Gut fermentation and health effects of Louisiana sweet potato varieties

Abstract

Sweet potatoes (SP) are high in phytonutrients and a healthy alternative to white potatoes (WP). Both are naturally low in calories and fat, high in vitamins, minerals and fiber with similar carbohydrate starch, sugar and fiber profiles, but preparation methods affect starch digestion in WP. Thus, 20% of carbohydrates in SP are resistant starches (RS) that slows digestion and the release of sugar. RS is fermented by microflora to produce short chain fatty acids (SCFA), affect peptide secretion, and improve absorption. New SP varieties developed for disease and pest resistance by the LSU AgCenter's Sweet Potato Research Station were tested in vivo to determine health benefits when included in a daily diet. For 12 weeks, rats were fed daily a purified diet with freshly baked potatoes as the carbohydrate source (2 orange flesh (O), 2 white flesh (W) SP varieties and a control WP). All SP groups had significantly less body fat with variety differences between WSP (lowest body fat) and OSP (lowest pH). Daily intake of SP can increase health benefits from gut fermentation as indicated by significantly lower cecal pH, larger cecum weights and greater production of total SCFA in all SP fed groups.