Poster Presentation Women's Health Forum 2021

Decreased short chain fatty acid-producing bacteria in women with future preeclampsia (#53)

Faisal Altemani 1 , Helen Barrett 2 , Leonie Callaway 3 4 , David McIntyre 3 , Mark Morrison 5 , Gene Tyson 6 , Marloes Dekker Nitert 1
  1. School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
  2. Mater Medical Research Institute, South Brisbane, QLD, Australia
  3. School of Medicine, The University of Queensland, Herston, QLD, Australia
  4. Women's and Newborns, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
  5. Diamantina Institute, The University of Queensland, Woolongabba, QLD, Australia
  6. School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia

BACKGROUND: The human gut microbiota plays an important role in human health and alterations in human gut microbiota community are associated with hypertension, metabolic abnormalities and systemic inflammation. Preeclampsia (PE) is a pregnancy-specific disorder that is characterised by severe hypertension and proteinuria and is associated with maternal morbidity and mortality. It is unclear if the gut microbiota is already altered before women develop PE (DPE) later in pregnancy.

METHODS: The gut microbiome community of 10 pregnant DPE women and 24 controls was analysed in the first trimester (T1) and third trimester (T3) by metagenomics shotgun sequencing in samples obtained from pregnant participants in the SPRING cohort (Study of Probiotics IN gestational diabetes). Taxonomical and functional gene profiles were investigated and serum short chain fatty acids (SCFA) measured with LC-MS.

RESULTS: Taxonomical analysis at T1 and T3 revealed decreased abundance of SCFA-producing bacteria in DPE women including the genera Coprococcus and Ruminococcus and increased abundance of sulphate-reducing bacteria of the Desulfovibrio genus compared to matched pregnant controls. Functional analysis showed the gut microbiota in the group of women with DPE had significantly higher abundance of Lipopolysaccharide (LPS), Insulin and Glycolysis/gluconeogenesis signalling pathways at T1 and of Folate biosynthesis and Glycolysis/gluconeogenesis pathways at T3 as compared to controls. The levels of circulating butyrate were reduced in the DPE group.

DISCUSSION: These findings suggest that women in the DPE group display an altered microbial community particularly with reduced SCFA-producers and increased sulfate producers and reduced circulating butyrate prior to the development of overt symptoms. The Desulfovibrio genus is known to reduce sulfate to hydrogen sulfide (H2S). H2S inhibits the oxidization of the SCFA-butyrate in colonocytes. A decrease in luminal SCFA concentration may cause impaired gut wall barrier function leading to inflammation which might contribute to the development of PE.