The present disclosure relates to novel boronic acid receptor compounds and their use in methods of quantifying a saccharide appearing in a sample. Provided are methods of measuring the concentration of a saccharide in a sample as well as methods of measuring the concentration of a halogenated saccharide in a sample. In certain aspects the sample is abiological sample and the methods further include correlating the measured concentration of saccharide in the biological sample to the gastrointestinal permeability in the individual. Disclosed are also kits for performing the above methods.