• Germfree life;
  • mucins;
  • electrophoresis

Water-soluble intestinal mucins were investigated in germfree (GF), exgermfree (EXG) and conventional (CONV) rats and in GF and CONV mice. After agar gel electrophoresis, all GF animals had similar specific band patterns demonstrated by PAS and Toluidine Blue. These patterns, never seen in CONV animals, disappeared in GF animals infected either with intestinal contents from CONV rats or mono—infected with a mucin converting microorganism, labelled Peptostreptococcus N. The intestinal microflora seem to have a profound influence on the water-soluble mucins, and specific microorganisms appear to be involved in the conversion of these substances. Any CONV animal with a GF mucin pattern in the faeces must be considered to have a disturbance of the normal intestinal microflora.