Cell wall fragments from major residents of the human intestinal flora induce chronic arthritis in rats.

To investigate the involvement of human intestinal flora in joint inflammation, cell wall fragments of 9 anaerobic gram positive bacteria of the human fecal flora were prepared and tested for arthropathic properties in the rat. A single intraperitoneal injection of cell wall fragments from Eubacterium aerofaciens or Bifidobacterium species induced persistent chronic arthritis, in contrast to those from Eubacterium rectale, Clostridium species and Lactobacillus leichmanii. The results show that cell wall fragments of major residents from the human fecal flora can induce chronic arthritis in the rat and support the hypothesis that normal human intestinal flora plays a role in the induction of arthritis in man.