New Insights into Porcine Milk N-Glycome and the Potential Relation with Offspring Gut Microbiome.

N-Glycans are an important source of milk oligosaccharides. In addition to free oligosaccharides found in milk, N-glycans can also be utilized by gut microbes. A potential for milk N-glycans to act as gut microbe regulators in suckling animals has attracted considerable attention; however, sow milk N-glycans and their potential effects upon the piglet's gut microbes in vivo remain unknown. In the present study, we profiled the milk N-glycans of Meishan and Yorkshire sows during lactation using UPLC and a mass spectrometry-based glycome method, and we explored the correlations between milk N-glycans and offspring gut microbiota. Twenty-two N-glycan structures were identified in sow milk, among which 36% (8 out of 22) were fucosylated, 41% (9 out of 22) were sialylated, and 14% (3 out of 22) were high mannosylated. An N-glycan with a NeuGc structure (namely PNO20, GlcNAc4-Man3-Gal2-Fuc-Neu5Gc) was identified in sow milk for the first time. No compositional differences between the two breeds or between different lactation times were found in porcine milk N-linked oligosaccharides (PNOs); however, the abundances of different structures within this class did vary. The relative abundances of fucosylated PNO3 (GlcNAc4-Man3-Fuc) and sialylated PNO18 (GlcNAc4-Man3-Gal2-NeuAc) increased during lactation, and Meishan sows demonstrated a higher ( P < 0.05) abundance of mannosylated PNO10 (GlcNAc2-Man6) and sialylated PNO17 (GlcNAc5-Man3-Gal-NeuAc) than Yorkshire sows. Apparent correlations between milk N-glycans and offspring gut microbial populations were found; for example, mannosylated PNO21 (GlcNAc2-Man9) was positively correlated with OTU706 ( Lactobacillus amylovorus) and OTU1380 ( Bacteroides uniformis). Overall, our results indicate that the milk N-glycome of Meishan and Yorkshire sows differs in N-glycome characteristics and that this is correlated to abundances of certain piglet gut microbes. These findings provide a reference for future elucidation of the involvement of gut microbes in milk N-glycan metabolism, which is important to the health both of large domestic animals and humans.

Age, introduction of solid feed and weaning are more important determinants of gut bacterial succession in piglets than breed and nursing mother as revealed by a reciprocal cross-fostering model.

A reciprocal cross-fostering model with an obese typical Chinese piglet breed and a lean Western breed was used to identify genetic and maternal effects on the acquisition and development gut bacteria from birth until after weaning. Pyrosequencing of 16S rRNA genes results revealed an age- and diet-dependent bacterial succession process in piglets. During the first 3 days after birth, the bacterial community was relatively simple and dominated by Firmicutes with 79% and 65% relative abundance for Meishan and Yorkshire piglets, respectively. During the suckling period until day 14, the piglet breed and the nursing mother lead to increasing differentiation of the fecal bacterial community, with specific bacteria taxa associated with breed, and others with the nursing sow most likely due to its milk composition. Although the effect of nursing mother and the breed were evident through the suckling period, the introduction of solid feed and subsequent weaning were the major events occurring that dominated succession of the gut microbiota in the early life of piglets. This piglet cross-fostering model is a useful tool for studying the effects of diet, host genetics and the environment on the development and acquisition of the gut microbiota and over longer studies the subsequent impact on growth, health and performance of pigs.

[Influences of maternal and external environment on the early establishment of gastrointestinal microflora of neonatal baby--a review].

The human intestinal microbiota is essential in nutrients utilization, organ development, host metabolism, pathogen resistance, and regulation of immune responses. The establishment of early gut microflora in newborn infants experiences periods from less to more, simple to complex and unstable to stable and can be influenced by various factors. This article summarizes the effects of delivery mode, delivery period, rearing methods as well as antibiotics on the development of intestinal bacterial community.

Comparisons of blood biochemical parameters, digestive enzyme activities and volatile fatty acid profile between Meishan and Yorkshire piglets.

This study was conducted to compare physiological characteristics between Meishan and Yorkshire piglets in their early lives. Six healthy purebred Meishan sows and Yorkshire sows with close farrowing dates were used in this research. The piglets sucked their respective sow's milk for 14 days, then they were slaughtered to collect samples of blood, pancreas, contents of stomach, jejunum, cecum, colon as well as feces for analysis of blood biochemical parameters, digestive enzymes, and volatile fatty acid (VFA). The results showed that Yorkshire piglets had higher concentrations of high-density lipoprotein cholesterol (HDL-C) and total cholesterol (TC) (P < 0.05). Gastric lipase activity was higher in Meishan piglets but Yorkshire piglets had higher lactase activity (P < 0.05). The total VFA together with acetate and propionate in cecum and colon were higher in Meishan piglets than in Yorkshire piglets (P < 0.05), but acetate in jejunum and ratio of acetate to propionate in colon were lower in Meishan piglets than in Yorkshire piglets (P < 0.05). In conclusion, in early suckling period, significant differences exist in host metabolism and intestinal microbial metabolism between Meishan and Yorkshire piglets.