Glutamine supplementation moderately affects growth, plasma metabolite and free amino acid patterns in neonatal low birth weight piglets

The correlation between serum total bile acid and alanine aminotransferase of pregnant women and the disorders of neonatal hyperbilirubinemia-related amino acid metabolism

BACKGROUND

To explore the association between liver metabolism-related indicators in maternal serum and neonatal hyperbilirubinemia (NHB), and further investigate the predictive value of these indicators in NHB-related amino acid metabolism disorders.

METHODS

51 NHB and 182 No-NHB newborns and their mothers who treated in the Fourth Hospital of Shijiazhuang from 2018 to 2022 were participated in the study. The differences in clinical data were compared by the Mann-Whitney U test and Chi-square test. Multivariate logistic regression was used to analyze the relationship between maternal serum indicators and the occurrence of NHB. The correlation analysis and risk factor assessment of maternal serum indicators with NHB-related amino acid metabolic disorders were performed using Spearman correlation analysis and multivariate logistic regression.

RESULTS

Compared to the non NHB group, the NHB group had higher maternal serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), ALT/AST, and total bile acid (TBA), while lower levels of serum albumin (ALB), total cholesterol (TC) and high-density lipoprotein (HDL). The levels of alanine (ALA), valine (VAL), ornithine (ORN), and proline (PRO) in the newborns were reduced in NHB group, while arginine (ARG) showed a tendency to be elevated. Multiple logistic regression analysis showed that maternal ALT, AST, ALT/AST, and TBA levels were all at higher risk with the development of NHB, whereas ALB, TC, and HDL levels were negatively associated with NHB development. Increasing maternal TBA level was associated with lower ALA (r=-0.167, p = 0.011), VAL (r=-0.214, p = 0.001), ORN (r=-0.196, p = 0.003), and PRO in the newborns (r=-0.131, p = 0.045). Maternal ALT level was negatively associated with ALA (r=-0.135, p = 0.039), VAL (r=-0.177, p = 0.007), ORN (r=-0.257, p < 0.001), while ALT/AST was positively correlated with ARG (r = 0.133, p = 0.013). After adjustment for confounding factors, maternal serum TBA and ALT were the independent risk factor for neonatal ORN metabolic disorders [(adjusted odds ratio (AOR) = 0.379, 95%CI = 0.188-0.762, p = 0.006), (AOR = 0.441, 95%CI = 0.211-0.922, p = 0.030)]. Maternal ALT level was an independent risk factor for neonatal VAL metabolic disorders (AOR = 0.454, 95%CI = 0.218-0.949, p = 0.036).

CONCLUSIONS

The levels of high TBA, ALT, AST, and low HDL, TC of maternal were associated with the risk of NHB. Maternal TBA and ALT levels were independent risk factors for NHB-related amino acid disturbances which have value as predictive makers.

Selected Nutrition and Management Strategies in Suckling Pigs to Improve Post-Weaning Outcomes

Weaning is a critical period in a pig's life. Piglets are confronted with abrupt changes to their physical and social environment, as well as management and nutritional changes. Weaning has always been associated with a growth check and is frequently accompanied by post-weaning diarrhoea in piglets. However, rapid increases in litter size in the last decade have increased within-litter piglet weight variation, with piglets now generally lighter at weaning, making the challenges associated with weaning even greater. Many interventions can be employed during the suckling period to ease the weaning transition for piglets. Pre-weaning strategies such as supervised farrowing (assistance with suckling and oxytocin provision), the provision of pain relief to sows around farrowing, split-suckling, early oral supplementation with glucose, bovine colostrum, faecal microbiota transplantation, feed additives and solid and liquid creep feeding (milk and liquid feed) have all been investigated. The objective of these strategies is to stimulate earlier maturation of the digestive tract, improve immunity, reduce latency to the first feed post-weaning and increase early post-weaning feed intake and growth. This review focuses in particular on: (1) pain relief provision to sows around farrowing, (2)split-suckling of piglets, (3) pre-weaning provision of supplementary milk and/or liquid feed, (4) other strategies to stimulate earlier enzyme production (e.g., enzyme supplementation), (5) other nutritional strategies to promote improved gut structure and function (e.g., L-glutamine supplementation), and (6) other strategies to modulate gut microbiota (e.g., probiotics and prebiotics). Correctly implementing these strategies can, not only increase post-weaning growth and reduce mortality, but also maximise lifetime growth in pigs.

Serum metabolomic characterization in pigs in relation to birth weight category and neonatal nutrition

The objective of this study was to characterize developmental differences in low birth weight (LBW) and normal birth weight (NBW) piglets with or without pre-weaning nutrient restriction using serum metabolomic profile analysis. At farrowing, 112 piglets were identified as LBW (1.22 ± 0.28 kg) or NBW (1.70 ± 0.27 kg) and were randomly assigned to receive normal nutrition (NN) or restricted nutrition (RN) (6 h/day no suckling) from days 2 to 28 post farrow (n = 8 pigs/group). On day 28, piglets were weaned onto a common diet. Fasted blood samples were obtained on days 28 and 56 (n = 8 pigs/group) and were analyzed using quantitative metabolomics via a combination of direct injection mass spectrometry with a reverse-phase LC-MS/MS custom assay. Data were normalized using logarithmic transformation and auto-scaling. Partial least squares discriminant analysis (PLS-DA) was carried out to further explore the differential metabolites among the groups (metaboanalyst.ca) with an integrated enrichment and pathway topography analysis. On day 28, LBW piglets had lower levels of essential amino acids as well as reduced metabolites associated with fatty acid oxidation, glycolysis, and the tri-carboxylic acid (TCA) cycle compared to the NBW group. The overall reduction of metabolites associated with energy production and regulation suggests that LBW vs. NBW are in an energy-survival state. On day 56, LBW pigs had increased utilization of fatty acids and resultant ketone production, evident by increased carnitines, acetoacetate, β-hydroxybutyrate, and glycerol compared to NBW pigs. In addition, compared to the NBW pigs LBW pigs had a consistent decrease in serum glucose and lactate as well as reduced TCA cycle metabolites: pyruvate, succinate, citrate, and α-ketoglutaric acid similar to day 28. Low reliance on glycolysis and the TCA cycle and higher glycerol production in the LBW pigs may indicate impairments in glucose tolerance at 56 d. In summary, LBW piglets appear to have more metabolic alterations in early life, which is not resolved with adequate nutrition or refeeding and may elucidate physiological and metabolic mechanisms of poor growth and life performance compared to NBW pigs later in life.

Effects of Oral Glutamine Supplementation, Birthweight and Age on Colonic Morphology and Microbiome Development in Male Suckling Piglets

Mortality, impaired development and metabolic dysfunctions of suckling low-birthweight piglets may be influenced by modulating the intestinal microbiome through glutamine supplementation. Therefore, this study examined whether glutamine supplementation may affect the colonic development and microbiome composition of male low- and normal-birthweight piglets at 5 and 12 days of age. Suckling piglets were supplemented orally with glutamine or alanine. Colonic digesta samples were obtained for 16S rDNA sequencing, determination of bacterial metabolites and histomorphological tissue analyses. Glutamine-supplemented piglets had lower concentrations of cadaverine and spermidine in the colonic digesta (p < 0.05) and a higher number of CD3+ colonic intraepithelial lymphocytes compared to alanine-supplemented piglets (p < 0.05). Low-birthweight piglets were characterised by a lower relative abundance of Firmicutes, the genera Negativibacillus and Faecalibacterium and a higher abundance of Alistipes (p < 0.05). Concentrations of cadaverine and total biogenic amines (p < 0.05) and CD3+ intraepithelial lymphocytes (p < 0.05) were lower in low- compared with normal-birthweight piglets. In comparison to the factor age, glutamine supplementation and birthweight were associated with minor changes in microbial and histological characteristics of the colon, indicating that ontogenetic factors play a more important role in intestinal development.

Effects of oral glutamine supplementation on jejunal morphology, development, and amino acid profiles in male low birth weight suckling piglets

Background

It has been shown that small intestine development in low birth weight (LBW) piglets is impaired. Glutamine (Gln) has been reported to improve piglet health and intestinal function in weaned piglets, but data is scarce in suckling piglets. This study was conducted to investigate the effects of oral Gln supplementation compared to Alanine (Ala) on jejunal development and function in 5 and 12 d old male LBW and normal birth weight (NBW) suckling piglets.

Results

Gln had no effect on the jejunal morphology, development, tissue and digesta amino acid profiles and mRNA abundance of genes involved in amino acid transport, metabolism, glutathione synthesis in LBW piglets when compared to Ala supplementation and birth weight controls at 5 and 12 d. Only the concentration of Gln in jejunal tissue was higher in NBW piglets supplemented with Gln compared to Ala at 5 d (P < 0.05). A comparison of the birth weight groups showed no differences between LBW and NBW piglets at 5 and 12 d in any parameter. Jejunal crypt depth, villus height / width, tunica muscularis thickness, number of goblet and IgA positive cells, the ratio of jejunal RNA to DNA and the concentration of DNA, protein and RNA changed (P < 0.05) from 5 compared to 12 d. The concentrations of several free, and protein bound amino acids as well as amino metabolites differed between age groups in jejunal tissue but the digesta concentrations were affected to a lesser extent.

Conclusions

Oral Gln supplementation to suckling male piglets over the first 12 d of life was not associated with changes in jejunal parameters measured in this study. The absence of effects may indicate that Gln is absorbed as well as metabolized in the upper intestinal tract and thus could benefit intestinal development at a more proximal location.