Intestinal Flora Modification of Arthritis Pattern in Spondyloarthropathy

The reactive form of spondyloarthropathy appears inducible by exposure to agents of infectious diarrhea, but do those organisms represent the tip of the iceberg, as indicated by renewed interest in gastrointestinal flora? Prevalence of spondyloarthropathy (20% of chimpanzees [Pan] and 28% of gorillas) is independent of subspecies and species, respectively. However, there are major differences in arthritis patterns, a characteristic shared with humans.

Do patterns of arthritis correlate with gastrointestinal flora? Could such associated modifications be in the form of disease induction or represent protective effectors (at least against the extent of peripheral arthritis)?

The skeletons of 2 chimpanzee subspecies (79 Pan troglodytes troglodytes and 26 Pan troglodytes schweinfurthii) and 2 gorilla species (99 Gorilla gorilla and 38 Gorilla beringei) adults were examined, and arthritis pattern noted. Feces of Eastern (P. schweinfurthii and G. beringei) and Western (great apes collected in their normal ranges) apes were assessed for 16S rRNA c and its character.

Patterns of arthritis recognized on examination of skeletons showed geographic variation in skeletal distribution. East African apes (P. troglodytes schweinfurthii and G. beringei) had pauciarticular arthritis and frequent sacroiliac disease, whereas West African apes (P. troglodytes troglodytes and G. gorilla) had polyarticular peripheral joint disease with minimal sacroiliac involvement. DNA evidence revealed that Corynebactericeae were prominently represented in great apes with polyarticular disease, whereas Dietzia and Bifidobacterium exposure correlated with reduced peripheral joint arthritis distribution.

Suggestions of a protective effect (in this case, limiting extent of peripheral arthritis, but not the disease itself) offered by these organisms are well represented by documented effects in other diseases (eg, tuberculosis) in the zoologic record. Perhaps it is this disease-modifying character that reduces the extent of the peripheral erosive disease, while increasing propensity to axial (sacroiliac) disease. A potential role for probiotic organisms in management of arthritis in humans is suggested, as has been documented for tuberculosis, gastrointestinal disorders, and food allergies.