Advanced analytical methodologies to study the microbial metabolome of the human gut

• Molecular sequencing methods have revealed the diversity of the gut microbiota.
• Metabolic studies with microbial isolates will identify functionality and redundancy.
• Metabolomics has highlighted novel pathways of aromatic amino-acid metabolism.
• Microbial metabolites of fiber and related phytochemicals impact on human health.

Emerging evidence suggests that the gut microbiota play an important role in the development of many diseases, including diabetes, cardiovascular disease and cancer. Spectroscopy-based methodologies provide a central, vital tool for the characterization of gut metabolites. This review explores the use and the importance of these techniques to evaluate the microbial metabolome with a particular focus on microbial transformation of dietary protein and fiber.