No abstract

Preventative effects of Lactobacillus fermentum and Bacillus coagulans against Clostridium perfringens infection in broilers have been well-demonstrated. The present study was conducted to investigate the modulation of these two probiotics on intestinal immunity and microbiota of C. perfringens-challenged birds. The 336 one-day-old broilers were assigned to four groups with six replicates in each group. Birds in the control were unchallenged and fed a basal diet, and birds in the three challenged groups were dietary supplemented with nothing (Cp group), 1 × 109 CFU/kg of L. fermentum (Lf_Cp group), or 1 × 1010 CFU/kg of B. coagulans (Bc_Cp group). Challenge was performed from days 14 to 20, and samples were collected on days 21 and 28. Challenge upregulated interleukin (IL)-1β and transforming growth factor (TGF)-β4 mRNA expression in jejunum on day 21, which was downregulated by B. coagulans and L. fermentum, respectively (P < 0.05). Both probiotic groups upregulated jejunal IL-1β, interferon (IFN)-γ, IL-17, and TGF-β4 on day 28 as well as IFN-γ on day 21 (P < 0.05). The Bc_Cp group increased CD3+ T cell counts in the jejunal crypt on day 21 (P < 0.05). Challenge decreased the ileal ACE index on day 21 and cecal microbial richness on day 28, which were increased by probiotic treatments, and ileal bacterial richness decreased in the Bc_Cp group on day 28 (P < 0.05). Only ileal microbiota on day 21 was distinctly affected with an R-value at 0.3116 by ANOSIM analysis (P < 0.05). Compared with the control, ileal Firmicutes increased on day 21, and ileal Bacteroidetes and cecal Proteobacteria decreased on day 28 in challenged groups (P < 0.05). Challenge increased Romboutsia spp. in the ileum as well as unclassified f_Lachnospiraceae and Ruminococcus_torques group in the cecum, and decreased Lactobacillus spp. in the ileum on day 21, which were all conversely modulated by L. fermentum (P < 0.05). Challenge increased amino acid metabolism of ileal microbiota and membrane transport of cecal microbiota, and decreased amino acid metabolism of cecal microbiota on day 21, which were conversely regulated by both probiotics (P < 0.05). In conclusion, L. fermentum and B. coagulans attenuated the intestinal inflammation and microbial dysbiosis soon after C. perfringens challenge.

A growing number of studies suggest that epidermal growth factor (EGF) plays an important role in early-weaned animals. The objective of this experiment was to compare the biological activity of intracellularly expressed EGF (IE-EGF), extracellularly expressed EGF (EE-EGF), and tagged EGF (T-EGF) from Saccharomyces cerevisiae (S. cerevisiae) both in vivo and in vitro. Strains of S. cerevisiae expressing IE-EGF, EE-EGF, and T-EGF were designated INVSc1-IE(+), INVSc1-EE(+), and INVSc1-TE(-), respectively. The production performance, intestinal development, physio-biochemical indexes, and immunological function of early-weaned rats were measured in vivo to evaluate the biological activity of IE-EGF, EE-EGF, and T-EGF. In addition, the proliferation of rat enterocyte was also measured in vitro. In the in vivo experiment, the recombinant S. cerevisiae was shown to survive throughout the intestinal tract. The production performance (e.g., body weight) and intestinal development (e.g., mean villous height, crypt depth, total protein, DNA, and RNA) of the rats were significantly enhanced in the INVSc1-IE(+) group compared with the INVSc1-EE(+) and INVSc1-TE(-) groups (P < 0.05). However, the levels of lactate dehydrogenase (LDH), immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) showed no difference in the INVSc1-IE(+) group compared to the INVSc1-EE(+) and INVSc1-TE(-) groups (P > 0.05), with the only significant difference being found for creatine kinase (CK) (P < 0.05). In the in vitro experiment, the proliferation of enterocyte was significantly stimulated by both IE-EGF and EE-EGF compared with T-EGF (P < 0.05). Herein, IE-EGF is more suitable for application to early-weaned animals compared with EE-EGF and T-EGF.

Epidermal growth factor (EGF) ameliorates stress and prevents incomplete gastrointestinal development in early-weaned piglets in commercial swine farming. This study aimed to further analyze the biological activities of intracellularly expressed EGF (IE-EGF), extracellularly expressed EGF (EE-EGF), and tagged EGF (T-EGF) from Saccharomyces cerevisiae in early-weaned pigs. In this study, we assigned 24 pigs to each of 5 groups that were provided a basic diet (the control group) or a diet supplemented with empty vector-expressing S. cerevisiae [the INVSc1(EV) group], T-EGF-expressing S. cerevisiae [the INVSc1-TE(-) group], EE-EGF-expressing S. cerevisiae [the INVSc1-EE(+) group], or IE-EGF-expressing S. cerevisiae [the INVSc1-IE(+) group]. All treatments were delivered at a dose of 60 μg EGF/kg body weight (BW) everyday. All the piglets were sacrificed after 21 day to determine their physio-biochemical indexes, immune functions, and intestinal development. In the piglet experiments, recombinant S. cerevisiae survived throughout the intestinal tract. The BW and intestinal development (e.g., mean villous height, crypt depth, villous height:crypt depth ratio (IVR), and total protein, DNA, and RNA contents) of the piglets were significantly enhanced in the INVSc1-IE(+) group compared with the animals in the INVSc1-EE(+) and INVSc1-TE(-) groups (P < 0.05). In addition, increased proliferating cell nuclear antigen (PCNA) staining was observed in the piglets that received the INVSc1-IE(+) treatment (approximately 80 %) compared with those that received the INVSc1-TE(-) (approximately 70 %) and INVSc1-EE(+) treatments (approximately 70 %). The levels of lactate dehydrogenase (LDH), creatine kinase (CK), alkaline phosphatase (ALP), immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) were also significantly increased in the INVSc1-IE(+) group compared with the INVSc1-EE(+) and INVSc1-TE(-) groups (P < 0.05). Furthermore, the proliferation of piglet enterocytes was also significantly stimulated by both IE-EGF and EE-EGF compared with T-EGF in vitro (P < 0.05). Our data further demonstrate the previously reported hypothesis that IE-EGF is more suitable than EE-EGF or T-EGF for applications in early-weaned pigs.

The aim of the present study was to assess the effects of dietary supplementation with epidermal growth factor (EGF)-expressing Saccharomyces cerevisiae on duodenal development in weaned piglets. In total, forty piglets weaned at 21-26 d of age were assigned to one of the five groups that were provided basic diet (control group) or diet supplemented with S. cerevisiae expressing either empty-vector (INVSc1(EV) group), tagged EGF (T-EGF) (INVSc1-TE(−) group), extracellular EGF (EE-EGF) (INVSc1-EE(+) group) or intracellular EGF (IE-EGF) (INVSc1-IE(+) group). All treatments were delivered as 60·00 μg/kg body weight EGF/d. On 0, 7, 14 and 21 d, eight piglets per treatment were sacrificed to analyse the morphology, activities and mRNA expressions of digestive enzymes, as well as Ig levels (IgA, IgM, IgG) in duodenal mucosa. The results showed significant improvement on 7, 14 and 21 d, with respect to average daily gain (P < 0·05), mucosa morphology (villus height and crypt depth) (P < 0·05), Ig levels (P < 0·01), activities and mRNA expressions of digestive enzymes (creatine kinase, alkaline phosphatase, lactate dehydrogenase and sucrase) (P < 0·05) and the mRNA expression of EGF-receptor (P < 0·01) in NVSc1-TE(−), INVSc1-EE(+) and INVSc1-IE(+) groups compared with control and INVSc1(EV) groups. In addition, a trend was observed in which the INVSc1-IE(+) group showed an improvement in Ig levels (0·05 < P < 0·10), mRNA expressions of digestive enzymes and EGF-receptor (P < 0·05) compared with NVSc1-TE(−) and INVSc1-EE(+) groups. These results indicate that supplementing recombinant EGF-expressing S. cerevisiae to the diet of weaned piglets enhanced duodenal development. Moreover, biological activity (Ig levels, mRNA expressions of digestive enzymes and EGF-receptor) of IE-EGF was better than either EE-EGF or T-EGF.