METABOLISM OF ERYTHRITOL IN HUMANS - COMPARISON WITH GLUCOSE AND LACTITOL

The metabolism of erythritol was assessed in six normal volunteers by measuring the amount of (CO2)-C-13 excretion and H-2 excretion in breath, and erythritol in urine after intake of 25 g C-13-labelled erythritol. The results were compared with the same variables obtained after intake of 25 g C-13-labelled glucose and C-13-labelled lactitol. In addition, the H-2 production by faecal flora supplemented with small amounts of erythritol, glucose and lactitol was measured in vitro, as an index of bacterial metabolism of non-adsorbed substrate. In contrast to the results obtained after intake of glucose and lactitol, no increase in breath (CO2)-C-13 and H-2 was observed after intake of erythritol, and erythritol was nearly completely recovered in urine. The in vitro experiments showed that no H-2 was formed by faecal flora from erythritol as compared with glucose and lactitol. It is concluded that erythritol is a substrate that is readily absorbed, and undergoes no metabolism by the host. If part of it escapes absorption, it is not metabolized by faecal flora.