Topographical variation in metabolic signatures of human gastrointestinal biopsies revealed by high-resolution magic-angle spinning 1H NMR spectroscopy. by Wang, Y, Holmes, E, Comelli, E, Fotopoulos, G, Dorta, G, Tang, H, Rantalainen, M, Lindon, J, Corthésy-Theulaz, I, Fay, L, Kochhar, S, Nicholson, J