Oral Presentation Society of Obstetric Medicine of Australia and New Zealand and Australasian Diabetes in Pregnancy Society Joint Scientific Meeting 2017

A low-fibre diet influences Collinsella abundance in the gut microbiome and alters maternal metabolism at 16 weeks gestation (#9)

Luisa F Gomez Arango 1 , Helen L Barrett 1 2 , Shelley Wilkinson 3 , Leonie K Callaway 1 2 , David McIntyre 3 4 , Mark Morrison 5 , Marloes Dekker Nitert 1 6 7
  1. UQ Centre for Clinical Research, The University of Queensland, Herston, QLD, Australia
  2. Obstetric Medicine, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
  3. Obstetric Medicine, Mater Health Services, South Brisbane, QLD, Australia
  4. School of Medicine, The University of Queensland, Herston, QLD, Australia
  5. Diamantina Institute, The University of Queensland, Woolongabba, QLD, Australia
  6. School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
  7. University of Queensland, St Lucia, QLD, Australia

Background: The gut microbiota has recently been identified as a regulator of glucose metabolism in early pregnancy. We have reported a positive correlation between circulating insulin and genus Collinsella, although the factors dictating its abundance in the gut are unknown. Here, we aimed to validate the observed microbial-hormonal association and to determine if maternal diet plays a role in Collinsella abundance at 16 weeks gestation.

Methods: Gut microbiome profiles from 57 overweight and 73 obese pregnant women were assessed by 16S rRNA sequencing. Fasting insulin and macronutrient intake were correlated with 16S Collinsella counts. Participants were classified based on fibre intake (low: 13.8(12.1-16.1), high: 21.6(19.4-26.2) grams/day) and differences in microbial structure were analysed.

Results: Insulin levels were positively associated with Collinsella abundance (rho=0.30, p=0.0006), independent of maternal BMI. Of all dietary components, fibre was negatively associated with Collinsella abundance (rho=-0.19, p=0.025). Women with low fibre intake harboured more Collinsella counts and more lactate-producing bacteria. Higher fibre intake was associated with lower Collinsella abundance and enrichment of beneficial short-chain fatty acid producers.

Conclusion: This study validates the Collinsella-insulin association at early pregnancy. Low fibre intake may promote Collinsella overgrowth and overall changes in the gut microbiota composition affecting maternal metabolism.