The Application of Lactobacillus reuteri CCM 8617 and Flaxseed Positively Improved the Health of Mice Challenged with Enterotoxigenic E. coli O149:F4

The aim of our study was to monitor the effects of dietary synbiotics on experimentally infected mice. Sixty mice were divided into the following three groups: negative control group C1, positive control group C2 (mice infected with enterotoxigenic Escherichia coli O149:F4_NAL), and experimental group LF (Lactobacillus reuteri CCM 8617_RIF + 10% flaxseed + E. coli O149:F4_NAL). Supplements were administered for 42 days. Microbiological, hematological, and biochemical analyses, electrophoretic analysis of lactate dehydrogenase (LDH) isoenzymes, and analysis of fatty acids using gas chromatography and isotachophoresis were performed. We recorded higher numbers of jejunal and ileal lactic acid bacteria, lower Enterobacteriaceae counts in the feces of the animals, and an increased production of organic acids in the synbiotic-fed group. The supplements applied favored n-3 polyunsaturated fatty acid (PUFA) metabolism and inhibited n-6 PUFA metabolism; thus, they influenced the n-6 to n-3 and eicosapentaenoic to arachidonic acid ratios. Additionally, the incorporation of n-3 PUFAs to the cell membrane decreased the activity of LDH, transaminases, and alkaline phosphatase. Results obtained in our study indicate the positive effect of continuous supplementation of combination of probiotic cheese enriched with L. reuteri CCM 8617_RIF and crushed flaxseed on composition of intestinal microflora and alleviation of the course of infection induced by pathogenic bacterium E. coli O149:F4_NAL.

Systemic immune response of gnotobiotic mice infected with porcine circovirus type 2 after administration of Lactobacillus reuteri L26 Biocenol™

In our previous study we confirmed an antiviral activity of probiotic Lactobacillus reuteri L26 which was mediated by stimulation of local intestinal immunity. The aim of this paper was to evaluate the influence of L. reuteri L26 on the systemic immune response in gnotobiotic mice infected with porcine circovirus type 2 (PCV2). A total of 30 germ-free mice were divided into 3 groups and animals in noninfected and infected control groups (NC and IC; n=10) received sterile de Man-Rogosa-Sharpe broth for 7 days and animals in experimental group L+PCV (n=10) were inoculated with L. reuteri L26. Subsequently, mice in L+PCV and IC groups were infected with PCV2; however, mice in the control group received virus cultivation medium (mock). The results showed an increase of percentage of cytotoxic cells (CD8+ and CD49b+CD8-) and oxidative burst of phagocytes, up-regulation of the gene expression of RANTES, granulocyte-macrophage colony-stimulating factor, interferon-γ and immunoglobulin A in blood above all in the later phase of infection (14 dpi) in L+PCV group accompanied by higher load of PCV2 in the serum. These findings indicate that L. reuteri L26 has a potential to induce systemic immune reaction, but in gnotobiotic mice immune stimulation can increase virus replication.

The Influence of Supplementation of Feed with Lactobacillus reuteri L2/6 Biocenol on Intestinal Microbiota of Conventional Mice

FISH (fluorescence in situ hybridization) analysis of the intestinal tract of conventional mice, following 14-day supplementation of feed with host non-specific (porcine) strain L. reuteri L2/6, showed in the presence of complex microbiota, a significant increase in the counts of representatives of the genera Lactobacillus and Bifidobacterium, and a significant decrease in the representatives of the genera Clostridium, Bacteroides and Enterobacteriaceae. At the same time, the supplemented strain stimulated the population of caecal lactobacilli of the species L. reuteri. These results demonstrated that the L. reuteri L2/6 colonised the jejunum, ileum and caecum and modulated the investigated intestinal microbiota.

The Efect of Probiotic Lactobacilli and Alginite on the Cellular Immune Response in Salmonella Infected Mice

Alginite is organic matter rich in humic substances and commonly found in nature, but despite that, the knowledge of its biological effects is limited. In our study we focused on monitoring the effects of alginite alone, as well as its effect as a carrier of probiotic lactobacilli on the cellular immune response in SPF mice after infection with Salmonella Typhimurium. Sixty six conventional SPF female mice of the Balb/c line were divided into 4 groups: 1. infection free negative control (NK) supplied neither alginite nor probiotic lactobacilli in the feed; 2. infection free alginite control (Alg) supplied feed with 10 % alginite; infected control supplied alginite in the feed but no lactobacilli; 3. infectious control (Alg + Sal) - animals infected with salmonella and supplied 10 % alginite in the feed but no lactobacilli;and 4. probiotic group (Lab + Alg + Sal) - animals infected with salmonella and administered 10 % alginite and Lactobacillus reuteri 2/6 in the feed. On day 21 of the experiments, the mice were bled and their mesenteric lymph nodes were taken after their death. The peripheral blood of the mice was analysed for the activity of phagocytes and the percentage of selected lymphocyte subpopulations was determined in the mesenteric lymph nodes and blood. The significantly highest phagocytic activity (FA) was noted in the infected group with alginite (Alg + Sal). The FA was significantly increased in groups Alg and Lab + Alg + Sal in comparison with the NK group. The highest engulfing ability of phagocytes (phagocytic index) was observed in the Lab + Alg + Sal group in comparison with other groups, but also in Alg group in comparison with NK. In the Lab + Alg + Sal group, we observed a significantly higher percentage of B-lymphocytes, CD4+CD8+ and natural killer T cells (NKT), but more significant impact on the numbers of subpopulations of lymphocytes was observed in the mesenteric lymph nodes, with the significantly highest proportions of CD4+CD8+lymphocytes and NK and NKT cells. Our results indicated immunomodulatory properties of alginite and L. reuteri 2/6 in salmonella infected mice, especially at the level of the innate immune system components. This activation of phagocytosis and NK cells can be used in the treatment of various infections.

Influence of Lactobacillus reuteri L26 Biocenol™ on immune response against porcine circovirus type 2 infection in germ-free mice

Probiotic bacteria are frequently used for prevention of bacterial infections of the gastrointestinal tract, but there are only limited studies on their efficacy against viral gut infections in animals. The aim of this study was to investigate the effect of probiotic Lactobacillus reuteri L26 Biocenol^TM on the innate and adaptive immune responses in germ-free Balb/c mice, experimentally infected by porcine circovirus type 2 (PCV2), which confers immunosuppressive effect. A total of 30 six-week-old female mice were divided into 3 groups and animals in experimental group LPCV (n=10) were inoculated with L. reuteri L26, animals in the control group (C; n=10) and experimental group PCV (n=10) received sterile De Man-Rogosa-Sharpe broth for 7 days. Subsequently, mice from both experimental groups were infected with PCV2; however, mice in the control group received virus cultivation medium (mock). Virus load in faeces, ileum and mesenteric lymph nodes (MLN); as well as gene expression of selected cytokines, immunoglobulin A (IgA) and polymeric Ig receptor (PIgR) in the ileum, and percentage of CD8+, CD19+ and CD49b+CD8- cells in the MLN were evaluated. Our results showed that L. reuteri significantly decreased the amount of PCV2 in faeces and in the ileum, and up-regulated the gene expression of chemokines, interferon (IFN)-γ, IgA and PIgR in the ileum. Increased IFN-γ mRNA level was accompanied by higher proportion of natural killer cells and up-regulated IgA and PIgR gene expressions were in accordance with significantly higher percentage of CD19+ lymphocytes in the MLN. These findings indicate that probiotic L. reuteri has an antiviral effect on PCV2 in the intestine which is mediated by stimulation of local gut immune response.

The Influence of Probiotic Lactobacilli and Flaxseed on the Health of Weaned Piglets and Metabolism of Polyunsaturated Fatty Acids (PUFAs)

This study investigated for 14 days post-weaning, the influence of dietary supplementation of synbiotics in the form of probiotic cheeses containing cultures of L. plantarum and L. fermentum and crushed flaxseed (source of ω-3 polyunsaturated fatty acids — PUFAs and fibre) on 36 commercial piglets originating from an infected herd (Coronavirus and E. coli) during the critical period of weaning. We focused on the health and metabolism of PUFAs in this critical period of a piglet’s life. The dietary supplementation positively affected: the overall health state of weaners, reduced diarrhoea by 29 % by 14 days post-weaning and significantly increased the counts of lactic acid bacteria, bifidobacteria and the production of volatile fatty acids. The PUFA concentrations in the m. biceps femoris of the piglets were analysed by gas chromatography. High levels of ω-3 alpha-linolenic acid (ALA) in flaxseed increased significantly the level of ALA, eicosapentaenic acid (EPA) and docosahexaenic acid (DHA) in the pig muscles on days 7 and 14 post-weaning. The levels of ω-6 linolenic acid (LA) were less affected by the diet, but were increased on day 14 post-weaning, while the conversion products of LA, and arachidonic acid (AA), were decreased on days 7 and 14. The increased level of dietary ALA favoured the activity of Δ-6-desaturase for the conversion of ALA to EPA and DHA, at the expense of AA synthesis from LA. The ability of synbiotics to incorporate high levels of DHA in the pig muscles appear prospective for improving the nutritional properties of pork and reducing the occurrence of civilization diseases in consumers of this product of animal origin.

Anti-inflammatory and immunoregulatory effects of flax-seed oil and Lactobacillus plantarum - Biocenol™ LP96 in gnotobiotic pigs challenged with enterotoxigenic Escherichia coli

The aim of this study was to determine the immune response after preventive administration of flax-seed oil (rich in n-3 PUFAs) or probiotic strain Lactobacillus plantarum - Biocenol™ LP96 or their combination in the jejunum of ETEC-challenged gnotobiotic pigs. Subsequently, gene expression of selected cytokines, phagocytic activity of leukocytes from peripheral blood and percentage of CD2(+), CD4(+), CD8(+) and CD4(+)CD25(+) lymphocytes in jejunal mucosa were evaluated. Our results showed that combined treatment down-regulates IL-1α and IL-8 gene expression, up-regulates IFN-γ and tends to regulate inflammation induced by ETEC through cytokine IL-10. In general, changes in cytokine gene expression correlated with the proportions of immune cells isolated from the same part of the jejunal mucosa. Results indicate that probiotic L. plantarum in combination with flax-seed oil rich in n-3 PUFAs has anti-inflammatory properties, stimulates Th1-mediated cell immunity and phagocytosis, and tends to regulate the inflammatory response induced by ETEC.