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Background: The hypothalamus plays a crucial role in the health and productivity of dairy cows, yet studies on its functionality and its impact on peripheral circulation in these animals are relatively scarce, particularly regarding dietary interventions. Therefore, our study undertook a comprehensive analysis, incorporating both metabolomics and transcriptomics, to explore the effects of a grain-based diet on the functionality of the hypothalamus, as well as on blood and milk in dairy cows. Results: The hypothalamic metabolome analysis revealed a significant reduction in prostaglandin E2 (PGE2) level as a prominent response to the grain-based diet introduction. Furthermore, the hypothalamic transcriptome profiling showed a notable upregulation in amino acid metabolism due to the grain-based diet. Conversely, the grain-based diet led to the downregulation of genes involved in the metabolic pathway from lecithin to PGE2, including phospholipase A2 (PLA2G4E, PLA2G2A, and PLA2G12B), cyclooxygenase-2 (COX2), and prostaglandin E synthase (PTGES). Additionally, the plasma metabolome analysis indicated a substantial decrease in the level of PGE2, along with a decline in adrenal steroid hormones (tetrahydrocortisol and pregnenolone) following the grain-based diet introduction. Analysis of the milk metabolome showed that the grain-based diet significantly increased uric acid level while notably decreasing PGE2 level. Importantly, PGE2 was identified as a critical metabolic marker in the hypothalamus, blood, and milk in response to grain intervention. Correlation analysis demonstrated a significant correlation among metabolic alterations in the hypothalamus, blood, and milk following the grain-based diet. Conclusions: Our findings suggest a potential link between hypothalamic changes and alterations in peripheral circulation resulting from the introduction of a grain-based diet. [ABSTRACT FROM AUTHOR]

Background: Providing high-quality roughage is crucial for improvement of ruminant production because it is an essential component of their feed. Our previous study showed that feeding bio-fermented rice straw (BF) improved the feed intake and weight gain of sheep. However, it remains unclear why feeding BF to sheep increased their feed intake and weight gain. Therefore, the purposes of this research were to investigate how the rumen microbiota and serum metabolome are dynamically changing after feeding BF, as well as how their changes influence the feed intake, digestibility, nutrient transport, meat quality and growth performances of sheep. Twelve growing Hu sheep were allocated into 3 groups: alfalfa hay fed group (AH: positive control), rice straw fed group (RS: negative control) and BF fed group (BF: treatment). Samples of rumen content, blood, rumen epithelium, muscle, feed offered and refusals were collected for the subsequent analysis. Results: Feeding BF changed the microbial community and rumen fermentation, particularly increasing (P < 0.05) relative abundance of Prevotella and propionate production, and decreasing (P < 0.05) enteric methane yield. The histomorphology (height, width, area and thickness) of rumen papillae and gene expression for carbohydrate transport (MCT1), tight junction (claudin-1, claudin-4), and cell proliferation (CDK4, Cyclin A2, Cyclin E1) were improved (P < 0.05) in sheep fed BF. Additionally, serum metabolome was also dynamically changed, which led to up-regulating (P < 0.05) the primary bile acid biosynthesis and biosynthesis of unsaturated fatty acid in sheep fed BF. As a result, the higher (P < 0.05) feed intake, digestibility, growth rate, feed efficiency, meat quality and mono-unsaturated fatty acid concentration in muscle, and the lower (P < 0.05) feed cost per kg of live weight were achieved by feeding BF. Conclusions: Feeding BF improved the growth performances and meat quality of sheep and reduced their feed cost. Therefore, bio-fermentation of rice straw could be an innovative way for improving ruminant production with minimizing production costs. [ABSTRACT FROM AUTHOR]

Background: Serotonin is an important signaling molecule that regulates secretory and sensory functions in the gut. Gut microbiota has been demonstrated to affect serotonin synthesis in rodent models. However, how gut microbes regulate intestinal serotonin production in piglets remains vague. To investigate the relationship between microbiota and serotonin specifically in the colon, microbial composition and serotonin concentration were analyzed in ileum-cannulated piglets subjected to antibiotic infusion from the ileum when comparing with saline infusion. Microbes that correlated positively with serotonin production were isolated from piglet colon and were further used to investigate the regulation mechanisms on serotonin production in IPEC-J2 and a putative enterochromaffin cell line RIN-14B cells. Results: Antibiotic infusion increased quantities of Lactobacillus amylovorus (LA) that positively correlated with increased serotonin concentrations in the colon, while no effects observed for Limosilactobacillus reuteri (LR). To understand how microbes regulate serotonin, representative strains of LA, LR, and Streptococcus alactolyticus (SA, enriched in feces from prior observation) were selected for cell culture studies. Compared to the control group, LA, LR and SA supernatants significantly up-regulated tryptophan hydroxylase 1 (TPH1) expression and promoted serotonin production in IPEC-J2 cells, while in RIN-14B cells only LA exerted similar action. To investigate potential mechanisms mediated by microbe-derived molecules, microbial metabolites including lactate, acetate, glutamine, and γ-aminobutyric acid were selected for cell treatment based on computational and metabolite profiling in bacterial supernatant. Among these metabolites, acetate upregulated the expression of free fatty acid receptor 3 and TPH1 while downregulated indoleamine 2,3-dioxygenase 1. Similar effects were also recapitulated when treating the cells with AR420626, an agonist targeting free fatty acid receptor 3. Conclusions: Overall, these results suggest that Lactobacillus amylovorus showed a positive correlation with serotonin production in the pig gut and exhibited a remarkable ability to regulate serotonin production in cell cultures. These findings provide evidence that microbial metabolites mediate the dialogue between microbes and host, which reveals a potential approach using microbial manipulation to regulate intestinal serotonin biosynthesis. [ABSTRACT FROM AUTHOR]

Background: Lignocellulose biomass is the most abundant and renewable material in nature. The objectives of this study were to characterize two endoglucanases TrepCel3 and TrepCel4, and determine the effect of the combination of them (1.2 mg TrepCel3, 0.8 mg TrepCel4) on in vitro rumen fermentation characteristics. In this study, three nature lignocellulosic substrates (rice straw, RS; wheat straw, WS; leymus chinensis, LC) were evaluated for their in vitro digestibility, gas, NH3-N and volatile fatty acid (VFA) production, and microbial protein (MCP) synthesis by adding enzymatic combination. Methods: Two endoglucanases' genes were successfully expressed in Escherichia coli (E. coli) BL21 (DE3), and enzymatic characteristics were further characterized. The combination of TrepCel3 and TrepCel4 was incubated with lignocellulosic substrates to evaluate its hydrolysis ability. Results: The maximum enzymatic activity of TrepCel3 was determined at pH 5.0 and 40 °C, while TrepCel4 was at pH 6.0 and 50 °C. They were stable over the temperature range of 30 to 60 °C, and active within the pH range of 4.0 to 9.0. The TrepCel3 and TrepCel4 had the highest activity in lichenan 436.9 ± 8.30 and 377.6 ± 6.80 U/mg, respectively. The combination of TrepCel3 and TrepCel4 exhibited the highest efficiency at the ratio of 60:40. Compared to maximum hydrolysis of TrepCel3 or TrepCel4 separately, this combination was shown to have a superior ability to maximize the saccharification yield from lignocellulosic substrates up to 188.4% for RS, 236.7% for wheat straw WS, 222.4% for LC and 131.1% for sugar beet pulp (SBP). Supplemental this combination enhanced the dry matter digestion (DMD), gas, NH3-N and VFA production, and MCP synthesis during in vitro rumen fermentation. Conclusions: The TrepCel3 and TrepCel4 exhibited the synergistic relationship (60:40) and significantly increased the saccharification yield of lignocellulosic substrates. The combination of them stimulated in vitro rumen fermentation of lignocellulosic substrates. This combination has the potential to be a feed additive to improve agricultural residues utilization in ruminants. If possible, in the future, experiments in vivo should be carried out to fully evaluate its effect. [ABSTRACT FROM AUTHOR]

Background: Lactic acid bacteria (LAB) participating in milk fermentation naturally release and enrich the fermented dairy product with a broad range of bioactive metabolites, which has numerous roles in the intestinal health-promoting of the consumer. However, information is lacking regarding the application prospect of LAB fermented milk in the animal industry. This study investigated the effects of lactic acid bacteria-fermented formula milk (LFM) on the growth performance, intestinal immunity, microbiota composition, and transcriptomic responses in weaned piglets. A total of 24 male weaned piglets were randomly divided into the control (CON) and LFM groups. Each group consisted of 6 replicates (cages) with 2 piglets per cage. Each piglet in the LFM group were supplemented with 80 mL LFM three times a day, while the CON group was treated with the same amount of drinking water. Results: LFM significantly increased the average daily gain of piglets over the entire 14 d (P < 0.01) and the average daily feed intake from 7 to 14 d (P < 0.05). Compared to the CON group, ileal goblet cell count, villus-crypt ratio, sIgA, and lactate concentrations in the LFM group were significantly increased (P < 0.05). Transcriptomic analysis of ileal mucosa identified 487 differentially expressed genes (DEGs) between two groups. Especially, DEGs involved in the intestinal immune network for IgA production pathways, such as polymeric immunoglobulin receptor (PIGR), were significantly up-regulated (P < 0.01) by LFM supplementation. Moreover, trefoil factor 2 (TFF2) in the LFM group, one of the DEGs involved in the secretory function of goblet cells, was also significantly up-regulated (P < 0.01). Sequencing of the 16S rRNA gene of microbiota demonstrated that LFM led to selective enrichment of lactate-producing and short-chain fatty acid (SCFA)-producing bacteria in the ileum, such as an increase in the relative abundance of Enterococcus (P = 0.09) and Acetitomaculum (P < 0.05). Conclusions: LFM can improve intestinal health and immune tolerance, thus enhancing the growth performance of weaned piglets. The changes in microbiota and metabolites induced by LFM might mediate the regulation of the secretory function of goblet cells. [ABSTRACT FROM AUTHOR]

Background: Galacto-oligosaccharides (GOS) are non-digestible food ingredients that promote the growth of beneficial bacteria in the gut. This study investigated the protective effect of the early-life GOS supplement on the piglets' gut function against the oxidative stress induced by lipopolysaccharide (LPS)-challenge. Methods: Eighteen neonatal piglets were assigned to three groups including CON, LPS and LPS + GOS groups. The piglets in CON group and LPS group received physiological saline, while those in LPS + GOS group received GOS solution for 13 d after birth. On d 14, the piglets in LPS group and LPS + GOS group were injected with LPS solutions, while the piglets in CON group were injected with the same volume of physiological saline. Results: The results showed that the early-life GOS supplement blocked the LPS-induced reactive oxygen species (ROS) secretion, malondialdehyde (MDA) production and the increase of pro-apoptotic factor expression. Meanwhile, the early-life GOS supplement improved the activities of antioxidant enzymes, disaccharidase enzymes activities, and digestive enzymes activities, and increased the mRNA abundance of the gene related to nutrient digestion and absorption and the relative protein expression of tight junction. The study also showed that the early-life GOS supplement improved the expression of Hemeoxygenase-1 (HO-1) and NAD(P)H/quinone acceptor oxidoreductase-1 (NQO-1), and activated the AMP-activated protein kinase (AMPK). Conclusions: These results suggested that GOS enhanced the gut function, reduced the ROS production and pro-apoptotic factors gene expression, and activated the AMPK signaling pathway in LPS-challenged piglets. [ABSTRACT FROM AUTHOR]

Background: Galacto-oligosaccharides (GOS) have been shown to modulate the intestinal microbiota of suckling piglets to exert beneficial effects on intestinal function. However, the modulation of intestinal microbiota and intestinal function by GOS in intestinal inflammation injury models has rarely been reported. In this study, we investigated the effects of GOS on the colonic mucosal microbiota composition, barrier function and inflammatory response of lipopolysaccharides (LPS)-challenged suckling piglets. Methods: A total of 18 newborn suckling piglets were divided into three groups, the CON group, the LPS-CON group and the LPS-GOS group. Piglets in the LPS-GOS group were orally fed with 1 g/kg body weight of GOS solution every day. On the d 14, piglets in the LPS-CON and LPS-GOS group were challenged intraperitoneally with LPS solution. All piglets were slaughtered 2 h after intraperitoneal injection and sampled. Results: We found that the colonic mucosa of LPS-challenged piglets was significantly injured and shedding, while the colonic mucosa of the LPS-GOS group piglets maintained its structure. Moreover, GOS significantly reduced the concentration of malondialdehyde (MDA) and the activity of reactive oxygen species (ROS) in the LPS-challenged suckling piglets, and significantly increased the activity of total antioxidant capacity (T-AOC). GOS significantly increased the relative abundance of norank_f__Muribaculaceae and Romboutsia, and significantly decreased the relative abundance of Alloprevotella, Campylobacter and Helicobacter in the colonic mucosa of LPS-challenged suckling piglets. In addition, GOS increased the concentrations of acetate, butyrate and total short chain fatty acids (SCFAs) in the colonic digesta of LPS-challenged suckling piglets. GOS significantly reduced the concentrations of interleukin 1β (IL-1β), interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α) and cluster of differentiation 14 (CD14), and the relative mRNA expression of Toll-like receptor 4 (TLR4) and myeloid differentiation primary response 88 (MyD88) in the LPS-challenged suckling piglets. In addition, GOS significantly reduced the relative mRNA expression of mucin2 (MUC2), and significantly increased the protein expression of Claudin-1 and zonula occluden-1 (ZO-1) in LPS-challenged suckling piglets. Conclusions: These results suggested that GOS can modulate the colonic mucosa-associated microbiota composition and improve the intestinal function of LPS-challenged suckling piglets. [ABSTRACT FROM AUTHOR]

Background: This study aimed to elucidate the molecular mechanisms of solid diet introduction initiating the cellular growth and maturation of rumen tissues and characterize the shared and unique biological processes upon different solid diet regimes. Methods: Twenty-four Hu lambs were randomly allocated to three groups fed following diets: goat milk powder only (M, n = 8), goat milk powder + alfalfa hay (MH, n = 8), and goat milk powder + concentrate starter (MC, n = 8). At 42 days of age, the lambs were slaughtered. Ruminal fluid sample was collected for analysis of concentration of volatile fatty acid (VFA) and microbial crude protein (MCP). The sample of the rumen wall from the ventral sac was collected for analysis of rumen papilla morphology and transcriptomics. Results: Compared with the M group, MH and MC group had a higher concentration of VFA, MCP, rumen weight, and rumen papilla area. The transcriptomic results of rumen wall showed that there were 312 shared differentially expressed genes (DEGs) between in "MH vs. M" and "MC vs. M", and 232 or 796 unique DEGs observed in "MH vs. M" or "MC vs. M", respectively. The shared DEGs were most enriched in VFA absorption and metabolism, such as peroxisome proliferator-activated receptor (PPAR) signaling pathway, butanoate metabolism, and synthesis and degradation of ketone bodies. Additionally, a weighted gene co-expression network analysis identified M16 (2,052 genes) and M18 (579 genes) modules were positively correlated with VFA and rumen wall morphology. The M16 module was mainly related to metabolism pathway, while the M18 module was mainly associated with signaling transport. Moreover, hay specifically depressed expression of genes involved in cytokine production, immune response, and immunocyte activation, and concentrate starter mainly altered nutrient transport and metabolism, especially ion transport, amino acid, and fatty acid metabolism. Conclusions: The energy production during VFA metabolism may drive the rumen wall development directly. The hay introduction facilitated establishment of immune function, while the concentrate starter enhanced nutrient transport and metabolism, which are important biological processes required for rumen development. [ABSTRACT FROM AUTHOR]

Background: Diet has a profound impact on the rumen microbiota, and the impact can vary among the different rumen ecological niches (REN). This study investigated the effects of dietary replacement of soybean meal (SBM) with dried distillers grains with solubles (DDGS) on the rumen microbiota occupying different REN of growing Hu lambs. After a 9-week feeding trial, 6 lambs from each dietary treatment (SBM vs. DDGS-based diets) were slaughtered for sample collection. The microbiota of the rumen solid, liquid, and epithelium fractions was examined using amplicon sequencing analysis of bacterial 16S rRNA gene, functional prediction, and qPCR. Results: No interaction of dietary protein source (PS) and REN were detected for virtually all the measurements made in this study. The DDGS substitution resulted in very limited influence on bacterial community structure. However, the metabolic pathways predicted from 16S rRNA gene sequences varied greatly between SBM- and DDGS-based diets. The populations of rumen total bacteria, fungi, sulfate-reducing bacteria (SRB), and methanogens were not influenced by DDGS substitution, but the population of protozoa was reduced. The bacterial communities in rumen solid (RS) and liquid (RL) were similar in taxonomic composition but were different in relative abundance of some taxa. In contrast, the bacterial composition and relative abundance of rumen epithelium (RE) were greatly distinct from those of the RS and the RL. In alignment with the bacterial relative abundance, the metabolic pathways predicted from 16S rRNA genes also varied greatly among the different REN. The populations of total bacteria, protozoa, and methanogens attached to the RE were smaller than those in the RS and RL, and the fungal population on the rumen epithelium was smaller than that in the RS but similar to that in the RL. On the contrary, the SRB population on the RE was greater than that in the RS and RL. Conclusions: Substitution of SBM with DDGS had greater impact to the protozoa than to the other microbes, and the microbial community structure and functions at different REN are distinct and niche-adapted. [ABSTRACT FROM AUTHOR]

Background: High-protein diets can increase the colonic health risks. A moderate reduction of dietary crude-protein (CP) level can improve the colonic bacterial community and mucosal immunity of pigs. However, greatly reducing the dietary CP level, even supplemented with all amino acids (AAs), detrimentally affects the colonic health, which may be due to the lack of protein-derived peptides. Therefore, this study evaluated the effects of supplementation of casein hydrolysate (peptide source) in low-protein (LP) diets, in comparison with AAs supplementation, on the colonic microbiota, microbial metabolites and mucosal immunity in pigs, aiming to determine whether a supplementation of casein hydrolysate can improve colonic health under very LP level. Twenty-one pigs (initial BW 19.90 ± 1.00 kg, 63 ± 1 days of age) were assigned to three groups and fed with control diet (16% CP), LP diets (13% CP) supplemented with free AAs (LPA) or casein hydrolysate (LPC) for 4 weeks. Results: Compared with control diet, LPA and LPC diet decreased the relative abundance of Streptococcus and Escherichia coli, and LPC diet further decreased the relative abundance of Proteobacteria. LPC diet also increased the relative abundance of Lactobacillus reuteri. Both LP diets decreased concentrations of ammonia and cadaverine, and LPC diet also reduced concentrations of putrescine, phenol and indole. Moreover, LPC diet increased total short-chain fatty acid concentration. In comparison with control diet, both LP diets decreased protein expressions of Toll-like receptor-4, nuclear factor-κB, interleukin-1β and tumor necrosis factor-α, and LPC diet further decreased protein expressions of nucleotide-binding oligomerization domain protein-1 and interferon-γ. LPC diet also increased protein expressions of G-protein coupled receptor-43, interleukin-4, transforming growth factor-β, immunoglobulin A and mucin-4, which are indicators for mucosal defense activity. Conclusions: The results showed that supplementing casein hydrolysate showed beneficial effects on the colonic microbiota and mucosal immunity and barrier function in comparison with supplementing free AAs in LP diets. These findings may provide new framework for future nutritional interventions for colon health in pigs. [ABSTRACT FROM AUTHOR]

Background: Among the gut microbiota, sulfate-reducing bacteria (SRB) is a kind of hydrogen-utilizing functional bacteria that plays an important role in intestinal hydrogen and sulfur metabolism. However, information is lacking regarding diversity and community structure of SRB in the gut of piglets. Middle cecum contents were collected from 6 Yorkshire and 6 Meishan piglets at postnatal days (PND) 14, 28 and 49. Piglets were weaned at PND28. Real-time quantitative PCR was performed to detect the number of SRB in the cecum based on dissimilatory sulfite reductase subunit A (dsrA) gene. Prior to real-time PCR, plasmid containing the dsrA gene was constructed and used as external standard to create a standard curve, from which the gene copies of dsrA were calculated. H2S concentration in the cecal contents was measured. Illumina PE250 sequencing of dsrA gene was used to investigate SRB diversity in cecum contents. Results: The qPCR results showed that the number of SRB at PND49 was significantly higher than that at PND28 in Meishan piglets. The concentration of H2S has no significant difference between piglet breeds and between different ages. The Illumina sequencing analysis revealed that the Chao1 richness index was significantly higher at PND49 than that at PND14 and PND28 in Yorkshire piglets. Based on dsrA gene similarities, Proteobacteria, Actinobacteria, and Firmicutes were identified at the phylum level, and most sequences were classified as Proteobacteria. At the genus level, most of sequences were classified as Desulfovibrio. At the species level, Desulfovibrio intestinalis was the predominant SRB in the piglet cecum. The relative abundance and the inferred absolute abundance of Faecalibacterium prausnitzii at PND49 were significantly higher than that at PND14 in Yorkshire piglets. Pig breeds did not affect the dsrA gene copies of SRB, diversity index and community pattern of SRB. Conclusions: Sulfate-reducing bacteria are widely colonized in the cecum of piglets and D. intestinalis is the dominant SRB. The age of piglets, but not the pig breeds affects the diversity and community pattern of SRB. [ABSTRACT FROM AUTHOR]

Background: Most research on galacto-oligosaccharides (GOS) has mainly focused on their prebiotic effects on the hindgut, but their beneficial effects on the small intestine (SI) have received little attention. Since jejunum is the important place to digest and absorb nutrients efficiently, optimal maturation of the jejunum is necessary for maintaining the high growth rate in the neonate. Therefore, this study investigates the effect of the early intervention with GOS on the intestinal development of the jejunum. Methods: A total of 6 litters of neonatal piglets (10 piglets per litter; Duroc × Landrace × Large White) with an average birth weight of 1.55 ± 0.05 kg received 1 of 2 treatments based on their assignment to either the control (CON) group or the GOS (GOS) group in each litter. Piglets in the GOS group were orally administrated 10 mL of a GOS solution (reaching 1 g GOS/kg body weight) per day from the age of 1 to 7 d; the piglets in the CON group were treated with the same dose of physiological saline. All piglets were weaned on d 21. On d 8 and 21 of the experimental trial, 1 pig per group from each of the 6 litters was euthanized. Results: The early intervention with GOS increased the average daily gains in the third week (P < 0.05). Decreased crypt depth was also observed in the jejunum of the piglets on d 21 (P < 0.05). The early intervention with GOS increased the jejunal lactase activity on d 8, maltase activity and sucrase activity on d 21 (P < 0.05). In addition, the early intervention with GOS also facilitated the mRNA expression of Sodium glucose co-transporter 1 (SGLT1) on d 8 and the mRNA expression of Glucose transporter type 2 (GLUT2) on d 21 (P < 0.05). It was further determined that GOS up-regulated the mRNA expression of preproglucagon (GCG), insulin-like growth factor 1 (IGF-1), insulin-like growth factor 1 receptor (IGF-1R) and epidermal growth factor (EGF). GOS also up-regulated the protein expression of glucagon-like peptide-2 (GLP-2) and EGF in the jejunum of the piglets. Furthermore, it was also found that GOS enhanced the protein expression of ZO-1 and occludin on d 8 (P < 0.05), as well as increased the mRNA expression of TGF-β and decrease the mRNA expression of IL-12 (P < 0.05). Conclusions: These results indicate that GOS have a positive effect on piglet growth performance in addition to decreasing the crypt depth and enhancing functional development in jejunum of suckling piglets. [ABSTRACT FROM AUTHOR]

Background: Compared with oral antibiotics (primarily disrupt foregut microbiota), the present study used antibiotics with ileum terminal infusion to disrupt the hindgut microbiota, and investigated the changes in specific bacterial composition and immune indexes in the jejunum and colon, and serum of growing pigs. Twelve barrows (45 d of age, 12.08 ± 0.28 kg) fitted with a T-cannula at the terminal ileum, were randomly assigned to two groups and infused either saline without antibiotics (Control) or with antibiotics (Antibiotic) at the terminal ileum. After 25 d experiment, all pigs were euthanized for analyzing bacterial composition and immune status. Results: Ileum terminal antibiotic infusion (ITAI) altered dominant bacteria counts, with a decrease in Bifidobacterium, Clostridium cluster IV and Clostridium cluster IV in the colon (P < 0.05), and an increase in Escherichia coli in the jejunum (P < 0.05). ITAI decreased (P < 0.05) short-chain fatty acids concentrations in the colon. ITAI decreased interleukin-8 (IL-8), IL-10 and secretory immunoglobulin A (sIgA) concentrations, and down-regulated IL-10, Mucin-1 (MUC1), Mucin-2 (MUC2) and zonula occludens-1 (ZO-1) mRNA expression in the colonic mucosa (P < 0.05). In the jejunal mucosa, ITAI decreased interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), sIgA and IgG levels together with down-regulation of IFN-γ, TNF-α, MUC2 and ZO-1 mRNA expression (P < 0.05). Furthermore, ITAI decreased IL-10, INF-γ, TNF-α, IgA and IgG concentrations in serum (P < 0.05). Correlation analysis revealed that the change in intestinal microbiota was correlated with alterations of Ig and cytokines. Conclusions: ITAI affected jejunal and colonic specific bacteria counts, and altered some immune markers levels in the jejunal and colonic mucosa and serum. These findings implicate the potential contribution of hindgut bacteria to immune response in the intestinal mucosa and serum of growing pigs. [ABSTRACT FROM AUTHOR]

Background: The objectives of this study were to characterize changes in the relative mRNA expression of candidate genes and proteins involved in cell cycle regulation, cell proliferation and apoptosis in the ruminal epithelium (RE) of sheep during high-grain (HG) diet adaptation. Results: Twenty sheep were assigned to four groups with five animals each. These animals were assigned to different periods of HG diet (containing 40% forage and 60% concentrate mix) feeding. The HG groups received an HG diet for 7 (G7, n = 5), 14 (G14, n = 5) and 28 d (G28, n = 5), respectively. In contrast, the control group (CON, n = 5) was fed the forage-based diet for 28 d. The results showed that HG feeding linearly decreased (P < 0.001) the ruminal pH, and increased the concentrations of ruminal total volatile fatty acid (linear, P = 0.001), butyrate (linear, P < 0.001), valerate (quadratic P = 0.029) and the level of IGF-1 (quadratic, P = 0.043) in plasma. The length (quadratic, P = 0.004), width (cubic, P = 0.015) and surface of the ruminal papillae (linear, P = 0.003) were all enlarged after 14 d of HG diet feeding. HG feeding cubically increased the number of cell layers forming the stratum corneum (SC, P < 0.001) and the thickness of the SC (P < 0.001) and stratum basale (P < 0.001). The proportion of basal layer cells in the RE decreased (linear, P < 0.001) in the G0/G1-phase, but it increased linearly (P = 0.006) in the S-phase and cubically (P = 0.004) in the G2/M-phases. The proportion of apoptosis cells in G7, G14 and G28 was reduced compared to the CON (quadratic, P < 0.001). HG diet feeding linearly decreased the mRNA expression of Cyclin E1 (P = 0.021) and CDK-2 (P = 0.001) and (P = 0.027) the protein expression of Cyclin E1. Feeding an HG diet linearly increased the mRNA expression of genes IGFBP-2 (P = 0.034) and IGFBP 5 (P < 0.009), while linearly decreasing (P < 0.001) the IGFBP 3 expression. The expression of cell apoptosis gene Caspase 8 decreased (quadratic, P = 0.012), while Bad mRNA expression tended to decrease (cubic, P = 0.053) after HG feeding. Conclusions: These results demonstrated sequential changes in rumen papillae size, cell cycle regulation and the genes involved in proliferation and apoptosis as time elapsed in feeding a high-grain diet to sheep. [ABSTRACT FROM AUTHOR]