Humanizing the gut microbiota of mice: Opportunities and challenges.

Mouse colonized with human fecal microbiota is an interesting model concept with pros and cons like any other model system. The concept provides an ecologically relevant context to study food component and drug metabolism, and is an invaluable tool for phenotype transfer studies to prove the role of the gut microbiota in health and disease. The major drawbacks are the difficulties with transferring certain components of the human microbiota to the recipient mice, and immunological abnormalities observed in these mice. There seem to be unexplored opportunities for trying to reduce these limitations, but careful evaluation of pros, cons and possible alternatives is still necessary.