Impact of a Fruit and Vegetable Diet Intervention in Young Adults with Metabolic Syndrome on Behavior and Gut Microbiome

Background: Metabolic Syndrome (MetS) is a clustering of factors that increases the risk of developing cardiovascular diseases and diabetes. The rates of MetS are on the rise, even among young adults. The primary objective of the Fruvedomics phase 2 study was to determine changes in behavior, cardiovascular, and gut microbiome health in a group of young adults with MetS following an 8-week, free-living, dietary intervention.;Methods: The dietary intervention followed the USDA Dietary Guidelines for Americans and focused on increasing fruit and vegetable intake to equal half their diet. University students (18--30 years old) with MetS were recruited on the West Virginia University (WVU) campus. Eligible, consented individuals (n=17) completed baseline measurements, including arterial stiffness, complete blood lipid panel, anthropometric measures, stool sample for microbial analysis, 24-hour diet recall, and body composition. Participants completed an 8-week dietary intervention including weekly consultations with a Registered Dietitian Nutritionist/trained researcher who assessed food logs, food receipts, and adherence to the diet.;Results: Two participants were excluded from analysis due to medical or dietary non-compliance (n=15). Fruit and vegetable (p\u3c0.0001), and fiber (0.05) intake did significantly increase over the intervention from 1.7 to 4.6 cups of fruits and vegetables and 16 to 28 grams of fiber. Clinical results yielded an increase in sodium (p=0.002). Erysipelotrichaceae (Firmicute phyla) decreased (log2 fold change: -1.78, p=0.01) and Caulobacteraceae (Proteobacteria phyla) increased (log2 fold change= -1.07, p= 0.01). The dietary intervention resulted in a time by intervention interaction in both the family Actinobacteria and its family taxa, Coriobacteraceae (p=0.033).;Conclusion: Overall, implementing a free-living 8-week diet, with intensive education and accountability, gave participants the knowledge, skills, and feedback to improve health behaviors, but did not result in many metabolic and gut microbiome changes. A longer diet intervention may be needed in this population to improve metabolic health