Oral Administration of Lactobacillus delbrueckii during the Suckling Phase Improves Antioxidant Activities and Immune Responses after the Weaning Event in a Piglet Model

Effects of probiotics on growth performance, intestinal morphology, intestinal microbiota weaning pig challenged with Escherichia coli and Salmonella enterica

This study aimed to evaluate the effects of mono- and multi-strain lactic acid bacteria (LAB) probiotics on the growth performance, nutrient digestibility, blood profiles, fecal noxious gas emission, intestinal microbiota and intestinal morphology of weaning pigs challenged with or without Escherichia coli (E. coli) and Salmonella enterica (SE). In Exp. 1, a total of 60 crossbred weaning pigs were randomly allotted to one of five dietary treatments. The dietary treatments included: negative control (NC; basal diet with no supplement), positive control (PC; basal diet with 0.01% Lactiplantibacillus plantarum [LP] containing 1.0 × 108 CFU/g), basal diet with 0.1% Pediococcus acidilactici K (K) containing 1.0 × 109 CFU/g (K), basal diet with 0.1% Pediococcus pentosaceus SMFM2016-WK1 (WK1) containing 1.0 × 109 CFU/g (WK1), basal diet with 0.05% K + 0.05% WK1 containing 1.0 × 109 CFU/g (K-WK1). The average daily gain (ADG) was higher in the K group than in the WK1 group. Diarrhea score was lower in the K-WK1 group than in the NC group. At the genus level, Roseburia abundance in WK1 was higher than in the other treatment groups. At the species level, Blautia wexlerae abundance was lower in WK1 than in the other groups, whereas Succinivibrio dextrinosolvens abundance was higher in WK1. The serum pro-inflammatory cytokine levels in the PC and WK1 groups were as low as those in the NC group. Experiment 2 was conducted with two trials in a 2 × 5 factorial arrangement of treatments consisting of two levels of challenge (challenge and non-challenge) with E. coli and SE and five levels of probiotics same as Exp.1. Supplementation with LP and WK1 resulted in higher ADG and lower diarrhea scores than those in the other groups. Consequently, supplementation of WK1 showed a particularly positive effect on growth performance and diarrhea, villus height and intestinal microbiota in oral challenge experiment and feeding trial. Therefore, WK1 might be the most effective among the probiotics used in this experiment.

Evaluating the probiotic effects of spraying lactiplantibacillus plantarum P-8 in neonatal piglets

BACKGROUND

Gut microbes play an important role in the growth and health of neonatal piglets. Probiotics can promote the healthy growth of neonatal piglets by regulating their gut microbes. The study investigated the effects of spraying Lactiplantibacillus plantarum P-8 (L. plantarum P-8) fermentation broth on the growth performance and gut microbes of neonatal piglets.

RESULTS

The animals were randomly divided into probiotics groups (109 neonatal piglets) and control groups (113 neonatal piglets). The probiotics group was sprayed with L. plantarum P-8 fermented liquid from 3 day before the expected date of the sow to the 7-day-old of piglets, while the control group was sprayed with equal dose of PBS. Average daily gain (ADG), immune and antioxidant status and metagenome sequencing were used to assess the changes in growth performance and gut microbiota of neonatal piglets. The results showed that L. plantarum P-8 treatment significantly improved the average daily gain (P < 0.05) of neonatal piglets. L. plantarum P-8 increased the activities of CAT and SOD but reduced the levels of IL-2 and IL-6, effectively regulating the antioxidant capacity and immunity in neonatal piglets. L. plantarum P-8 adjusted the overall structure of gut microflora improving gut homeostasis to a certain extent, and significantly increased the relative abundance of gut beneficial bacteria such as L. mucosae and L. plantarum.

CONCLUSION

Spraying L. plantarum P-8 can be a feasible and effective probiotic intervention not only improving the growth of neonatal piglets, regulating the antioxidant capacity and immunity of neonatal piglets, but also improving the gut homeostasis to a certain extent.

Lactiplantibacillus argentoratensis AGMB00912 alleviates salmonellosis and modulates gut microbiota in weaned piglets: a pilot study

This study aimed to evaluate the efficacy of Lactiplantibacillus argentoratensis AGMB00912 (LA) in reducing Salmonella Typhimurium infection in weaned piglets. The investigation focused on the influence of LA on the gut microbiota composition, growth performance, and Salmonella fecal shedding. The results indicated that LA supplementation significantly improved average daily gain and reduced the prevalence and severity of diarrhea. Fecal analysis revealed reduced Salmonella shedding in the LA-supplemented group. Furthermore, LA notably altered the composition of the gut microbiota, increasing the levels of beneficial Bacillus and decreasing those of harmful Proteobacteria and Spirochaetes. Histopathological examination showed less intestinal damage in LA-treated piglets than in the controls. The study also observed that LA affected metabolic functions related to carbohydrate, amino acid, and fatty acid metabolism, thereby enhancing gut health and resilience against infection. Short-chain fatty acid concentrations in the feces were higher in the LA group, suggesting improved gut microbial activity. LA supplementation enriched the population of beneficial bacteria, including Streptococcus, Clostridium, and Bifidobacterium, while reducing the number of harmful bacteria, such as Escherichia and Campylobacter. These findings indicate the potential of LA as a probiotic alternative for swine nutrition, offering protective effects to the gut microbiota against Salmonella infection.

Dietary supplementation with Lactiplantibacillus plantarum P-8 improves the growth performance and gut microbiota of weaned piglets

Weaning is a stressful event in the pig life cycle. We hypothesized that probiotics could be potential alternatives to antibiotics for promoting growth and ameliorating stress in weaning piglets via gut microbiota modulation and, thus, investigated the beneficial effects of dietary probiotic supplementation in weaning pigs. Ninety weaning piglets (Landrace × large white, 45 males and 45 females, 25 days of age) were randomized into three dietary treatments (30 piglets/treatment, divided into five replicates/treatment, i.e., six piglets/replicate) in this 28-day trial: control (C group, basal diet); probiotic [lactic acid bacteria (LAB) group, basal diet plus Lactiplantibacillus plantarum P-8]; and antibiotic (A group; basal diet plus chlortetracycline). The piglets' growth performance [average daily gain, average daily feed intake (ADFI), and feed conversion ratio (FCR)], immune and antioxidant markers, ileal mucosal morphology, and ileal and colonic microbiomes were compared among treatment groups. Compared to the C and A groups, probiotic supplementation significantly decreased the ADFI, FCR, and ileal mucosal crypt depth while increasing the villus height-to-crypt depth ratio, hepatic glutathione peroxidase and catalase activities, and serum levels of interleukin-2. Both probiotic and antibiotic treatments modulated the piglets' gut microbiomes, with more L. plantarum in the LAB group and more Eubacterium rectale and Limosilactobacillus reuteri in the A group. Probiotic supplementation significantly increased the relative abundance of genes encoding the acetylene, galactose, and stachyose degradation pathways, potentially enhancing nutrient absorption, energy acquisition, and growth performance. Probiotics are effective alternatives to antibiotics for promoting the health of piglets, possibly via gut microbiome modulation.IMPORTANCEWeaning impacts piglet health, performance, and mortality. Antibiotic treatment during weaning can mitigate the negative effects on growth. However, antibiotic use in livestock production contributes to the emergence of antibiotic resistance, which is a threat to global public health. This comprehensive study describes the gut microbial composition and growth performance of weaned piglets after dietary supplementation with Lactiplantibacillus plantarum P-8 or antibiotics. L. plantarum P-8 ameliorated stress and improved antioxidant capacity and growth performance in weaned piglets, accompanied by gut microbiota improvement. L. plantarum P-8 is an effective substitute for antibiotics to promote the health of weaned piglets while avoiding the global concern of drug resistance.

Alternatives to antibiotics in pig production: looking through the lens of immunophysiology

In the livestock production system, the evolution of porcine gut microecology is consistent with the idea of "The Hygiene Hypothesis" in humans. I.e., improved hygiene conditions, reduced exposure to environmental microorganisms in early life, and frequent use of antimicrobial drugs drive immune dysregulation. Meanwhile, the overuse of antibiotics as feed additives for infectious disease prevention and animal growth induces antimicrobial resistance genes in pathogens and spreads related environmental pollutants. It justifies our attempt to review alternatives to antibiotics that can support optimal growth and improve the immunophysiological state of pigs. In the current review, we first described porcine mucosal immunity, followed by discussions of gut microbiota dynamics during the critical weaning period and the impacts brought by antibiotics usage. Evidence of in-feed additives with immuno-modulatory properties highlighting probiotics, prebiotics, and phytobiotics and their cellular and molecular networking are summarized and reviewed. It may provide insights into the immune regulatory mechanisms of antibiotic alternatives and open new avenues for health management in pig production.

Bio surfactants from lactic acid bacteria: an in-depth analysis of therapeutic properties and food formulation

Healthy humans and animals commonly harbor lactic acid bacteria (LAB) on their mucosal surfaces, which are often associated with food fermentation. These microorganisms can produce amphiphilic compounds, known as microbial surface-active agents, that exhibit remarkable emulsifying activity. However, the exact functions of these microbial surfactants within the producer cells remain unclear. Consequently, there is a growing urgency to develop biosurfactant production from nonpathogenic microbes, particularly those derived from LAB. This approach aims to harness the benefits of biosurfactants while ensuring their safety and applicability. This review encompasses a comprehensive analysis of native and genetically modified LAB biosurfactants, shedding light on microbial interactions, cell signaling, pathogenicity, and biofilm development. It aims to provide valuable insights into the applications of these active substances in therapeutic use and food formulation as well as their potential biological and other benefits. By synthesizing the latest knowledge and advancements, this review contributes to the understanding and utilization of LAB biosurfactants in the food and nutritional areas.

Early-Life Intervention of Lactoferrin and Probiotic in Suckling Piglets: Effects on Immunoglobulins, Intestinal Integrity, and Neonatal Mortality

The aim of this study was to determine the effects of early-life bovine lactoferrin and host specific probiotic interventions on growth performance, mortality, and concentrations of immunoglobulin A and immunoglobulin G and transforming growth factor beta 1 (a marker of intestinal integrity) in serum of neonatal piglets. A total of eight piglet litters from parity matched sows were randomly divided into four groups and assigned to one of the four interventions: control (sterile normal saline), bovine lactoferrin (100 mg bovine lactoferrin), probiotic (1 × 109 colony forming unit (cfu) of swine origin Pediococcus acidilactici FT28 probiotic), and bovine lactoferrin + probiotic (100 mg bovine lactoferrin and 1 × 109 CFU of P. acidilactici FT28 probiotic). All the interventions were given once daily through oral route for first 7 days of life. The average daily gain (p = 0.0004) and weaning weight (p < 0.0001) were significantly improved in the probiotic group. The piglet survivability was significantly higher in bovine lactoferrin and probiotic groups than control group in Log-rank (Mantel-Cox) test. The concentrations of immunoglobulin A on day 21 in bovine lactoferrin, probiotic, and bovine lactoferrin + probiotic groups increased significantly (p < 0.05). Immunoglobulin G concentrations on day 7 and 15 in bovine lactoferrin and bovine lactoferrin + probiotic groups and on day 15 in probiotic group were significantly (p < 0.05) elevated, whereas, the concentration of transforming growth factor-β1 was significantly (p < 0.05) increased from day 7 to 21 in all the supplemented groups. In conclusion, the early-life bovine lactoferrin and P. acidilactici FT28 probiotic interventions reduced the mortality in the suckling piglets by promoting the systemic immunity and enhancing the intestinal integrity.

Influence of dietary n-3 long-chain fatty acids on microbial diversity and composition of sows' feces, colostrum, milk, and suckling piglets' feces

Introduction

Very little is known about the impact of n-3 long-chain fatty acids (n-3 LCFAs) on the microbiota of sows and their piglets. The aim of this study was to evaluate the effect of n-3 LCFA in sow diets on the microbiota composition of sows' feces, colostrum, and milk as well as that of piglets' feces.

Methods

Twenty-two sows were randomly assigned to either a control or an n-3 LCFA diet from service to weaning. Sows' and piglets' performance was monitored. The gestating and lactating sows' microbiomes in feces, colostrum, and milk were characterized by 16s ribosomal RNA gene sequencing. The fecal microbiome from the two lowest (>800 g) and the two highest birth weight piglets per litter was also characterized, and the LPS levels in plasma were analyzed at weaning.

Results and Discussion

n-3 LCFA increased microbiota alpha diversity in suckling piglets' and gestating sows' feces. However, no effects were observed in colostrum, milk, or lactating sows' feces. Dietary n-3 LCFA modified the microbiota composition of gestating sows' feces, milk, and suckling piglets' feces, without affecting lactating sows' feces or colostrum. In gestating sows' feces and milk, the decrease in genus Succinivibrio and the increase of Proteobacteria phylum, due to the increased genera Brenneria and Escherichia, respectively, stand out. In the feces of suckling piglets, the higher abundance of the beneficial genus Akkermansia and Bacteroides, and different species of Lactobacillus are highlighted. In addition, positive correlations for families and genera were found between lactating sows' feces and milk, milk and suckling piglets' feces, and lactating sows' feces and suckling piglets' feces. To conclude, dietary n-3 LCFA had a positive impact on the microbiome of suckling piglet's feces by increasing microbial diversity and some beneficial bacteria populations, had a few minor modifications on the microbiome of milk and gestating sows' feces and did not change the microbiome in lactating sows' feces or colostrum. Therefore, this study shows the effect of dietary n-3 LCFA on the microbiota of sows, colostrum, milk, and suckling piglets during the lactation period providing crucial information on the microbiota status at the early stages of life, which have an impact on the post-weaning.

Maternal catalase supplementation regulates fatty acid metabolism and antioxidant ability of lactating sows and their offspring

Introduction and methods

As a crucial antioxidant enzyme, catalase (CAT) could destroy the cellular hydrogen peroxide to mitigate oxidative stress. The current study aimed to investigate the effects of maternal CAT supplementation from late gestation to day 14 of lactation on antioxidant ability and fatty acids metabolism with regard to the sow-piglet-axis. On day 95 of gestation, forty sows were divided into control (CON) group (fed a basal diet) and CAT group (fed a basal diet supplemented with 660 mg/kg CAT), the feeding experiment ended on day 14 of lactation.

Results

The lactating sows in the CAT group produced more milk, and had higher antioxidant enzymes activity including POD and GSH-Px (P < 0.05), lower content of serum LDL as well as plasmic C18:3n3 content (P < 0.05). Additionally, maternal CAT supplementation improved offspring's body weight at day 14 of nursing period and ADG (P < 0.05), and regulated the antioxidant ability as evidenced by decreased related enzymes activity such as T-AOC and CAT and changed genes expression level. It significantly affected lipid metabolism of suckling piglets manifested by increasing the serum ALT, CHOL, and LDL (P < 0.05) level and modulating plasma medium- and long-chain fatty acids (MCFAs and LCFAs), as well as regulating the genes expression involved in lipid metabolism.

Conclusion

Maternal CAT supplementation could regulate the fatty acid composition and enhance the antioxidant ability of sows and offspring during the lactating period and further promote the growth of suckling piglets. These findings might provide a reference value for the utilization of CAT as supplement for mother from late pregnancy to lactation period to promote the fatty acid metabolism of offspring.

Dietary supplementation ellagic acid on the growth, intestinal immune response, microbiota, and inflammation in weaned piglets

Piglets are susceptible to weaning stress, which weakens the barrier and immune function of the intestinal mucosa, causes inflammation, and ultimately affects animal growth and development. Ellagic acid (EA) is a natural polyphenol dilactone with various biological functions. However, The mechanisms underlying the effects of EA on animal health are still poorly known. Herein, we examined whether dietary supplementation with EA has a positive effect on growth performance, intestinal health, immune response, microbiota, or inflammation in weaned piglets. Sixty weaned piglets (age, 30 days) were randomly divided into two groups: the control group (basic diet) and the test group (basic diet + 500 g/t EA). The pigs were fed for 40 days under the same feeding and management conditions, and the growth performance of each individual was measured. At the end of the feeding period, samples were collected from the small intestinal mucosa for further analysis. Using these tissues, the transcriptome sequences and intestinal microbial diversity were analyzed in both groups. An inflammation model using small intestinal mucosal epithelial cells (IPEC-J2) was also constructed. Dietary EA supplementation significantly increased the average daily weight gain (ADG) and reduced diarrhea rate and serum diamine oxidase (DAO) levels of weaned piglets. Transcriptome sequencing results revealed 401 differentially expressed genes in the jejunum mucosal tissue of pigs in the control and test groups. Of these, 163 genes were up-regulated and 238 were down-regulated. The down-regulated genes were significantly enriched in 10 pathways (false discovery rate &lt; 0.05), including seven pathways related to immune response. The results of bacterial 16s rDNA sequencing show that EA affects the composition of the intestinal microbiota in the cecum and rectum, and reveal significant differences in the abundances of Prevotella_9, Lactobacillus delbrueckii, and Lactobacillus reuteri between the test and control groups (P &lt; 0.05). Experiments using the inflammation model showed that certain doses of EA promote the proliferation of IPEC-J2 cells, increase the relative mRNA expression levels of tight junction-related proteins (ZO-1 and Occludin), improve the compactness of the intestine, reduce the expression of inflammatory factors TNF-α and IL-6, and significantly reduce LPS-induced inflammation in IPEC-J2 cells. In conclusion, we found for the first time that dietary supplementation of EA affects the gut immune response and promotes the beneficial gut microbiota in weaned piglets, reduces the occurrence of inflammatory responses, and thereby promotes the growth and intestinal health of piglets.

The Role of Probiotics in Alleviating Postweaning Diarrhea in Piglets From the Perspective of Intestinal Barriers

Early weaning of piglets is an important strategy for improving the production efficiency of sows in modern intensive farming systems. However, due to multiple stressors such as physiological, environmental and social challenges, postweaning syndrome in piglets often occurs during early weaning period, and postweaning diarrhea (PWD) is a serious threat to piglet health, resulting in high mortality. Early weaning disrupts the intestinal barrier function of piglets, disturbs the homeostasis of gut microbiota, and destroys the intestinal chemical, mechanical and immunological barriers, which is one of the main causes of PWD in piglets. The traditional method of preventing PWD is to supplement piglet diet with antibiotics. However, the long-term overuse of antibiotics led to bacterial resistance, and antibiotics residues in animal products, threatening human health while causing dysbiosis of gut microbiota and superinfection of piglets. Antibiotic supplementation in livestock diets is prohibited in many countries and regions. Regarding this context, finding antibiotic alternatives to maintain piglet health at the critical weaning period becomes a real emergency. More and more studies showed that probiotics can prevent and treat PWD by regulating the intestinal barriers in recent years. Here, we review the research status of PWD-preventing and treating probiotics and discuss its potential mechanisms from the perspective of intestinal barriers (the intestinal microbial barrier, the intestinal chemical barrier, the intestinal mechanical barrier and the intestinal immunological barrier) in piglets.

Hydrolyzation of snail (Achatina fulica) meat with rice water as novel probiotic supplements for animal feed

Background and Aim: Snail meat and digestive tract hydrolyzate fermented with a consortium of preserved rice water microorganisms could serve as new sources of probiotics. Microorganisms from the examined feed supplement were isolated, identified, and characterized for resistance at low pH and with bile salts. The study aimed to determine the potential hydrolysate of the snail meat and digestive tract as a novel probiotic supplement for animal feed at various pH values and Oxgall. Materials and Methods: The submerged fermentation method was conducted for 21 days to examine the novel probiotic that originated from snail microorganisms in the hydrolyzed liquid fermented by finely ground snail meat and the digestive tract. The microorganisms in the hydrolyzate were isolated by a spread plate method, while the potential of the probiotic hydrolyzate was tested for resistance to pH values of 2, 2.5, 3, and 4, as well as resistance to bile salts at Oxgall concentrations of 0.2%, 0.3%, 0.5%, 1%, and 2%. Results: The hydrolyzate profile of snail meat and digestive tract contained five isolates of lactic acid bacteria that could serve as potential probiotics. Conclusion: The application of fermentation technology using a consortium of preserved rice water microorganisms can convert snail meat and the digestive tract into novel probiotic products that could be utilized in feed supplements.

Soya saponin improves egg-laying performance and immune function of laying hens

BACKGROUND

Soya saponin (SS), an active compound in soybean meals, has been widely studied in the medical field. However, it was considered as an anti-nutritional factor in poultry diets. The objective of this experiment was to measure the effects of dietary SS using three dietary treatments on egg-laying performance and immune function of laying hens. Birds were fed a low soybean meal basal diet (CON), a low-SS diet (50 SS) containing 50 mg/kg SS, or a high-SS diet (500 SS) containing 500 mg/kg SS for 10 weeks. At the end of the 5th and 10th week of the trial, samples were collected for analysis.

RESULTS

Results showed that with 50 mg/kg SS supplementation, the egg production rate, feed conversion ratio (FCR), and eggshell quality tended to be improved. Serum follicle stimulating hormone (FSH) and Interleukin-4 (IL-4) levels were also elevated as well as the peripheral blood LPS stimulation index, the proportion of B lymphocytes, and antibody titer of bovine serum albumin (BSA). We also found that mRNA levels of follicle stimulating hormone receptor (FSHR) in ovarian, nuclear transcription factor kappa B (NF-κB), Transforming growth factor (TGF-β) and interferon γ (IFN-γ) in spleen were up-regulated at the end of the trial. Additionally, dietary 50 mg/kg SS improved the ileal flora via up-regulating the relative abundance of Lactobacillus, Romboutsia and Lactobacillus delbrueckii. Although the immune related indicators were improved with 500 mg/kg SS supplemented, it seemed to have a negative influence on the laying-performance. Specifically, serum alanine aminotransferase (ALT), alkaline phosphatase (ALP), and the ratio of IFN-γ to IL-4 were increased in the 500 SS group at the end of the trial. The mRNA levels of gonadotropin releasing hormone 1 (GnRH1) in Hypothalamus, the estrogen related receptor (ERR) in ovaries were downregulated as well as the egg production rate during the trial with 500 mg/kg SS supplemented.

CONCLUSIONS

The egg production performance was improved by dietary supplemented with 50 mg/kg SS via increasing ovarian FSHR transcription level and serum estrogen level. A beneficial shift in intestinal microflora was recorded, and the immune function of laying hens was also improved with 50 mg/kg SS supplementation. Surprisingly, the long-term supplementation of 500 mg/kg SS exerted a negative impact on the laying performance and physiological functions of the liver of laying hens.

Effect of probiotic supplementation on performance, morphology and gene expression associated with immune responses in early age of broiler chickens exposed to stress induced by corticosterone injection

Context Broiler chickens are exposed to various stressors, which can affect production performance. The use of dietary probiotics is one of the feasible methods to maintain performance, intestinal health, humeral immunity, and ameliorating physiological stress in the broiler. Aims In all, 288 1-day-old male broiler chicks were used to evaluate the effect of probiotic supplementation on performance, morphology, and gene expression associated with immune responses in the starter phase of broiler chickens exposed to stress. Methods In total, 288 1-day-old male broiler chicks (Ross 308) were assigned to evaluate the effects of Bacillus subtilis spore (BSS; Gallipro®200) supplementation at three levels (0, 0.8 × 105 colony-forming units (CFU) and 1.6 × 105 CFU/g feed) with corticosterone (CORT; 4 mg/kg BW at 7–9 days of age) or without CORT (oil) subcutaneous injection. The experiment was conducted in a completely randomised 2 × 3 factorial design. Key results CORT injection and probiotic supplementation led to an increase and decrease respectively, in food conversion ratio compared with the control group (P < 0.05). CORT injections reduced the expression of TLR4, HSP70 and IgA in all parts of the intestine. However, the TLR4 gene expression increased in jejunum by CORT injections. BSS supplementation induced the expression of TLR4 in all sections of the intestine, both in stress and non-stress conditions. In stress-exposed chickens, IgA expression in the jejunum was affected by BSS supplementation. Interaction effects between CORT injections and BSS supplementation on the gene expression were significant in different parts of the intestine. Conclusions Chicks exposed to stress conditions induced by CORT injection showed that the ileum was more susceptible than were the other parts, especially for TLR4 and HSP70 gene expression. BSS-supplemented birds showed more capability to face the stress condition, probably due to intestinal health and immunity-modulated effect of BSS. Implication Formulating a ration with a probiotic can be more effective in stress conditions, through modulating immune-responsive genes in the intestine.

The Probiotic Properties of Lactic Acid Bacteria and Their Applications in Animal Husbandry

The intestinal tract of animals is a complex ecosystem in which nutrients, microbiota and host cells interact extensively. Probiotics can be considered as part of the natural microbiota of the gut and are involved in improving homeostasis. Lactic acid bacteria (LAB) is a general term for a class of non-spore forming, gram-positive bacteria whose main product of fermented sugar is lactic acid. LAB are considered to be a type of probiotic due to their health-promoting effects on the host, and are very effective in the treatment of human and animal diseases. LAB have been widely used as a class of microbial agents in the field of livestock and poultry breeding. They are also considered to be the best substitutes for antibiotics to improve animal health. Here, we review the biological functions, probiotic characteristics and applications of LAB in livestock and poultry breeding. This review is designed to provide a theoretical base for the in-depth exploration and promotion of LAB use in animal diets.

Effects of Clostridium butyricum and a Bacteriophage Cocktail on Growth Performance, Serum Biochemistry, Digestive Enzyme Activities, Intestinal Morphology, Immune Responses, and the Intestinal Microbiota in Rabbits

The objective of this study was to assess the effects of dietary supplementation with Clostridium butyricum (CB) and a bacteriophage cocktail (BP) on growth performance, serum biochemical parameters, intestinal digestive and oxidase enzymes, intestinal morphology, immune responses, and the cecum microbiota in rabbits. In total, 108 New Zealand rabbits (5 weeks old) were randomly and equally allotted into three dietary treatment groups (four replicates per treatment, n = 36/treatment): (1) the control (CN) group-rabbits fed the basal diet; (2) CB group-rabbits fed the basal diet supplemented with 100 mg/kg diet Clostridium butyricum; and (3) BP group-rabbits fed the basal diet supplemented with 200 mg/kg diet BP cocktail, respectively, for 6 weeks. Compared with the CN diet, dietary CB and BP inclusion increased the average daily gain (ADG) and average daily feed intake (ADFI) and decreased the feed/gain (F/G) ratio of rabbits. Furthermore, CB increased the digestive enzyme activity (α-amylase and trypsin in the ileum); the chymotrypsin activity was also significantly increased in the duodenum and jejunum. Supplementation with CB significantly enhanced antioxidant capacity (SOD and GSH-Px) in the jejunum and ileum and reduced MDA levels. Additionally, rabbits fed CB had significantly elevated villus height (V) and (V/C) ratios but reduced crypt depth (C). Moreover, dietary CB supplementation markedly increased the ileal expression of tight junction proteins (occludin, ZO-1, and claudin-1) and increased secretory immunoglobulin A (sIgA) production. High-throughput sequencing indicated that the microbiota in the rabbit intestine was altered by CB and BP. Venn diagrams and heatmap plots revealed that the gut microbial community composition varied obviously among rabbits fed different diets. Specifically, CB increased the relative abundance of beneficial bacteria to maintain intestinal barrier homeostasis, whereas BP decreased the relative abundance of Gammaproteobacteria, which included a plenty of pathogenic bacteria.

Effects of Dietary Supplementation of Lactobacillus delbrueckii on Gut Microbiome and Intestinal Morphology in Weaned Piglets

Lactobacillus delbrueckii is a Gram-positive bacterium mostly used in the dairy industry for yogurt and cheese. The present study was designed to evaluate the effects of Lactobacillus delbrueckii on serum biochemical parameters, intestinal morphology, and performance by supplementing at a dietary level of 0.1% in diets for weaned piglets. Eighty healthy weaned piglets (initial body weight: 7.56 ± 0.2 kg) were randomly divided into two feeding groups with four replicates in each group (n = 10 animals per replicate); piglets were fed with basal diet (CON) or basal diet containing 0.1% Lactobacillus delbrueckii (LAC). The results showed that dietary supplementation of Lactobacillus delbrueckii improved growth performance and increased serum HDL and insulin levels in piglets on the 28th day of the experimental time (p < 0.05). The gut microbe analysis revealed that Lactobacillus delbrueckii significantly decreased the relative abundance of the phyla Bacteroidetes, but increased the relative abundance of the phyla Firmicutes. The Lactobacillus delbrueckii also significantly increased the relative abundance of Bifidobacterium and Lactobacillus at the genus level of the bacterial community in the ileum, but decreased the relative abundance of unclassified Clostridiales. Moreover, Lactobacillus delbrueckii improved mucosal morphology by obtaining higher intestinal villus height (p < 0.05), significantly increasing the concentrations of butyrate, isobutyric acid, and isovaleric acid in colonic chyme of piglets, but decreasing the intestinal pH at the duodenum and ileum on the 28th day of the experimental time. In conclusion, dietary supplementation of Lactobacillus delbrueckii in the diet of weaned piglets can improve intestinal morphology and modulate the microbiota community to promote growth performance.

In vitro evaluation of the probiotic potential of Lactobacillus isolated from native swine manure

Background and Aim:

Using antimicrobials as a feed additive in swine production is prohibited because it is a major cause of the emergence of antimicrobial-resistant bacteria. Probiotics such as Lactobacillus spp. are an attractive alternative to reduce antimicrobial resistance and promote swine growth. This study aimed to evaluate the in vitro probiotic properties of Lactobacillus isolated from indigenous swine manure.

Materials and Methods:

A total of 30 fecal samples from healthy individual indigenous pigs were collected and isolated on de Man, Rogosa, and Sharpe agar. The preliminary screen identified candidates with antibacterial activity against six pathogens and >50% survival and tolerance to acid (pH 3.0) and 1% bile salt. Isolates that passed the initial screen will be tested for other probiotic properties.

Results:

Of the 314 isolates from 30 pig manure samples, 17 isolates satisfied all initial conditions for probiotic properties. Each isolate has unique, distinctive properties. Isolates B4, B5, B8, B17, B87, and B144 formed thick biofilms, whereas isolates B5, B8, and 27 adhered well to the intestinal wall and exhibited strong autoaggregation properties. Isolate B4 aggregated with Enterohemorrhagic Escherichia coli and Enteropathogenic E. coli. Tests in pH-adjusted cell-free medium indicated that the antibacterial activity resulted from bacterial acidification rather than bacteriocin formation. Sequence analysis (16S rRNA) revealed 16 of the isolates were Lactobacillus plantarum, and only one isolate was Lactobacillus salivarius.

Conclusion:

We isolated 17 Lactobacillus from swine manure and demonstrated that their probiotic properties might be useful as a probiotic cocktail for swine feed.

Lactobacillus delbrueckii Protected Intestinal Integrity, Alleviated Intestinal Oxidative Damage, and Activated Toll-Like Receptor-Bruton's Tyrosine Kinase-Nuclear Factor Erythroid 2-Related Factor 2 Pathway in Weaned Piglets Challenged with Lipopolysaccharide

Oxidative stress is increasingly being recognized as a player in the pathogenesis of intestinal pathologies, and probiotics are becoming an attractive means of addressing it. The present study investigated the effects of dietary supplementation with Lactobacillus delbrueckii (LAB) on intestinal integrity and oxidative damage in lipopolysaccharide (LPS)-challenged piglets. A total of 36 crossbred weaned piglets (Duroc × Landrace × Large Yorkshire) were randomly divided into three groups: (1) non-challenged controls (CON), (2) LPS-challenged controls (LPS), and (3) 0.2% LAB (2.01 × 10¹⁰ CFU/g) + LPS treatment (LAB + LPS). On the 29th day of the experiment, the LPS and CON groups were injected intraperitoneally with LPS and saline at 100 ug/kg body weight, respectively. The results show that the LPS-induced elevation of the serum diamine oxidase (DAO) level and small intestinal crypt depth (CD) were reversed by the dietary addition of LAB, which also markedly increased the ileal expression of tight junction proteins (occludin, ZO-1, and claudin-1) in the LPS-challenged piglets. Furthermore, LAB supplementation normalized other LPS-induced changes, such as by decreasing malondialdehyde (MDA) in both the serum and intestinal mucosa and 8-hydroxy-2-deoxyguanosine (8-OHdG) in the jejunal mucosa, increasing glutathione reductase (GR) and glutathione peroxidase (GSH-Px) in both the serum and intestinal mucosa, and increasing glutathione (GSH) and superoxide dismutase (SOD) in the jejunal mucosa. LAB also activated Toll-like receptor (TLR)–Bruton’s tyrosine kinase (Btk)–nuclear factor erythroid 2-related factor 2(Nrf2) signaling pathways in the intestine, suggesting that it plays a vital role in the ameliorative antioxidant capacity of weaned piglets. In summary, LAB increased intestinal integrity by improving the intestinal structure and tight junctions while enhancing antioxidant functions via the activation of the TLR–Btk–Nrf2 signaling pathway.

The impact of probiotics on gut health via alternation of immune status of monogastric animals

The intestinal immune system is affected by various factors during its development, such as maternal antibodies, host genes, intestinal microbial composition and activity, and various stresses (such as weaning stress). Intestinal microbes may have an important impact on the development of the host immune system. Appropriate interventions such as probiotics may have a positive effect on intestinal immunity by regulating the composition and activity of intestinal microbes. Moreover, probiotics participate in the regulation of host health in many ways; for instance, by improving digestion and the absorption of nutrients, immune response, increasing the content of intestinal-beneficial microorganisms, and inhibiting intestinal-pathogenic bacteria, and they participate in regulating intestinal diseases in various ways. Probiotics are widely used as additives in livestock and the poultry industry and bring health benefits to hosts by improving intestinal microbes and growth performance, which provides more choices for promoting strong and efficient productivity.

Lactobacillus salivarius, a Potential Probiotic to Improve the Health of LPS-Challenged Piglet Intestine by Alleviating Inflammation as Well as Oxidative Stress in a Dose-Dependent Manner During Weaning Transition

Intestinal health is a critical issue for piglets during their weaning transition period. Previous reports have emphasized the promise of distinct probiotics in improving the enteric health. Here in this research, a newly isolated Lactobacillus salivarius strain was pretreated to Lipopolysaccharide (LPS)-challenged piglets and its association with integrity of the intestinal barrier coupled with effective dosage were expected to be signified. In the present study, 72 piglets (Landrace × Yorkshiere × Duroc) were randomly allotted to four groups, each group with six replicates. The subjects in the control group were provided with basal diet while those in other tested groups with extra 0.05, 0.1, and 0.2% L. salivarius, respectively. Fourteen days later, LPS was intraperitoneally injected and sodium pentobarbital was then delivered to euthanize those LPS-challenged piglets. An increase of average daily gain and body weight along with an apparent decline of diarrhea rate were observed in L. salivarius-treated groups. Both 0.1 and 0.2% L. salivarius supplement in total diet had the capability to markedly elevate levels of CAT, GSH-Px, SOD, anti-inflammatory cytokine from the serum as well as tight junction proteins (Claudin-1, Occludin, and ZO-1) extracted from intestine in LPS-challenged piglets. These changes were accompanied by the obvious downregulation of D-lactic acid, DAO, MDA and pro-inflammatory mediators in the serum, including IL-1β, IL-6, IFN-γ, and TNF-α. Meanwhile, the expression levels of TLR2 and TLR4 in spleen and mesenteric lymph nodes were significantly lower whereas the oxidation-related gene, ho-1 was up-regulated with L. salivarius administration. Our findings suggested that relatively high dose L. salivarius (0.1–0.2%) could regulate the progression of inflammatory response and oxidative stress when individuals were exposed to LPS, thus probably offering valuable assistance in restoring barrier function and improving overall performance.

Oxidative stress tolerance and antioxidant capacity of lactic acid bacteria as probiotic: a systematic review

Lactic acid bacteria (LAB) are the most frequently used probiotics in fermented foods and beverages and as food supplements for humans or animals, owing to their multiple beneficial features, which appear to be partially associated with their antioxidant properties. LAB can help improve food quality and flavor and prevent numerous disorders caused by oxidation in the host. In this review, we discuss the oxidative stress tolerance, the antioxidant capacity related herewith, and the underlying mechanisms and signaling pathways in probiotic LAB. In addition, we discuss appropriate methods used to evaluate the antioxidant capacity of probiotic LAB. The aim of the present review is to provide an overview of the current state of the research associated with the oxidative stress tolerance and antioxidant capacity of LAB.

NUTRITION AND HEALTH: COMPANION ANIMAL APPLICATIONS: Functional nutrition in livestock and companion animals to modulate the immune response

Advances in the understanding of how the immune system functions in response to diet have altered the way we think about feeding livestock and companion animals on both the short (weeks/months) and long-term (years) timelines; however, depth of research in each of these species varies. Work dedicated to understanding how immune function can be altered with diet has revealed additional functions of required nutrients such as vitamins D and E, omega-3 polyunsaturated fatty acids (PUFA), and minerals such as zinc, while feed additives such as phytogenics and probiotics add an additional layer of immunomodulating potential to modern diets. For certain nutrients such as vitamin D or omega-3 PUFA, inclusion above currently recommended levels may optimize immune function and reduce inflammation, while for others such as zinc, additional pharmacological supplementation above requirements may inhibit immune function. Also to consider is the potential to over-immunomodulate, where important functions such as clearance of microbial infections may be reduced when supplementation reduces the inflammatory action of the immune system. Continued work in the area of nutritional immunology will further enhance our understanding of the power of nutrition and diet to improve health in both livestock and companion animals. This review collects examples from several species to highlight the work completed to understand how nutrition can be used to alter immune function, intended or not.

Lactobacillus delbrueckii Ameliorates Intestinal Integrity and Antioxidant Ability in Weaned Piglets after a Lipopolysaccharide Challenge

This study was conducted to evaluate the effect of dietary supplementation with Lactobacillus delbrueckii (LAB) on intestinal morphology, barrier function, immune response, and antioxidant capacity in weaned piglets challenged with lipopolysaccharide (LPS). A total of 36 two-line crossbred (Landrace × large Yorkshire) weaned piglets (28 days old) were divided into three groups: (1) nonchallenged control (CON); (2) LPS-challenged control (LPS); and (3) LAB+LPS treatment (0.2% LAB+LPS). Compared to the LPS piglets, the LAB+LPS piglets improved intestinal morphology, indicated by greater (P < 0.05) villus height in the duodenum and ileum; villus height : crypt depth ratio in the duodenum, jejunum, and ileum, as well as decreased (P < 0.05) crypt depth in the jejunum and ileum; and better intestinal barrier function, indicated by upregulated (P < 0.05) mRNA expression of tight junction proteins in the intestinal mucosa. Moreover, compared to the LPS piglets, LAB significantly decreased (P < 0.05) concentrations of TNF-α and IL-1β in the small intestine and increased (P < 0.05) IL-10 levels in the jejunum and ileum. Additionally, LAB increased (P < 0.05) T-AOC activities of the colon, GSH concentrations of the jejunum, and mRNA expression of CAT and Cu/Zn-SOD, while reduced (P < 0.05) MDA concentrations in the jejunum and ileum in LPS-changed piglets. Collectively, our results indicate that supplementation of LAB improved intestinal integrity and immune response and alleviated intestinal oxidative damage in LPS-challenged piglets.

Probiotics in Animal Husbandry: Applicability and Associated Risk Factors

Probiotics have been emerging as a safe and viable alternative to antibiotics for increasing performance in livestock. Literature was collated via retrieved information from online databases, viz, PubMed, MEDLINE, ScienceDirect, Scopus, Web of Science and Google Scholar. Besides improved immunomodulation and nutrient digestibility, in-feed probiotics have shown drastic reductions in gastrointestinal tract-invading pathogens. However, every novel probiotic strain cannot be assumed to share historical safety with conventional strains. Any strain not belonging to the wild-type distributions of relevant antimicrobials, or found to be harbouring virulence determinants, should not be developed further. Modes of identification and the transmigration potential of the strains across the gastrointestinal barrier must be scrutinized. Other potential risk factors include the possibility of promoting deleterious metabolic effects, excessive immune stimulation and genetic stability of the strains over time. Adverse effects of probiotics could be strain specific, depending on the prevailing immunological and physiological condition of the host. The most crucial concern is the stability of the strain. Probiotics stand a good chance of replacing antibiotics in animal husbandry. The possibility of the probiotics used in animal feed cross-contaminating the human food chain cannot be downplayed. Thus, the established safety measures in probiotic development must be adhered to for a successful global campaign on food safety and security.