Dietary Methionine Restriction Improves Gut Health and Alters the Plasma Metabolomic Profile in Rats by Modulating the Composition of the Gut Microbiota.

Dietary methionine restriction (MetR) offers an integrated set of beneficial health effects, including delaying aging, extending health span, preventing fat accumulation, and reducing oxidative stress. This study aimed to investigate whether MetR exerts entero-protective effects by modulating intestinal flora, and the effect of MetR on plasma metabolites in rats. Rats were fed diets containing 0.86% methionine (CON group) and 0.17% methionine (MetR group) for 6 weeks. Several indicators of inflammation, gut microbiota, plasma metabolites, and intestinal barrier function were measured. 16S rRNA gene sequencing was used to analyze the cecal microbiota. The MetR diet reduced the plasma and colonic inflammatory factor levels. The MetR diet significantly improved intestinal barrier function by increasing the mRNA expression of tight junction proteins, such as zonula occludens (ZO)-1, claudin-3, and claudin-5. In addition, MetR significantly increased the levels of short-chain fatty acids (SCFAs) by increasing the abundance of SCFAs-producing Erysipclotxichaceae and Clostridium_sensu_stricto_1 and decreasing the abundance of pro-inflammatory bacteria Proteobacteria and Escherichia-Shigella. Furthermore, MetR reduced the plasma levels of taurochenodeoxycholate-7-sulfate, taurocholic acid, and tauro-ursodeoxycholic acid. Correlation analysis identified that colonic acetate, total colonic SCFAs, 8-acetylegelolide, collettiside I, 6-methyladenine, and cholic acid glucuronide showed a significant positive correlation with Clostridium_sensu_stricto_1 abundance but a significant negative correlation with Escherichia-Shigella and Enterococcus abundance. MetR improved gut health and altered the plasma metabolic profile by regulating the gut microbiota in rats.

Mixed ensiling plus nitrate destroy fiber structure of rape straw, increase degradation, and reduce methanogenesis through in vitro ruminal fermentation.

BACKGROUND: Better utilization of rape straw can provide alternative strategies for sustainable ruminant and food production. The research reported here investigated changes in the carbohydrate composition of rape straw as a result of mixed ensiling with whole-crop corn or inoculated with nitrate, and the consequent effects on ruminal fermentation through in vitro batch culture. The three treatments included: rape straw and corn silage (RSTC), and ensiling treatment of rape straw with whole-crop corn (RSIC) or with calcium nitrate inoculation (RSICN). RESULTS: Ensiling treatment of rape straw and whole-crop corn or plus nitrate enriched lactic acid bacteria and lactate. The treatments broke the fiber surface connections of rape straw, leading to higher neutral detergent soluble (NDS) content and lower fiber content. Ensiling treatments led to greater (P < 0.05) dry matter degradation (DMD), molar proportions of propionate and butyrate, relative abundance of the phylum Bacteroidetes and genus Prevotella, and lower (P < 0.05) methane production in terms of g kg-1 DMD, molar proportions of acetate, and lower acetate to propionate ratio than the RSTC treatment. The RSICN treatment led to the lowest (P < 0.05) hydrogen concentration and methane production among the three treatments. CONCLUSION: Ensiling treatments of rape straw and whole-crop corn destroy the micro-structure of rape straw, promote substrate degradation by enriching the phylum Bacteroidetes and the genus Prevotella, and decrease methane production by favoring propionate and butyrate production. Nitrate inoculation in the ensiling treatment of rape straw and whole-crop corn further decreases methane production without influencing substrate degradation by providing an additional hydrogen sink. © 2023 Society of Chemical Industry.

Mannan oligosaccharides selenium ameliorates intestinal mucosal barrier, and regulate intestinal microbiota to prevent Enterotoxigenic Escherichia coli -induced diarrhea in weaned piglets.

Enterotoxigenic Escherichia coli (ETEC) is a common diarrheal pathogen in humans and animals. To prevent and treat ETEC induced diarrhea, we synthesized mannan oligosaccharide selenium (MOSS) and studied its beneficial effect on ETEC-induced diarrhea. A total of 32 healthy weaned piglets (6.69 ± 0.01 kg) were randomly divided into four groups: NC group (Basal diet), MOSS group (0.4 mg/kg MOSS supplemented diet), MOET group (0.4 mg/kg MOSS supplemented diet + ETEC treatment), ETEC group (ETEC treatment). NC and ETEC group fed with basal diet, MOSS and MOET group fed with the MOSS supplemented diet. On the 8th and 15th day of the experiment, MOET and ETEC group were gavaged with ETEC, and NC and MOSS group were gavaged with stroke-physiological saline solution. Our data showed that dietary MOSS supplementation increased average daily gain (ADG) and average daily feed intake (ADFI) and significantly decreased diarrhea index and frequency in ETEC-treated piglets. MOSS did not affect the α diversity and ß diversity of ileal microbial community, but it significantly decreased the proportion of lipopolysaccharide biosynthesis in ileal microbial community. MOSS supplementation regulated colonic microbiota community composition, which significantly increased carbohydrate metabolism, and inhibited lipopolysaccharide biosynthesis pathway in colonic microbial community. Moreover, MOSS significantly decreased inflammatory stress, and oxidative stress in ETEC treated piglets. Furthermore, dietary MOSS supplementation significantly decreased intestinal barrier permeability, and alleviated ETEC induced intestinal mucosa barrier irritation. In conclusion, our study showed that dietary MOSS supplementation ameliorated intestinal mucosa barrier, and regulated intestinal microbiota to prevent ETEC induced diarrhea in weaned piglets.

The nanocomposites of modified attapulgite with vitamin E and mannan oligosaccharide regulated the intestinal epithelial barrier and improved intestinal microbiota composition to prevent diarrhea in weaned piglets.

BACKGROUND: Overuse of antibiotics contributes to bacterial resistance in animals. Therefore, it is necessary to find a new way to ensure animal health and promote animal growth. This experiment was conducted to investigate the effect of mannan oligosaccharide (MOS)/vitamin E (VE)/attapulgite (APT) nanocomposites (SLK1, SLK3, SLK5) on growth performance and intestinal health in weaned piglets. Each 1 kg of SLK1, SLK3 or SLK5 contains 50 g of vitamin E, and each had a different MOS concentration [SLK1 (50 g kg -1 MOS), SLK3 (100 g kg -1 MOS), SLK5 (150 g kg -1 MOS)]. In total, 135 piglets were randomly divided into five groups (normal control group, traditional antibiotic substitutes group, SLK1 group, SLK3 group and SLK5 group), and growth performance, diarrhea index, intestinal epithelial barrier function and intestinal microbial composition were measured. RESULTS: SLK1 and SLK5 significantly decreased diarrhea frequency in weaned piglets (p < 0.05). Furthermore, SLK5 significantly increased survival rate of weaned piglets compared to the traditional antibiotic substitutes group (p < 0.05). SLK5 also increased villus height of ileum, and increased goblet number of the jejunum (p < 0.05). 16S rRNA sequencing showed that SLK5 significantly regulated intestinal colonic microbiota composition (p < 0.05). Specifically, SLK5 significantly increased the abundance of Phascolarctobacterium succinatutens in the cecum and increased the abundance of Lactobacillus and Bifidobacterium in the colon (p < 0.05). In addition, dietary supplementation with 1 kg T-1 SLK5 also significantly increased the propionate content in the colon, which is significantly correlated with Phascolarctobacterium (p < 0.05). CONCLUSION: Dietary supplementation with 1 kg T-1 SLK5 improved intestinal epithelial barrier function, and regulated intestinal microbiota composition to prevent diarrhea in weaned piglets. © 2023 Society of Chemical Industry.

Effects of soluble glucomannan and insoluble cellulose treatment on mucin secretion and mucin glycosylation-related gene expression in the colons of mice.

BACKGROUND: Fiber added to the diet can promote intestinal mucin secretion, relieve intestinal inflammation, and enhance the intestinal barrier function. Glycosylation is the key to mucin function. However, there are few studies on the correlation between dietary fiber and mucin glycosylation, especially two kinds of dietary fiber with different solubility. The aim of this study was to investigate the effects of soluble glucomannan (GM) and insoluble cellulose (CL) treatment on mucin secretion and mucin glycosylation-related gene expression in the colons of mice. RESULTS: The GM group significantly increased the goblet cell number, crypt depth, and the expression of mucin 2 (Muc2) and mucin 3a (Muc3a) genes in the colon. At the same time, the analysis of the colon transcriptome showed that the GM group changed the expression of genes related to the mucin glycosylation process, and the GM group up-regulated the expression of Gcnt3, Gcnt4, St3gal1, Galnt13, and B3gnt6 genes involved in the O-glycosylation process. Similarly, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that differentially glycosylated genes in the GM group were mainly related to the biosynthesis of mucin type O-glycans, while the genes in the CL group were related to the biosynthesis of various types of N-glycans. The correlation analysis between colonic microbes and differentially glycosylated genes also showed that the abundance of Alistipes in the GM group was significantly associated with the expression of Gcnt3, a key glycosylation gene. CONCLUSION: Glucomannan treatment was more favorable for colonic Muc2 and Muc3a secretion and mucin O-glycosylation gene expression. © 2023 Society of Chemical Industry.

Analysis of transcriptome differences between subcutaneous and intramuscular adipose tissue of Ningxiang pigs.

To compare and analyze the molecular mechanisms of adipose deposition in subcutaneous fat (SAF)and intramuscular fat (IMF) tissues in Ningxiang pigs, differential gene expression profiles in SAF and IMF tissues of Ningxiang pigs were identified and analysed using RNA-seq technology. Six healthy 250-day-old male Ningxiang pigs with similar body weights (approximately 85 kg) of intraspecific individuals were selected as experimental material and samples of SAF and IMF tissues were collected. Differential genes associated with fat deposition and lipid metabolism were obtained by sequencing two adipose tissue transcriptomes and performing GO (Gene Ontology) functional annotation and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis. To verify the reliability of the sequencing results, six differential genes were randomly selected to validate using qRT-PCR. The results showed that we identified 2406 DEGs, with 1422 up-regulated and 984 down-regulated genes in two tissues. GO functional annotation analysis revealed that the differentially expressed genes were mainly involved in lipid metabolism related pathways, such as steroid biosynthesis, unsaturated fatty acid biosynthesis, glycerophospholipid metabolism and autophagy pathway. KEGG pathway enrichment showed that the differentially expressed genes were mainly enriched in the biological processes related to lipid binding, fatty acid metabolism, glycol ester metabolism, lipid biosynthesis and other biological processes related to lipid metabolism. Genes related to lipid metabolism, such as TCAP, NR4A1, ACACA, LPL, ELOVL6, DGAT1, PRKAA1, ATG101, TP53INP2, FDFT1, ACOX1 and SCD were identified by bioinformatic analyses and verified by qRT-PCR. Our results indicated that these genes may play important roles in the regulation of fat deposition and metabolism in the SAF and IMF tissue, providing the further mechanistic investigation of fat deposition in Ningxiang pigs.

The microbiota-gut-brain axis: A novel nutritional therapeutic target for growth retardation.

Growth retardation (GR), which commonly occurs in childhood, is a major health concern globally. However, the specific mechanism remains unclear. It has been increasingly recognized that changes in the gut microbiota may lead to GR through affecting the microbiota-gut-brain axis. Microbiota interacts with multiple factors such as birth to affect the growth of individuals. Microbiota communicates with the nerve system through chemical signaling (direct entry into the circulation system or stimulation of enteroendocrine cells) and nervous signaling (interaction with enteric nerve system and vagus nerve), which modulates appetite and immune response. Besides, they may also influence the function of enteric glial cells or lymphocytes and levels of systemic inflammatory cytokines. Environmental stress may cause leaky gut through perturbing the hypothalamic-pituitary-adrenal axis to further result in GR. Nutritional therapies involving probiotics and pre-/postbiotics are being investigated for helping the patients to overcome GR. In this review, we summarize the role of microbiota in GR with human and animal models. Then, existing and potential regulatory mechanisms are reviewed, especially the effect of microbiota-gut-brain axis. Finally, we propose nutritional therapeutic strategies for GR by the intervention of microbiota-gut-brain axis, which may provide novel perspectives for the treatment of GR in humans and animals.

Advanced single-cell pooled CRISPR screening identifies C19orf53 required for cell proliferation based on mTORC1 regulators.

Multiplexed single-cell CRISPR screening has accelerated the systematic dissection of biological discoveries; however, the efficiency of CRISPR-based gene knockout has inherent limitations. Here, we present DoNick-seq, an advanced method for facilitating gene knockout and reducing off-target activity. We re-engineered two popular plasmid constructs suitable for use in pooled CRISPR screening of the single-cell transcriptome. We then used DoNick-seq to probe mTORC1 regulators and obtain genomic perturbation and transcriptome profiles from the same cell. Thus, DoNick-seq enabled us to simultaneously evaluate multiple gene interactions and the effect of amino acid depletion. By analyzing more than 20,000 cells from two cell lines, DoNick-seq efficiently identified gene targets, cell numbers, and cellular profiles. Our data also revealed the characteristics of mTORC1 negative and positive regulators, thereby shedding new insights into the mechanisms regulating cell growth and inhibition. We demonstrate that mTORC1 hyperactivation exhausts cellular free amino acids via increased proliferation ability. Furthermore, DoNick-seq identified the gene C19orf53, which mediates excessive cell proliferation, resulting in metabolic imbalance, and greatly enhances oxidative stress in response to toxins. Thus, our findings suggest that DoNick-seq facilitates high-throughput functional dissection of complex cellular responses at the single-cell level and increases the accuracy of CRISPR single-cell transcriptomics.

Postnatal growth retardation is associated with deteriorated intestinal mucosal barrier function using a porcine model.

Individuals with postnatal growth retardation (PGR) are prone to developing chronic diseases. Abnormal development in small intestine is casually implicated in impaired growth. However, the exact mechanism is still implausible. In this present study, PGR piglets (aged 42 days) were employed as a good model to analyze developmental changes in intestinal mucosal barrier function. Our data demonstrated that PGR piglets exhibited impaired jejunal and ileal epithelial villous morphology and permeability, accompanied by decreased cell proliferation ability and increased apoptosis rate. In addition, the expression of tight junction proteins (ZO-1, claudin 1, and occludin) and E-cadherin was markedly inhibited by PGR. The expression of P-glycoprotein was significantly reduced in PGR piglets, as well as decreased activity of lysozyme. Moreover, the mRNA abundance and content of inflammatory cytokines were significantly increased in the intestinal mucosa and plasma of PGR piglets, respectively. PGR also contributed to lower level of sIgA, and higher level of CD68-positive rate, ß-defensins, and protein expression involved p38 MAPK/NF-κB pathway. Furthermore, PGR altered the intestinal microbial community such as decreased genus Alloprevotella and Oscillospira abundances, and led to lower microbial-derived butyrate production, which may be potential targets for treatment. Collectively, our findings indicated that the intestinal mucosal barrier function of PGR piglets could develop the nutritional intervention strategies in prevention and treatment of the intestinal mucosal barrier dysfunction in piglets and humans.

The Role of Oxidative Stress and Antioxidant Balance in Pregnancy.

It has been widely known that oxidative stress disrupts the balance between reactive oxygen species (ROS) and the antioxidant system in the body. During pregnancy, the physiological generation of ROS is involved in a variety of developmental processes ranging from oocyte maturation to luteolysis and embryo implantation. While abnormal overproduction of ROS disrupts these processes resulting in reproductive failure. In addition, excessive oxidative stress impairs maternal and placental functions and eventually results in fetal loss, IUGR, and gestational diabetes mellitus. Although some oxidative stress is inevitable during pregnancy, a balancing act between oxidant and antioxidant production is necessary at different stages of the pregnancy. The review aims to highlight the importance of maintaining oxidative and antioxidant balance throughout pregnancy. Furthermore, we highlight the role of oxidative stress in pregnancy-related diseases.

Postnatal growth retardation is associated with intestinal mucosa mitochondrial dysfunction and aberrant energy status in piglets.

Individuals with postnatal growth retardation (PGR) are prone to developing chronic disease. Abnormal development in small intestine is casually implicated in impaired growth performance. However, the exact mechanism is still unknown. In this present study, PGR piglets (aged 42 days) were employed as a good model to analyse changes in nutrient absorption and energy metabolism in the intestinal mucosa. The results showed lower serum concentrations of free amino acids, and lipid metabolites in PGR piglets, which were in accordance with the down-regulated mRNA expressions involved in fatty acid and amino acid transporters in the jejunal and ileal mucosa. The decreased activities of digestive enzymes and the marked swelling in mitochondria were also observed in the PGR piglets. In addition, it was found that lower ATP production, higher AMP/ATP ratio, deteriorated mitochondrial complex III and ATP synthase, and decreased manganese superoxide dismutase activity in the intestinal mucosa of PGR piglets. Furthermore, altered gene expression involved in energy metabolism, accompanied by decreases in the protein abundance of SIRT1, PGC-1α and PPARγ, as well as phosphorylations of AMPKα, mTOR, P70S6K and 4E-BP1 were observed in intestinal mucosa of PGR piglets. In conclusion, decreased capability of nutrient absorption, mitochondrial dysfunction, and aberrant energy status in the jejunal and ileal mucosa may contribute to PGR piglets.

Flavonoids and type 2 diabetes: Evidence of efficacy in clinical and animal studies and delivery strategies to enhance their therapeutic efficacy.

Diabetes mellitus type 2 (T2DM) is a metabolic disorder develops due to the overproduction of free radicals where oxidative stress could contribute it. Possible factors are defective insulin signals, glucose oxidation, and degradation of glycated proteins as well as alteration in glutathione metabolism which induced hyperglycemia. Previous studies revealed a link between T2DM with oxidative stress, inflammation and insulin resistance which are assumed to be regulated by numerous cellular networks such as NF-κB, PI3K/Akt, MAPK, GSK3 and PPARγ. Flavonoids are ubiquitously present in the nature and classified according to their chemical structures for example, flavonols, flavones, flavan-3-ols, anthocyanidins, flavanones, and isoflavones. Flavonoids indicate poor bioavailability which could be improved by employing various nano-delivery systems against the occurrences of T2DM. These bioactive compounds exert versatile anti-diabetic activities via modulating targeted cellular signaling networks, thereby, improving glucose metabolism, α -glycosidase, and glucose transport or aldose reductase by carbohydrate metabolic pathway in pancreatic ß-cells, hepatocytes, adipocytes and skeletal myofibres. Moreover, anti-diabetic properties of flavonoids also encounter diabetic related complications. This review article has designed to shed light on the anti-diabetic potential of flavonoids, contribution of oxidative stress, evidence of efficacy in clinical, cellular and animal studies and nano-delivery approaches to enhance their therapeutic efficacy. This article might give some new insights for therapeutic intervention against T2DM in near future.

Circadian rhythms and obesity: Timekeeping governs lipid metabolism.

Almost all living organisms have evolved autoregulatory transcriptional-translational feedback loops that produce oscillations with a period of approximately 24-h. These endogenous time keeping mechanisms are called circadian clocks. The main function of these circadian clocks is to drive overt circadian rhythms in the physiology of the organisms to ensure that main physiological functions are in synchrony with the external environment. Disruption of circadian rhythms caused by genetic or environmental factors has long-term consequences for metabolic health. Of relevance, host circadian rhythmicity and lipid metabolism are increasingly recognized to cross-regulate and the circadian clock-lipid metabolism interplay may involve in the development of obesity. Multiple systemic and molecular mechanisms, such as hormones (ie, melatonin, leptin, and glucocorticoid), the gut microbiome, and energy metabolism, link the circadian clock and lipid metabolism, and predictably, the deregulation of circadian clock-lipid metabolism interplay can increase the risk of obesity, which in turn may exacerbate circadian disorganization. Feeding time and dietary nutrients are two of key environmental Zeitgebers affecting the circadian rhythm-lipid metabolism interplay, and the influencing mechanisms in obesity development are highlighted in this review. Together, the characterization of the clock machinery in lipid metabolism aimed at producing a healthy circadian lifestyle may improve obesity care.

Dynamic changes in circulating levels of metabolites in the portal-drained viscera of finishing pigs receiving acute administration of l-arginine.

In this study, we examined the effects of acute intravenous administration of l-arginine on circulating levels of metabolites in the portal-drained viscera (PDV) of 12 barrows surgically fitted with chronic catheters in the portal vein. At day 14 post-surgery, the pigs were fasted for 12 hr and then randomly allocated to one of three groups to receive administration of normal saline, l-alanine [103 mg/kg body weight (BW), isonitrogenous control] or l-arginine-HCl (61 mg/kg BW), via the portal vein. Blood samples were obtained from the carotid artery before and at 30-min intervals for 5 hr after the administration of saline or amino acid in order to determine metabolic profiles. The results showed that, compared with the saline treatment, arginine infusion increased plasma concentrations of insulin-like growth factor-I, arginine and cystine in the portal vein plasma, whereas plasma concentrations of threonine, serine, leucine and methionine were reduced. These findings indicate that increasing arginine concentrations in the portal vein alters the metabolic profile in swine, an established animal model for studying human nutrition and metabolism.

Effects of dietary amylose/amylopectin ratio and amylase on growth performance, energy and starch digestibility, and digestive enzymes in broilers.

This study was conducted to investigate the effects of dietary amylose/amylopectin (AM/AP) ratio and amylase on growth performance, apparent digestibility of energy and starch, serum biochemical index, and digestive enzymes. The experiment used a 4 × 3 factor design, and 960 one-day-old Arbor Acres (AA) broilers were randomly divided into 12 groups fed diets containing different AM/AP ratio of 0.11, 0.23, 0.35 and 0.47 and combined with 0, 3,000 and 6,000 U/kg amylase. Results showed that 0.23-0.35 AM/AP ratio increased growth performance, while dietary addition of 6,000 U/kg amylase significantly reduced average daily weight gain in broilers. The energy digestibility was significantly reduced along with the increase of dietary AM/AP ratio and in the 6,000 U/Kg amylase-supplemented groups. The digestibility of starch also decreased significantly with the increase of dietary AM/AP ratio, but high dose (6,000 U/Kg) of amylase increased. High AM/AP diet reduced serum insulin concentration, which was increased in amylase-supplemented groups. Furthermore, exogenous amylase increased amylase activity in the jejunal chyme. In conclusion, dietary 0.23-0.35 AM/AP ratio was suggested to maintain a higher growth performance in broilers and high AM/AP ratio diets reduced energy and starch digestibility and serum insulin concentration, which was reversed by dietary amylase.

Excess Iron Enhances Purine Catabolism Through Activation of Xanthine Oxidase and Impairs Myelination in the Hippocampus of Nursing Piglets.

BACKGROUND: Few studies have addressed the risk of nutritional iron overexposure in infancy. We previously found that excess dietary iron in nursing piglets resulted in iron overload in the liver and hippocampus and diminished socialization with novel conspecifics in a test for social novelty preference. OBJECTIVES: This experiment aimed to identify metabolites and metabolic pathways affected by iron overload in the liver and hippocampus of nursing piglets. METHODS: Liver and hippocampal tissues collected from 22-d-old piglets (Hampshire × Yorkshire crossbreed; 5.28 ± 0.53 kg body weight; 50% male) that received orally 0 (NI group) or 50 mg iron/(d · kg body weight) (HI group) from postnatal day (PD) 2 to PD21 were analyzed for mRNA and protein expression and enzyme activity of xanthine oxidase (XO). Untargeted metabolomics was performed using GC-MS. Expression of myelin basic protein (MBP) in the hippocampus was determined using western blot. RESULTS: There were 108 and 126 metabolites identified in the hippocampus and liver, respectively. Compared with NI, HI altered 15 metabolites (P < 0.05, q < 0.2) in the hippocampus, including a reduction in myo-inositol (0.86-fold) and N-acetylaspartic acid (0.84-fold), 2 metabolites important for neuronal function and myelination. Seven metabolites involved in purine and pyrimidine metabolism (e.g., hypoxanthine, xanthine, and ß-alanine) were coordinately changed in the hippocampus (P < 0.05, q < 0.2), suggesting that iron excess enhanced purine catabolism. The mRNA expression (2.3-fold) (P < 0.05) and activity of XO, a rate-limiting enzyme in purine degradation, was increased. Excess iron increased hippocampal lipid peroxidation by 74% (P < 0.05) and decreased MBP by 44% (P = 0.053). The hepatic metabolome was unaffected. CONCLUSIONS: In nursing piglets, excess iron enhances hippocampal purine degradation through activation of XO, which may induce oxidative stress and alter energy metabolism in the developing brain.

Influence of supplemented coated-cysteamine on morphology, apoptosis and oxidative stress status of gastrointestinal tract.

BACKGROUND: Cysteamine was coated to cover its odor and maintain the stability. However, coated cysteamine (CC) has not been clearly evaluated for its effects on the gastrointestinal mucosa status. We hypothesize that the appropriate CC supplementation in diet impacts the stomach and intestinal mucosa variously through regulating the morphology, apoptosis, and oxidative stress status in model of pigs. RESULTS: The results showed that villus height increased (P < 0.05), and crypt depth decreased (P < 0.05) in the ileum when pigs were fed the diet with low cysteamine (LCS) compared with the control diet. The ileal lesion score in the LCS group was significantly (P < 0.01) lower than that in the control group, while the gastric lesion score in the CC group was significantly (P < 0.01) higher compared with that of the control group. It also showed that the activities of total superoxide dismutase (T-SOD) and diamine oxidase (DAO) were upregulated (P < 0.05) in the LCS group. In addition, Bax and caspase 3 immunore-activity increased (P < 0.01), and Bcl-2 immunoreactivity decreased (P < 0.01) in the gastric mucosa of pigs fed the diet with high cysteamine (HCS). The Bax and caspase 3 immunoreactivity decreased (P < 0.01), and Bcl-2 immunoreactivity increased (P < 0.01) in ileum mucosa of pigs fed the HCS diet. CONCLUSIONS: Although moderate dietary coated cysteamine showed positive effects on GI mucosal morphology, apoptosis, and oxidative stress status, the excess coated cysteamine may cause apoptosis leading to GI damage in pigs.

Chemical Composition and Antioxidant Properties of Essential Oils from Peppermint, Native Spearmint and Scotch Spearmint.

Natural antioxidants have drawn growing interest for use in animal feed and the food industry. In the current study, essential oils (EOs) obtained from hydrodistillation of three mentha species, including Mentha piperita (peppermint), Mentha spicata (native spearmint) and Mentha gracilis (Scotch spearmint), harvested in the Midwest region in the United States, were analyzed for their chemical composition using gas chromatography-mass spectrometry, and their antioxidant properties were assessed through chemical assays, in vitro cell culture modeling and in Caenorhabditis elegans (C. elegans). The activity of ferric iron reduction and free-radical scavenging capacity were assessed through chemical-based assays, including the reducing power assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, and Trolox equivalent antioxidant capacity assay (TEAC). Subsequently, the capacity of EOs to mitigate lipid peroxidation was analyzed at various doses using fresh liver homogenates from pigs. A porcine jejunum epithelial cell line (IPEC-J2) was employed as in vitro model to study the cellular antioxidant activity of the mint EOs. Finally, the effectiveness of mint EOs to alleviate acute systemic oxidative damage were evaluated in vivo using C. elegans. Data were analyzed by the MIXED procedure of SAS. Contrast statement was performed to assess linear or quadratic effects of mint EOs given at various doses. All three EOs are mostly composed of monoterpenes and their derivatives (76-90%), but differed in the major compounds, which are menthol and menthone (50%) in peppermint EO and carvone (70%) in spearmint EOs. Three mint EOs demonstrated prominent radical scavenging and Fe3+ reducing activity in chemical-based assays. In comparison with native and Scotch spearmint EOs, peppermint EO had the lowest (p < 0.05) half maximal effective concentration (EC50) in DPPH and TEAC assays and higher efficacy in the reducing power assay. All three EOs exhibited equivalent activity in mitigation of chemical-induced lipid peroxidation in liver tissues in a dose-dependent manner (linear, p < 0.001). The maximal cellular antioxidant activity (CAA) was observed at 5 µg/mL for peppermint, and 100 µg/mL for native and Scotch spearmint EOs. The addition of 25 µg/mL of both spearmint EOs increased (p < 0.05) cellular concentrations of glutathione in H2O2-treated IPEC-J2 cells, suggesting enhanced endogenous antioxidant defense. Supplementation of 100 µg/mL of peppermint or Scotch spearmint EO significantly increased (p < 0.05) the survival rate of C. elegans in response to H2O2-induced oxidative stress. The protective effect is comparable to that of supplementation of 10 µg/mL of ascorbic acid. However native spearmint EO failed to reduce the death rate within the same supplementation dose (10-200 µg/mL).

Involvement of calcium-sensing receptor activation in the alleviation of intestinal inflammation in a piglet model by dietary aromatic amino acid supplementation.

Ca2+-sensing receptor (CaSR) represents a potential therapeutic target for inflammatory bowel diseases and strongly prefers aromatic amino acid ligands. We investigated the regulatory effects of dietary supplementation with aromatic amino acids - tryptophan, phenylalanine and tyrosine (TPT) - on the CaSR signalling pathway and intestinal inflammatory response. The in vivo study was conducted with weanling piglets using a 2 × 2 factorial arrangement in a randomised complete block design. Piglets were fed a basal diet or a basal diet supplemented with TPT and with or without inflammatory challenge. The in vitro study was performed in porcine intestinal epithelial cell line to investigate the effects of TPT on inflammatory response using NPS-2143 to inhibit CaSR. Dietary supplementation of TPT alleviated histopathological injury and decreased myeloperoxidase activity in intestine challenged with lipopolysaccharide. Dietary supplementation of TPT decreased serum concentration of pro-inflammatory cytokines (IL-1ß, IL-6, IL-8, IL-12, granulocyte-macrophage colony-stimulating factor, TNF-α), as well as the mRNA abundances of pro-inflammatory cytokines in intestine but enhanced anti-inflammatory cytokines IL-4 and transforming growth factor-ß mRNA levels compared with pigs fed control diet and infected by lipopolysaccharide. Supplementation of TPT increased CaSR and phospholipase Cß2 protein levels, but decreased inhibitor of NF-κB kinase α/ß and inhibitor of NF-κB (IκB) protein levels in the lipopolysaccharide-challenged piglets. When the CaSR signalling pathway was blocked by NPS-2143, supplementation of TPT decreased the CaSR protein level, but enhanced phosphorylated NF-κB and IκB levels in IPEC-J2 cells. To conclude, supplementation of aromatic amino acids alleviated intestinal inflammation as mediated through the CaSR signalling pathway.

Melatonin alleviates weanling stress in mice: Involvement of intestinal microbiota.

Melatonin influences intestinal microbiota and the pathogenesis of various diseases. This study was conducted to explore whether melatonin alleviates weanling stress through intestinal microbiota in a weanling mouse model. Melatonin supplementation in weanling mice (provided in the drinking water at a dosage of 0.2 mg/mL for 2 weeks) significantly improved body weight gain (1.4 ± 0.03 g/day in melatonin group vs 1.2 ± 0.06 g/day in control group) and intestinal morphology (ie, villus length, crypt depth, and villus to crypt ratio), but had little effect on the proliferation or apoptosis of intestinal cells, the numbers of Paneth cells and goblet cells, as well as the expression of makers related to enterocytes (sucrase) and endocrine cells (chromogranin A and peptide YY) in the ileum. Melatonin supplementation had little effect on serum levels of amino acids or stress-related parameters (eg, SOD, TNF-α, and angiotensin I). 16S rRNA sequencing suggested that melatonin supplementation increased the richness indices of intestinal microbiota (observed species, Chao 1, and ACE) and shaped the composition of intestinal microbiota (eg, increase in the abundance of Lactobacillus [19 ± 3% in melatonin group vs 6 ± 2% in control group]), which was demonstrated using an ex vivo proliferation assay and colonic loop proliferation assay. Melatonin supplementation also significantly influenced the metabolism of intestinal microbiota, such as amino acid metabolism and drug metabolism. More importantly, in antibiotic-treated weanling mice and germ-free weanling mice, melatonin failed to affect body weight gain or intestinal morphology. Melatonin significantly reduced (by about 60%) the bacterial load in enterotoxigenic Escherichia coli (ETEC)-infected weanling mice, but had little effect on ETEC load in antibiotic-pretreated animals. In conclusion, melatonin affects body weight gain, intestinal morphology, and intestinal ETEC infection through intestinal microbiota in weanling mice. The findings highlight the importance of intestinal microbiota in mediating the various physiological functions of melatonin in the host.