Natural killing (NK) cells play a central role in host defense against pathogenic bacteria. Probiotics are able to modulate mucosal immune system in the intestine by maintaining intestinal homeostasis and tolerance towards resident microbiota. We previously found a strain of probiotics, Lactobacillus plantarum (L. plantarum), to significantly improve mucosal barrier integrity and function of the small intestine in a pig model. The present study is designed to investigate the anti-inflammatory potential of L. plantarum in NK cell-mediated intestinal epithelial barrier function under Escherichia coli (ETEC) K88 infection. To study the effect of L. plantarum on the function of NK cells, a L. plantarum strain CGMCC1258 was cultured with NK-92MI cells without direct contact using a transwell system for 2 to 6 hours before collection of NK cells for mRNA and protein expression analysis. To study the anti-inflammatory potential of L. plantarum in NK cell-mediated epithelial cell integrity, NCM460 (an epithelial cell line) was exposed to ETEC K88 for 2 hours using transwell culturing system and subsequently stimulated in a cell-cell contact manner with NK-92MI cells pre-treated with L. plantarum for 4 hours. L. plantarum efficiently increased the protein and mRNA levels of NCRs, and the mRNA abundance of IL-10, perforin, INF-ɤ, TNF-α, IL-8 and IL-26. In addition, the protein levels of IL-10, LIF and IL-22 were increased by L. plantarum. Protein level of IL-22 was increased in the L. plantarum-treated NK cells supernatant. Transfer of L. plantarum-treated NK cells conferred protection against ETEC K88-induced intestinal epithelial barrier damages in NCM460 cells. Protection was associated with an increased expression of ZO-1 and occludin mRAN and protein in ETEC K88-infected NCM460 cells. Furthermore, adding L. plantarum-treated NK cells to ETEC K88-infected NCM460 cells, the protein and mRNA levels of IL-22R1 was increased in NCM460. L .plantarum-treated NK cells were also observed to induce an augmentation in protein levels of phosphorylated p38, JAK1, Stat3 and Tyk2 in ETEC K88-infected NCM460 cells. L. plantarum-treated NK cells improved intestinal epithelial barrier function via IL-22-IL-22R pathway in NCM460 cells during ETEC-K88 infection.
Abstract Data from 655 treatments of 116 studies were used in a meta‐analysis to determine the daily digestible energy (DE), metabolizable energy (ME) and net energy (NE) intake of Chinese growing–finishing pigs, and to predict feed efficiency responses to change in dietary DE, ME and NE. Three alternative functions (i.e., polynomial, Bridges and asymptotic function) were employed for fitting daily DE, ME or NE intakes to mean body weight. The results showed that the three models from the current study provided reasonable fit (all R 2 > 0.83) for the energy intake data. However, under the same energy system, the polynomial function had the smallest Akaike's information criteria (AIC) and residual standard deviation (RSD), followed by Bridges and asymptotic functions. The three model‐generated energy intakes of growing pigs were significantly less than that of the Chinese Feeding Standard of Swine, but similar to that of the National Research Council (2012), while the values of finishing pigs were greater than both standards. Compared with those that predict feed efficiency based on DE or ME, the equation with NE as a predictor had the minimized AIC and RSD. It was also found that feed efficiency increased with increasing dietary energy density (DED), but this response varied with pig body weight, and the lighter pigs were more sensitive to DED than heavier pigs.
The purpose of this study was to evaluate the effects of different levels of potassium magnesium sulfateon (PMS) on growth performance, diarrhea rate, intestinal morphology, antioxidant capacity, intestinal immunity, and gut microbiota in weaned piglets. A total of 216 weaned piglets were randomly divided into six dietary groups: the basal diet with 0% (CON), 0.15, 0.3, 0.45, 0.6, and 0.75% PMS. The results showed that the ADFI of 29-42 days and 1-42 days was linearly and quadratically increased by the PMS supplementation (P < 0.05), and significantly reduced the diarrhea rate in weaned piglets (P < 0.05). Moreover, dietary supplementation with PMS significantly reduced the serum adrenaline and noradrenaline levels in weaned piglets (P < 0.05). Furthermore, 0.3% PMS significantly increased the activity of glutathione peroxidase (GSH-Px) in the jejunum (P < 0.05) and tended to increase the activity of superoxide dismutase (SOD) in the jejunal mucosa of piglets (P < 0.1). Additionally, dietary supplementation with PMS significantly reduced the interleukin-1β (IL-1β) level in the jejunal mucosa (P < 0.05), and 0.3% PMS increased the serum IgM content in piglets (P < 0.05). Furthermore, the analysis of colonic microbiota by 16S RNA sequencing showed that the addition of PMS increased the Shannon index (P < 0.05) and Observed Species index (P < 0.05). Based on linear discriminant analysis effect size (LEfSe) and T-test analysis, the addition of PMS increased the relative abundance of Ruminococcaceae and Peptostreptococcaceae in the colonic digesta (P < 0.05). Spearman analysis showed that there was a positive correlation between intestinal GSH-Px activity and the relative abundance of Peptostreptococcaceae. These results showed that dietary supplementation with PMS could improve growth performance, alleviate diarrhea incidence, and modulate the antioxidant capacity and intestinal immunity in weaned piglets, which was partially related to the significant changes in colonic microbiota composition.
This experiment studied the effects of dietary protein sources and levels on the gut health of piglets, pH value, and concentrations of microbial metabolites (ammonia-N, volatile fatty acids [VFA], and polyamines) in the distal colonic and proximal colonic digesta of piglets weaned at 21 d of age. A total of 150 early-weaned piglets were allotted randomly to 5 diets: 1) control diet (CT; 17% CP), 2) CT formulated with more soy protein concentrate (SPC19; 19% CP), 3) more fish meal (FM19; 19% CP), 4) CT formulated with more soy protein concentrate (SPC23; 23% CP), and 5) more fish meal (FM23; 23%CP). Results showed high protein level increased fecal score (P < 0.05), but different protein sources did not (P > 0.05). The pH value and ammonia-N concentration of digesta in the proximal and distal colon of FM23 were significantly higher (P < 0.05) than those of CT. Acetic acid, propionic acid, butyric acid and valeric acid concentrations in the proximal colon of FM23 exceeded those of CT, SPC19, and FM19 (P < 0.05); however, isobutyric acid and isovaleric acid were not affected (P > 0.05). Histamine and spermidine concentrations of FM23 were higher than those of other treatments (P < 0.05). Propionic acid and butyric acid concentrations in the distal colon were higher of FM23 than of FM19 (P < 0.05); putrescine, histamine and spermidine were higher of FM23 than of LP and FM19 (P < 0.05). It was concluded that high dietary CP content increased microbial metabolites (ammonia-N, histamine, putrescine) in colonic digesta and aggravated piglets' diarrhea.
Trueperella pyogenes is a prevalent opportunistic pathogen responsible for a wide range of infections in livestock and wildlife, such as in cattle, pigs, European bison and forest musk deer. Much of the successful infection of T. pyogenes relies on its virulence factors, including pyolysin as well as adhesion factors. The swift rise of bacterial resistance has highlighted the urgent need for developing new therapeutic strategies. Currently, virulence factor-mediated vaccine development and other therapeutic approaches are widely regarded as the primary interventions for addressing diseases associated with this pathogen. This review examines the broader virulence potential of T. pyogenes, focusing on haemolysin, host cell adhesion proteins, the prevalence of antibiotic resistance, and the development of vaccines mediated by virulence factors. Additionally, it discusses current and future approaches aimed at improving therapeutic interventions.
Transport stress prior to slaughter frequently induces a stress response, negatively affecting meat quality. This study investigated the impact of dietary potassium magnesium sulphate (PMS) supplementation during the fattening stage on the stress response and meat quality in finishing pigs subjected to transport stress. The experiment involved two phases. Initially, 48 finishing pigs (68.00 ± 0.40 kg) were randomly allocated into two groups: a control group receiving a basal diet (CON) and a PMS-supplemented group receiving the basal diet with 0.50% PMS. Each group was housed in six pens, with four pigs per pen. After 60 days of feeding, in the second phase, two pigs from each pen were randomly selected for slaughter, with one pig subjected to a 4 h transportation stress prior to slaughter. Pigs were categorized into four treatment groups based on diet and stress: (1) control without transport stress, (2) control with transport stress, (3) PMS-supplemented without transport stress, and (4) PMS-supplemented with transport stress. Serum, jejunum, and longissimus thoracis muscle (LM) samples were collected. The results indicated that dietary PMS supplementation did not significantly affect growth performance during the fattening stage (p > 0.05). However, following transport, the PMS pigs showed a reduction in norepinephrine and cortisol concentrations (p = 0.09, p < 0.05) and a significant increase in serum glutathione peroxidase (GSH-Px) activity (p < 0.05). Furthermore, PMS supplementation significantly increased serum catalase (CAT), total antioxidant capacity (T-AOC), alkaline phosphatase (AKP) activity, and high-density lipoprotein cholesterol (HDL-C) levels (p < 0.05), while significantly reducing cholesterol (CHO) levels (p < 0.05). Transport stress adversely affected the intestinal health of finishing pigs, as evidenced by a decrease in intestinal villus height (0.05 < p < 0.1), a condition ameliorated by PMS supplementation. Additionally, transported pigs exhibited a higher drip loss24h in LM (p < 0.05), which was also alleviated through PMS supplementation. In conclusion, PMS supplementation mitigates transport stress and improves meat quality in finishing pigs.