Administration of folate-producing bifidobacteria enhances folate status in Wistar rats

To develop a probiotic that provides the host with folate, we administered folate-overproducing bifidobacteria (Bifidobacteria adolescentis MB 227, B. adolescentis MB 239, and B. pseudocatenulatum MB 116) to Wistar rats with induced folate deficiency. Four groups of rats were fed a solid, low-folate diet with no supplements, folate-producing bifidobacteria [probiotic (PRO)], oligofructose [prebiotic (PRE)], or PRO plus PRE [symbiotic (SYM)] for 14 d. The SYM group also had a significantly higher (16.4 +/- 3.7 nmol/L) than in the PRO group (9.1 +/- 0.3 nmol/L), which was greater than in the control (4.8 +/- 0.5 nmol/L) and PRE groups (5.3 +/- 1.4 nmol/L). The SYM group also had a significantly higher hepatic folate concentration than in the other groups, whereas the kidney folate concentration did not differ among the groups. In the unsupplemented group, the pH of feces did not change during the trial, whereas diets containing bifidobacteria and/or oligofructose led to significant acidification due to enhanced saccharolytic metabolism. As a consequence of feeding rats PRE, PRO, and SYM diets, lactobacilli and bifidobacteria were significantly greater than in controls, whereas coliforms and enterococci were lower. This experiment showed that B. adolescentis MB 227, B. adolescentis MB 239, and B. pseudocatenulatum MB 116 exert both the beneficial effects of probiotics and produce folate in vivo, positively affecting the folate status of rats. The simultaneous administration of oligofructose and folate-producing bifidobacteria enhance their effectiveness on folate status. This study provides new perspectives on the specific use of probiotics to deliver important vitamins such as folate.