Lactobacillus gasseri PA-3, but not L. gasseri OLL2996, reduces the absorption of purine nucleosides in rats.

Lactobacillus gasseri PA-3 (PA-3) is a bacterial strain with a strong ability to degrade purine nucleosides. We previously showed that PA-3 incorporates purines in vitro and that oral administration of PA-3 and purines to rats attenuated their absorption of purines. It remains unclear whether these effects of PA-3 depend on bacterial strains. This study therefore compared the abilities of PA-3 and another bacterial strain of L. gasseri, OLL2996, which has shown decreased ability to degrade purine nucleosides in vitro, to incorporate purine nucleosides and to inhibit the absorption of purines fed to rats. Each bacterial strain was incubated in the presence of 14C-adenosine or 14C-inosine and the incorporation of each purine was evaluated by measuring their radioactivity. In vivo, rats were fed 14C-labeled purines along with PA-3 or OLL2996 and the absorption of these 14C-labeled purines was evaluated by analyzing radioactivity of blood samples. PA-3 incorporated about twice as much 14C-adenosine and 14C-inosine as OLL2996. The elevation of radioactivity levels in blood was 10-20% lower in rats treated with PA-3 than in control rats, after feeding with both 14C-adenosine and 14C-inosine as purines. In contrast, treatment with OLL2996 did not have statistically significant effects on radioactivity compared with the control group. These results indicate that the magnitude of bacterial inhibition of purine absorption is dependent on bacterial strain, correlating at least partly with the ability to incorporate and degrade purines.

Lactobacillus gasseri PA-3 utilizes the purines GMP and guanosine and decreases their absorption in rats.

Excessive intake of purine-rich foods elevates serum uric acid levels, making it a risk factor for hyperuricemia. We hypothesized that lactic acid bacteria ingested with food might utilize purines and contribute to their decreased absorption in the intestines, thereby preventing hyperuricemia. We previously reported that Lactobacillus gasseri PA-3 (PA-3) incorporates adenosine/inosine and related purines and that oral ingestion of PA-3 reduced the absorption of these purines in rats. However, it is unclear whether PA-3 also decreases the absorption of other purines, such as guanosine 5'-monophosphate (GMP) and guanosine. This study investigated whether PA-3 incorporates GMP and guanosine and reduces their absorption in rats. PA-3 incorporated both purines, with 14C-GMP uptake being greater than that of 14C-guanosine. Radioactivity in rat blood was significantly lower 30, 45, and 60 minutes after administration of 14C-GMP plus PA-3 than after administration of 14C-GMP alone and was significantly lower 15 minutes after administration of 14C-guanosine plus PA-3 than after administration of 14C-guanosine alone. PA-3 incorporates GMP and guanosine in vitro. Oral administration of PA-3 with GMP and guanosine reduces the intestinal absorption of these purines in vivo. These findings, together with those of previous studies, indicate that PA-3 reduces the absorption of major purines contained in foods. PA-3 may also attenuate the excessive absorption of dietary purines in humans, protecting these individuals against hyperuricemia.