Ambient fecal reactive oxidative species (ROS) buffering capacity as a function of geography and habitual diet: A comparison of rural and urban Guatemalan subjects

Abstract

BackgroundIn the ambient state, fecal matrix has a powerful capacity to buffer ROS induction in an in situ assay system.ObjectivesTo examine factors influencing the buffering capacity of stools across differing dietary habits, with emphasis on dietary fiber (DF), and between sexes.MethodsAmbient stool samples were collected on 2 nonconsecutive days in 20 rural women (RW) and 20 urban women (UW), with concurrent 24‐h recalls, and on 3 consecutive days in 27 urban men (UM). An assay for Fe‐induced adducts of salicylic acid in mg/mL units gauged fecal buffering. Stool non‐heme Fe was measured by a colorimetric test.>ResultsRW consumed 2.5 X the DF as UW: 40±21 vs 16±8 g, p<0.001, but ROS generation was identical across areas: 0.077±0.015 vs 0.078±0.019 mg/mL, p=0.86. UM had ROS levels 150% higher than women: 0.20±0.11 mg/mL, p<0.0001. Fecal non‐heme Fe associated poorly with ROS production, r=−0.05 (p=0.71), and failed to explain sex difference in buffering capacity.>ConclusionHigh and low DF intakes have no influence on ROS buffering in women, but sex strongly determines ambient oxidative quenching in stools. The latter could explain gender disparities for certain intestinal diseases.Funded by Hildegard Grunow Foundation