Probiotic properties of genetically engineered Lactobacillus plantarum producing porcine lactoferrin used as feed additive for piglets

Exploring the modulatory role of bovine lactoferrin on the microbiome and the immune response in healthy and Shiga toxin-producing E. coli challenged weaned piglets

BACKGROUND

Post-weaned piglets suffer from F18+ Escherichia coli (E. coli) infections resulting in post-weaning diarrhoea or oedema disease. Frequently used management strategies, including colistin and zinc oxide, have contributed to the emergence and spread of antimicrobial resistance. Novel antimicrobials capable of directly interacting with pathogens and modulating the host immune responses are being investigated. Lactoferrin has shown promising results against porcine enterotoxigenic E. coli strains, both in vitro and in vivo.

RESULTS

We investigated the influence of bovine lactoferrin (bLF) on the microbiome of healthy and infected weaned piglets. Additionally, we assessed whether bLF influenced the immune responses upon Shiga toxin-producing E. coli (STEC) infection. Therefore, 2 in vivo trials were conducted: a microbiome trial and a challenge infection trial, using an F18+ STEC strain. BLF did not affect the α- and β-diversity. However, bLF groups showed a higher relative abundance (RA) for the Actinobacteria phylum and the Bifidobacterium genus in the ileal mucosa. When analysing the immune response upon infection, the STEC group exhibited a significant increase in F18-specific IgG serum levels, whereas this response was absent in the bLF group.

CONCLUSION

Taken together, the oral administration of bLF did not have a notable impact on the α- and β-diversity of the gut microbiome in weaned piglets. Nevertheless, it did increase the RA of the Actinobacteria phylum and Bifidobacterium genus, which have previously been shown to play an important role in maintaining gut homeostasis. Furthermore, bLF administration during STEC infection resulted in the absence of F18-specific serum IgG responses.

Effects of Fermented Bamboo Shoot Processing Waste on Growth Performance, Serum Parameters, and Gut Microbiota of Weaned Piglets

Gut microbiota (GM) plays a vital role in the nutrition and metabolism of weaned piglets. Some feed additives can be used to adjust the composition of GM to improve the health of weaned piglets. In this study, we investigated the effects of adding fermented bamboo shoot processing waste (FBSPW) to diet on growth performance, serum parameters, and GM of weaned piglets. Seventy-two piglets were divided into four groups and were fed diets containing 0% (control), 4% (group A), 8% (group B), and 12% (group C) FBSPW for 50 days. We found that the addition of FBSPW significantly decreased the average daily feed intake, serum triglyceride content, and urea nitrogen of weaned piglets compared to the control. The cecum and cecal microbiota of weaned piglets fed the basal diet with 12% FBSPW were significantly different compared to the control. A basal diet with 12% FBSPW significantly reduced the taxon feature number, and the relative abundance of Tenericutes in the cecum and cecal microbiota of weaned piglets compared with the control. The addition of 12% FBSPW to weaned piglet feed could improve their nitrogen and lipid metabolisms and have beneficial effects on GM.

Screening of Lactic Acid Bacteria with Inhibitory Activity against ETEC K88 as Feed Additive and the Effects on Sows and Piglets

Simple Summary

Numerous reports have suggested that lactic acid bacteria (LAB), which are important probiotics, can protect animals against pathogen-induced injury and inflammation, regulate gut microflora, enhance digestive tract function, improve animal growth performance, and decrease the incidence of diarrhea caused by enterotoxigenic (ETEC) that expresses K88. This research selected Lactobacillus (L.) reuteri P7, L. amylovorus P8, and L. johnsonii P15 with good inhibition against ETEC K88 and excellent probiotic properties screened from 295 LAB strains isolated from fecal samples from 55 healthy weaned piglets for a study on feeding of sows in late pregnancy and weaned piglets. Feed supplementation with these three strains improved reproductive performance of sows and growth performance of piglets, decreased the incidence of diarrhea in piglets, and increased the antioxidant capacity of serum in both sows and piglets. Therefore, L. reuteri P7, L. amylovorus P8, and L. johnsonii P15 might be considered as potential antibiotic alternatives for further study.

Abstract

Enterotoxigenic Escherichia coli (ETEC), which expresses K88 is the principal microorganism responsible for bacterial diarrhea in pig husbandry, and the indiscriminate use of antibiotics has caused many problems; therefore, antibiotics need to be replaced in order to prevent diarrhea caused by ETEC K88. The objective of this study was to screen excellent lactic acid bacteria (LAB) strains that inhibit ETEC K88 and explore their effects as probiotic supplementation on reproduction, growth performance, diarrheal incidence, and antioxidant capacity of serum in sows and weaned piglets. Three LAB strains, P7, P8, and P15, screened from 295 LAB strains and assigned to Lactobacillus (L.) reuteri, L. amylovorus, and L. johnsonii with high inhibitory activity against ETEC K88 were selected for a study on feeding of sows and weaned piglets. These strains were chosen for their good physiological and biochemical characteristics, excellent exopolysaccharide (EPS) production capacity, hydrophobicity, auto-aggregation ability, survival in gastrointestinal (GI) fluids, lack of hemolytic activity, and broad-spectrum activity against a wide range of microorganisms. The results indicate that LAB strains P7, P8, and P15 had significant effects on improving the reproductive performance of sows and the growth performance of weaned piglets, increasing the activity of antioxidant enzymes and immune indexes in both.

A prospective on multiple biological activities of lactoferrin contributing to piglet welfare

Piglets, especially weaning piglets, show a lower level of immunity and higher morbidity and mortality, owing to their rapid growth, physiological immaturity, and gradual reduction of maternal antibodies, which seriously affects their growth and thus, value. It is important that piglets adapt to nutrient digestion and absorption and develop sound intestinal function and colonization with gut microbiota as soon as possible during their early life stage. Lactoferrin is a natural glycoprotein polypeptide that is part of the transferrin family. It is widely found in mucosal secretions such as saliva and tears, and most highly in milk and colostrum. As a multifunctional bioactive protein and a recommended food additive, lactoferrin is a potential alternative therapy to antibiotics and health promoting additive for piglet nutrition and development. It is expected that lactoferrin, as a natural food additive, could play an important role in maintaining pig health and development. This review examines the following known beneficial effects of lactoferrin: improves the digestion and capacity for absorption in the intestinal tract; promotes the absorption of iron and reduces the incidence of iron deficiency anemia; regulates intestinal function and helps to balance the microbial biota; and enhances the resistance to disease of the piglets via modulating and enhancing the immune system.

A Single Plasmid of Nisin-Controlled Bovine and Human Lactoferrin Expressing Elevated Antibacterial Activity of Lactoferrin-Resistant Probiotic Strains

Lactoferrin (LF) is a multifunctional protein found in mammals, and it shows broad-spectrum antimicrobial activity. To improve the functional properties of specific probiotics in order to provide both the beneficial characteristics of lactic acid bacteria and the biological activity of LF, cDNAs of bovine LF (BLF), human LF (HLF), or porcine LF (PLF) were cloned into a nisin-inducible plasmid. These were then transformed into the selected eight probiotics, which are LF-resistant hosts. Expression of recombinant LFs (rLFs) was analyzed via SDS-PAGE and Western blot analysis. Although the selected host strains may not contain the nisRK genes (NisK, the sensor kinase; NisR, the regulator protein), the components of autoregulation, a low level of LFs expression can be successfully induced by using nisin within bacterial cells in a time-dependent manner in three engineered clones, including Lactobacillus delbrueckii/HLF, L. delbrueckii/BLF, and L. gasseri/BLF. Lactobacillus delbrueckii and Lactobacillus gasseri originate from yogurt and human milk, respectively, and both strains are functional probiotic strains. Therefore, we further compared the antibacterial activities of disrupted recombinant probiotic clones, conventional strains (host control), and vector control ones by using agar diffusion and broth inhibition analysis, and the expression of rLFs in the above three clones considerately improved their antibacterial efficacies against four important food-borne pathogens, namely, Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, and Salmonellaenterica. In conclusion, this study provides a simple strategy for the production of functional LFs (BLF and HLF) in both functional and LF-resistant hosts for applications in the field.

Recent systems biology approaches for probiotics use in health aspects: a review

The market of probiotics is growing dynamically for the food and supplements, which provides better health to an individual. Probiotics are used as dietary management for diseases, but it varies between regions and persons. Systems biology can help in resolving the strain specificity of probiotics by studying their genome level organization. In this review, we have compiled facets of systems biology and next-generation omics methods such as metagenomics, proteomics and metabolomics. These tools are crucial for the optimization of the metabolic processes in probiotics and hence, their use for human health. The limitations and challenges associated with the development of probiotics involve their stability and function in different individuals. Systems biology facilitates emerging metabolic engineering approaches to improve probiotics strain for their broader application. This review provides comprehensive and updated knowledge of engineered probiotics as therapeutics and various challenges in the development of engineered probiotics.

Review: Are we using probiotics correctly in post-weaning piglets?

Intensive farming may involve the use of diets, environments or management practices that impose physiological and psychological stressors on the animals. In particular, early weaning is nowadays a common practice to increase the productive yield of pig farms. Still, it is considered one of the most critical periods in swine production, where piglet performance can be seriously affected and where they are predisposed to the overgrowth of opportunistic pathogens. Pig producers nowadays face the challenge to overcome this situation in a context of increasing restrictions on the use of antibiotics in animal production. Great efforts are being made to find strategies to help piglets overcome the challenges of early weaning. Among them, a nutritional strategy that has received increasing attention in the last few years is the use of probiotics. It has been extensively documented that probiotics can reduce digestive disorders and improve productive parameters. Still, research in probiotics so far has also been characterized as being inconsistent and with low reproducibility from farm to farm. Scientific literature related to probiotic effects against gastrointestinal pathogens will be critically examined in this review. Moreover, the actual practical approach when using probiotics in these animals, and potential strategies to increase consistency in probiotic effects, will be discussed. Thus, considering the boost in probiotic research observed in recent years, this paper aims to provide a much-needed, in-depth review of the scientific data published to-date. Furthermore, it aims to be useful to swine nutritionists, researchers and the additive industry to critically consider their approach when developing or using probiotic strategies in weaning piglets.

Effects of soybean meal fermented by L. plantarum, B. subtilis and S. cerevisieae on growth, immune function and intestinal morphology in weaned piglets

BACKGROUND

The present study compared the effects of soybean meal fermented by three different probiotics organisms with non-fermented soybean meal on growth performance, serum parameters, immune chemistry and intestinal morphology in weaned piglets.

METHODS

One hundred and forty-four 35-day old crossbred (Duroc × Landrace × Yorkshire) piglets were randomly allocated into four different dietary treatments (n = 36 per group) containing 0, 5, 10 and 15% fermented soybean meal.

RESULTS

The piglets fed fermented soybean meal showed an increase (p < 0.05) in average daily weight gain and a reduction in feed consumption (p < 0.05).The piglets fed 10 and 15% fermented soybean meal showed the greatest growth improvement with higher levels of serum alkaline phosphatase and total serum proteins. Serum urea nitrogen in the experimental group was significantly lower than control whereas serum IgG, IgM and IgA levels were all significantly higher. Moreover, villus height in the duodenum, jejunum, and ileum was significantly higher (p < 0.05) and the crypt depth was significantly lower (p < 0.05). The levels of the autophagy factor LC3B in piglets showed a downward trend in the jejunum and ileum compared to control.

CONCLUSIONS

Fermented soybean meal could significantly improve the growth, immune function and intestinal health in weaned piglets, and the best effective benefits showed in 10% FSBM group.