Rheumatoid arthritis (RA) may be linked to the lack of certain intestinal bacteria, according to research being conducted at Turku University in Finland. Using chemical bacteria-specific probes, the researchers tested early-stage RA patients against a control group. The control group had far more bacteria from the bacteroides, prevetella, and porphyromonas families in their intestines than the RA patients, suggesting that these bacteria may form some kind of defense against the disease. The researchers surmise that the bacteria may be necessary to maintain the intestinal epithelium and that fewer of them may result in a weaker intestinal barrier. The latter condition could somehow make a person more likely to develop RA.