Sialylated milk oligosaccharides alter neurotransmitters and brain metabolites in piglets: an In vivo magnetic resonance spectroscopic (MRS) study

ABSTRACT

Background: Human milk contains high concentrations and diversity of sialylated oligosaccharides that have multifunctional health benefits, however, their potential role in optimizing neurodevelopment remains unknown.

Objective: To investigate the effect of sialylated milk oligosaccharides (SMOS) intervention on neurotransmitters and brain metabolites in piglets.

Methods: 3-day-old piglets were randomly allocated to one of three groups and fed either standard sow milk replacer (SMR) alone (n = 15), SMR supplemented with sialyllactose 9.5 g/kg (SL, n = 16) or a combination of SL and 6′-sialyllactosamine 9.5 g/kg (SL/SLN, n = 15) for 35 days. Brain spectra were acquired using a 3T Magnetic Resonance Spectroscopic (MRS) system.

Results: SMOS fed piglets were observed to have significantly increased the absolute levels of myo-inositol (mIns) and glutamate + glutamine (Glx), in particular, the SL/SLN group. Similar findings were found in the relative amount of these metabolites calculated as ratios to creatine (Cr), choline (Cho) and N-acetylaspartate (NAA) respectively (P < .05). In addition, there were significant positive correlations of brain NAA, total NAA (TNAA), mIns, total Cho (TCho), total Cr (TCr), scyllo-Inositol (SI) and glutathione (Glth) with total white matter volume; Glu and SI with whole brain volume; and SI with whole brain weight respectively (P < .01). SLN and 3′SL intake were closely correlated with the levels of brain Glu, mlns and Glx in the treatment groups only (P < .01–.05).

Conclusions: We provide in vivo evidences that milk SMOS can alter many important brain metabolites and neurotransmitters required for optimizing neurodevelopment in piglets, an animal model of human infants.

KEYWORDS:

• 3′ and 6′-sialyllactose
• 6′-sialyllactosamine
• brain metabolites
• MRS
• sialylated milk oligosaccharides
• neurodevelopment
• piglet

Acknowledgments

We greatly acknowledge Dr. Chao Suo from Brain & Mental Health laboratory, Monash University for his advice in MRS acquisitions and data analysis; Mr. Richard McIntryre from Monash Biomedical Imaging, Monash University for his assistance with MRS data acquisitions and Dr. Leah Bradbury, a registered specialist veterinary anaesthetist for her assistance with pig anaesthesia.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by a research grant from Fonterra Co-Operative Group (NZ) and New Zealand Ministry of Primary Industry (Primary Growth Partnership Program). The study design, data collection, data analysis and interpretation of results were made independently from Fonterra.

Notes on contributors

Hong Xin Wang

Hong Xin Wang collected the MRI&MRS data, performed data analysis, interpretation and produced the initial draft of the manuscript.

Yue Chen

Yue Chen was involved with data collection, animal husbandry and the initial draft of the tables and figures.

Ziaul Haque

Ziaul Haque was involved in data collection and animal feeding.

Michael de Veer

Michael de Veer as involved in data collection of MRI&MRS and manuscript editing.

Gary Egan

Gary Egan performed data analysis and data interpretation of MRI&MRS study and reviewed the manuscript.

Bing Wang

Bing Wang conceptualized and designed the study, analysed and interpreted the results, and was responsible for writing of the manuscript. All authors have read and approved the manuscript.