(P14-027-23) Compositional Map of Dietary Fibers and Subcomponents in the Mediterranean Diet (MeDi) Based on MeDi Randomized Controlled Trials

Objectives: The Mediterranean Diet (MeDi) is associated with numerous health benefits. MeDi is also characterized by foods rich in dietary fiber (DF). However, there is limited analysis of fiber composition specific to MeDi, which is critical to better understand fiber’s role in MeDi health effects, particularly those mediated via the microbiome. Thus, we sought to construct a foundational map of reported DF types and subcomponents characteristic of MeDi, based on MeDi randomized controlled trials (RCTs).

Methods: RCTs investigating MeDi interventions providing defined guidelines were selected. High fiber foods prescribed in these MeDi RCTs were identified and grouped. Daily serving size for each group was quantified, and model foods in each group were selected, based on prevalence in intervention diets. Total DF intake, by soluble and insoluble fractions, was estimated for each model food; and DF, monosaccharide, and polysaccharide subcomponents were identified and mapped into a 2-D matrix through analysis of existing data.

Results: Sixteen RCTs were included, of which 39 model foods were selected and categorized into five high fiber food groups. RCTs reflected a wide variety foods and guidelines with average daily intakes for high fiber food groups estimated at 45 g nuts, 384 g fruit, 293 g vegetables, 45 g legumes, and 297 g whole grains. Soluble analysis identified 6 fiber types, 4 polysaccharides, and 7 monosaccharides; pectin, gums, fructans, and beta-glucan were reported most frequently (24 model foods). Insoluble analysis identified 3 fiber types, 5 polysaccharides, and 2 monosaccharides; lignin, cellulose, and hemicellulose were reported most frequently (22 model foods). Mapping suggests walnuts, berries, apples, pears, carrots, chickpeas, lentils, and whole grain wheat have the most extensive reporting of DF and subcomponents.

Conclusions: Understanding of MeDi DF composition is limited, particularly mono- and polysaccharide subcomponents, despite MeDi’s public health importance. Intake estimation and mapping of MeDi DF and subcomponents herein reveals specific and numerous gaps in fiber research to help isolate associations with the microbiome and subsequent health effects, one day enabling clinical, precision fiber recommendations.

Funding Sources: NeuroReserve Inc.