Application of Lactobacillus reuteri B1/1 (Limosilactobacillus reuteri) Improves Immunological Profile of the Non-Carcinogenic Porcine-Derived Enterocytes.

In our previous studies, Lactobacillus reuteri B1/1, which was renamed Limosilactobacillus reuteri (L. reuteri), was able to modulate the production of pro-inflammatory cytokines and other components of the innate immune response in vitro and in vivo. In this study, we evaluated the effect of Lactobacillus reuteri B1/1 in two concentrations (1 × 107 and 1 × 109 CFU) on the metabolic activity, adherence ability and relative gene expression of pro-inflammatory interleukins (IL-1ß, IL-6, IL-8, IL-18), lumican and olfactomedin 4 produced by non-carcinogenic porcine-derived enterocytes (CLAB). CLAB cells were cultured in a 12-well cell culture plate at a concentration of 4 × 105 cells/well in DMEM medium in a controlled humidified atmosphere for 48 h. A 1 mL volume of each probiotic bacterial suspension was added to the CLAB cells. Plates were incubated for 2 h and 4 h. Our results revealed that L. reuteri B1/1 was able to adhere to CLAB cells in sufficient numbers in both concentrations. In particular, the concentration of 109L. reuteri B1/1 allowed to modulate the gene expression of pro-inflammatory cytokines, as well as to increase the metabolic activity of the cells. In addition, administration of L. reuteri B1/1 in both concentrations significantly stimulated gene expression for both proteins in the CLAB cell line after 4 h of incubation.

Silybin Showed Higher Cytotoxic, Antiproliferative, and Anti-Inflammatory Activities in the CaCo Cancer Cell Line while Retaining Viability and Proliferation in Normal Intestinal IPEC-1 Cells.

The anticancer potential of silymarin is well known, including its anti-inflammatory as well as antiproliferative effect mediated by influencing the cell cycle, suppression of apoptosis, and inhibition of cell-survival kinases. However, less is known about silybin, the main component of the silymarin complex, where studies indicate its dual effect on the proliferation and immune response of various cell types in a dose-dependent manner. Moreover, there is a lack of studies comparing the effect of silybin on the same type of healthy and tumor cells, especially intestinal ones. Therefore, our study aimed to investigate the concentration-dependent effect of silybin on the normal intestinal porcine epithelial cell line-1 (IPEC-1) and the human epithelial colorectal adenocarcinoma cell line (CaCo-2). The metabolic viability, cell cycle, mitochondrial membrane potential, apoptosis, and the relative gene expression for pro- and anti-inflammatory cytokines were monitored in cells treated with silybin. Silybin stimulates metabolic viability as well as proliferation in IPEC-1 cells, protects the mitochondrial membrane, and thus exerts a cytoprotective effect, and has only a minimal effect on the gene expression of pro-inflammatory cytokines but significantly increases the expression of anti-inflammatory TGF-ß. In contrast, it inhibits metabolic viability in tumor intestinal CaCo-2 cells, has an antiproliferative effect accompanied by increased apoptosis, and significantly reduces the expression of genes for pro-inflammatory interleukins as well as TGF-ß. The antiproliferative and anti-inflammatory effect of silybin on tumor intestinal cells without a negative effect on healthy cells is a prerequisite for its potential use in the adjuvant therapy of colon cancer; however, further studies are necessary.

Effect of Dietary Microalgae (Spirulina platensis) on Growth Performance, Ingestive Behavior, Hemato-Biochemical Parameters, and Economic Efficiency of Fayoumi Broilers.

This study was conducted to evaluate the effect of dietary supplementation with Spirulina platensis (SP) on the productive performance, carcass characteristics, behavior, blood serum metabolites, hematological indices, and economic efficiency of Fayoumi broiler chickens for a 56-day. In total, 120 one-day-old broiler chicks were randomly distributed among four dietary treatments with three replicates (n = 10/group) for 8 weeks. The dietary treatments were a control basal diet without SP and the same basal diets supplemented with 0.25, 0.5, or 1.0% SP. Birds fed 1% Spirulina-supplemented diets recorded significantly (p < 0.05) higher body weight, weight gain, and feed conversion ratio and less overall feed intake and feeding behavior than those in the control group. No significant changes (p > 0.05) were recorded in the dressing percentage or the relative weights of internal organs among the different experimental groups, except for the thymus. Diets containing 0.5 or 1.0% SP saw an increase (p < 0.05) in serum total protein and globulin and a reduction (p < 0.05) in serum cholesterol concentration. The lymphocyte percentage in birds fed SP diets was significantly (p < 0.05) higher than in birds fed the control diet. These results suggest that adding SP up to 1% to the broiler diets could positively affect some important blood biochemical parameters, enhance their immunity response, and improve their growth performance. However, from an economic point of view, supplementation with 0.25% of SP is recommended for Fayoumi broiler chickens.

Effects of the Probiotic Enterococcus faecium on Muscle Characteristics of Chickens.

The use of antibiotics in farm animals is one of the main reasons for the development of resistant bacterial strains (e.g., zoonotic pathogens). Therefore, save alternatives are needed. Here, we examined how post-hatch application (day one to seven of life) of the probiotic Enterococcus faecium AL41 (EF) affects the development and tissue properties of the broiler pectoralis major muscle (PM). Expression of regulators, namely IGF-1, PAX7, and MYF5, was also investigated. At day 1 (n = 6), and days 5, 8, and 12 (n = 10), muscle samples were taken from control and EF supplemented chicks. From day 5 on, myonuclei number per fiber was elevated in EF chicks. Improved capillarization (from day 8), larger myofibers, increased body and PM weights (day 12) were found in the EF group. Part of our findings is explainable by higher intramuscular expression of IGF-1 and lower MYF5 expression in EF birds. In both groups IGF-1 expression decreases with age, thereby increasing the cellular myogenic potential. However, a strong increase in PAX7 expression and more PAX7-positive nuclei were found in EF chicks at day 12. We conclude that EF supplementation improves PM growth and health due to positive effects on bioavailability and fusion capacity of SATC progeny and better tissue perfusion.

The Effect of Enterococcus faecium AL41 on the Acute Phase Proteins and Selected Mucosal Immune Molecules in Broiler Chickens.

Probiotic bacteria, including the Enterococcus faecium strain, can improve intestinal mucosal health by several mechanisms, including modulation of the immune response, as well as by improving the protective function of the epithelial barrier. In this study, we tested the effect of Enterococcus faecium AL41 on the acute phase proteins response (blood), gene expression of selected molecules of mucosal immunity (immunoglobulin A, mucin-2, insulin-like growth factor 2) and mucus production (all parts of the small intestine) in broilers. Eighty broiler chicks were divided into two groups: a control and E. faecium AL41 (birds were inoculated with AL41 for 7 days) group. The whole experiment lasted 11 days. Our results revealed that the administration of E. faecium AL41 had no substantial effect on the concentrations of acute phase proteins, but we recorded a significant increase in ß- and γ-globulin fractions at the end of the experiment, which may indicate an improvement in the immune status. A significant prolonged stimulatory effect of E. faecium AL41 on the relative expression of molecules (immunoglobulin A, mucin-2) as well as on the dynamic of mucus production in the chicken intestine was observed. In addition, AL41 significantly reduced the total number of enterococci in the cecum and faeces.

Relationship of mRNA Expression of Selected Genes in Peripheral Blood and Synovial Fluid in Cranial Cruciate Ligament Deficient Stifles of Dogs.

The cranial cruciate ligament rupture (CrCLR) is characterized by chronic inflammation and osteoarthritis (OA) of the stifle joint and extracellular matrix (ECM) degeneration of the ligament itself in dogs. Generally, OA may arise from chronic low-grade systemic inflammation. We assessed the possible relationship of inflammatory markers in the peripheral blood (PB) and synovial fluid (SF) of affected stifle joints in comparison to a control. Moreover, no study has shown the possible association between PB and SF levels of inflammatory markers in CrCLR stifles of dogs in veterinary medicine yet. We also evaluated components of ECM of CrCLR and finally compared the tibial plateau angle (TPA) and the anatomical-mechanical angle (AMA) between groups. Samples from PB and SF were examined for mRNA expression of interleukins, TNF-α and INF-γ. ECM components-collagen 1A1 and 3A1 and elastin-were examined for mRNA expression from SF. The level of relative expression for IL-1ß, IL-8 and IFN-γ was significantly increased in both PB and SF in CrCLR stifles as compared with the control. Collagens were also significantly increased in CrCLR stifles. TPA was not significantly different; however, the AMA angle significantly increased in the CrCLR group. Our results suggest a possible relationship between PB and SF levels of inflammatory markers in CrCLR stifles of dogs.

Influence of Immune Parameters after Enterococcus faecium AL41 Administration and Salmonella Infection in Chickens.

Immune response of day-old chicks infected with Salmonella Enteritidis PT4 and preventive administration of Enterococcus faecium AL41 were studied using hematology and flow cytometry of immunocompetent cells in blood, cecum, bursa and spleen for 11 days, and included 220 animals divided into four groups (n = 55). E. faecium AL41 was administered for 7 days to EF and EFSE groups and on day 4 SE and EFSE groups were infected with Salmonella Enteritidis. Values of monocytes at 4 dpi significantly increased in EFSE and lymphocytes at 7 dpi in EF groups. Blood CD3, CD4, CD8 and IgM lymphocytes improved in EF and EFSE groups and IgA in EF group at 4 dpi. Phagocytic activity of probiotic groups was improved in both samples. Cecal IEL and LPL lymphocytes showed at 7 dpi stimulation of CD3, CD4 and CD8 subpopulations in probiotic groups, especially in EFSE group, IgA IEL and IgA with IgM LPL in EF groups. Bursa Fabricii at 7 dpi presented overstimulation of IgG subpopulation in SE group, spleen CD3 and CD8 in EF and EFSE groups. E. faecium AL41 revealed the protective effect and positive influence on the local and systemic immune response in Salmonella Enteritidis PT4 infected chickens.

Production of Intestinal Mucins, sIgA, and Metallothionein after Administration of Zinc and Infection of Ascaridia galli in Chickens: Preliminary Data.

The effect of inorganic zinc and Ascaridia galli infection was studied on MUC1, MUC2 (mucin), sIgA (secretory immunoglobulin A), and metallothionein in the intestines of broilers. Thirty-five-day-old chickens (n = 24), COBB 500 breed, were included in a 14-day experiment. Chickens were divided into 4 groups of 6 chickens each: control ©, Ascaridia galli (AG), Zinc group (Zn), and combined group (AG + Zn). Samples from the intestine for determination of MUC1, MUC2, sIgA, and metallothionein were taken at 7 and 14 days during necropsy. Samples from the jejunum for determination of MUC1, MUC2, sIgA, and metallothionein were taken at 7 and 14 days during necropsy. The results demonstrated that 12 days' administration of inorganic zinc increased production of MUC1 (p < 0.0001) and MUC2 (p < 0.001) in the Ascaridia galli-infected group (Ag + Zn) in comparison to control (C). The beneficial effect of zinc was also revealed in the production of sIgA (p < 0.0001) in the combined group (AG + Zn) at 7 days. The concentration of metallothionein increased mainly in the zinc group (p < 0.01) of first sampling and was upregulated in Zn and AG + Zn groups. The obtained data indicate the use of inorganic zinc as a suitable immunomodulator of intestinal immunity in Ascaridia galli-infected chickens.

Differences in Immune Response and Biochemical Parameters of Mice Fed by Kefir Milk and Lacticaseibacillus paracasei Isolated from the Kefir Grains.

The health benefits of kefir consumption have been well-known for hundreds of years. The objective of this study was to investigate the effect of kefir milk and the probiotic strain Lacticaseibacillus paracasei Z2 isolated from kefir grains on the immune response and selected parameters of the lipid and liver enzymatic profiles of mice. Mice fed with kefir milk showed significantly increased phagocytic activity and percentages of B cells in the blood and increased gene expression for mucins and percentages of CD8+ lymphocytes in the gut. By applying kefir, we achieved a significant reduction in serum LDL cholesterol and an LDL/HDL ratio that favored an increase in HDL cholesterol. Regarding the hepatic enzymes, in particular a significant reduction in ALT activity was observed. L. paracasei Z2 alone stimulated the immune response more markedly compared with kefir milk. Regarding the systemic level, we observed increases in the proportion of all T cells (CD3+), CD4+ lymphocytes and the ratio of CD4+:CD8+ cells, and regarding the local intestinal level we noted a significant increase in gene expression for mucins (MUC-1 and MUC-2) and IgA. Moreover, we confirmed the formation of a biofilm on the surface of the forestomach only after the application of L. paracasei Z2 alone, but not after kefir administration. The results confirmed the hypothesis that the final effect of the probiotic does not correspond with the effect of the individual strain but is the result of mutual interactions of the microorganisms presented in a preparation, and therefore in the case of multi-strain probiotics, in vivo testing of the complex preparation is necessary.

The Probiotic Lactobacillus fermentum Biocenol CCM 7514 Moderates Campylobacter jejuni-Induced Body Weight Impairment by Improving Gut Morphometry and Regulating Cecal Cytokine Abundance in Broiler Chickens.

This research was conducted to investigate if the administration of the probiotic Lactobacillus fermentum could influence body weight, intestinal morphometry and the cecal cytokine response in Campylobacter jejuni-infected chickens. Seventy-two 1-day old COBB 500 male chicks were allocated randomly into four experimental groups. (I) Control group (C), in which chicks were left untreated. (II) LB group, treated with L. fermentum. (III) Cj group, infected with C. jejuni and (IV) coexposure group in which both bacteria were administered. Body weight was registered and then all birds were slaughtered; samples from the small intestine and caecum were collected at 4- and 7-days post infection. The experiment lasted eleven days. Villi height and crypt depth ratios of the duodenum, jejunum and ileum were evaluated using appropriate software, while reverse transcription quantitative PCR (RT-qPCR) was utilized for assessing transcript levels of key cecal inflammatory cytokines (IL-1ß, IL-18, IL-17, IL-15, IL13 and IL-4). Campylobacter-infected birds showed lower body weight values than those supplemented with the probiotic; these birds, in turn, proved to be heavier than those reared under control conditions. L. fermentum administration improved morphometrical parameters of the duodenum, jejunum and ileum; in general, villi were larger and crypts deeper than those identified in control conditions. Moreover, the negative effects elicited by C. jejuni were not observed in chickens exposed to the probiotic. Significant differences were also determined with regards to transcript abundance of all evaluated cytokines in the caecum. C. jejuni induced a downregulation of the studied interleukins; however, such a response was heightened by administration of L. fermentum, with an increase rate of transcription that promoted a more effective response to a C. jejuni infection. The effects of experimental treatments proved to vary between sampling points. Conclusively, these results demonstrate that L. fermentum lessens the negative effects elicited by C. jejuni on body weight by alleviating the impact on intestinal morphometry and cecal cytokine response, which ultimately improve chicken growth performance.

Effects of Lactobacillus Fermentum Supplementation on Body Weight and Pro-Inflammatory Cytokine Expression in Campylobacter Jejuni-Challenged Chickens.

Due to the interest in using probiotic bacteria in poultry production, this research was focused on evaluating the effects of Lactobacillus fermentum Biocenol CCM 7514 administration on body weight gain and cytokine gene expression in chickens challenged with Campylobacter jejuni. One-hundred and eight 1-day old COBB 500 broiler chickens were equally assigned to four experimental groups at random. In the control group (C) chicks were left untreated, whereas in groups LB and LBCj a suspension of L. fermentum was administered. A suspension of C. jejuni was subsequently applied to groups Cj and LBCj. Body weight was registered, and the individuals were later slaughtered; cecum samples were collected at 12, 36 and 48 h post-infection (hpi). The entire experiment lasted seven days. Reverse transcription quantitative PCR (RT-qPCR) was used to determine expression levels of IL-1ß, IL-15, IL-17, and IL-18 at each time point. Pathogen-infected individuals were observed to weigh significantly less than those fed with the probiotic. Significant differences were also found in transcript abundance; expression of IL-15 was downregulated by the probiotic and upregulated by C. jejuni. The effects of bacterial treatments were time-dependent, as the expression profiles differed at later stages. The present outcomes demonstrate that L. fermentum both reduces the impact of C. jejuni infection on chicken body weight and regulates positively pro-inflammatory cytokine expression, which ultimately increase bird well-being and improves production.

Lactobacillus fermentum Administration Modulates Cytokine Expression and Lymphocyte Subpopulation Levels in Broiler Chickens Challenged with Campylobacter coli.

This investigation was performed to assess the supplementation of probiotics on cytokine expression and lymphocyte subpopulation in Campylobacter coli challenged chickens. Thirty-six individuals were equally separated into four experimental treatments: C = untreated chickens, LB = probiotic control (Lactobacillus fermentum), Cc = Campylobacter-challenged control, LBCc = probiotic + Cc. All chicks were slaughtered and cecum samples were collected on day 4 postinfection. Gene expression analysis, using reverse transcription quantitative PCR (RT-qPCR), revealed significant differences in cytokine transcript expression between untreated and probiotic-treated chickens. In addition, flow cytometry was used to quantitate the levels of lymphocyte subpopulations. Principal component analysis showed that probiotic administration induced an overall downregulation of cytokine expression. C. coli exposure provoked a similar response to that of L. fermentum but to a lesser extent. Colonization of C. coli in the presence of the probiotic evoked a complex response with an upregulation of some type II cytokines, including interleukin IL-4 and IL-13, which could explain the increased presence of antibodies in both lamina propria and epithelium. Moreover, despite that the percentage of CD8 intraepithelial lymphocytes (IELs) was found to be higher, downregulation of proinflammatory cytokines IL-15, IL-16, and interferon γ was observed. This suggests that the detected CD8 are not effector cells but induced IELs, which release antimicrobial peptides, and are ready to be primed upon encountering antigen. These outcomes demonstrate that probiotic administration promotes a humoral response to a C. coli infection while dampening any potential inflammation mediated by effector T cells in 1-week-old chicks.

Cytokine response after stimulation of culture cells by zinc and probiotic strain.

Intestinal porcine epithelial cells were used for an in vitro analysis of mRNA expression levels of inflammatory cytokines (IL-8, IL-18) and transcriptional factors (MyD88 and NF-κß). Cells were exposed to inorganic and organic zinc sources (in two different concentrations-50 µmol/L and 100 µmol/L) alone or combined with Lactobacillus reuteri B6/1, which was also applied individually. The total exposure time was 4 h. Quantitative reverse transcriptase PCR was used to determine expression levels of the aforementioned parameters. In general, upregulation was observed; however, a decrease of some mRNA's abundance was also determined. Differences in expression were analysed statistically using ANOVA and Tukey analyses. High relative expression was shown for IL-8, IL-18 and MyD88 in groups treated with 100 µmol/L of inorganic sources of zinc (ZnSO4) (p < 0.05), while groups treated with the organic form did not exhibit significant changes in expression. Also, 50 µmol/L of either zinc source did not significantly modify the transcriptional profile of the cytokines and transcription factors, showing that even inorganic sources, at lower concentrations, do not elicit a significant inflammatory reaction. In summary, supplementation of organic zinc source (Gly-Zn chelate) ensures that IL-8, IL-18, MyD88 and NF-κß expression levels are not positively regulated. In contrast, inorganic sources of zinc (ZnSO4) could induce an inflammatory reaction. However, this response could be dampened if L. reuteri B6/1 is administered, showing the helpful aspect of using probiotics to modulate an inflammatory response. Conclusively, the use Gly-Zn chelate appears as an optimal alternative for Zn administration that does not compromise normal intestinal homeostasis.

The influence of Farmatan® and Flimabend® on the mucosal immunity of broiler chicken1.

The aim of the present study was to monitor selected parameters of mucosal immunity in jejunum and ileum (immunoglobulin A [IgA], mucin 2 [MUC-2], and pro-inflammatory cytokines) in commercial broiler farm chicken after treatment with flubendazole (Flimabend®) and natural extract from chestnut wood (Farmatan®). A total of 24 forty-day-old Kalimero-Super Master hybrid chickens were divided into 4 groups (n = 6): the Fli group received Flimabend® per os, 100 mg/g suspension in 1.43 mg of active substance/kg body weight during 7 d of experiment; the Far group received Farmatan®per os at 0.2% concentration for 6 h/d during 5 d (experimental d 3 to 7); the Far + Fli group received a combination of doses administered in the same way as for the first two groups; and the C group represented control with no active substance administration. The concentrations of secretory IgA (sIgA) and MUC-2 and relative expression of selected immune parameters were evaluated. Our results show strong suppressive effect of the Farmatan® and Flimabend® combination on relative expression of IL-1ß and IL-18 in selected parts of the intestine. On the other hand, administration of natural extract from selected chestnut wood (Farmatan®) increased expression of total IgA as well as concentration of sIgA in the studied parts of the chicken intestine. Moreover, expression and concentration of MUC-2 was positively affected by addition of Farmatan®. In contrast, 7-d administration of Flimabend® resulted in upregulation of pro-inflammatory cytokines and decrease in IgA and MUC-2 gene expression. In conclusion, for maintenance of mucosal immunity via activation of IgA and mucin production, the long-term preventive use of Farmatan® is a suitable choice.

Influence of oral application of Enterococcus faecium AL41 on TGF-ß4 and IL-17 expression and immunocompetent cell distribution in chickens challenged with Campylobacter jejuni.

Campylobacteriosis is mainly caused by infection with Campylobacter jejuni following consumption or handling of Campylobacter-contaminated poultry meat. The aim of this study was to investigate the effect of probiotic Enterococcus faecium AL41 on TGF-ß4 and IL-17 expression and on immunocompetent cell distribution after C. jejuni infection in broiler chicken, as a second part of the previous study of Karaffová et al. (2017). Accordingly, day-old chicks were randomly divided into four experimental groups of 10 chicks each (n = 10): control (C), E. faecium AL41 (EFAL41), C. jejuni CCM6191 (CJ), and combined E. faecium AL41 + C. jejuni CCM6191 (EFAL41 + CJ). Samples from the caecum were collected on days 4 and 7 post Campylobacter infection (dpi), for the isolation of mRNA of TGF-ß4, IL-17 and for immunohistochemistry. The relative mRNA expression of TGF-ß4 was upregulated in the combined (EFAL41 + CJ) group compared to other groups during both samplings, but the expression of IL-17 was downregulated. Similarly, the highest density of CD3+ was detected in the combined group at 7 dpi, but the number of IgA+ cells was increased in both groups with EFAL41. It was concluded that the EFAL41 probiotic E. faecium strain can modulate the expression of selected cytokines (upregulation of TGF-ß4 but downregulation of IL-17 relative expression), and activate IgA-producing cells in the caeca of chicks infected with C. jejuni CCM6191.

IgA gene expression and quantification of cecal IgA+, IgM+, and CD4+ cells in chickens treated with EFAL41 and infected with Salmonella Enteritidis.

IgA gene expression and quantification of mucous IgA+, IgM+ and CD4+ lymphocytes in the cecum of chicks was studied by qRT-PCR, immunohistochemistry and flow cytometry. A total of 220 1-day-old Salmonella-free chicks of Cobb 500 were divided into four groups (n=55). Group 1 served as control (C), group 2 was pretreated with probiotic bacterial strain Enterococus faecium AL41 (EFAL41), group 3 was infected with Salmonella Enteritidis PT4 (SE), and group 4 was pretreated with E. faecium AL41 and subsequently challenged with Salmonella Enteritidis PT4 (EFAL41+SE). The relative mRNA expression of IgA was upregulated in the EFAL41 group (P<0.05) when compared to control group at 4dpi. In comparison to the control, EFAL41 and SE group, the relative mRNA expression of IgA was also upregulated in EFAL41+SE group at 7dpi (P<0.001). Immunohistochemistry revealed, that the density of IgA+ cells was higher in EFAL41+SE group comparing to the controls and SE groups (P<0.001). Significantly more CD4+ cells were present in the SE group than in EFAL41 (P<0.05), and EFAL41+SE groups (P<0.001) at 4dpi. In contrast, higher density of CD4+cells at 7dpi was seen in EFAL41+SE group as compared with controls (P<0.05). Flow cytometry determined that relative percentage of intraepithelial lymphocytes (IEL) IgA+ cells was higher in EFAL41 than in SE and EFAL41+SE groups (P<0.05). Comparing to controls the number IgM+ cells increased in SE group (P<0.05) at 7dpi. The results demonstrated beneficial effect of E. faecium AL41 on the mRNA expression of IgA and number of IgA+ cells. Lamina propria lymphocytes (IgA+, IgM+) were not affected by EFAL41 intake or salmonella infection. Probiotic bacterial strain EFAL41 positively influenced the number of IEL during the first days of infection.

Interaction of TGF-ß4 and IL-17 with IgA secretion in the intestine of chickens fed with E. faecium AL41 and challenged with S. Enteritidis.

The relative mRNA expression of IgA, TGF-ß4, IL-17, and concentration of secretory IgA (sIgA) in small intestine of chickens pretreated with Enterococcus faecium AL41 and challenged with Salmonella Enteritidis PT4 were studied. Salmonella-free day-old chicks (40) Cobb 500 breed, were divided into four groups of 10 chicks each (n = 10): control (C), treated with E. faecium AL41 strain (EFAL41), challenged with Salmonella Enteritidis PT4 (SE), and combined (EFAL41+SE). Expression of IgA and sIgA concentration was upregulated in EFAL41 group in jejunum and ileum on 4 days post-Salmonella infection (dpi). Chicks in combined group demonstrated upregulation of cytokines and IgA expression, and increased sIgA concentration in the intestine flush on 7 dpi. The experiment demonstrated beneficial effect of E. faecium AL41 on IgA production and secretion in intestine. Findings also indicated that IgA played important role in decrease of S. Enteritidis in the intestine, and cytokines TGF-ß4 and IL-17 contributed to the increased IgA secretion.