A colony of mice that do not harbor lactobacilli in their digestive tracts but whose intestinal microflora is otherwise functionally similar to that of conventional animals was derived. Methods used to reconstitute the intestinal microflora of the mice included inoculation of the animals with cultures of specific microbes, noncultivable microbes attached to epithelial cells, and cecal contents from conventional mice treated with chloramphenicol. Twenty-six microflora-associated characteristics were monitored by using relatively simple tests to determine the microflora status of the mice.

A method by which non‐cultivable filamentous segmented microbes colonising the ileal epithelium of mice can be harvested was devised. Intact epithelial cells with attached filamentous microbes were obtained. An ethanol‐treated preparation of epithelial material was used to restore the filamentous segmented microbes to the normal microflora of mice maintained by gnotobiotic methodology.