[Immunomodulating effects of antibiotics influencing digestive flora].

Mucosal surfaces are habitats of the physiological microflora and are closely related to the mucosal immune compartment (mucosa-associated lymphoid tissue, MALT). Recently, considerable evidence has been accumulated showing that various members of the physiological microflora liberate low molecular weight peptides which, apparently, are essential for adequate immune responses of the host. Antibiotic decontamination (e.g. of the BALB/c-mouse intestinal tract) results in a lack of generation of immunopriming microbial peptides leading to immunosuppression. Biochemical analysis of the peptides revealed reproducible chromatographic fractions which selectively influence maturation, proliferation, and activation of lymphatic cells.