Table 1.

Summary on findings from experimental studies on the interplay between the intestinal microbiota and exogenous and host-related factors.

•Genetic setup of the host is associated with a tendency towards a specific microbial composition •Microbial communities mature early in life •Intestinal microbiota affects the incidence of immune-mediated diseases •Prolonged or repetitive deviation from the optimal microbial homeostasis (dysbiosis) may lead to loss of self-tolerance and spreading of proinflammatory signals and effector cells •In spite of a plethora of microbes, the functional net effects of the co-occurring microbial colonies resemble each other •Considering the whole superorganism (host with its microbiota), crosstalk networks are extensive, ranging from molecular interactions to communication between microbiota and various organs of the host •Sum vectors of these crosstalk networks may point towards proinflammatory or anti-inflammatory reactivity •Modulation of the intestinal microbiota may lead to prevention or enhancement of the immune-mediated disease process, depending on the resulting compositional and functional changes •Nutritional factors drive rodents towards tolerance or disease