The present study was conducted to investigate the effects of gastric infusion of short-chain fatty acids (SCFA) on gut barrier function in a pig model. In this study, 21 DLY barrows with an average initial body weight of (8.31 ± 0.72) kg were randomly allotted into three treatments: (1) control, (2) infusing low SCFA, S1, (3) infusing high SCFA, S2. The experimental period lasted for 7 days. Gastric infusion of SCFA increased the concentrations of SCFA in serum and digesta, and enhanced the mRNA and protein abundances of SCFA receptors in pig intestine (P < 0.05). Moreover, gastric infusion of SCFA led to alteration of intestinal morphology, elevation of intestinal development-related gene abundances, and decrease of apoptotic cell percentage, as well as reduction of pro-apoptosis gene and protein abundances (P < 0.05). Besides, the jejunal SLC7A1 and ileal DMT1 mRNA abundances in the SCFA infusion groups were higher than those in the control group (P < 0.05). Additionally, gastric infusion of SCFA increased the mRNA abundances of Occludin and Claudin-1 in the duodenum and ileum, enhanced Lactobacillus spp counts in the ileal digesta, decreased the mRNA and protein abundances of IL-1β in the colon, and reduced Escherichia coli count in the ileal digesta (P < 0.05). These data indicated that gastric infusion of SCFA, especially high SCFA concentration, may be beneficial to gut development of piglets via improving gut morphology, decreasing apoptotic cell percentage, and maintaining intestinal barrier function.

The present study was conducted to compare the differences in gut microbiota composition and gut-phenotypes among pig breeds, and determine whether these differences would transmit to mice colonized with fecal microbiota of different pig breeds. A total of 24 1-day-old germ-free BALB/C mice were divided into 3 groups (TFM, YFM and RFM), which were transplanted with intact fecal microbiota of Tibetan pig (TP), Yorkshire pig (YP) and Rongchang pig (RP), respectively. Results showed that different pig breeds exhibited distinct gut microbiota profile based on high-throughput pyrosequencing. YP exhibited a lower Firmicutes/Bacteroidetes ratio and apparent genera differences compared with RP and TP, and higher levels of bacteria from Spirochaetes were observed in TP compared with RP and YP (P < 0.05). Transplanted porcine microbiota into GF mice replicated the phenotypes of pig donors. Moreover, the three groups of donor pigs and their mice recipients exhibited different intestinal index and morphology. TP and RP had higher intestinal weight and relative CDX2 mRNA expression in ileum than YP, and longer intestine, higher villus height of duodenum and jejunum were observed in TP compared with YP and RP (P < 0.05). TP exhibited higher GLP-2 mRNA expression in duodenum and jejunum than RP (P < 0.05). Similarly, YFM had lower intestine weight and CDX2 mRNA expression in ileum than TFM and RFM (P < 0.05). The intestine length in TFM was longer than that in RFM, and TFM had higher villus height in duodenum and jejunum and GLP-2 mRNA expression in ileum than the other two groups (P < 0.05). Besides, the digestive and absorptive ability was different among the three groups in donor pigs and mice recipients. YP had higher jejunal lactase and maltase activities than TP and RP, while TP had higher activities of jejunal ATPase, γ-GT, and relative SGLT1 mRNA expression in duodenum and jejunum than YP and RP (P < 0.05). Likewise, YFM had higher jejunal sucrase and maltase activities than TFM and RFM, whereas higher jejunal γ-GT activity and relative SGLT1 mRNA expression in duodenum and ileum were observed in TFM compared with YFM and RFM (P < 0.05). In addition, Tibetan pigs-derived microbiota improved gut barrier in mice recipients. The concentration of MDA in YP was higher than that in TP and RP (P = 0.078), and the relative ZO-1 mRNA expression in ileum in TP was higher than that in YP (P < 0.05). Likely, compared with TFM and RFM, YFM exhibited increasing MDA concentration in jejunum (P = 0.098), and the relative ZO-1 mRNA expression in duodenum and ileum in TFM were higher than that in YFM (P < 0.05). There were huge differences in gut microbiota composition and gut characteristics among pig breeds, and gut microbiota could partially convey host gut characteristics from pigs to mice.

Accumulating evidence has demonstrated that the imbalance of lipid metabolism and antioxidant capacity leads to damage to liver. The present study aimed to investigate the effects of ellagic acid (EA), a phenolic compound, on hepatic lipid metabolism and antioxidant activity in mice. In our study, 24 C57BL/6J mice were divided into three groups: (1) control (CON); (2) basal diet+0.1% EA (EA1); and (3) basal diet+0.3% EA (EA2). After the 14-day experiment, the liver was sampled for analysis. The results showed that 0.3% EA administration increased the liver weight. Total cholesterol and low-density lipoprotein cholesterol activities decreased and high-density lipoprotein cholesterol activity increased by EA supplementation. Meanwhile, dietary supplementation with EA dose-dependently decreased the acetyl-CoA carboxylase protein abundance and increased the phospho-hormone-sensitive lipase, carnitine palmitoyltransferase 1B, and peroxisome proliferator-activated receptor alpha protein abundances. Moreover, EA supplementation reduced the malonaldehyde concentration and increased the superoxide dismutase and catalase concentrations. The protein abundances of phospho-nuclear factor-E2-related factor 2, heme oxygenase-1, and NAD(P)H: quinone oxidoreductase 1 increased by EA supplementation in a dose-dependent manner. Taken together, EA supplementation promoted the lipid metabolism and antioxidant capacity to maintain the liver health in mice.

The present study aimed to investigate the effects of dietary fiber on the gut health of growing pigs. In total, 30 growing pigs with an initial average body weight of 45.8 ± 2.78 kg were divided into three groups with 10 replicates per treatment, and one pig per replicate. The treatments included a corn–soybean meal-based diet (control group, 1.5% crude fiber (CF)), corn–soybean meal + beet pulp-based diet (beet pulp group, 5.74% CF) and corn–soybean meal-based diet (feed intake-pairing group (pairing group); the feed intake was equal to the beet pulp group, 1.5% CF). The whole trial lasted 28 days. The beet pulp group had a longer length of the large intestine, higher weight of the small intestine and whole intestine, greater density of the large intestine and whole intestine, and higher villus height in the jejunum and ileum than the control group (p < 0.05). The messenger RNA (mRNA) expression levels of epidermal growth factor (EGF), glucagon-like peptide 2 (GLP-2), and glucagon-like peptide 2 receptor (GLP-2R) in the duodenum, EGF and GLP-2 in the jejunum, EGF in the ileum, and GLP-2 in the colon were higher in the beet pulp group than in the control group (p < 0.05). Moreover, the apparent total tract digestibility of crude ash, energy, dry matter (DM), and crude protein (CP) was lower in the beet pulp group than in the control group (p < 0.05), while the apparent total tract digestibility of CF, the activity of jejunal lactase, and the mRNA abundance of duodenal GLP-2 were higher in the beet pulp group than in the control and pairing groups (p < 0.05). In addition, the beet pulp group had more goblet cells in the colon, more Bifidobacterium spp. in the cecal digesta, higher concentrations of acetic acid and butyric acid in the cecal digesta, and higher mRNA abundance of duodenal regeneration protein Ⅲγ (REG-Ⅲγ), jejunal mucin 2 (MUC-2), and ileal G protein-coupled receptor 43 (GPR-43) than the control group (p < 0.05). However, these parameters did not differ between the control and pairing groups (p > 0.05). These findings indicate feeding a high-fiber diet (5.74% CF, obtained from beet pulp) to pigs could modulate the gut microbiota composition, increase the short-chain fatty-acid (SCFA) content in the hindgut, and improve gut health, which is independent of the feed intake.

We investigated the effects of dietary supplementation of lactic acid bacteria on the immune and antioxidant performance of weaned pigs. A total of 128 Duroc × Landrace × Yorkshire piglets weaned on day 28 with an average body weight of 8.95 ± 1.15 kg were selected and randomly divided into four treatment groups according to body weight and sex for a 28-day study. The four dietary treatments were basal diet (CON), and CON with 0.05% (LJ0.05), 0.1% (LJ0.1), and 0.2% (LJ0.2) Lactobacillus johnsonii RS-7, respectively. The lowest feed-to-gain ratio (F:G) was found when LJ0.1 was added to the diet. The addition of compound lactic acid bacteria to the diet increased the concentrations of TP, ALB, IgA, and IgM on day 14 and IgG, IgA, and IgM on day 28 (p < 0.05) in the blood, with trait values greater for pigs fed LJ0.1 than CON pigs (p < 0.05). Concentrations of antioxidants (CAT, T-AOC, MDA, T-SOD, and GSH) in serum, intestinal mucosa, spleen, liver, and pancreas improved. In summary, dietary supplementation of Lactobacillus johnsonii RS-7 improved the antioxidant and immune function of weaned piglets.

At present, probiotics are being extensively evaluated for their efficacy as an alternative to antibiotics, and their safety in livestock production. In this study, 128 (Duroc, Yorkshire and Landrace) pigs with an average initial body weight of 28.38 ± 0.25 kg were allocated to four dietary treatments in a randomized complete-block design. There were eight pens per treatment, with four pigs per pen (two barrows and two gilts). Dietary treatments included: (1) control diet; (2) control diet + 0.05% complex probiotic; (3) control diet + 0.1% complex probiotic; (4) control diet + 0.2% complex probiotic. During the 28-day experimental period, the feeding of 0.1% complex probiotic in the diet increased body weight and average daily gain (p < 0.05). The addition of complex probiotics decreased total cholesterol and glucose concentrations in the blood (p < 0.01). Acetate concentrations in the blood increased from 0.1% complex probiotic in the diet (p < 0.05), while NH₃ and H₂S emissions in the feces decreased (p < 0.05) from 0.1% or 0.2% complex probiotic in the diet. In conclusion, dietary complex probiotic supplementation changed the composition of intestinal short-chain fatty acids and improved growth performance for growing pigs.