Ms Min Yan1, Associate Professor Helen Barrett2, Ms Grace Murphy1, Ms Hui Ting Ng1, Dr Helen Tanner3, Professor David McIntyre4, Professor Leonie Callaway3, A/Prof. Marloes Dekker Nitert1
1The University Of Queensland, St Lucia, Australia, 2The University of New South Wales, Randwick, Australia, 3Women's and Newborns, RBWH, Herston, Australia, 4Mater Research Institute-The University of Queensland, South Brisbane, Australia
Biography:
Associate Professor Dekker Nitert is a teaching and research academic in metabolism at the School of Chemistry and Molecular Biosciences. Her research focuses on the interactions between the gut microbiome and cardiometabolic health parameters in healthy pregnancies and pregnancy with adverse pregnancy outcomes.
Abstract:
Background: Maternal circulating ketone levels, while low, are highly variable between women and not correlated with habitual carbohydrate intake. The maternal gut microbiota could contribute to the regulation of ketogenesis through bacterial metabolites affecting maternal adipocyte metabolism. This study compared the gut microbiota in women with lower and higher circulating β-hydroxybutyrate (B-OHB) concentrations.
Methods: In 90 participants of the Study of PRobiotics in Gestational Diabetes (SPRING), divided by having ≤65 or >65 μmol/L circulating B-OHB at 28 weeks’ gestation, gut microbiota composition at 28 weeks’ gestation was analysed by 16S rRNA sequencing using α- and β-diversity parameters using the VEGAN package in R. Taxonomy difference of the gut microbiota at genus level were compared using LEfSE analysis. Given the large variability in carbohydrate intake in the women, the effect of carbohydrate intake on the composition of the gut microbiota was also analysed.
Results: 48 women had low B-OHB concentrations (mean (SD) 36.1 (21.7) μmol/L) and 42 women had high B-OHB concentrations (mean (SD) =139.0 (67.8) μmol/L). There were no differences in the ⍺ and β-diversity nor in the abundance of different genera between the groups. When the gut microbiota was compared in women with low carbohydrate intake (n=44, mean (SD) 123 (36) g/day) and high carbohydrate intake (n=46, (mean (SD) 204 (49) g/day), no differences in α and β diversity were identified. The Lachnospiraceae family were more abundant in the low carbohydrate group (P = 0.03).
Conclusion: Gut microbiota composition is not altered in women with lower or higher circulating ketones. Similarly, maternal carbohydrate intake was not associated with large differences to the gut microbiota. This suggests that the gut microbiota in pregnancy does not regulate ketogenesis and is not determined by carbohydrate intake.
Keywords
ketones, carbohydrates, gut microbiota,