“…Concerning the metabolome, until now several metabolomics studies have been performed to unravel the microbial metabolism following different biological questions. Many of these studies investigated the particular role of metabolites in inflammatory bowel diseases by using primarily NMR studies (Lin et al, 2011). Non-targeted metabolomics approaches in gut microbial sample matrices and liver, analysing changes occurring in metabolic diseases like obesity, are rarely given, but many studies addressed obesity-related metabolome characterization (Dumas et al, 2006;Williams et al, 2006;Fearnside et al, 2008;Li et al, 2008Li et al, , 2010aShearer et al, 2008;Newgard et al, 2009;Waldram et al, 2009;Kim et al, 2009Kim et al, , 2010Kim et al, , 2011Calvani et al, 2010;Xie et al, 2010Xie et al, , 2012Zhao et al, 2010;Oberbach et al, 2011;Duggan et al, 2011a,b;Jung et al, 2012;Hanhineva et al, 2013;Schäfer et al, 2014;Seyfried et al, 2013;Won et al, 2013;Xu et al, 2013;Daniel et al, 2014;Eisinger et al, 2014).…”