[Effect of oral lactosucrose supplementation on human enteric oxalate-degrading bacteria]

A variety of oxalate-degrading bacteria including Oxalobacter formigenes and some species of Bifidobacterium are known to colonize the human intestinal tract. Oral lactosucrose supplementation promotes the growth of Bifidobacterium in the human intestine. Therefore, we investigated the effect of oral lactosucrose supplementation on enteric oxalate-degrading bacteria in twelve healthy men (age ranging from 25 to 39 years). Lactosucrose was orally administered 10 g daily for 2 weeks without restriction of dietary intake. The total number of oxalate-degrading bacteria in feces and the 24-hour urinary excretion of oxalate were examined before and after lactosucrose supplementation. The total number of oxalate degrading-bacteria was significantly increased by lactosucrose supplementation (9.20 +/- 0.44 versus 9.77 +/- 0.46, p<0.05), although there was no significant change in the urinary oxalate excretion. The oxalate degrading-bacteria isolated from feces was biochemically identified as Bifidobacterium adolescentis. In conclusion, oral supplementation of 10 g lactosucrose daily for 2 weeks was effective in multiplying oxalate-degrading bacteria, but not in reducing urinary oxalate excretion under free non-restricted dietary intake. In addition, it was suggested that various species of Bifidobacterium were related to degradation of oxalate in the human intestine.