The composition of porcine milk oligosaccharides (PMO) was analyzed during early lactation and their relation to piglet gut microbiome was investigated. Pigs are considered ideal intestinal models to simulate humans because of the striking similarity in intestinal physiopathology to humans. The evolution of PMO was investigated in the milk from 3 healthy sows at prefarrowing, farrowing, and d 7 and 14 postpartum by Nano-LC Chip Quadrupole-Time-of-Flight mass spectrometer (Agilent Technologies, Santa Clara, CA). Previously sequenced metagenome libraries were reanalyzed to examine changes with specific gut bacterial populations. Over 30 oligosaccharides (OS) were identified in the milk, with 3′-sialyllactose, lacto-N-tetraose, α1–3,β1–4-d-galactotriose, 2′-fucosyllactose, and 6′-sialyllactose being the most abundant species (accounting for ~70% of the total OS). Porcine milk had lower OS diversity (number of unique structures) than human milk, and appeared closer to bovine and caprine milk. In agreement with previous studies, only 3 fucosylated OS were identified. Surprisingly, their contribution to total OS abundance was greater than in bovine milk (9 vs. 1%). Indeed, fucosylated PMO increased during lactation, mirroring a similar trend observed for neutral and type I OS content during early lactation. Taken together, these results suggest that, in terms of abundance, PMO are closer to human milk than other domestic species, such as bovine and caprine milks. Metagenomic sequencing revealed that fucose-consuming bacterial taxa in the gut microbiota of piglets were qualitatively but not quantitatively different between nursing and weaning stages, suggesting that both the composition and structure of dietary glycans may play a critical role in shaping the distal gut microbiome. The similarity of both intestinal physiopathology and milk OS composition in human and porcine species suggests similar effects on gastrointestinal development of early nutrition, reinforcing the use of the pig intestinal model to simulate human intestinal models in the clinical setting.

A detailed qualitative and quantitative characterization of goat colostrum oligosaccharides (GCO) has been carried out for the first time. Defatted and deproteinized colostrum samples, previously treated by size exclusion chromatography (SEC) to remove lactose, were analyzed by nanoflow liquid chromatography-quadrupole-time of flight mass spectrometry (Nano-LC-Chip-Q-TOF MS). Up to 78 oligosaccharides containing hexose, hexosamine, fucose, N-acetylneuraminic acid or N-glycolylneuraminic acid monomeric units were identified in the samples, some of them detected for the first time in goat colostra. As a second step, a hydrophilic interaction liquid chromatography coupled to mass spectrometry (HILIC-MS) methodology was developed for the separation and quantitation of the main GCO, both acidic and neutral carbohydrates. Among other experimental chromatographic conditions, mobile phase additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry of target carbohydrates. Narrow peaks (wh: 0.2–0.6 min) and good symmetry (As: 0.8–1.4) were obtained for GCO using an acetonitrile:water gradient with 0.1% ammonium hydroxide at 40 °C. These conditions were selected to quantify the main oligosaccharides in goat colostrum samples. Values ranging from 140 to 315 mg L−1 for neutral oligosaccharides and from 83 to 251 mg L−1 for acidic oligosaccharides were found. The combination of both techniques resulted to be useful to achieve a comprehensive characterization of GCO.

BackgroundMilk oligosaccharides (OSs) are bioactive components known to influence neonatal development. These compounds have specific physiological functions acting as prebiotics, immune system modulators, and enhancing intestine and brain development.ObjectivesThe pig is a commonly used model for studying human nutrition, and there is interest in quantifying OS composition of porcine milk across lactation compared with human milk. In this study, we hypothesized that OS and sialic acid (SA) composition of porcine milk would be influenced by stage of lactation.MethodsUp to 250 mL of milk were collected from seven sows at each of three time points: day 0 (colostrum), days 7–9 (mature), and days 17–19 (weaning). Colostrum was collected within 6 h of farrowing and 3-day intervals were used for mature and weaning milk to ensure representative sampling. Milk samples were analyzed for OS profiles by Nano-LC Chip–QTOF MS, OS concentrations via HPAEC-PAD, and SA (total and free) was assessed by enzymatic reaction fluorescence detection.ResultsSixty unique OSs were identified in porcine milk. Neutral OSs were the most abundant at each lactation stage (69–81%), followed by acidic-sialylated OSs (16–29%) and neutral-fucosylated OSs (2–4%). As lactation progressed, acidic OSs decreased (P = 0.003), whereas neutral-fucosylated (P < 0.001) and neutral OSs (P = 0.003) increased throughout lactation. Six OSs were present in all samples analyzed across lactation [lacto-N-difucohexaose I (LNDFH-I), 2′-fucosyllactose (2′-FL), lacto-N-fucopentaose I (LNFP-I), lacto-N-neohexaose (LNnH), α1-3,β-4-d-galactotriose (3-Hex), 3′-sialyllactose (3′-SL)], while LDFT was present only in colostrum samples. Analysis of individual OS concentrations indicated differences (P = 0.023) between days 0 and 7. Conversely, between days 7 and 18, OS concentrations remained stable with only LNnH (P < 0.001) and LNDFH-I (P = 0.002) decreasing over this period. Analysis of free SA indicated a decrease (P < 0.001) as lactation progressed, while bound (P < 0.001) and total (P < 0.001) SA increased across lactation.ConclusionConcentrations of OS differ between colostrum and mature milk in the pig, and SA concentrations shift from free to bound forms as lactation progresses. Our results suggest that although porcine milk OS concentration and the number of structures is lower than human milk, the OS profile appears to be closer to human milk rather than to bovine milk, based on previously published profiles.

No abstract

No abstract