A randomized controlled trial of the effects of whole grains versus refined grains diets on the microbiome in pregnancy.

Haipeng Sun, Pamella Yamada, Alexandra Paetow, Michael Chan, Alan Arslan, Rikard Landberg, Maria Gloria Dominguez-Bello, Bruce K Young

Journal: Scientific reports 2022;12(1):7509

PMID: 35525865

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Plain Language Summary

The whole grain content of the carbohydrates consumed in pregnancy has been considered to influence outcomes such as maternal weight gain, large for date infants and childhood obesity. The aim of this study was to evaluate the effects of a diet with different proportions of total carbohydrates, as either 75% refined grains or 75% whole grains, on pregnancy associated changes in the maternal microbiome and pregnancy outcomes. This study is a randomised interventional study which enrolled 303 pregnant women in their first and second gestational trimester. The mother was followed throughout her pregnancy and postpartum. Participants were randomly assigned to one of the two groups: refined vs whole grains. Results did not show any significant difference between the two diets (whole grains vs refined grains) in relation to intestinal microbiome. However, it marginally affected the gestational dynamics of the vaginal microbiome. In the whole grains diet group, there was a trend of reduced vaginal alpha diversity, during gestation, while in the refined grains group, vaginal diversity remained stable. Authors conclude that diet modulations of the vaginal microbiome during gestation may have important implications for maternal and neonatal health and in the intergenerational transfer of maternal microbiome.

Abstract

Dietary whole grain consumption has been postulated to have metabolic benefits. The purpose of this study was to compare a pregnancy diet containing 75% of total carbohydrates as refined grains with a diet of 75% of total carbohydrates as whole grains for pregnancy outcomes and effects on the microbiome. Gestational weight gain, glucose tolerance and newborn outcomes were measured on 248 enrolled compliant women from whom a subset of 103 women consented to give 108 vaginal and 109 anal swabs. The data presented here are limited to the patients from whom the vaginal and anal swabs were obtained in order to study the microbiome. A microbiome-16SrRNA survey-was characterized in these samples. Samples and measurements were obtained at the first obstetrical visit, before beginning a prescribed diet (T1-baseline) and after 17-32 weeks on the prescribed diet (T3). Food frequency questionnaires and total plasma alkylresorcinols were used as a measure of whole grain consumption. There were no dietary differences in maternal weight gain, birth weight, or glucose tolerance test. Mothers consuming the whole grains diet showed a trend of gestational decrease in vaginal bacterial alpha diversity, with increasing Lactobacillus-dominance. No significant difference was observed for the anal microbiome. The results suggest that diet modulations of the vaginal microbiome during gestation may have important implications for maternal and neonatal health and in the intergenerational transfer of maternal microbiome. Trial registration: ClinicalTrials.gov Identifier: NCT03232762.

Address: Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, USA.; Department of Obstetrics and Gynecology, New York University Langone Health, 462 First Avenue, Building D, Room 572, New York, NY, 10016, USA.; Division of Food and Nutrition Science (RL), Department of Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.; Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, USA.; Department of Anthropology, Rutgers University, New Brunswick, USA.; Institute of Food, Nutrition, and Health, Rutgers University, New Brunswick, USA.; Department of Obstetrics and Gynecology, New York University Langone Health, 462 First Avenue, Building D, Room 572, New York, NY, 10016, USA. [email protected].

DOI: 10.1038/s41598-022-11571-4