Lactobacillus gasseri PA-3 reduces serum uric acid levels in patients with marginal hyperuricemia.

Several studies have reported that Lactobacillus gasseri PA-3 reduces the level of serum uric acid (SUA) in patients with hyperuricemia. However, it remains unknown how PA-3 affects uric acid metabolism. In the present study, we examined effects of PA-3-containing yoghurt on uric acid metabolism in patients with marginal hyperuricemia. Sixteen patients with SUA > 357 µmol/L (marginal hyperuricemia) were enrolled. PA-3-containing yoghurt was administered for 8 weeks. Uric acid metabolism was evaluated just before and 8 weeks after the administration and at 4 weeks after the administration ended (post-administration). SUA levels after the administration were significantly lower than that before the administration and remained low at post-administration. Urinary uric acid concentration (Uur) after the administration were significantly lower than that before the administration. However, post-administration Uur levels were comparable to those before the administration. Therefore, PA-3-containing yoghurt significantly reduced the levels of SUA and Uur in patients with marginal hyperuricemia.

Lactobacillus gasseri PA-3 directly incorporates purine mononucleotides and utilizes them for growth.

Lactococcus lactis has been reported unable to directly incorporate mononucleotides but instead requires their external dephosphorylation by nucleotidases to the corresponding nucleosides prior to their incorporation. Although Lactobacillus gasseri PA-3 (PA-3), a strain of lactic acid bacteria, has been found to incorporate purine mononucleotides such as adenosine 5'-monophosphate (AMP), it remains unclear whether these bacteria directly incorporate these mononucleotides or incorporate them after dephosphorylation to the corresponding nucleosides. This study evaluated whether PA-3 incorporated radioactively-labeled mononucleotides in the presence or absence of the 5'-nucleotidase inhibitor α,ß-methylene ADP (APCP). PA-3 took up 14C-AMP in the presence of APCP, as well as incorporating 32P-AMP. Furthermore, radioactivity was detected in the RNA/DNA of bacterial cells cultured in the presence of 32P-AMP. Taken together, these findings indicated that PA-3 incorporated purine mononucleotides directly rather than after their dephosphorylation to purine nucleosides and that PA-3 utilizes these purine mononucleotides in the synthesis of RNA and DNA. Although additional studies are required to identify purine mononucleotide transporters in PA-3, this study is the first to show that some lactic acid bacteria directly incorporate purine mononucleotides and use them for growth.

Effect of Lactobacillus gasseri PA3 on gut microbiota in an in vitro colonic simulation.

It has been reported that Lactobacillus gasseri PA3 has an ability to absorb exogenous purines in the intestine to reduce a risk of gout and hyperuricemia. However, influences of this strain on gut microbiota and their metabolisms remain unclear. Herein, we aimed to investigate the effect of L. gasseri PA3 on microbiota composition and metabolisms. L. gasseri PA3 was isolated from yogurt and supplemented into a single-stage colonic fermentation in a culture volume of 30 ml and subjected to in vitro colonic simulation for 8 days. Microbiota composition was determined with 16S rRNA (V3 + V4) sequencing, and their metabolisms were predicted by PICRUSt. Short-chain fatty acids were measured by GC-MS. We found that L. gasseri PA3 reduced the diversity of microbiota, increased the relative abundances of Lactobacillus (73.5%) and Escherichia (36.5%), and decreased Bacterioides and Phascolarctobacterium. Total amount of short-chain fatty acids was found to decline. Fundamental metabolisms, especially nucleotide, was significantly higher after intervention with L. gasseri PA3, but the purine metabolism was lower, which means that PA3 might reduce uric acid concentrations by weakening purine metabolism. Our results indicated that L. gasseri PA3 can survive and play a role in the ascending colon environment. Therefore, the evaluation of the effect of L. gasseri PA3 on intestinal microbes and their metabolisms has great guiding significance for the development of treatment to prevent gout.

Hypouricaemic effects of yoghurt containing Lactobacillus gasseri PA-3 in patients with hyperuricaemia and/or gout: A randomised, double-blind, placebo-controlled study.

PURPOSE: Lactobacillus gasseri PA-3 (PA-3) has been previously shown to decrease serum uric acid (SUA) levels in subjects with increased SUA. In this study, we investigated whether PA-3 is also capable of decreasing SUA levels in patients with hyperuricaemia and/or gout. METHODS: Twenty-five patients with hyperuricaemia and/or gout completed this study. Urate-lowering drugs were discontinued for 12 weeks (week -4 to week 8). After flushing of urate-lowering drugs for 4 weeks (week 0), patients were randomised equally to receive diets containing yoghurt beverages with PA-3 or without PA-3 for a duration of 8 weeks (week 8). The intention to treat (ITT) population included all subjects who were randomised, and the per-protocol (PP) population included subjects who completed the experiment with compliance. We evaluated SUA levels at the end of the study as well as changes in SUA levels in comparison to week 0. RESULTS: In both ITT and PP analyses, there were no significant differences in SUA levels or in the changes in SUA levels compared to week 0 between the two groups. However, in a sub-population whose SUA levels at week 0 were within one SD of the mean of the whole PP population, changes in SUA levels in the group consuming PA-3-containing yoghurt were significantly lower than those of the control group (p = .0378). CONCLUSION: PA-3-containing yoghurt improves SUA levels, even in patients with hyperuricaemia and/or gout.

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 Uses the Purines IMP, Inosine and Hypoxanthine and Reduces their Absorption in Rats.

Excessive intake of purine-rich foods elevates serum levels of uric acid. Animal and fish meats contain high amounts of inosine and its related purines, and the reduction of taking those purines is crucial for the improvement of serum uric acid levels. We previously showed that Lactobacillus gasseri PA-3 (PA-3) incorporates adenosine and its related purines and that oral treatment with PA-3 reduced adenosine absorption in rats. This study investigated whether PA-3 also incorporates IMP (inosine 5'-monophosphate), inosine, and hypoxanthine, and whether it reduces their absorption in rats. PA-3 was incubated in vitro with radioisotope (RI)-labeled IMP, inosine, and hypoxanthine, and the incorporation of these compounds by PA-3 was evaluated. In addition, rats were orally administered PA-3 along with RI-labeled inosine 5'-monophosphate, inosine, or hypoxanthine, and the ability of PA-3 to attenuate the absorption of these purines was determined. PA-3 incorporated all three purines and displayed greater proliferation in the presence than in the absence of these purines. Oral administration of PA-3 to rats reduced the absorption of IMP, inosine, and hypoxanthine. These results indicate that PA-3 reduces the absorption of purines contained in foods and it is expected that PA-3 contributes attenuation of the excessive intake of dietary purines.

Evaluation of purine utilization by Lactobacillus gasseri strains with potential to decrease the absorption of food-derived purines in the human intestine.

It is well accepted that frequent and heavy intake of purine-rich foods causes elevation of serum uric acid levels, which is a risk factor of hyperuricemia. Reducing intestinal absorption of dietary purines may attenuate the elevation of serum uric acid levels and exacerbation of hyperuricemia. This reduction may be achieved by the ingestion of lactic acid bacteria that take up purines in the intestine. In this study, we investigated the degree of uptake and utilization of purines of three lactobacilli strains. Among them, Lactobacillus gasseri PA-3 (PA-3) showed the greatest incorporation of 14C-adenine. PA-3 also incorporated 14C-adenosine and 14C-AMP. Additionally, using defined growth medium, PA-3 demonstrated greater proliferation in the presence of these purines than in their absence. Although further investigation is required, ingestion of PA-3 may lower serum uric acid levels by reducing intestinal absorption of purines in humans.