Human flora-associated (HFA) animals as a model for studying the role of intestinal flora in human health and disease

Although the intestinal flora in animals plays an important role in health and disease, there is little direct information regarding the role of the human intestinal flora. By inoculating germfree animals with human faeces, the major components of the human flora can be transferred into the ex-germfree animals, i.e. human flora-associated (HFA) animals. HFA animals therefore provide a stable model for studying the ecosystem and metabolism of the human intestinal flora. Results with HFA animals suggest the role of the human intestinal flora is somewhat different from the role of the animal flora in conventional experimental animals. Studies using HFA animals, therefore, will provide much needed information on the precise role of the intestinal flora in relation to humans. HFA animals also can be used as models to investigate the interactions between the human intestinal flora, host factors, dietary manipulations, and therapeutics, such as probiotics, prebiotics, and antibiotics.