Educational intervention improves fruit and vegetable intake in young adults with metabolic syndrome components

Abstract

The FRUVEDomics study investigates the effect of a diet intervention focused on increasing fruit and vegetable intake on the gut microbiome and cardiovascular health of young adults with/at risk for metabolic syndrome (MetS). It was hypothesized that the recommended diet would result in metabolic and gut microbiome changes. The 9-week dietary intervention adhered to the US Department of Agriculture Dietary Guidelines for Americans and focused on increasing fruit and vegetable intake to equal half of the diet. Seventeen eligible young adults with/or at high risk of MetS consented and completed preintervention and postintervention measurements, including anthropometric, body composition, cardiovascular, complete blood lipid panel, and collection of stool sample for microbial analysis. Participants attended weekly consultations to assess food logs, food receipts, and adherence to the diet. Following intention-to-treat guidelines, all 17 individuals were included in the dietary, clinical, and anthropometric analysis. Fruit and vegetable intake increased from 1.6 to 3.4 cups of fruits and vegetables (P < .001) daily. Total fiber (P = .02) and insoluble fiber (P < .0001) also increased. Clinical laboratory changes included an increase in sodium (P = .0006) and low-density lipoprotein cholesterol (P = .04). In the fecal microbiome, Erysipelotrichaceae (phylum Firmicutes) decreased (log2 fold change: -1.78, P = .01) and Caulobacteraceae (phylum Proteobacteria) increased (log2 fold change = 1.07, P = .01). Implementing a free-living 9-week diet, with intensive education and accountability, gave young adults at high risk for/or diagnosed with MetS the knowledge, skills, and feedback to improve diet. To yield greater impact, a longer diet intervention may be needed in this population.

Keywords: Fruits and vegetables; Healthy diet; Metabolic syndrome; MyPlate diet; Young adults.

Fig. 1 -

Consort diagram depicting the flow of participants from recruitment to statistical analysis. Prescreening determined risk of MetS, then the in-person clinical screen where participants were screened for the 5 different components of MetS according to the NCEP-ATP III. Nineteen individuals then consented to participate, but 2 never began the intervention. This left a total of 17 individuals who started and completed the study.

Fig. 2 -

Effect of intervention and covariates on microbiome in 12 adult subjects. In GLM analysis, differences in 2 families between preintervention and postintervention were detected. A, Specifically, Erysipelotrichaceae (phylum Firmicutes) decreased (Log₂ fold change: −1.78, p = .01) and so was about 0.29 of the values before intervention, and Caulobacteraceae (phylum Proteobacteria) increased (Log₂ fold change = 1.07, p = .01), corresponding to 2.1 times higher abundance after the intervention. Analysis of covariance microbiome depicted relationship of the covariates (dietary or anthropometric, mostly continuous variables) on specific OTU. B, Specifically, increasing dietary fat percent inversely affected proportion of family Lachnospiraceae. C, Increased DBP increased proportion of family Clostridiaceae. D, Proportion of Family Ruminococaceae decreased with increased soluble fiber. For these relationships (B-D), no direct effect of intervention on microbiome was detected.