A High-Fiber Diet Intervention Improves Diet Quality and Is Related to Blood Pressure and Bacteriome Composition in Caregiver-Child Dyads

Abstract

ObjectivesHigh-fiber dietary patterns are associated with cardiovascular health and intestinal microbiome composition. Caregivers influence diets of children, affecting dyadic health and microbiomes. The objectives of this study were to evaluate the relationship between changes in caregiver diet quality and caregiver and child: 1) systolic blood pressure (SBP) and 2) fecal bacteriome composition. MethodsCaregiver-child (age 8–9 years) dyads were randomized to either a 10-week high-fiber diet intervention (fruits, vegetables, and whole grains) or control. Caregiver diet quality (30-day FFQs and Healthy Eating Index (HEI)), and caregiver and child SBP and fecal samples were collected pre- and post-intervention. Fecal bacteriomes were analyzed via 16S rRNA gene amplicon sequencing. HEI and SBP were tested via 2-way ANOVA. Bacteriome differentials (i.e., ratio of amplicon sequence variants (ASVs) with related relative abundances) associated with HEI were identified via Songbird and Qurro. Caregiver HEI was used to guide differential assembly in caregiver bacteriomes and as a proxy for child diet quality to guide differential assembly in child bacteriomes. Pearson correlations assessed inter-data relationships. ResultsComplete data were collected from 19 caregivers and 16 children. Intervention caregivers increased total (T) HEI (+4.4 vs – 1.7 points, P = 0.047) and whole grain (WG) HEI component scores (+1.7 vs 0 points, P = 0.014) compared to control. WG-HEI was correlated with caregiver SBP (r = –0.37, P = 0.046). T-HEI was correlated with caregiver and child T-HEI bacteriome differentials (r = 0.36, P = 0.027 and r = 0.57, P = 0.001). WG-HEI correlated with caregiver and child WG-HEI bacteriome differentials (r = 0.45, P = 0.013 and r = 0.60, P < 0.001). Child WG-HEI differential correlated with child SBP (r = –0.46, P = 0.01). Five ASVs were shared between caregiver and child T-HEI bacteriome differentials, implying shared bacterial responses to intervention. ConclusionsA high-fiber dietary intervention positively impacts diet quality and is related to changes in SBP and bacteriome composition in caregiver-child dyads. Metabolites derived from bacterial metabolism of dietary fiber should be investigated for their role in blood pressure. Funding SourcesUSDA NIFA, Nationwide Children’s Hospital.