Polyarthritis in rats following the systemic injection of Lactobacillus casei cell walls in aqueous suspension.

Postdysenteric Reiter's syndrome and the arthritis associated with jejunal bypass surgery for obesity suggest that the gastrointestinal tract is a possible source of bacterial products capable of initiating chronic inflammatory arthritis. Lactobacillus casei, a common component of the enteric flora, has a cell wall structure similar to that of arthritogenic streptococci. In this study we have demonstrated that a single intraperitoneal injection of an aqueous suspension of the cell walls of Lactobacillus casei induces a dose-dependent, chronic, symmetric, erosive, peripheral polyarthritis in inbred LEW/N female rats. This model suggests that bacteria in the "normal enteric flora" may be a source of inflammatory products capable of inducing chronic erosive polyarthritis.