Role of human milk oligosaccharides in Group B Streptococcus colonisation

14 October 2016
Group B Streptococcus (GBS) infection is a major cause of morbidity and mortality in infants. The major risk factor for GBS disease is maternal and later infant colonisation. It is well established that breastfeeding is important for neonatal health: research has already shown that it decreases infant susceptibility to gastrointestinal and respiratory tract infections.

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A mother breastfeeding her infant outside her house

Whether particular ingredients of human breastmilk can play a specific role in protection against certain bacteria would be important to find out, as this might open up areas for intervention.We therefore investigated whether human milk oligosaccharides (HMOs) protect against GBS colonisation, by studying the association between HMOs and infant GBS colonisation between birth and postnatal day 90. The study was conducted at MRC Unit The Gambia, lead by Professor Beate Kampmann (Theme Leader Vaccines and Immunity) in collaboration with Dr Kirsty LeDoare and Dr Nick Andreas at Imperial College Biomedical Research Centre. The study was jointly funded by a Wellcome Trust Clinical Research Training Fellowship, the Medical Research Council and the NIHR-funded biomedical research centre at Imperial College, in collaboration with the Al Thrasher Foundation.

This study was nested in a larger study in The Gambia where rectovaginal swabs were collected at delivery, as well as colostrum/breast milk, infant nasopharyngeal and rectal swabs at birth, 6 days and days 60–89 postpartum from 750 Gambian mother/infant pairs. GBS colonisation and serotypes were determined using culture and PCR. H nuclear magnetic resonance spectroscopy was used to characterise the mother’s Lewis phenotype status, which is associated with the mother’s blood group and also determines HMO profile in breast milk.

Our research shows that the Lewis phenotype and its related HMOs in breast milk are strongly associated with inhibition of GBS colonisation in the mother and a reduced risk of transmission to the infant. In addition, the study also indicates a possible role for specific HMOs in the prevention and clearance of maternal GBS colonisation during pregnancy.

By reducing the burden of maternal, and thus infant, colonisation, HMOs added to breastmilk may be a low cost, non-invasive first step in reducing the burden of neonatal GBS disease globally, and future studies are ongoing.

Professor Beate Kampmann, Theme Leader, Vaccines and Immunity said, “This work is based on our GBS project in The Gambia and has led to a new discovery by applying very advanced technologies available through Imperial College- it is a perfect example of what our “Open Lab” approach can deliver, where our science can combine the best methodologies in north and south. I thank Dr LeDoare, Dr Andreas and the team for maximizing the scientific output from the GBS project, as we try to develop novel interventions to protect babies against this lethal bug.”

Acknowledgement

We thank the study participants, field workers, laboratory staff of MRCG and the Imperial College Biomedical Research Centre (BRC) for supporting our work. We also thank the staff at the Clinical Phenome Centre at Imperial College London, for the spectroscopy analysis.

Author

Nicholas J Andreas, Asmaa Al-Khalidi, Mustapha Jaiteh, Edward Clarke, Matthew J Hyde, Neena Modi, Elaine Holmes, Beate Kampmann, Kirsty Mehring Le Doare

Read more about the study on the PubMed Central website

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5007626/