Effects of Niacin on Resistance to Enterotoxigenic Escherichia coli Infection in Weaned Piglets

Antimicrobial peptide-chitosan nanoparticles combat ETEC-induced bacterial infection in mice

Antimicrobial peptides (AMPs) are promising alternatives to antibiotics. However, the disadvantage of AMPs in combating bacterial infections in vivo restricts their practical application. In this study, 3W-2-chitosan-nanoparticles (3W-2-CS-NPs) were successfully constructed by encapsulating the porcine-derived AMPs 3W-2 (WRLRWKTRWRLK-NH2), previously developed by our team, with chitosan (CS). This novel formulation aims to enhance the antibacterial activity and stability of AMPs in vivo, with the specific goal of mitigating the systemic organ impairments induced by Enterotoxigenic Escherichia coli (ETEC) infection. In vitro studies demonstrated that 3W-2-CS-NPs exhibited sustained-release properties and stronger antibacterial activity in comparison to chitosan-nanoparticles (CS-NPs). Additionally, 3W-2-CS-NPs maintained better antibacterial activity in gastric and intestinal fluid environments compared to 3W-2. In vivo studies showed that the gavage of 3W-2-CS-NPs alleviated weight loss, liver damage, systemic inflammation, and intestinal mucosal injury induced by ETEC infection in mice. Furthermore, 3W-2-CS-NPs were demonstrated to promote intestinal microecological balance, as evidenced by 16S rRNA sequencing analysis. Conclusively, this study suggests that the construction of AMPs-CS-NPs has the potential to enhance the in vivo therapeutic efficacy of AMPs and lays the theoretical foundation for the application of AMPs as additives in food and animal husbandry.

Meta-analyses of the global impact of non-antibiotic feed additives on livestock performance and health

INTRODUCTION

The impact of non-antibiotic feed additives on livestock performance and health is contingent upon a multitude of variables, including the animal species, dosage and type of feed additives, and duration of oral administration. However, there is a paucity of knowledge regarding the relationship between these factors and the performance of livestock animals.

OBJECTIVES

The objective of this study was to conduct a global meta-analysis based on a pool of empirical studies to investigate the effects of dietary additives on growth, production, blood metabolites, immunity, intestinal morphology, and the abundance of gut microbiota in livestock.

METHODS

A meta-regression coupled with dose-effect analysis was performed to ascertain the optimal dosage and feeding duration for the optimal body function. A total of 71 papers, estimating 1, 035 effect size across 9 species and 7 types of non-antibiotic feed additives were recruited in our meta-dataset.

RESULTS

Overall assessment confirmed that these additives in diet can significantly improve livestock production and immune function across species. Our findings indicated that the effects of additives on animal performance were more pronounced in herbivores than in omnivores. The dose-response results indicated that the overall optimal doses for antimicrobial peptides, enzymes, oligosaccharides, organic acids, phytogenic, probiotics and prebiotics were 100 mg/kg, 30 mg/kg, 200 mg/kg, 50 mg/kg, 200 mg/kg, 10⁶ CFU/kg, and 10 mg/kg, respectively. Oral administration of these additives for a 2-month period effectively improves livestock performance and health.

CONCLUSION

This evidence-based approach provides a foundation for implementing customized feeding strategies designed to optimize livestock performance, enhance immunity and reduce feed costs. Our assessment shows that these feed additives are promising alternatives to antibiotics in reducing the use of antibiotics. Furthermore, these findings suggest that the use of these feed additives can lead to evidence-based recommendations for practical feeding strategies, providing livestock producers with a sustainable and cost-effective approach to animal health management.

Effects of gut microbiota and metabolites on the host defense peptide expression

The widespread use of antibiotics has led to the emergence of multidrug-resistant bacteria, which pose significant threats to animal health and food safety. Host defense peptides (HDPs) have emerged as promising alternatives because of their unique antimicrobial properties and minimal resistance induction. However, the high costs associated with HDP production and incorporation into animal management practices hinder their widespread application. Alternatively, promoting endogenous HDP expression has gained attention as a sustainable and cost-effective approach. This study summarizes the latest research findings on the modulation of HDP expression by the gut microbiota and its metabolites. By exploring the intricate relationships among the gut microbiota, metabolites, and HDP expression, this study aims to provide a theoretical foundation for the development of targeted strategies to increase endogenous HDP production, thereby promoting animal health and resistance to infectious diseases. KEY POINTS: • Host defense peptides (HDPs) are expressed via various factors, such as nutrients, the gut microbiota, and microbial metabolites. • Recent trends include mechanisms among the gut microbiota, microbiota metabolites, and the intestine on HDP expression. • A comprehensive overview of mechanisms of HDP expression and gut microbiota-host interaction is provided.

The Mechanism of Zinc Oxide in Alleviating Diarrhea in Piglets after Weaning: A Review from the Perspective of Intestinal Barrier Function

Weaning is one of the most challenging phases for piglets, and it is also the time when piglets are the most susceptible to diarrhea, which may result in significant economic losses for pig production. One of the dietary strategies for reducing post-weaning diarrhea (PWD) in piglets is to provide them with a pharmacological dose of zinc oxide (ZnO). However, excessive or long-term usage of high-dose ZnO has significant impacts on pig health and the ecological environment. Therefore, caution should be exercised when considering the use of high-dose ZnO for the prevention or treatment of PWD in piglets. In this paper, the significant role of zinc in animal health, the potential mode of action of ZnO in alleviating diarrhea, and the impact of innovative, highly efficient ZnO alternatives on the regulation of piglet diarrhea were reviewed to offer insights into the application of novel ZnO in pig production.

Berberine alleviates ETEC-induced intestinal inflammation and oxidative stress damage by optimizing intestinal microbial composition in a weaned piglet model

Introduction

Enterotoxigenic Escherichia coli (ETEC) is the main diarrhea-causing pathogen in children and young animals and has become a global health concern. Berberine is a type of "medicine and food homology" and has a long history of use in China, particularly in treating gastrointestinal disorders and bacterial diarrhea.

Methods

In this study, we explored the effects of berberine on growth performance, intestinal inflammation, oxidative damage, and intestinal microbiota in a weaned piglet model of ETEC infection. Twenty-four piglets were randomly divided into four groups-a control group (fed a basal diet [BD] and infused with saline), a BD+ETEC group (fed a basal diet and infused with ETEC), a LB+ETEC group (fed a basal diet with 0.05% berberine and infused with ETEC infection), and a HB+ETEC group (fed a basal diet with 0.1% berberine and infused with ETEC).

Results

Berberine significantly improved the final body weight (BW), average daily gain (ADG), and average daily feed intake (ADFI) (P<0.05) of piglets, and effectively decreased the incidence of diarrhea among the animals (P<0.05). Additionally, berberine significantly downregulated the expression levels of the genes encoding TNF-α, IL-1β, IL-6, IL-8, TLR4, MyD88, NF-κB, IKKα, and IKKβ in the small intestine of piglets (P<0.05). ETEC infection significantly upregulated the expression of genes coding for Nrf2, CAT, SOD1, GPX1, GST, NQO1, HO-1, GCLC, and GCLM in the small intestine of the animals (P<0.05). Berberine significantly upregulated 12 functional COG categories and 7 KEGG signaling pathways. A correlation analysis showed that berberine significantly increased the relative abundance of beneficial bacteria (Gemmiger, Pediococcus, Levilactobacillus, Clostridium, Lactiplantibacillus, Weissella, Enterococcus, Blautia, and Butyricicoccus) and decreased that of pathogenic bacteria (Prevotella, Streptococcus, Parabacteroides, Flavonifractor, Alloprevotella) known to be closely related to intestinal inflammation and oxidative stress in piglets. In conclusion, ETEC infection disrupted the intestinal microbiota in weaned piglets, upregulating the TLR4/MyD88/NF-κB and Nrf2 signaling pathways, and consequently leading to intestinal inflammation and oxidative stress-induced damage.

Discussion

Our data indicated that berberine can optimize intestinal microbiota balance and modulate the TLR4/MyD88/NF-κB and Nrf2 signaling pathways, thus helping to alleviate intestinal inflammation and oxidative damage caused by ETEC infection in weaned piglets.

Artificial parasin I protein (API) supplementation improves growth performance and intestinal health in weaned piglets challenged with enterotoxigenic Escherichia coli

Diarrheas are common risks faced by piglets during the weaning period. This study investigated the alleviating effects of artificial parasin I protein (API) on growth performance and intestinal health of weaned pigs upon enterotoxigenic Escherichia coli (ETEC) challenge. Sixty piglets were randomly divided into five groups and fed a basal diet (CON) or basal diet supplemented with API at 0, 750, and 1500 mg/kg or antibiotics for 5 weeks. On d 15 and 25, piglets were challenged with ETEC K88 except for the CON group. Before the ETEC challenge (d 1-14), dietary API supplementation improved growth performance, and 750 mg API increased (P < 0.05) the average daily gain (ADG), decreased (P < 0.05) feed to gain ratio (F/G) and diarrhea index of weaned piglets. ETEC challenge (during d 15-35) reduced growth performance and increased (P < 0.01) the F/G, diarrhea rate, and diarrhea index. This event was accompanied by the numerically increased malondialdehyde (MDA) levels in serum and ileum, the decreased (P < 0.05) zonula-occludens-1 (ZO-1) and interleukin-6 (IL-6) in the ileum, and the increased (P = 0.04) secretory immunoglobulin A (sIgA) protein in the ileum. Artificial parasin I protein supplementation alleviated the negative impact of ETEC. The 750 mg/kg API inclusion elevated (P < 0.05) ADG and decreased (P < 0.05) F/G. Two levels of API decreased (P < 0.01) the diarrhea rate and diarrhea index. Meanwhile, API inclusion decreased (P < 0.01) the crypt depth in the jejunum, elevated (P < 0.05) villus height in the duodenum and villus height to crypt depth ratio in the duodenum and ileum, up-regulated (P < 0.05) ZO-1 gene, and down-regulated (P < 0.05) mucin-2 gene in the jejunum, and 1500 mg/kg API decreased (P < 0.01) sIgA level and down-regulated (P < 0.05) IL-1β gene in the ileum. Furthermore, 750 mg/kg API elevated (P < 0.01) Bifidobacteria population and acetic acid concentrations in the cecal chyme. In conclusion, API supplementation alleviates the negative impact of ETEC on growth performance and intestinal health, thus can be applied as an antibiotic alternative in weaned piglets.

Nutritional Modulation of Host Defense Peptide Synthesis: A Novel Host-Directed Antimicrobial Therapeutic Strategy?

The escalating threat of antimicrobial resistance underscores the imperative for innovative therapeutic strategies. Host defense peptides (HDPs), integral components of innate immunity, exhibit profound antimicrobial and immunomodulatory properties. Various dietary compounds, such as short-chain fatty acids, vitamins, minerals, sugars, amino acids, phytochemicals, bile acids, probiotics, and prebiotics have been identified to enhance the synthesis of endogenous HDPs without provoking inflammatory response or compromising barrier integrity. Additionally, different classes of these compounds synergize in augmenting HDP synthesis and disease resistance. Moreover, dietary supplementation of several HDP-inducing compounds or their combinations have demonstrated robust protection in rodents, rabbits, pigs, cattle, and chickens from experimental infections. However, the efficacy of these compounds in inducing HDP synthesis varies considerably among distinct compounds. Additionally, the regulation of HDP genes occurs in a gene-specific, cell type-specific, and species-specific manner. In this comprehensive review, we systematically summarized the modulation of HDP synthesis and the mechanism of action attributed to each major class of dietary compounds, including their synergistic combinations, across a spectrum of animal species including humans. We argue that the ability to enhance innate immunity and barrier function without triggering inflammation or microbial resistance positions the nutritional modulation of endogenous HDP synthesis as a promising host-directed approach for mitigating infectious diseases and antimicrobial resistance. These HDP-inducing compounds, particularly in combinations, harbor substantial clinical potential for further exploration in antimicrobial therapies for both human and other animals.

Trimethoprim-Based multicomponent solid Systems: Mechanochemical Screening, characterization and antibacterial activity assessment

In this work, multicomponent trimethoprim-based pharmaceutical solid systems were developed by mechanochemistry, using coformers from the GRAS list and other active pharmaceutical ingredients. The choice of coformers took into account their potential to increase the aqueous solubility/dissolution rate of TMP or its antibacterial activity. All the binary systems were characterized by thermal analysis, powder X-ray diffraction and infrared spectroscopy, and 3 equimolar systems with FTIR pointing to salts, and 4 eutectic mixtures were identified. The intrinsic dissolution rate of TMP in combination with nicotinic acid (a salt) and with paracetamol (eutectic mixture) were 25% and 5% higher than for pure TMP, respectively. For both Gram-positive and -negative strains, the antibacterial activity of TMP with some of the coformers was improved, since the dosage used was lower than the TMP control. A significant increase in antibacterial activity against E. coli was found for the eutectic mixture with curcumin, with the best results being obtained for the eutectic and equimolar mixtures with ciprofloxacin. Combining trimethoprim with coformers offers an interesting alternative to using trimethoprim alone: multicomponent forms with enhanced TMP dissolution rates were identified, as well as combinations showing enhanced antibacterial activity relatively to the pure drug.

The Effects of Poria cocos Polysaccharides on Growth Performance, Immunity, and Cecal Microflora Composition of Weaned Piglets

This paper aims to identify Poria cocos polysaccharides (PCPs) as a potential feed additive used for swine production; thus, we explored the effects of different dietary inclusion levels of PCP on growth performance, immunity, and cecal microflora composition in weaned piglets. For this, a total of 120 28-day-old Duroc × Landrace × Yorkshire weaned piglets (8.51 ± 0.19 kg; 28 ± 1 days of age) were randomly allocated to five groups that were fed a basal diet supplemented with 0, 0.025%, 0.05%, 0.1%, and 0.2% PCP, respectively, for 42 days. The results indicated that the average daily gain (ADG) and gain/feed ratio were higher in the PCP treatment groups than in the control group, with a linear effect. The serum concentrations of IgG, IgA, IL-2, IFN-γ, the number of CD4+ T cells, and the CD4+-to-CD8+ T-cell ratio (CD4+/CD8+) were increased, while the levels of IL-6 and TNF-α were decreased in the PCP supplementation groups compared with those in the control group. Furthermore, the cytokine mRNA expression levels exhibited a similar trend in the spleen. PCP supplementation also reduced the abundance of Escherichia coli and Salmonella and enhanced that of Lactobacilli and Bifidobacteria in the cecum. In summary, dietary PCP inclusion exerted positive effects on the growth performance, immunity, and cecal microbiota of piglets and showed potential for use as a feed additive for improving the health of weaned piglets, with 0.1% being the optimal dosage.

Protective effects of maternal administration of total saponins of Codonopsis pilosula in the mice offspring following diarrhea: role of immune function, antioxidant function, and intestinal inflammatory injury

Total saponins of Codonopsis (TSC) are a kind of critical bioactive substances in Codonopsis, which have anti-inflammatory, antioxidant, anti-ulcer, immunomodulatory effects, and protective effects on ulcerative enteritis. In this study, TSC (3.75 mL/kg, gavage) was administered once a day to 13-day gestation Kunming mice for 5 days. On day 13 of birth, the offspring were given Escherichia coli solution (0.15 mL/mouse, intraperitoneal injection) and senna leaf decoction (0.15 mL/mouse, gavage) once a day for 6 days. The results showed that gestation maternal administration of TSC effectively reduced the diarrhea index, increased the content of sIgA, IgG, SOD, and GSH, inhibited the TLR4/MyD88/NF-κB pathway in the intestine, reduced the expression of inflammatory factors, and alleviated intestinal injury in the littermates. The results provided a critical reference for the clinical application of TSC to control diarrhea in animal offspring.

NAD+ Precursors and Intestinal Inflammation: Therapeutic Insights Involving Gut Microbiota

The oxidized form of nicotinamide adenine dinucleotide (NAD+) is a critical metabolite for living cells. NAD+ may act either as a cofactor for many cellular reactions as well as a coenzyme for different NAD+-consuming enzymes involved in the physiological homeostasis of different organs and systems. In mammals, NAD+ is synthesized from either tryptophan or other vitamin B3 intermediates that act as NAD+ precursors. Recent research suggests that NAD+ precursors play a crucial role in maintaining the integrity of the gut barrier. Indeed, its deficiency has been associated with enhanced gut inflammation and leakage, and dysbiosis. Conversely, NAD+-increasing therapies may confer protection against intestinal inflammation in experimental conditions and human patients, with accumulating evidence indicating that such favorable effects could be, at least in part, mediated by concomitant changes in the composition of intestinal microbiota. However, the mechanisms by which NAD+-based treatments affect the microbiota are still poorly understood. In this context, we have focused specifically on the impact of NAD+ deficiency on intestinal inflammation and dysbiosis in animal and human models. We have further explored the relationship between NAD+ and improved host intestinal metabolism and immunity and the composition of microbiota in vivo. Overall, this comprehensive review aims to provide a new perspective on the effect of NAD+-increasing strategies on host intestinal physiology.