Vitamin B5 supplementation enhances intestinal development and alters microbes in weaned piglets.

This study explored the effects of different vitamin B5 (VB5) levels on intestinal growth and function of weaned piglets. Twenty-one piglets (7.20 ± 1.11 kg) were included in a 28-day feeding trial with three treatments, including 0 mg/kg (L-VB5), 10 mg/kg (Control) and 50 mg/kg (H-VB5) of VB5 supplement. The results showed that: Large intestine weight/body weight was the highest in H-VB5 group, Control and H-VB5 groups had significantly higher villus height and villus height/crypt depth than the L-VB5 in the ileum (p < .05). Goblet cells (ileal crypt) and endocrine cells (ileal villus) significantly increased in Control and H-VB5 (p < .05). The H-VB5 group exhibited significantly higher levels of ki67 and crypt depth in the cecum and colon, colonic goblet cells and endocrine cells were both rising considerably (p < .05). Isobutyric acid and isovaleric acid were significantly reduced in the H-VB5 group (p < .05), and there was a decreasing trend in butyric acid (p = .073). At the genus level, the relative abundance of harmful bacteria such as Clostridium_Sensu_Structo_1 Strecto_1, Terrisporbacter and Streptococcus decreased significantly and the relative abundance of beneficial bacteria Turicibacter increased significantly in H-VB5 group (p < .05). Overall, the addition of 50 mg/kg VB5 primarily enhanced the morphological structure, cell proliferation and differentiation of the ileum, cecum and colon. It also had a significant impact on the gut microbiota and short-chain fatty acids.

Effects of Dietary Supplementation with Tea Residue on Growth Performance, Digestibility, and Diarrhea in Piglets.

Thirty-six healthy 21-day-old weaned ternary piglets (Duroc × Landrace × Yorkshire) were randomly divided into two treatments with 18 replicates per treatment and one pig per replicate. The control group was fed with a basal diet and the test group was fed with diets supplemented with 1 kg/t tea residue. The test period was 28 days. The results are as follows: The addition of tea residue in the diet had no significant effect on the growth performance of weaned piglets (p > 0.05), but it could significantly reduce the diarrhea rate of piglets from 1 to 7 days and 1 to 28 days (p < 0.05). Compared with the control group, the dietary supplementation of tea residue had no significant effect on nutrient apparent digestibility, plasma biochemical indexes and plasma immune indexes (p > 0.05) but increased the content of glutathione in plasma (p < 0.05). Tea residue had no significant effect on the morphology of the jejunum and ileum of piglets (p > 0.05), but it could significantly reduce the content of chloride ions in feces (p < 0.05). Compared with the basal diet group, there was no significant difference in the relative expression of TMEM16A and CFTR mRNA in the colon of weaned piglets (p > 0.05). The whole-cell patch clamp recording showed that the TMEM16A and CFTR ion channels could be activated by ionomycin and forskolin, respectively. However, when HT-29 cells transfected with TMEM16A and CFTR channels were treated with tea residue extract, it could significantly inhibit the chloride current of the TMEM16A and CFTR ion channels (p < 0.05).

Expression Profile of miR-199a and Its Role in the Regulation of Intestinal Inflammation.

Early weaning stress impairs intestinal health in piglets. miRNAs are crucial for maintaining host homeostasis, while their implication for animal health remains unclear. To identify weaning-associated miRNAs, piglets were sampled at day 0, 1, 3, 7 and 14 after weaning. The data indicated that the highest levels of miR-199a-5p in jejunal villus upper cells were observed on day 14 after weaning, while the lowest levels in crypt cells were noted on day 7 and 14. In contrast, miR-199a-3p was down-regulated in both of these two cells on day 7 after weaning compared with day 0. Both miR-199a-5p and -3p were differently expressed along the villus-crypt axis. To further clarify the function of miR-199a, mice deficient in miR-199a were exposed to dextran sulfate sodium (DSS) to induce colitis. Results revealed that silencing of miR-199a enhanced sensitivity to DSS-induced colitis. Moreover, the increased morbidity and mortality were correlated with enhanced inflammatory cell infiltration, elevated pro-inflammatory cytokine expression, impaired barrier function, and a concomitant increase in permeability-related parameters. Bioinformatic analysis further demonstrated that lipid metabolism-related pathways were significantly enriched and Ndrg1 was verified as a target of miR-199a-3p. These findings indicate that miR-199a may be important for animal health management.

Mechanism of iron on the intestinal epithelium development in suckling piglets.

This study aimed to investigate the mechanism of iron on intestinal epithelium development of suckling piglets. Compared with newborn piglets, 7-day-old and 21-day-old piglets showed changes in the morphology of the jejunum, increased proliferation, differentiated epithelial cells, and expanded enteroids. Intestinal epithelium maturation markers and iron metabolism genes were significantly changed. These results suggest that lactation is a critical stage in intestinal epithelial development, accompanied by changes in iron metabolism. In addition, deferoxamine (DFO) treatment inhibited the activity of intestinal organoids at passage 4 (P4) of 0-day-old piglets, but no significant difference was observed in epithelial maturation markers at passage 1 (P1) and P4, and only argininosuccinate synthetase 1 (Ass1) and ß-galactosidase (Gleb) were up-regulated at passage 7 (P7). These results in vitro show that iron deficiency may not directly affect intestinal epithelium development through intestinal stem cells (ISCs). The iron supplementation significantly down-regulated the mRNA expression of interleukin-22 receptor subunit alpha-2 (IL-22RA2) in the jejunum of piglets. Furthermore, the mRNA expression of IL-22 in 7-day-old piglets was significantly higher than that in 0-day-old piglets. Adult epithelial markers were significantly up-regulated in organoids treated with recombinant murine cytokine IL-22. Thus, IL-22 may play a key role in iron-affecting intestinal epithelium development.

Porcine intestinal antimicrobial peptide as an in-feed antibiotic alternative improves intestinal digestion and immunity by shaping the gut microbiota in weaned piglets.

Antibiotic resistance of pathogens, which is caused by the abuse of in-feed antibiotics, threatens the sustainable development of livestock production. The present study aimed to investigate the efficiency of porcine intestinal antimicrobial peptide (PIAP) as an alternative to in-feed antibiotics in terms of growth performance, intestinal morphology, digestive enzymes and immunity, and microbiota community of the post-weaning piglets. A total of 204 piglets (Duroc × Landrace × Yorkshire, weaned at 28 d age) with a similar body weight of 7.97 ± 1.04 kg were randomly allocated to 4 groups (51 piglets per group): (1) control group: basal diet; (2) AB group: antibiotic, basal diet + chlortetracycline (1000 mg/kg from d 1 to 24; 500 mg/kg from d 25 to 37); (3) P1 group: basal diet + a relatively low dose of PIAP (400 mg/kg from d 1 to 24; 300 mg/kg from d 25 to 37); (4) P2 group, basal diet + a relatively high dose of PIAP (600 mg/kg from d 1 to 24; 500 mg/kg from d 25 to 37). The results showed that serum indicators of hepatocyte damage and relative organ weight were not affected by these treatments (P > 0.05). Compared with the AB treatment, the P1 treatment remarkably decreased jejunal crypt depth and increased jejunal and ileal villus height:crypt depth ratio (P < 0.05). The values of jejunal maltase, lactase, sucrase, intestinal alkaline phosphatase, and secretory immunoglobulin A (SIgA) in the P1 group were sharply increased compared with those in the control and P2 groups (P < 0.05). Compared with the control group, the P1 group decreased serum concentrations of D-lactate, diamine oxidase, and endotoxin (P < 0.05), and increased the abundance of Lactobacillus reuteri (P < 0.05) in the colonic feces. Furthermore, there was a positive correlation between the abundance of L. reuteri and the concentrations of maltase, lactase, sucrase, and SIgA (P < 0.05). Collectively, dietary supplementation with a relatively low dose of PIAP (400 mg/kg from d 1 to 24; 300 mg/kg from d 25 to 37) demonstrates beneficial effects on intestinal morphology, digestive enzymes, immunity, and permeability by shaping the gut microbiota composition in weaned piglets. This study will provide a valuable reference for using PIAP as an in-feed antibiotic alternative in swine production.

Biosynthetic Gene Clusters from Swine Gut Microbiome.

The abuse of antibiotics has become a serious health challenge in the veterinary field. It creates environmental selection pressure on bacteria and facilitates the rapid spread of antibiotic resistance genes. The speed of discovery and application of cost-effective alternatives to antibiotics is slow in pig production. Natural products from biosynthetic gene clusters (BGCs) represent promising therapeutic agents for animal and human health and have attracted extraordinary passion from researchers due to their ability to participate in biofilm inhibition, stress resistance, and the killing of competitors. In this study, we detected the presence of diverse secondary metabolite genes in porcine intestines through sequence alignment in the antiSMASH database. After comparing variations in microbial BGCs' composition between the ileum and the colon, it was found that the abundance of the resorcinol gene cluster was elevated in the ileal microbiome, whereas the gene cluster of arylpolyene was enriched in the colonic microbiome. The investigation of BGCs' diversity and composition differences between the ileal and colonic microbiomes provided novel insights into further utilizing BGCs in livestock. The importance of BGCs in gut microbiota deserves more attention for promoting healthy swine production.

Effects of ß-alanine on intestinal development and immune performance of weaned piglets.

Beta-alanine is an important amino acid involved in several metabolic reactions in the body. The study aimed to investigate the effect of ß-alanine supplementation on intestinal development and the immune performance of weaned piglets. Thirty-two 21-day-old healthy weaned piglets (half female and half male; Duroc × Landrace × Yorkshire) with an initial body weight of 8.11 ± 0.21 kg were randomly divided into 4 groups with 8 replicates of 1 pig each. The control group was fed a basal diet and the three experimental treatment groups were fed diets supplemented with 300, 600 and 1,200 mg/kg ß-alanine, respectively. The trial lasted 28 days and the diets fed were divided into 2 phases: the late lactation period (day 1 to 14) and the nursery period (day 15 to 28), during which the weaned piglets had free access to food and water. The regulatory effects of ß-alanine were further investigated in vitro using organoids obtained from the jejunum of piglets. In vivo, the addition of ß-alanine to the diet had no significant effect on the growth performance of weaned piglets (P > 0.05), but significantly reduced serum levels of immunoglobulin G (IgG) (P < 0.01), immunoglobulin M (IgM) (P = 0.005), and complement 3 (C3) (P = 0.017). The serum interleukin- 6 (IL-6) levels (P < 0.01) were significantly reduced in the 1,200 mg/kg treatment group. The addition of ß-alanine increased ileal villus height, with the most significant effect at a concentration of 300 mg/kg (P = 0.041). The addition of 600 mg/kg ß-alanine significantly up-regulated the expression of superoxide dismutase (SOD) activity (P = 0.020) and the zonula occludens-1 (ZO-1) gene (P = 0.049) in the jejunum. Diets supplemented with 300 mg/kg ß-alanine significantly increased the number of Ki67 positive cells in the jejunal crypts (P < 0.01). In vitro, ß-alanine increased the organoid budding rates (P = 0.001) and the budding height of the crypt significantly (P = 0.004). In conclusion, ß-alanine can improve intestinal morphology and barrier function, reduce inflammatory responses and alleviate the adverse effects of weaning stress on piglet intestinal health.

The beneficial effects of alpha-tocopherol on intestinal function and the expression of tight junction proteins in differentiated segments of the intestine in piglets.

Alpha (α)-tocopherol is a major component of dietary vitamin E. Despite being one of the most widely used food supplements in both animals and humans, its role in intestinal functions remains unknown. We were able to examine and accurately demonstrate its permeability effect in vitro and its differentiated effect on tight junction expression in different segments of the intestine in vivo using cultured intestinal porcine epithelial cell line (IPEC-J2) and piglets. A cultured IPEC-J2 demonstrated that α-tocopherol upregulated the expression of tight junction proteins and improved their integrity, with a maximum effect at concentrations ranging from 20 to 40 µmol/L. In vivo data from weaned pigs fed different doses of α-tocopherol for 2 weeks revealed that α-tocopherol effectively increases the expression of tight junction proteins in all sections of the intestinal mucosa, with the highest effect on the duodenum at an optimum dose of 20-50 mg/kg. In contrast, α-tocopherol did not affect intestinal inflammation. These findings suggest that α-tocopherol maintains intestinal integrity and increases the expression of tight junction proteins both in vitro and in vivo.

Effect of riboflavin on intestinal development and intestinal epithelial cell function of weaned piglets.

Riboflavin is a water-soluble vitamin involved in the metabolism of protein, fats and carbohydrates as a coenzyme. Pigs, mainly weaned piglets, are prone to riboflavin deficiency. Therefore, this study devoted to explore the effects of riboflavin on intestinal development and function of weaned piglets. A total of 21 piglets, weaned at day 21 of age, were randomly divided into three treatments. The experiment lasted 28 days. The three treatment groups were administered with 0 mg/kg (L_VB2), 3.5 mg/kg (M_VB2) and 17.5 (H_VB2) mg/kg riboflavin by addition into the dry matter basal diets of each group. During the 28-day trial, the feed conversion ratio of the M_VB2 group was lowest (p < 0.05). Duodenum villus height (VH) and the ratio of VH to crypt depth (VH:CD) in L_VB2 group was significantly lower compared with that in M_VB2 group and H_VB2 group (p < 0.05). In the L_VB2 group the number of Ki67 cells in the crypts of the duodenum was increased significantly (p < 0.05). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis using transcriptomic data showed that pathways related to apoptosis were significantly enriched in the L_VB2 group (p < 0.01). In addition, pathways related to inflammatory factors were significantly enriched in the H_VB2 group. The total antioxidant capacity (p < 0.05) and glutathione peroxidase (GSH-PX) activity (p < 0.05) of the L_VB2 group were lowest. In summary, riboflavin levels may regulate the intestinal morphology of piglet duodenum by affecting the renewal and differentiation of intestinal epithelial cells.

Effect of dietary protein on growth performance, and serum biochemical index in late pregnant Hu ewes and their offspring.

The purpose of this study was to investigate the effects of different protein levels in late pregnancy on ewe and lamb growth performance, serum biochemical indexes. Thirty-three ewes (46.4 ± 1.38 kg initial weight) were randomly divided into 3 groups, with 11 ewes in each group. The protein levels of three diets formulated to provide components to meet 10.00 MJ/kg ME requirements diets were: 10.12%, 11.26%, 12.4%. Ewes were raised from the 90th day of pregnancy to the end of delivery, and the lambs were weaned at 60 days. Dietary protein levels had significant effects on blood urea nitrogen, glucose, ammonia nitrogen and triglyceride of ewes (p < 0.05). The height, chest depth, chest circumference, straight crown hip length and curved crown hip length of lambs decreased at first and then increased with the increase of protein. The body length, chest circumference, head width and head length of weaned lambs decreased at first and then increased with the increase of protein. The results showed that when the dietary protein level was increased to 12.4%, the amino acid, glucose and fat metabolism of ewes were affected. The body size development of lambs was better than 10.12% and 11.26% proteins.

The impact of lactating Hu sheep's dietary protein levels on lactation performance, progeny growth and rumen development.

This study aimed to investigate whether lactating Hu sheep's dietary protein levels could generate dynamic effects on the performance of their offspring. Twelve ewes with similar parity were fed iso-energy diets which contained different protein levels (P1: 9.82%, P2: 10.99%) (n = 6), and the corresponding offspring were divided into SP1 and SP2 (n = 12). At 60 days, half of the lambs were harvested for further study: the carcass weight (p = 0.043) and dressing percentage (p = 0.004) in the SP2 group were significantly higher than SP1. The acetic acid (p = 0.007), propionic acid (p = 0.003), butyric acid (p < 0.001) and volatile fatty acids (p < 0.001) in rumen fluid of SP2 were significantly lower than SP1. The expression of MCT2 (p = 0.024), ACSS1 (p = 0.039) and NHE3 (p = 0.006) in the rumen of SP2 was lower than SP1, while the HMGCS1 (p = 0.026), HMGCR (p = 0.024) and Na+/K+-ATPase (p = 0.020) was higher than SP1. The three dominant phyla in the rumen are Bacteroidetes, Proteobacteria and Firmicutes. The membrane transport, amino acid metabolism and carbohydrate metabolism of SP1 were relatively enhanced, the replication and repair function of SP2 was relatively enhanced. To sum up, the increase of dietary protein level significantly increased the carcass weight and dressing percentage of offspring and had significant effects on rumen volatile fatty acids, acetic acid activation and cholesterol synthesis related genes. HIGHLIGHTSIn the early feeding period, the difference in ADG of lambs was mainly caused by the sucking effect.The increase in dietary protein level of ewes significantly increased the carcass weight and dressing percentage of offspring.The dietary protein level of ewes significantly affected the volatile fatty acids (VFAs) and genes related to acetic acid activation and cholesterol synthesis in the rumen of their offspring.The membrane transport, amino acid metabolism and carbohydrate metabolism of the offspring of ewes fed with a low protein diet were relatively enhanced.The replication and repair function of the offspring of ewes fed with a high protein diet was relatively strengthened.

Optimal dietary standardized ileal digestible lysine level for pigs during the grower, early and late finisher periods.

BACKGROUND: Lysine (Lys) is the first limiting amino acid for pigs fed corn-soybean meal diets. Three experiments were conducted to estimate the optimal standardized ileal digestible (SID) Lys requirement for growing (Exp. 1), early finishing (Exp. 2), and late finishing (Exp. 3) pigs under commercial conditions. RESULTS AND CONCLUSIONS: In Exp. 1, a total of 650 growing pigs (32.21 ± 0.33 kg bodyweight), were allocated to 5 dietary treatments supplemented with 0.75, 0.85, 0.94, 1.03, and 1.13% SID Lys. Each treatment had 5 replicate pens with 26 pigs per pen. The lowest feed to gain ratio (F:G) was obtained by pigs fed the 1.03% Lys diet and F:G showed both a linear and a quadratic response with increasing Lys (P < 0.05). Based on broken-line and quadratic analysis models, dietary SID Lys levels for the minimum F:G were 0.94%. In Exp. 2, 650 finishing pigs (57.24 ± 2.00 kg bodyweight) were allotted to 5 dietary treatments providing SID Lys of 0.63, 0.71, 0.79, 0.87, and 0.95%. Each treatment had 5 replicates, 26 pigs per replication. The highest final bodyweight was achieved by 0.79% Lys while the highest average daily gain (ADG) and average daily feed intake (ADFI) was achieved by pigs consuming the 0.87% Lys diet (P < 0.05). Additionally, the lowest F:G was obtained by pigs fed the 0.79 and 0.87% Lys diet (P < 0.05). Based on broken-line and quadratic analysis models, the optimum Lys was 0.81 and 0.82% for ADG and F:G, respectively. In Exp. 3, 600 late finishing pigs (92.22 ± 2.41 kg bodyweight), were divided into 5 treatments providing Lys levels of 0.53, 0.60, 0.66, 0.73, and 0.79%. Each treatment had 5 replicates, 24 pigs per replication. Results showed that final bodyweight, ADG, ADFI, and F:G was not affected by increasing dietary Lys level, suggesting that the lowest SID Lys (0.53%) was sufficient for this group of pigs. Taken together, the SID Lys requirement for pigs from 30 to 60 kg, 60 to 90 kg, 90 to 120 kg was 0.94%, 0.81 to 0.82, and 0.53%, respectively, depending on the response criteria with performance maximized.

Tannic acid attenuates intestinal oxidative damage by improving antioxidant capacity and intestinal barrier in weaned piglets and IPEC-J2 cells.

Tannic acid (TA) has received widespread attention for its beneficial biological function with antioxidant capacity. This study investigated the protective role of TA on the intestinal antioxidant capacity and intestinal barrier in weaned piglets and porcine intestinal epithelial cells (IPEC-J2). A total of 18 weaned piglets were randomly allocated into two groups (n = 9) and fed with a basal diet (control, CON) and a basal diet containing 1,000 mg/kg TA for two weeks. The in vivo results showed that treatment with TA increased both glutathione peroxidase (GSH-PX) activity and the protein expression of ZO-1 in the jejunum of weaned piglets, and reduced the level of malondialdehyde (MDA) in the serum and the mRNA and protein expression of Keap1 in the jejunum of weaned piglets. Furthermore, in vitro results indicated that TA treatment effectively alleviated tert-butyl hydroperoxide (TBH)-induced oxidative stress in IPEC-J2 cells, improved the antioxidant capacity by elevating the cell redox state and activating the Nrf2 pathway, and improved the intestinal barrier by upregulating the mRNA and protein expression of intestinal tight junction proteins and increasing the transepithelial electrical resistance (TEER) value. In conclusion, these results confirmed that TA relieves oxidative injury and improves intestinal barrier function and intestinal antioxidant capacity by activating the Nrf2 signaling pathway. These findings suggest that TA has the potential application in alleviating oxidative stress in the intestine of weaned piglets.

Effect of Different Levels of Niacin on Serum Biochemical Parameters, Antioxidant Status, Cytokine Levels, Inflammatory Gene Expression and Colonic Microbial Composition in Weaned Piglets.

Niacin plays an important role in regulating the gut health of weaned piglets. In this study, 48 25-day-old weaned piglets (7.9 ± 0.20 kg) produced by 14 sows (3 to 4 piglets per sow) were randomly divided into 4 groups with 6 replicates in each group and 2 piglets in each replicate. Each group was fed diets supplemented with 22.5 (N1), 30 (N2), 45 (N3), and 75 (N4) mg/kg of niacin, respectively. Samples were taken at 7 and 14 d, respectively. The study shows that changes in niacin levels significantly affected the content of IgG and IgM in the serum (p < 0.05). Niacin had a significant effect on antioxidant parameters such as MDA, T-SOD, and CuZn-SOD in the jejunal mucosa of weaned piglets (p < 0.05). Moreover, significant differences were observed in the expression of cytokines such as TGF-ß, TNF-α, and COX2 in the jejunal mucosa (p < 0.05). The 16S rRNA sequencing analysis showed that there were significant differences in the colonic species composition, which were also accompanied by changes in the isovaleric acid content (p < 0.05). In conclusion, an appropriate increase in niacin dose based on NRC (2012) has an important role in improving the antioxidant status of weaned piglets, alleviating intestinal inflammation in piglets, improving immunity, and regulating the structure of the microbiota.

Colicins of Escherichia coli Lead to Resistance against the Diarrhea-Causing Pathogen Enterotoxigenic E. coli in Pigs.

Gut microbes can affect host adaptation to various environment conditions. Escherichia coli is a common gut species, including pathogenic strains and nonpathogenic strains. This study was conducted to investigate the effects of different E. coli strains in the gut on the health of pigs. In this study, the complete genomes of two E. coli strains isolated from pigs were sequenced. The whole genomes of Y18J and the enterotoxigenic E. coli strain W25K were compared to determine their roles in pig adaptation to disease. Y18J was isolated from feces of healthy piglets and showed strong antimicrobial activity against W25K in vitro. Gene knockout experiments and complementation analysis followed by modeling the microbe-microbe interactions demonstrated that the antagonistic mechanism of Y18J against W25K relied on the bacteriocins colicin B and colicin M. Compared to W25K, Y18J is devoid of exotoxin-coding genes and has more secondary-metabolite-biosynthetic gene clusters. W25K carries more genes involved in genome replication, in accordance with a shorter cell cycle observed during a growth experiment. The analysis of gut metagenomes in different pig breeds showed that colicins B and M were enriched in Laiwu pigs, a Chinese local breed, but were scarce in boars and Duroc pigs. IMPORTANCE This study revealed the heterogeneity of E. coli strains from pigs, including two strains studied by both in silico and wet experiments in detail and 14 strains studied by bioinformatics analysis. E. coli Y18J may improve the adaptability of pigs toward disease resistance through the production of colicins B and M. Our findings could shed light on the pathogenic and harmless roles of E. coli in modern animal husbandry, leading to a better understanding of intestinal-microbe-pathogen interactions in the course of evolution.

Dietary butyrate, lauric acid and stearic acid improve gut morphology and epithelial cell turnover in weaned piglets.

This study was to evaluate the effects of the supplementation of saturated fatty acids with different chain lengths on growth performance, intestinal morphology, epithelial cell proliferation, differentiation and apoptosis in weaned piglets. Thirty-two weaned piglets (Duroc × Landrace × Yorkshire, BW = 7.81 ± 0.26 kg) were weaned at 21 d and randomly assigned to 1 of 4 experimental treatments: (1) a basal diet (control); (2) control + 0.3% butyrate (BT); (3) control + 0.3% lauric acid (LA); (4) control + 0.3% stearic acid (SA). All piglets were then slaughtered for tissue sampling after having been fed experimental diets for 28 d after weaning. Supplementation of BT increased the gain-to-feed ratio (G:F) (P < 0.05) compared to piglets fed the control diet from 14 to 28 d. In addition, the villus height (VH) to crypt depth (CD) ratio (VH:CD ratio) of the ileum were higher in the BT and LA diets than that of the control diet (P < 0.05). The SA-supplemented diet increased ileal VH (P < 0.05), whereas the BT-supplemented diet increased jejunal CD (P < 0.05). Compared to the control, diets supplemented with BT, LA, or SA all tended to increase jejunal proliferation (Ki67/crypt positive cells) (P = 0.190); diets supplemented with BT or SA significantly increased the number of ki67-positive cells in the ileal crypt (P < 0.05). Furthermore, in the jejunum, the protein expression of activated caspase 3 and villin were increased in piglets fed BT, LA, or SA diets compared to those on the control diet (P < 0.05). In the ileum, compared with the control diet, the BT diet tended to increase the protein level of mammalian phosphorylation target of rapamycin (p-mTOR, P < 0.10); LA or SA diets significantly increased p-mTOR protein expression (P < 0.05). These results show that dietary supplementation of BT, LA, or SA promotes jejunal cell renewal in weaned piglets. At the same time, increased proliferation of ileal crypt cells by promoting p-mTOR expression has beneficial effects on ileal morphology in weaned piglets.

Higher niacin intakes improve the lean meat rate of Ningxiang pigs by regulating lipid metabolism and gut microbiota.

As one of the local pig breeds in China with a high fat rate, improving the lean meat rate of Ningxiang pigs through nutritional intervention is an urgent issue to be solved. As an important feed additive, niacin plays an important role in lipid metabolism. The purpose of this study was to investigate the regulation and mechanism of niacin on fat deposition in Ningxiang pigs. Thirty-four Ningxiang pigs (53.34 ± 2.78 kg) were randomly divided into two groups with five replicates each, with three to four Ningxiang pigs per replicate. The control group was fed a basal diet (contained 22 mg/kg niacin), and the experimental group was fed the same diet supplemented with an additional 100 mg/kg of niacin. The experimental period lasted 60 days. One Ningxiang pig was selected for slaughter sampling for each replicate. This study found that lean meat percentage of Ningxiang pigs in the experimental group was significantly increased (P < 0.05), accompanied by a significant decrease in fat percentage (P < 0.05). 16S rRNA sequencing analysis found an abundance of Streptococcus in the experimental group (P < 0.05), along with significantly decreased levels of Lactobacillus (P < 0.05). The changes in some OTUs belonging to Firmicutes, Bacteroidota, and Actinobacteriota were closely related to the changes in the fat rate and lean meat rate of Ningxiang pigs (P < 0.05). LC-MS metabolomics analysis found that about 43.75% of the differential metabolites were related to lipids and lipid-like molecules in the liver (P < 0.05). Spearman's correlation analysis showed correlations between the carcass traits, microbiota, and liver metabolites. In conclusion, niacin improves lean meat percentage and reduces fat deposition by regulating lipid metabolism and gut microbiota composition in Ningxiang pigs.

Dietary High Dose of Iron Aggravates the Intestinal Injury but Promotes Intestinal Regeneration by Regulating Intestinal Stem Cells Activity in Adult Mice With Dextran Sodium Sulfate-Induced Colitis.

The effects of excessive dietary iron intake on the body have been an important topic. The purpose of this study was to investigate the effects of high-dose iron on intestinal damage and regeneration in dextran sodium sulfate (DSS)-induced colitis model mice. A total of 72 8-week-old adult C57BL/6 mice were randomly divided into two dietary treatment groups: the basal diet supplemented with 45 (control) and 450 mg/kg iron (high-iron) from ferrous sulfate. The mice were fed different diets for 2 weeks, and then 2.5% DSS was orally administered to all mice for 7 days. Samples of different tissues were collected on days 0, 3, and 7 post administration (DPA). High-iron treatment significantly decreased the relative weight of the large intestine at 7 DPA but not at 0 DPA or 3 DPA. High dietary iron increased the jejunal villus width at 0 DPA, decreased the villus width and the crypt depth of the jejunum at 3 DPA, and decreased the number of colonic crypts at 7 DPA. Meanwhile, high dietary iron decreased the number of goblet cells in the jejunal villi and the Paneth cells in the jejunal crypts at 0 DPA, increased the number of goblet cells per crypt of the colon at 3 DPA, and the number of Paneth cells in the jejunal crypts, the goblet cells in the colon, the Ki67-positive proliferating cells in the colon, and the Sex-determining region Y-box transcription factor 9+ (SOX9) cells in the jejunum crypts and colon at 7 DPA. The organoid formation rate was increased by high-iron treatments at 3 DPA and 7 DPA. High dietary iron treatment decreased the mRNA level of jejunal jagged canonical Notch ligand 2 (Jag-2) at 0 DPA and bone morphogenetic protein 4 (Bmp4) and neural precursor cell-expressed developmentally downregulated 8 (Nedd8) in the jejunum and colon at 7 DPA, whereas it increased the mRNA expression of the serum/glucocorticoid-regulated kinase 1 (Sgk1) in the colon at 3 DPA. The results suggested that a high dose of iron aggravated intestinal injury but promoted intestinal repair by regulating intestinal epithelial cell renewal and intestinal stem cell activity in adult mice with colitis.

Effects of Dietary Amylose-Amylopectin Ratio on Growth Performance and Intestinal Digestive and Absorptive Function in Weaned Piglet Response to Lipopolysaccharide.

This study investigated the effects of diet with different amylose−amylopectin ratios (AAR) on the growth performance, intestinal morphology, digestive enzyme activities and mRNA expression of nutrients transporters in piglets with short-term lipopolysaccharide (LPS) intraperitoneal injections. Sixty 21 days-old piglets (Landrace × Yorkshire; 6.504 ± 0.079) were randomly assigned based on their body weight (BW) and litters of origins to five groups with experimental diets with an AAR of 0.00, 0.20, 0.40, 0.60, or 0.80 (namely, the 0.00, 0.20, 0.40, and 0.80 groups), respectively. Each treatment included 12 piglets (one piglet per pen). This experiment lasted for 28 days. On the 28th day, six piglets in each treatment were randomly selected for an LPS intraperitoneal injection (100 µg/kg BW), and other piglets were injected with normal saline. Twelve hours after LPS injection, all piglets were sacrificed to collect small intestinal mucosa for analysis. Although different AAR did not influence the final BW in piglets, the piglets in the 0.40 group represented the poorest feed-to-gain ratio (F/G) in the first, second and fourth week (p < 0.05) and the lowest average daily gain (ADG) in the fourth week (p < 0.05) compared with other groups. In terms of the small intestinal morphology, piglets in the 0.20 and 0.60 groups showed better ileal villous width (p < 0.05). Piglets in the 0.60 group presented greater activities of jejunal maltase, sucrase and alkaline phosphatase (p < 0.05) than those of 0.20 and 0.40. However, a low amylose diet increased the mRNA expression of jejunal glucose and amino acid transporters (p < 0.05). In addition, compared to saline injection, the LPS challenge significantly lessened jejunal digestive enzyme activities (p < 0.01) and, ileal villous width and downregulated the gene expression of glucose and amino acid transporters (p < 0.05) in piglets. Interestingly, certain diet -LPS interactions on duodenal VH/CD, jejunal maltase activity (p < 0.05) and the expression of glucose transporters (p < 0.05) were observed. Taken together, in terms of small intestinal digestion and absorption capacity, these results demonstrated that a diet with an AAR of 0.60 diets could improve the intestinal digestive and absorptive capability by affecting small intestinal morphology, digestive enzymes, and nutrients absorptions in piglets. In addition, the diets containing an AAR of 0.40−0.60 were more likely to resist the damage of LPS stress to intestinal morphology and nutrient absorption.

Antioxidant potential of Pediococcus pentosaceus strains from the sow milk bacterial collection in weaned piglets.

BACKGROUND: In modern animal husbandry, breeders pay increasing attention to improving sow nutrition during pregnancy and lactation to favor the health of neonates. Sow milk is a main food source for piglets during their first three weeks of life, which is not only a rich repository of essential nutrients and a broad range of bioactive compounds, but also an indispensable source of commensal bacteria. Maternal milk microorganisms are important sources of commensal bacteria for the neonatal gut. Bacteria from maternal milk may confer a health benefit on the host. METHODS: Sow milk bacteria were isolated using culturomics followed by identification using 16S rRNA gene sequencing. To screen isolates for potential probiotic activity, the functional evaluation was conducted to assess their antagonistic activity against pathogens in vitro and evaluate their resistance against oxidative stress in damaged Drosophila induced by paraquat. In a piglet feeding trial, a total of 54 newborn suckling piglets were chosen from nine sows and randomly assigned to three treatments with different concentrations of a candidate strain. Multiple approaches were carried out to verify its antioxidant function including western blotting, enzyme activity analysis, metabolomics and 16S rRNA gene amplicon sequencing. RESULTS: The 1240 isolates were screened out from the sow milk microbiota and grouped into 271 bacterial taxa based on a nonredundant set of 16S rRNA gene sequencing. Among 80 Pediococcus isolates, a new Pediococcus pentosaceus strain (SMM914) showed the best performance in inhibition ability against swine pathogens and in a Drosophila model challenged by paraquat. Pretreatment of piglets with SMM914 induced the Nrf2-Keap1 antioxidant signaling pathway and greatly affected the pathways of amino acid metabolism and lipid metabolism in plasma. In the colon, the relative abundance of Lactobacillus was significantly increased in the high dose SMM914 group compared with the control group. CONCLUSION: P. pentosaceus SMM914 is a promising probiotic conferring antioxidant capacity by activating the Nrf2-Keap1 antioxidant signaling pathway in piglets. Our study provided useful resources for better understanding the relationships between the maternal microbiota and offspring. Video Abstract.