More bacterial smoke than expected in low back pain (but still no fire)

Scientists found these little P. acnes buggers in most of the spines they checked. But were they already there causing a problem? Or were they contamination from the procedure?
I wouldn’t bet on it yet. “The mechanism by which bacteria may enter the lumbar spinal tissue is unclear,” wrote Urquhart et al, but it’s not unclear if it’s contamination! And there is already evidence that it is just contamination. And almost any evidence of contamination puts the whole business deep in the shadow of doubt. (This is probably why Dr. David Colquhoun tweeted at me, “‘moderate quality evidence’ — I doubt it”.)
Seems like the role of bacteria in back pain is still just a big question mark. It’s plausible and there’s smoke — much more plausible that I expected two years ago — but there could easily still be no fire here at all.
All together now: “more study needed”! As usual!
I’ve updated my low back pain book with this, because it’s the kind of odd back pain science I like to include just for kicks, even if it doesn’t amount to much.