Dietary fiber (DF) can promote human health through its specific physicochemical functions. For instance, bile acid binding of DF may lower cholesterol level. Ultrafine grinding, a new equipment for making micro-powders, can pulverize DF into small scales. The objective of this study is to explore the effects of ultrafine grinding on bile acid binding capacity and physicochemical properties (water retention properties, swelling power, water solubility index, light transmittance, turbidity, syneresis, viscosity and pasting properties) of DFs (Konjac glucomannan, beta-glucan, guar gum, inulin). The study also aimed to study the correlation between bile acid binding capacity and physicochemical properties of DFs. Bile add binding capacity was determined by ELISA method. The results showed that ultrafine grinding could effectively pulverize particle size, significantly increase sample bile acid binding capacity and change the pasting properties. The transmittance was found to be gradually decreased. Water retention capacity and turbidity were increased by ultrafine grinding. This study indicated that ultrafine grinding could improve sample bile acid binding capacity and dramatically change some properties of the samples. (C) 2017 Elsevier B.V. All rights reserved.