The human microbiome in health and disease: hype or hope 
Gwen Falony a,b, Doris Vandeputte a,b, Clara Caenepeelc c , Sara Vieira-Silva a,b, Ta
nine Daryousha,b, Séverine Vermeire c and Jeroen Raesa*,b a
a:Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium;
b: Center for Microbiology, VIB, Leuven, Belgium;
c: Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, Leuven, Belgium
Objectives: The prognostic, diagnostic, and therapeutic potential of the human gut microbiota is widely recognised. However, translation of microbiome findings to clinical practice is challenging. Here, we discuss current knowledge and applications in the field.
Methods: We revisit some recent advances in the field of faecal microbiome analyses with a focus on covariate analyses and ecological interpretation.
Results: Population-level characterization of gut microbiota variation among healthy volunteers has allowed identifying microbiome covariates required for clinical studies. Currently, microbiome research is moving from relative to quantitative approaches that will shed a new light on microbiota–host interactions in health and disease.
Conclusions: Covariate characterization and technical advances increase reproducibility of microbiome research. Targeted in vitro/in vivo intervention studies will accelerate clinical implementation of microbiota findings.