Interesting article in this week's New Scientist on blood bacteria. Blood is normally considered sterile as nothing grows when in a petri dish. But DNA analysis points to about 1000 dormant bacteria per ml. They probably get into the blood via gum disease, but do nothing unless there is sufficient free iron in the blood. If sufficient iron is present, the bacteria can create lipopolysaccharides, which are then recognised by the immune system, causing inflammation and clots. These clots resemble those associated with strokes and heart attacks. Aspirin reduces inflammation and mops up free iron, and has long been recommended (in small doses) for those at risk of strokes and heart attacks. More recently it's been counter-indicated for those at low risk (due to side effects of aspirin). But inflammation is also linked to diabetes and rheumatoid arthritis. Looks like a new field of investigation opening up.