Gut Microbiome Composition Is Associated with Blood Pressure in Mother-Child Pairs 5 Years After Birth

Abstract

Abstract Objectives Adult studies have indicated that the gut microbiome plays a role in blood pressure regulation, however, there have been no studies on this association in children or mother-child pairs. This study's aim is to determine whether gut microbiome composition is associated with systolic blood pressure (SBP) in children and their mothers 5 years after birth. Methods We obtained stool samples from Canadian mother-child pairs (n = 164 children, 168 mothers) on average 5 years after birth in the prospective Gen3G pre-birth cohort. We characterized the microbiome using 16S rRNA gene sequencing of the V4 region. We categorized SBP (measured automatically, in duplicate) into tertiles separately for mothers and children and used the lowest tertile as the reference group. We fitted beta-binomial regression models to identify differentially abundant (FDR P < 0.05) amplicon sequence variants (ASVs) of bacterial taxa, adjusting for: fruit and vegetable intake (servings/week), current smoking (mothers only), sex (children), and BMI (mothers) or BMI z-score (children). Results Mothers and children were similar across SBP tertiles with respect to all clinical characteristics, except for BMI. Mothers in the highest SBP tertile (113-166 mmHg) had a median BMI of 25.4 vs. the lowest tertile (91-106 mmHg) at 23.1, and children in the highest tertile (104-128 mmHg) had a median BMI z-score of 0.3 vs. the lowest tertile (87-98 mmHg) at -0.1. SBP was not associated with microbial diversity, but was associated with composition. After adjusting for covariates (including BMI), 4 ASVs were differentially abundant in children in the highest vs. lowest SBP tertile. Children with higher SBP had greater % of Bacteroides (sp. unknown), Collinsella (sp. unknown), and Coprococcus catus and lower % of butyrate-producing Lachnospira (sp. unknown). Among mothers, 12 ASVs were differentially abundant in the highest vs. lowest SBP tertile, with higher SBP associated with greater % of Lachnoclostridium symbiosum, a candidate-marker for colon cancer, and lower % of butyrate-producing Eubacterium eligens and Porphyromonadaceae Butyricimonas. Conclusions Altered gut microbiota composition, including lower abundance of butyrate-producing bacteria, is associated with higher blood pressure in both mothers and their children 5 years after birth. Funding Sources NHLBI.