and to enhance humoral and cellular immunity as well as the intestinal structure and function.

Intraepithelial lymphocytes in the pig intestine: T cell and innate lymphoid cell contributions to intestinal barrier immunity

Intraepithelial lymphocytes (IELs) include T cells and innate lymphoid cells that are important mediators of intestinal immunity and barrier defense, yet most knowledge of IELs is derived from the study of humans and rodent models. Pigs are an important global food source and promising biomedical model, yet relatively little is known about IELs in the porcine intestine, especially during formative ages of intestinal development. Due to the biological significance of IELs, global importance of pig health, and potential of early life events to influence IELs, we collate current knowledge of porcine IEL functional and phenotypic maturation in the context of the developing intestinal tract and outline areas where further research is needed. Based on available findings, we formulate probable implications of IELs on intestinal and overall health outcomes and highlight key findings in relation to human IELs to emphasize potential applicability of pigs as a biomedical model for intestinal IEL research. Review of current literature suggests the study of porcine intestinal IELs as an exciting research frontier with dual application for betterment of animal and human health.

Starch-protein interaction effects on lipid metabolism and gut microbes in host

The purpose of this experiment was to investigate the effects of different starch and protein levels on lipid metabolism and gut microbes in mice of different genders. A total of 160 male mice were randomly assigned to sixteen groups and fed a 4 × 4 Latin square design with dietary protein concentrations of 16, 18, 20, and 22%, and starch concentrations of 50, 52, 54, and 56%, respectively. The results of the study showed that different proportions of starch and protein had obvious effects on the liver index of mice, and there was a significant interaction between starch and protein on the liver index (p = 0.005). Compared with other protein ratio diets, 18% protein diet significantly increased the serum TBA concentration of mice (p < 0.001), and different starch ratio diets had no effect on serum TBA concentration (p = 0.442). It was proved from the results of ileal tissue HE staining that the low protein diet and the low starch diet were more favorable. There was a significant interaction between diets with different starch and protein levels on Bacteroidetes, Firmicutes and Proteobacteria abundance in feces of mice (p < 0.001). Compared with 16 and 18% protein ratio diets, both 20 and 22% protein diets significantly decreased the Parabacteroides and Alistipes abundance in feces of mice (p < 0.05), and 52% starch ratio diet significantly decreased the Parabacteroides and Alistipes abundance than 50% starch ratio diet of mice (p < 0.05). There was a significant interaction between diets with different starch and protein levels on Parabacteroides (p = 0.014) and Alistipes (p = 0.001) abundance in feces of mice. Taken together, our results suggest that a low protein and starch diet can alter lipid metabolism and gut microbes in mice.

Effects of essential oil extracted from Artemisia argyi leaf on lipid metabolism and gut microbiota in high-fat diet-fed mice

Artemisia argyi leaf is a well-known species in traditional Chinese medicine, and its essential oil (AAEO) has been identified to exert various physiological activities. The aim of this study was to investigate the effects of AAEO on lipid metabolism and the potential microbial role in high-fat diet (HFD)-fed mice. A total of 50 male mice were assigned to five groups for feeding with a control diet (Con), a high-fat diet (HFD), and the HFD plus the low (LEO), medium (MEO), and high (HEO) doses of AAEO. The results demonstrated that dietary HFD markedly increased the body weight gain compared with the control mice (p < 0.05), while mice in the HEO group showed a lower body weight compared to the HFD group (p < 0.05). The weight of fatty tissues and serum lipid indexes (TBA, HDL, and LDL levels) were increased in response to dietary HFD, while there was no significant difference in AAEO-treated mice (p < 0.05). The jejunal villus height was dramatically decreased in HFD-fed mice compared with the control mice, while HEO resulted in a dramatically higher villus height than that in the HFD group (p < 0.05). Microbial α-diversity was not changed in this study, but β-diversity indicated that microbial compositions differed in control, HFD, and EO subjects. At the genus level, the relative abundance of Bacteroides was greater (p < 0.05) in the feces of the Con group when compared to the HFD and EO groups. On the contrary, the abundance of Muribaculum was lower in the Con group compared to the HFD and EO groups (p < 0.05). Although the Muribaculum in the EO group was lower than that in the HFD group, there was no statistically notable difference between the HFD and EO groups (p > 0.05). Simultaneously, the relative abundance of Alistipes (p < 0.05) and Rikenella (p < 0.05) was also dramatically higher in the Con group than in the HFD and EO groups. The abundance of norank_f__norank_o__Clostridia_UCG-014 was lower in the HFD or EO group than in the Con group (p < 0.05). In conclusion, the results suggested that HEO could affect body weight and lipid metabolism without gut microbes in ICR mice, and it was beneficial for the structure of the jejunal epithelial tissue.

Linkages of Various Calcium Sources on Immune Performance, Diarrhea Rate, Intestinal Barrier, and Post-gut Microbial Structure and Function in Piglets

The purpose of this experiment was to investigate the effects of different sources of calcium on immune performance, diarrhea rate, intestinal barrier, and post-intestinal flora structure and function in weaned piglets. A total of 1,000 weaned piglets were randomly assigned to five groups 10 replicate pens per treatment, 20 piglets per pen and fed calcium carbonate, calcium citrate, multiple calcium, and organic trace minerals of different concentrations of acidifier diets. The results of the study showed that the replacement of calcium carbonate with calcium citrate and multiple calcium had almost no significant effect on immune indexes (IL-1β, IL-6, IL-10, TNF-α) of piglets compared with the control group (p > 0.05). The five groups did not show a change in the diarrhea rate and diarrhea index (p > 0.05). The diet containing multiple calcium dramatically decreased the TP compared to the C and L diet (p < 0.05). No significant difference in HDL was noted in the five groups (p > 0.05). However, the concentration of LDL in blood in the multiple calcium group was significantly higher than that in groups L and D (p < 0.05). Moreover, the concentration of Glu in blood in the multiple calcium group was significantly higher than that in group C (p < 0.05). Compared with the control group, calcium citrate plus organic trace minerals diet markedly increased UCG-005 abundance in the colon (p < 0.05). In addition, the relative abundance of Prevotellaceae_NK3B31_group had an upward trend in the colon of the M group compared to the D group (p = 0.070). Meanwhile, calcium citrate plus organic trace minerals diet markedly increased Clostridium_sensu_stricto_1 abundance in the colon (p < 0.05). Metagenomic predictions by PICRUSt suggested that the colonic and fecal microbiota was mainly involved in carbohydrate metabolism, amino acid metabolism, energy metabolism, and metabolism of cofactors and vitamins.

Effects of Diets With Different Protein Levels on Lipid Metabolism and Gut Microbes in the Host of Different Genders

The purpose of this experiment was to investigate the effects of different protein levels on lipid metabolism and gut microbes in mice of different genders. A total of 60 mice (30 female and 30 male) were randomly assigned to six groups and fed female mice with low protein diet (FLP), basal protein diet (FBD), and high protein diet (FHP). Similarly, the male mice fed with low protein diet (MLP), basal protein diet (MBD), and high protein diet (MHP). The low protein diet contained 14% CP, the basal diet contained 20% CP, and the high protein diet contained 26% CP. The results of the study showed that both basal and high protein diets significantly reduced the perirenal adipose tissues (PEAT) index in male mice compared to low protein diet (p < 0.05). For the gut, the FHP significantly increased the relative gut weight compared to the FBD and FLP (p < 0.05). At the same time, the FHP also significantly increased the relative gut length compared with the FBD and FLP (p < 0.05). The MHP significantly increased TC concentration compared with the MLP (p < 0.05), and the MBD tended to increase TC concentration compared with the MLP in serum (p = 0.084). The histomorphology result of the jejunum and ileum showed that a low protein diet was beneficial to the digestion and absorption of nutrients in the small intestine of mice. While different protein levels had no effect on the total number of fecal microbial species in mice, different protein levels had a significant effect on certain fecal microbes in mice, the absolute abundance of Verrucomicrobia in the feces of male mice was significantly higher in both high and basal protein diets than in the low protein diet (p < 0.05). The high protein diet significantly reduced the absolute abundance of Patescibacteria in the feces of female mice compared to both the basal and low protein diets (p < 0.05). The absolute abundance of Patescibacteria in male feces was not affected by dietary protein levels (p > 0.05). Taken together, our results suggest that a low protein diet can alter fat deposition and lipid metabolism in mice, and that it benefited small intestinal epithelial structure and microbes.

De-oiled soy lecithin positively influenced growth performance, nutrient digestibility, histological intestinal alteration, and antioxidant status in turkeys fed with low energy diets

1. The purpose of this research was to investigate the effects of supplementing an emulsifier (de-oiled soybean lecithin (DSL)) in a low metabolisable energy (ME) diet on growth performance, nutrient digestibility, carcase characteristics, intestinal morphology, blood metabolites, and antioxidant status in growing turkeys.2. A total of 480 one-day-old turkeys were assigned to one of four dietary treatments with of eight replicates of 15 birds each. Experimental treatments included a basal diet (BE) with commercially recommended levels of ME, a reduced energy diet (RE) with 0.42 MJ/kg reduction in dietary ME content, the RE diet + 1 g/kg DSL (DSL-1), and RE + 2 g/kg DSL (DSL-2).3. After 112 days, the body weight, average daily gain, and feed:gain in turkeys fed the supplemented for BE diets were better (P < 0.05) than in those fed RE, and those fed diet DSL-2 had the best performance. Although the RE diet decreased abdominal fat and relative liver weight (P < 0.05), compared to the BE diet, and supplementation with either level of DSL did not influence these variables.4. There were linear increases (P < 0.05) in fat digestibility, nitrogen-corrected apparent ME, and duodenal villus height, villus height/crypt depth ratio, and villus surface area in LE diet supplemented with DSL. From the jejunal morphology, crypt depth was decreased by DSL-supplemented diets (P < 0.05).5. Serum triglyceride, total cholesterol, and malondialdehyde concentrations were lower, whereas the serum superoxide dismutase activity was greater for the DSL-2 group compared to the BE and RE groups (P < 0.05).6. The findings suggested that, while low-ME diets impaired turkey growth performance, dietary supplementation of DSL could reverse such impacts of these diets. The DSL-supplemented diet at the inclusion level of 2 g/kg was advantageous over both BE and RE diets in terms of intestinal morphology, lipid profile, and antioxidant status in growing turkeys.

Immunomodulatory responses in plectasin-supplemented broilers under tropical environmental conditions

The present study was aimed to determine the immunomodulatory effects of dietary supplementation of the antimicrobial peptide (AMP) plectasin on broiler chickens. The experiment involved 300-day-old Ross chicks reared in a conventional housing system and subjected to ambient temperature and relative humidity. The birds were randomly allocated to five treatment groups: the non-supplemented negative control group (T1), enramycin-supplemented group (T2), and groups supplemented with varying doses of plectasin at 150 ppm, 300 ppm, and 450 ppm (T3, T4, and T5, respectively) from day 1 to 35. The results indicated that plectasin supplementation increased jejunal and ileal goblet cell (GC) counts, serum interferon-gamma (IFN-γ) levels at neonatal age, and serum immunoglobulin Y (IgY) titer on days 7, 21, 28, and 35. These findings confirmed that plectasin induces positive immunomodulatory responses by specifically enhancing gut mucosal barriers, early innate immunity, and humoral immune response. Specifically, supplementation at 150 ppm may be considered as the optimal dose for inclusion in broiler chicken feeds.

Effect of vitamin E and alpha lipoic acid on intestinal development associated with wooden breast myopathy in broilers

Intestinal development is closely associated with inflammatory wooden breast (WB) myopathy. Vitamin E (VE) and alpha lipoic acid (ALA) with antioxidant and anti-inflammatory effects were used independently and in combination to evaluate their effects on intestinal developmental changes in ileal morphology and expression of genes related with gut nutrient transport, structure, and inflammation in broilers during the first 3 wk posthatch. A total of 160 newly hatched Ross 708 broiler chicks were randomly assigned into a control and 3 dietary treatments with 10 replicates of 4 birds each. Supplementation of VE (160 mg/kg) and ALA (500 mg/kg) independently and in combination were fed during the first 3 wk. At 1, 2, and 3 wk of age, one chick from each pen was harvested. Plasma VE concentration and ileal morphology were determined. Gene expression was measured by real-time quantitative PCR. Broilers in VE and combination of ALA and VE group had higher plasma VE concentration than the control and ALA group at 1, 2, and 3 wk of age (P < 0.01). All dietary treatments increased ileal villus height at 1 wk of age (P < 0.01) and decreased intraepithelial lymphocytes at 3 wk of age compared to the control (P ≤ 0.05). Combination of VE and ALA increased collagen type IV alpha 1 chain expression (P ≤ 0.05) and improved basement membrane structure indicating increased gut basement membrane integrity at 2 and 3 wk of age compared to the control. Expression of lipopolysaccharide-induced tumor necrosis factor-alpha factor associated with inflammation was decreased in all dietary treatments at 3 wk of age compared to the control (P < 0.01). Ileal morphology and gene expression were closely correlated with breast muscle morphology and gene expression. These results suggest that VE and ALA especially when they were combined in the diet had positive effects on mitigating intestinal inflammation and improving nutrient transport beginning at 1 wk of age, which is likely critical in reducing the severity of WB.

Supplementation of vitamin E and omega-3 fatty acids during the early posthatch period on intestinal morphology and gene expression differentiation in broilers

Early posthatch nutrition is important for gut health. Vitamin E (VE) and omega-3 (n-3) fatty acids can improve gut health through antioxidative and anti-inflammatory effects. The objective of this study was to identify the effects of VE, n-3 fatty acids, and combination of both during the starter phase (0–10 d) or grower phase (11–24 d) on intestinal morphology and expression of genes associated with gut health. A total of 210 Ross 708 broilers were randomly assigned into 7 treatments with 10 replicates of 3 birds each. The control group was fed a corn–soybean meal–basal diet during the entire study (0–58 d). Supplementation of VE (200 IU/kg), n-3 fatty acids (n-6/n-3 ratio of 3.2:1), and combination of both were fed during the starter phase (0–10 d) or grower phase (11–24 d). All of the broilers were harvested at 58 d of age. Villus height, crypt depth, villus width, distance between villi, and number of intraepithelial lymphocytes were obtained. Expression of 21 genes was measured using NanoString analysis. Expression of solute carrier family 15 member 1 (P = 0.01) associated with peptide transport and mucin 2 (P = 0.03) related with intestinal mucus barrier was increased in the broilers supplemented with n-3 fatty acids in the grower diet compared with the control. Expression of solute carrier family 7 member 1 associated with amino acid transport was decreased in the group supplemented with n-3 fatty acids during the starter phase compared with the group supplemented with n-3 fatty acids (P = 0.01) or VE and n-3 fatty acids during the grower phase (P = 0.03). These data suggest that VE and n-3 fatty acids supplemented during the grower phase have a positive effect on improving nutrient transport with n-3 fatty acids supplementation in the grower diet showing the most beneficial effect. These findings can be used in the development of nutritional management strategies to improve broiler growth performance and meat quality.

Intraepithelial T Cells Diverge by Intestinal Location as Pigs Age

T cells resident within the intestinal epithelium play a central role in barrier integrity and provide a first line of immune defense. Intraepithelial T cells (IETs) are among the earliest immune cells to populate and protect intestinal tissues, thereby giving them an important role in shaping gut health early in life. In pigs, IETs are poorly defined, and their maturation in young pigs has not been well-studied. Given the importance of IETs in contributing to early life and long-term intestinal health through interactions with epithelial cells, the microbiota, and additional environmental factors, a deeper characterization of IETs in pigs is warranted. The objective of this study was to analyze age- and intestinal location-dependent changes in IETs across multiple sites of the small and large intestine in pigs between 4- and 8-weeks of age. IETs increased in abundance over time and belonged to both γδ and αβ T cell lineages. Similar compositions of IETs were identified across intestinal sites in 4-week-old pigs, but compositions diverged between intestinal sites as pigs aged. CD2⁺CD8α⁺ γδ T cells and CD4^-CD8α⁺ αβ T cells comprised >78% of total IETs at all intestinal locations and ages examined. Greater percentages of γδ IETs were present in large intestine compared to small intestine in older pigs. Small intestinal tissues had greater percentages of CD2⁺CD8α^- γδ IETs, while CD2⁺CD8α⁺ γδ IET percentages were greater in the large intestine. Percentages of CD4^-CD8α⁺ αβ IETs increased over time across all intestinal sites. Moreover, percentages of CD27⁺ cells decreased in ileum and large intestine over time, indicating increased IET activation as pigs aged. Percentages of CD27⁺ cells were also higher in small intestine compared to large intestine at later timepoints. Results herein emphasize 4- to 8-weeks of age as a critical window of IET maturation and suggest strong associations between intestinal location and age with IET heterogeneity in pigs.

Supplementing neonatal Jersey calves with a blend of probiotic bacteria improves the pathophysiological response to an oral Salmonella enterica serotype Typhimurium challenge

The objectives of the current study were to determine the effects of supplementing a blend of probiotic bacteria (Provida Calf, MB Nutritional Sciences, Lubbock, TX) on the pathophysiological response to an oral Salmonella enterica serotype Typhimurium challenge in neonatal Jersey calves. Twenty-four Jersey bull calves within 24 h of birth were acquired from a local calf ranch, blocked by total serum protein and initial body weight, and randomly assigned to 1 of 3 treatments (n = 8). Calves were assigned to either (1) Control (CON); base milk replacer, (2) Control + Salmonella Typhimurium (CON+ST); base milk replacer and challenged with Salmonella Typhimurium on d 7; or (3) Provida Calf probiotics + Salmonella Typhimurium (PRO+ST); same milk replacer supplemented with a proprietary blend of Lactobacillus casei and Enterococcus faecium strains and challenged with Salmonella Typhimurium on d 7. The PRO+ST calves were supplemented for the first 3 d with 2 × 10¹⁰ cfu/d and then with 2 × 10⁹ cfu/d for the remainder of the study. The CON+ST and PRO+ST calves were each challenged with approximately 5 × 10⁶ cfu of Salmonella Typhimurium (ATCC# 14028), which was a mild challenge that did not cause scours in the calves. Peripheral blood samples were collected on d 0, 7, 10, 14, and 21 and analyzed for hematology; serum was collected and analyzed for haptoglobin, glucose, and urea N. Rectal temperatures were collected daily from d 6 to 21, when all calves were killed, so that persistent colonization of Salmonella Typhimurium and histomorphology of both the duodenum and ileum could be determined. Serum haptoglobin and urea N concentrations were increased among CON+ST on d 10. In contrast, the peak rectal temperature on d 10 in PRO+ST calves was 40.4°C, which was greater than that for CON and CON-ST (38.9°C and 39.7°C, respectively). The neutrophil percentage in peripheral circulation in PRO+ST calves was 55.4%, which was greater than that for CON and CON+ST (34.8 and 41.8%, respectively). Seven of the 8 PRO+ST calves had elevated neutrophil percentages on d 10 compared with d 7, whereas 4 of the 8 CON+ST calves had reduced neutrophil percentages on d 10 compared with d 7. Villus height-to-crypt depth ratios in the duodenum were greater among CON and PRO+ST calves, being 1.38, 0.84, and 1.43 for CON, CON+ST, and PRO+ST, respectively. In the ileum, the PRO+ST calves had greater villus height-to-crypt depth ratios than both the CON and CON+ST calves (1.64, 1.53, and 2.43 for CON, CON+ST, and PRO+ST, respectively). These data indicate that supplementing neonatal calves with the blend of probiotic bacteria used in the current study can influence the pathophysiological response to a mild enteric Salmonella Typhimurium challenge.

Effect of Probiotics and Herbal Products on Intestinal Histomorphological and Immunological Development in Piglets

The aim of the study was to evaluate the effect of probiotics and herbal products on the intestinal histomorphological and immunological development in piglets. Accordingly, 2-week-old piglets were allocated in 4 groups: C (basal diet), Pro (basal diet + probiotics), Pro+B (basal diet + probiotics + buckwheat bran), and H (powder of herbs). After 6 weeks of the experiment, 4 piglets from each experimental group were randomly selected and slaughtered at a slaughterhouse. Samples of tissue and digestive content from the jejunum and colon were collected for bacteriological, histological, and immunohistochemical examination. The results showed that probiotics increased the number of Lactobacillus spp. in the small (p < 0.05) and large intestines. The intestinal histomorphology was improved (p < 0.05) in all experimental groups by an increased villus height, VH : CD ration, colon crypt depth, and number of Ki-67⁺ epithelial cells. A higher number (p < 0.05) of goblet cells and their acidification were observed in group Pro, while the density of goblet cells was decreased by the herbs. Probiotics increased (p < 0.05) the number of intraepithelial lymphocytes (IELs), density of CD3⁺ cells in Peyer's patches (PPs), and lamina propria (LP). In group H, a dual effect on the CD3⁺ cell distribution was observed. The herbs reduced (p < 0.05) the number of IELs and CD3⁺ in LP but increased the distribution of CD3⁺ cells in PPs. In the colon, herbs increased CD3⁺ cells in LP as well. It suggests that probiotics and herbs had influence on the intestinal histomorphology and the ability to modulate the mucosal immune system; however, the combination of probiotics and buckwheat bran was not so convincing, probably due to the inhibitory effect of the buckwheat bran on the probiotics used.

The pig as a model for immunology research

The pig is an omnivorous, monogastric species with many advantages to serve as an animal model for human diseases. There are very high similarities to humans in anatomy and functions of the immune system, e g., the presence of tonsils, which are absent in rodents. The porcine immune system resembles man for more than 80% of analyzed parameters in contrast to the mouse with only about 10%. The pig can easily be bred, and there are less emotional problems to use them as experimental animals than dogs or monkeys. Indwelling cannulas in a vein or lymphatic vessel enable repetitive stress-free sampling. Meanwhile, there are many markers available to characterize immune cells. Lymphoid organs, their function, and their role in lymphocyte kinetics (proliferation and migration) are reviewed. For long-term experiments, minipigs (e.g., Göttingen minipig) are available. Pigs can be kept under gnotobiotic (germfree) conditions for some time after birth to study the effects of microbiota. The effects of probiotics can be tested on the gut immune system. The lung has been used for extracorporeal preservation and immune engineering. After genetic modifications are established, the pig is the best animal model for future xenotransplantation to reduce the problem of organ shortage for organ transplantation. Autotransplantation of particles of lymphnodes regenerates in the subcutaneous tissue. This is a model to treat secondary lymphedema patients. There are pigs with cystic fibrosis and severe combined immune deficiency available.

Construction and immune efficacy of recombinant Lactobacillus casei strains expressing Malt from Aeromonas veronii

Aeromonas veronii is an important zoonotic pathogen that causes significant economic losses in the aquaculture industry. The use of probiotics in aquaculture is a practical alternative to antibiotics to promote animal health and aid in disease prevention. In the present study, we aimed to construct a recombinant Lactobacillus casei(surface-displayed or secretory) strain containing Malt from A. veronii TH0426 and assess its potential as an oral vaccine. A 1314-bp Malt gene fragment was successfully amplified and cloned into a prokaryotic protein expression system. Protein expression in resulting recombinant strains Lc-MCS-Malt (surface-displayed) and Lc-pPG-Malt (secretory) was then verified by Western blotting and indirect immunofluorescence. A single band was observed on the Western blots, with the molecular weight of the corresponding protein shown to be 48 kDa. Furthermore, a fluorescent signal for Lc-MCS-Malt was observed by fluorescence microscopy. At 0, 7, 16, 25, and 34 days post-immunization, tissue and blood samples were collected from common carp orally administered with the recombinant L. casei strains for immune-related index analyses. Treatment of common carp with the recombinant vaccine candidate stimulated high serum or skin mucus specific antibody titers and induced a higher lysozyme, ACP, SOD activity, while fish fed with Lc-pPG or PBS had no detectable immobilizing immune responses. Expression of IL-10, IL-1β, TNF-α, and IFN-γ genes in the group immunized with recombinant L. casei were significantly (P < 0.05) up regulated as compared with control groups, indicating that inflammatory response and cell immune response were triggered. Results also showed that recombinant L. casei could stimulate the mucosa through colonization of the intestine, resulting in increased transcription of IL-10, IL-1β, TNF-α, and IFN-γ. Immunity and colonization assays also showed that after 34 days of fasting, recombinant L. casei were still present in the intestines of the immunized fish. Common carp that received Lc-MCS-Malt(53.3%) and Lc-pPG-Malt (46.7%) exhibited higher survival rates than the controls after challenge with the pathogen A. veronii. Our findings suggested that recombinant L. casei can adequately protect fish and improve immunity, providing a theoretical basis for the future development of an oral Lactobacillus vaccine for use in aquaculture.

Effect of a "diluted" diet containing 10% lignocellulose on the gastrointestinal tract, intestinal microbiota, and excreta characteristics of dual purpose laying hens

Low performing dual purpose hens have different nutritional requirements compared to conventional hybrid hens. Lignocellulose is a low fermentable polymer, acting as a diet diluent and may influence physiological and digestive processes. This study investigated the effect of a 10% dietary lignocellulose dilution on the development of gastrointestinal organs, intestinal morphology, intestinal microbiota, and excreta characteristics of dual purpose hens. One-day-old female Lohmann Dual chicks were allocated to 12 pens and fed two different diets: A standard control diet (CON) and a treatment diet (LC), based on CON but diluted with 10% lignocellulose (ARBOCEL®). At 52 wk of age, gastrointestinal organs were extracted and weights determined. Colorectal tissue samples were chemically fixed and stained for histomorphological examinations. Cecal digesta samples were analyzed for bacterial metabolites and composition using gas chromatography, HPLC, photometry, and PCR. Excreta dry matter and viscosity was consistently assessed during the trial. LC-fed hens showed increased weights of the gizzard (P = 0.003), small (P < 0.001), and large intestine (P = 0.048) compared to hens fed CON. LC-fed hens had a larger colorectal villus area (P = 0.049), a higher mucosal enlargement factor of villi (P = 0.016) and crypts (P = 0.030) than CON-fed hens. The concentration of short-chain fatty acids (SCFAs) (P = 0.017) and ammonia (P = 0.013) was higher in CON-fed hens compared to LC-fed hens. Bacterial composition and activity was generally not affected by feeding the different diets. LC-fed hens had a higher excreta dry matter content than hens fed CON at 10 (P < 0.001), 17 (P < 0.001), and 22 (P = 0.002) wk of age. Correlation analyses revealed a negative relationship between the concentration of SCFAs in the cecum and the colorectal villus surface area (P < 0.01). In conclusion, the feeding of high levels of lignocellulose increased gastrointestinal organ weights and colorectal surface area in dual purpose laying hens. A higher intestinal surface area in combination with lower concentrations of SCFAs might indicate a compensatory reaction of hens fed LC enhancing the absorption of bacterial metabolites by increasing the intestinal mucosal surface.

Influence of monostrain and multistrain probiotics on immunity, intestinal ultrastructure and microbiota in experimental dysbiosis

The biological effects of three probiotic strains Lactobacillus rhamnosus K32, Bifidobacterium longum GT15, Enterococcus faecium L3 and their mixture were studied using a model of dysbiosis induced in rats by antibiotics. It was found that after taking different probiotics intestinal microbiota changed in a strain-specific manner. The maximal activity against pathogens was revealed after the administration of a mixture of bacterial strains under study or a single strain of enterococci. The strain E. faecium L3 showed the most activity against both Klebsiella spp. and Bacteroides fragilis. It helped to restore the original content of Faecalibacterium prausnitzii. The number of Klebsiella spp. was the same in the group receiving L. rhamnosus K32 and the group of animals, which was not consuming probiotics. Different probiotic strains included in the composition had various immunological effects. Probiotic bifidobacteria, enterococci and the mixture of three probiotics stimulated of mRNA expression of interleukin (IL)-10 in mesenteric lymph nodes. The changes in microbiota after consuming an enterococcal probiotic correlated with an increase in transforming growth factor (TGF)-β and IL-10 content in blood serum and an increase of the intestinal mucus layer. Consumption of L. rhamnosus K32 led to the stimulation of IL-8 expression in mesenteric lymph nodes. Control group not receiving probiotics was characterised by expression of pro-inflammatory cytokines, damage of epithelial cells and the destruction of their tight junctions. The damage to the ultrastructure of the mucosa was prevented in all the groups taking probiotics.

Comparison of the gastrointestinal tract of a dual-purpose to a broiler chicken line: A qualitative and quantitative macroscopic and microscopic study

The transition to using dual-purpose chickens is an alternative to killing male hatchlings of high performance egg-laying chickens. This study aimed to compare the gastrointestinal tract of a recently developed genetic line of dual purpose male chicken, Lohmann Dual (LD), with that of a broiler line, Ross 308. Eighty birds from each line were grown until they reached an average body weight 2000 g (5 weeks for Ross and 9 for LD birds). Six birds of each line were sampled weekly. Body weight (BW), normalized mass of gastrointestinal segments and relative length of intestine were determined. Histologically the villus height, epithelium height, crypt depth, mucosal enlargement factor and the tunica muscularis thickness were measured in jejunum and ileum. Data were regressed against body weight and genetic line. Jejunal enterocyte microvilli and junctional complexes length were measured. Normalized mass and relative length of the gastrointestinal segments were greater in LD birds than in Ross birds at all ages. After day 7 these decreased steadily over the lifetime of the birds in both genetic lines. The growth curves of the gastrointestinal segments of the LD birds were similar to those of the Ross birds. In birds of the same BW, LD birds had a significantly heavier gizzard, shorter intestine, higher jejunal villi, thicker ileal tunica muscularis and smaller ileal mucosal enlargement factor than were found in Ross birds. The large gizzard in LD chickens presumably increases the degree of food processing and enhances availability of nutrients in the orad part of the intestine leading to a lower nutrient concentration and a smaller absorption surface area in the ileum of the LD compared to the Ross chickens. The anatomical differences between the two lines are important criteria for further selection and should be considered in their feeding management.

Effect of probiotic Saccharomyces boulardii in experimental giardiasis

The aim of the study was to assess the efficacy of Saccharomyces boulardii in experimental treatment of giardiasis and its impact on intestinal integrity and some functions of gerbils infected with Giardia lamblia. 28 gerbils (Meriones unguiculatus), aged 4-6 weeks, were divided into four groups: untreated and uninfected control (CT); infected with G. lamblia (IGL); treated with S. boulardii (SB); and infected with G. lamblia and treated with S. boulardii (ITSB). The SB and ITSB groups received S. boulardii 15 days prior to being infected with G. lamblia. The treatment continued until completion of the experiment (22nd day). The IGL and ITSB groups were gavage-inoculated with G. lamblia ensuring one-week infection. 4 h before euthanasia, all animals were gavaged with a solution containing diethylenetriamine-pentaacetic acid (DTPA) marked with technetium-99mTc DTPA to determine intestinal permeability. The small intestine was removed for histopathological, morphometric analysis and count of trophozoites adhered to the mucosa. The selected probiotic caused an approximate reduction of 70% of parasite load, which was determined by attached trophozoites (P<0.01) and immune-marked trophozoites (P<0.05). Treatment with S. boulardii (SB and ITSB groups) also increased the height of the intestinal villi and crypt depth compared to the CT and IGL groups (P<0.05). The area of mucus production and the number of goblet cells of the SB and ITSB groups were higher compared to the CT and IGL groups (P<0.01). The animals treated with S. boulardii also exhibited a significant increase of intraepithelial lymphocytes counts (P<0.01). There was no difference in the intestinal permeability between the groups studied. The efficacy of S. boulardii in reducing damages caused by Giardia was demonstrated, with an approximate reduction of 70% of the parasite load, suggesting its use as a coadjuvant in giardiasis treatment.

Effect of dietary oridonin supplementation on growth performance, gut health, and immune response of broilers infected with Salmonella pullorum

Background

The effects of dietary supplementation of oridonin (ORI) on growth performance, cecal microbiota, epithelium development and antioxidant and immune parameters of broilers infected with S. pullorum were studied. A total of 300 1-d-old male chicks were selected and divided into 5 trial groups (6 replicates of 10 chickens): 1) nonchallenge control chicks (CON), 2) chicks treated with Salmonella Challenged Control (SCC), 3) chicks treated with S. pullorum challenge and 50 mg/kg ORI (O1), 4) chicks treated with S. pullorum challenge and 80 mg/kg ORI (O2), and 5) chicks treated with S. pullorum challenge and 100 mg/kg ORI (O3).

Results

The results showed that S. pullorum had no effect on the feed intake (FI), body weight gain (BWG) or feed conversion ratio (FCR) of broilers compared with the values measured for the CON group (P > 0.05). However, compared with the characteristics of CON, S. pullorum showed effects on the counts of Salmonella and Lactobacillus at 7 d and at 14 d (P < 0.05), on jejunal development at 7 d (P < 0.05), and on jejunal immunoglobulin A (IgA) concentration at 7 d (P < 0.05). The addition of 100 mg/kg ORI had the greatest effect on the counts of Lactobacillus and Salmonella in cecal content (P < 0.05), malonaldehyde (MDA) content in the jejunum (P < 0.05), villi height of the small intestine, and IgA concentrations in the jejunum (P < 0.05).

Conclusions

The results suggest that ORI can improve Salmonella-induced immune responses and protect intestinal health, not only through its immune inhibitory properties but also through its multi-protective effects on gut health.

Effect of sodium butyrate on performance, immune status, microarchitecture of small intestinal mucosa and lymphoid organs in broiler chickens

Objective

This study aimed to examine the effect of sodium butyrate (SB) on growth performance, immune status, organs weights, and microarchitecture of lymphoid organs and small intestine.

Methods

A total of 120, 1-d-old broiler chicks were distributed into the following four treatment groups: corn-soy based basal diet (BD) without supplement (control), or the same BD supplemented with 0.1 g/kg zinc bacitracin (ZnB), 0.5 g/kg SB (SB-0.5), or 1.0 g/kg SB (SB-1), respectively. Six birds/group were killed on d-21 and d-35, and samples were collected.

Results

Cell-mediated immune response at 48 h post-Phytohemagglutinin-P injection, and antibody titer against Newcastle disease vaccine and sheep red blood cells on d-35 was noted higher (p<0.05) in SB-1 compared to ZnB and control. Lower (p<0.05) feed conversion ratio (FCR) was attained by the supplemented groups. Thymus and spleen weighed more (p<0.05) in SB-1, and bursa registered more (p<0.05) weight in both SB groups compared to control. On d-21, areas of thymus medulla and spleen germinal centers were noted higher (p<0.05) in SB-1 group. The villus height and villus surface area increased (p<0.05) in duodenum and jejunum in both SB groups on d-21, and in SB-1 on d-35, respectively compared to ZnB and control. On d-21, number of goblet cells containing mucins of acidic nature increased (p<0.05) in all the segments of small intestines in SB-1 group compared to control, and on d-35 in ileum compared to other groups.

Conclusion

In conclusion, SB improved growth performance and immunity as well as modulated morphology of lymphoid organs and gut mucosa in broiler chickens.

Isolation of lactic acid bacteria from swine milk and characterization of potential probiotic strains with antagonistic effects against swine-associated gastrointestinal pathogens

Probiotics are usually isolated from the gastrointestinal tract of humans and animals. The search of probiotics in human milk is a recent field of research, as the existence of the human milk microbiome was discovered only about a decade ago. To our knowledge, no reports regarding the potential probiotic effect of bacteria from swine milk have been published. In this work, we isolated several lactic acid bacteria from swine milk and evaluated them for them potential as probiotics. Among the isolated strains, Lactobacillus curvatus TUCO-5E showed antagonistic effects against swine-associated gastrointestinal pathogens. TUCO-5E was able to reduce the growth of enterotoxigenic and enterohemorrhagic Escherichia coli strains as well as pathogenic salmonella. In vitro exclusion and displacement assays in intestinal epithelial cells showed a remarkable antagonistic effect for L. curvatus TUCO-5E against Salmonella sp. strain TUCO-I7 and Salmonella enterica ATCC 13096. Moreover, by using a mouse model of Salmonella infection, we were able to demonstrate that preventative administration of L. curvatus TUCO-5E for 5 consecutive days was capable of decreasing the number of Salmonella enterica serovar Typhimurium in the liver and spleen of treated mice, compared with the controls, and prevented dissemination of the pathogen to the blood stream. Therefore, we have demonstrated here that swine milk is an interesting source of beneficial bacteria. In addition, the results of this work suggest that L. curvatus TUCO-5E is a good candidate to study in vivo the protective effect of probiotics against intestinal infection and damage induced by Salmonella infection in the porcine host.

Enhancement of immunohistochemical detection of Salmonella in tissues of experimentally infected pigs

Salmonella Typhimurium is one of the main pathogens compromising porcine and human health as well as food safety, because it is a prevailing source of foodborne infections due to contaminated pork. A prominent problem in the management of this bacteriosis is the number of subclinically infected carrier pigs. As very little is known concerning the mechanisms allowing Salmonella to persist in pigs, the objective of this study was to develop an immunohistochemical approach for the detection of salmonellae in tissue of pigs experimentally infected with Salmonella Typhimurium. Samples were obtained from a challenge trial in which piglets of the German Landrace were intragastrically infected with Salmonella enterica serovar Typhimurium DT104 (1.4-2.1x1010 CFU). Piglets were sacrificed on days 2 and 28 post infection. Tissue samples of jejunum, ileum, colon, ileocecal mesenteric lymph nodes (Lnn. ileocolici), and tonsils (Tonsilla veli palatini) were fixed in Zamboni's fixative and paraffin-embedded. Different immunohistochemical staining protocols were evaluated. Salmonella was detected in varying amounts in the tissues. Brown iron-containing pigments in the lymph nodes interfered with the identification of Salmonella if DAB was used as a staining reagent. Detergents like Triton X-100 or Saponin enhanced the sensitivity. It seems advisable not to use a detection system with brown staining for bacteria in an experimental setup involving intestinal damage including haemorrhage. The use of detergents appears to result in a higher sensitivity in the immunohistochemical detection of salmonellae.