Progressive Changes in the Plasma Metabolome during Malnutrition in Juvenile Pigs

Severe acute malnutrition (SAM) is one of the leading nutrition-related causes of death in children under five years of age. The clinical features of SAM are well documented, but a comprehensive understanding of the development from a normal physiological state to SAM is lacking. Characterizing the temporal metabolomic change may help to understand the disease progression and to define nutritional rehabilitation strategies. Using a piglet model we hypothesized that a progressing degree of malnutrition induces marked plasma metabolite changes. Four-week-old weaned pigs were fed a nutrient-deficient maize diet (MAL) or nutritionally optimized reference diet (REF) for 7 weeks. Plasma collected weekly was subjected to LC-MS for a nontargeted profiling of metabolites with abundance differentiation. The MAL pigs showed markedly reduced body-weight gain and lean-mass proportion relative to the REF pigs. Levels of eight essential and four nonessential amino acids showed a time-dependent deviation in the MAL pigs from that in the REF. Choline metabolites and gut microbiomic metabolites generally showed higher abundance in the MAL pigs. The results demonstrated that young malnourished pigs had a profoundly perturbed metabolism, and this provides basic knowledge about metabolic changes during malnourishment, which may be of help in designing targeted therapeutic foods for refeeding malnourished children

Antibiotic Treatment Preventing Necrotising Enterocolitis Alters Urinary and Plasma Metabolomes in Preterm Pigs

Necrotising enterocolitis (NEC) is a serious gut inflammatory condition in premature neonates, onset and development of which depend on the gut microbiome. Attenuation of the gut microbiome by antibiotics can reduce NEC incidence and severity. However, how the antibiotics-suppressed gut microbiome affects the whole-body metabolism in NEC-sensitive premature neonates is unknown. In formula-fed preterm pigs, used as a model for preterm infants, plasma and urinary metabolomes were investigated by LC–MS and ¹H NMR, with and without antibiotic treatment immediately after birth. While it reduced the gut microbiome density and NEC lesions as previously reported, the antibiotic treatment employed in the current study affected the abundance of 44 metabolites in different metabolic pathways. In antibiotics-treated pigs, tryptophan metabolism favored the kynurenine pathway, relative to the serotonin pathway, as shown by specific metabolites. Metabolites associated with the gut microbiome, including 3-phenyllactic acid, 4-hydroxyphenylacetic acid, and phenylacetylglycine, all from phenylalanine, and three bile acids showed lower levels in the antibiotics-treated pigs where the gut microbiome was extensively attenuated. Findings in the current study warrant further investigation of metabolic and developmental consequences of antibiotic treatment in preterm neonates

Western-blot.

<p><b><i>Panel A</i></b>: Laminin receptor. <b><i>Panel B:</i></b> pyrophosphatase 1. <b><i>Panel C:</i></b> HSPB1. <b><i>Panel D:</i></b> haptoglobin. Expression levels are presented as mean±SEM. * p<0.05 in AB <i>vs</i> untreated pigs.</p

Intestinal proteins identified with differential expression between the AB and the untreated pigs (p<0.05).

a<p>Spot number consistent with those indicated in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044929#pone-0044929-g003" target="_blank"><b>Figure 3</b></a>.</p>b<p>GI ID: Genbank identifier.</p>c<p>Protein score indicating the confidence of identification.</p>d<p>Expression quantity defined as the sum of optical density for each pixel of spot area (mean ± SEM, ×10⁴).</p

Intestinal proteins identified with differential expression between the AB and the untreated pigs (p<0.05).

a<p>Spot number consistent with those indicated in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044929#pone-0044929-g003" target="_blank"><b>Figure 3</b></a>.</p>b<p>GI ID: Genbank identifier.</p>c<p>Protein score indicating the confidence of identification.</p>d<p>Expression quantity defined as the sum of optical density for each pixel of spot area (mean ± SEM, ×10⁴).</p

Small intestine weight, mucosa weight, villus height, crypt depth and enzymatic activities of ApN and ApA. Data are presented as mean±SEM.

<p>** p<0.01 in AB <i>vs</i> untreated pigs.</p

2-DE proteome graphs of the mid small intestine and blood plasma.

<p><b><i>Panel</i></b><i> </i><b><i>A</i></b><i>:</i> small intestine, untreated; <b><i>Panel B</i></b>, small intestine, AB; <b><i>Panel C</i></b>, plasma, untreated; <b><i>Panel D</i></b>, plasma, AB. Spot number was assigned by the analysis software and correlated with the ones presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044929#pone-0044929-t001" target="_blank"><b>Tables 1</b></a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044929#pone-0044929-t002" target="_blank"><b>2</b></a>.</p

Changes in serum phosphate in malnourished piglets refed with either CSB+ (n = 9), CSB+/wp (n = 9) or CSB++ (n = 10) or continuously malnourished (REF, n = 8) for 3 weeks.

<p>Values are mean (95% CI). Repeated measurement analysis was used to calculate the effects of diet (P diet), time (P time) and their interaction (P diet-time). The diet-time interaction was significant (P <0.01).</p

Corn-Soy-Blend Fortified with Phosphorus to Prevent Refeeding Hypophosphatemia in Undernourished Piglets - Fig 1

<p>Changes in body weight (A) and supine length (B) in malnourished piglets refed with either CSB+ (n = 9), CSB+/wp (n = 9) or CSB++ (n = 10) or continuously malnourished (REF, n = 8) for 3 weeks. Values are mean (95% CI). Repeated measurement analysis was used to calculate the effects of diet (P diet), time (P time) and their interaction (P diet-time). The diet-time interaction was significant (P<0.001) for the weight increment. There was an effect of time and diet on the increment in supine length (P diet <0.01, P time <0.001). The data were log-transformed prior to analysis.</p

Compositions of reference and the 3 refeeding diets¹.

<p>Compositions of reference and the 3 refeeding diets<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0170043#t001fn001" target="_blank">¹</a>.</p