Fecal Metabolomics by NMR Spectroscopy

Metabolites were extracted as described previously (35 (link)). Briefly, 100 mg of fecal powder was disrupted with the specialized lysing matrix E (MP Biomedicals, Eschwege, Germany) by FastPrep treatment. The supernatant was transferred to a new tube and the FastPrep treatment was repeated once with 2 ml ice-cold water and 500 μl dichloromethane and once with 2 ml ice-cold water. Afterwards, supernatants were combined, vortexed, stored on ice, and finally centrifuged. Finally, the water/methanol phase was lyophilized. Samples for ¹H-NMR analysis were resuspended in phosphate-buffered saline (PBS) and vortexed, and the supernatant was measured with a Bruker Advance II 600 NMR spectrometer (85 (link)). As described previously for the 16S rRNA gene sequencing and metaproteome analyses, the results of metabolomics were also compared with the findings of the study by Gierse et al. (35 (link)).