Abstract
The influence of Bifidobacterium longum supplements on the faecal microflora in 10 healthy volunteers was studied before, during and after B. longum administration. The supplement was given as a fermented milk product containing 8 ± 107-6 ± 108 c.f.u./ml of B. longum. A 250-ml portion was administered twice daily for 21 d. No significant changes were observed in the aerobic Gram-positive and Gram-negative microflora during or after the B. longum administration. In the anaerobic microflora the number of bifidobacteria was constant during the whole period. There were minor variations in the number of lactobacilli. The numbers of Clostridia and bacteroides were not significantly altered. The faecal pH decreased significantly after 3 d of B. longum supplementation (P=001).