Gut microbiome composition is similar between pregnant women with excess body fat with healthy and less healthy dietary intake patterns.

Dietary composition influences the composition of the gut microbiota in healthy adults. Little is known about the effect of dietary patterns on gut microbiota composition in pregnancy. This cross-sectional study aimed to investigate the associations between two diet quality scores adapted from the Australian Recommended Food Score (ARFS) and the Mediterranean Dietary score (MDS) with the composition of the gut microbiota in pregnant women with excess body fat at 28 weeks' gestation. Women from the Study of Probiotics IN Gestational diabetes (SPRING) who had completed a food frequency questionnaire (n = 395) were classified according to tertiles of ARFS and the MDS. Higher dietary pattern scores in both the ARFS and the MDS represent better diet quality. Gut microbiota composition was assessed using 16S rRNA gene amplicon sequencing and analysed using Microbiome Analyst in a subset of 196 women with faecal samples. No significant difference was found in alpha or beta diversity. A higher ARFS was associated with a greater Ruminococcus abundance and decreased abundance of Akkermansia, whilst a higher MDS was associated with a higher abundance of Ruminococcus and Butyricicoccus though these changes disappeared after correction for multiple testing. These results suggest that dietary patterns defined by the ARFS and MDS were not associated with gut microbiota composition in pregnant women classified as overweight and obese at 28 weeks gestation within this study. This article is protected by copyright. All rights reserved.