Food supplements laced with bacteria may
someday protect divers from the ravages of
decompression sickness, reports New Scientist
magazine. Experiments with pigs have shown
that methane-producing microorganisms
that live in the gut can help ward off the bends.
Susan Kayar and her colleagues at the Naval Medical Research Center
in Bethesda, Maryland, reasoned that deep dives would be made safer if
more dissolved hydrogen could be removed from the divers’ blood. They
turned to a bacterium called Methanobrevibacter smithii, which lives in
the gut and metabolizes hydrogen to form methane. They injected
cultures of the bacteria into the intestines of pigs, then put the animals in
a hyperbaric chamber for an ascent from a three-hour dive at 240 meters.
The researchers found that pigs that were not given the bacterial
cultures were nearly twice as likely to show DCS symptoms. The treated
pigs were more flatulent, releasing large quantities of methane. The more
bacteria that were added to their guts, the more methane they produced:
indeed, a new form of offgassing.
Kayar says the bacterial supplements appear as harmless as live yogurt.
“These are microbes that you have in your intestine right now,” she says.
The treated pigs seemed to suffer no ill effects and their altered gut
microflora later returned to normal.