Diets supplemented with fiber do not increase accumulation of 1-naphthol

Abstract 

The influence of fiber on the absorption, accumulation and elimination of environmental contaminants varies among amounts and types of fiber and contaminants. We performed a study in mice to examine how different fibers (cellulose, rice bran, chitosan, lactosucrose, polydextrose, indigestible dextrin, and soy polysaccharides) influence accumulation and elimination of 1-naphthol and retinol. Urine and feces were collected daily during a 2-week exposure period, and blood samples were collected on days 1, 3, 7, and 14. Accumulation at day 14 was measured in the small and large intestine, liver, gallbladder, mesentery, kidney, and brain. Urinary excretion was the principal route of 1-naphthol elimination but was not responsive to fiber type. The colon contents of mice fed poorly fermented fibers had higher 1-naphthol concentrations, but this did not increase 2-week fecal elimination. Accumulation of 1-naphthol varied among tissues and fiber types except in the brain and kidney. Fecal retinol loss varied among fiber types, but not tissue accumulation except in the mesentery.

Keywords:  1-Naphthol, Fiber, Contaminant, Xenobiotic, Metabolism, Intestine