Colonization resistance of the digestive tract and gastrointestinal transit time in SPF mice

The gastro-intestinal colonization resistance to Escherichia coli was assessed in individual CBA/Rij, C3H/StZ and Swiss/Cpb:SE mice. Gastro-intestinal transit time was determined by feeding small steel balls and x-ray examination of sequentially collected faeces. No correlation was found between transit times measured on 3 subsequent days, nor between them and colonization resistance.