Background & aim: Supplementation with probiotic Bifidobacteria or Lactobacilli or the combination of both, has been shown to maintain a healthy balance of bacterial flora in the intestinal lumen. A placebo-controlled, crossover, self-comparing clinical study evaluated the probiotic effects of Lactobacillus fermentum P.C.C. (ProBioPCC) on gastrointestinal bacterial flora. Methods: This 8-week trial comprised an initial lead-in week with no study intervention, a 3-week treatment phase (taking ProBio, 1 capsule/day), a 1-week washout phase, a 3-week control phase (taking placebo, 1 capsule/day), followed by a final week of washout. Thirty healthy adults (age: 25-43 years) having no gastrointestinal diseases were recruited into the study. Stool samples were collected once at each experimental week, and cultured for counting colonies of total anaerobic bacteria, Lactobacillus spp., Bifidobacterium spp., and Clostridium perfringens. Results: We found significantly increased colony counts of Lactobacillus spp. In stool samples after the treatment phase (p < 0.05). Colony counts of probiotic Bifidobacterium spp. were significantly increased with the study intervention (p < 0.05), while those of harmful C. perfringens were reduced (p < 0.05). Ratios of Bifidobacterium spp. to total anaerobic bacteria and to C. perfringes were increased significantly (p < 0.05). The bacteria colony counts and ratios returned toward baselines during and after the placebo control phase. In order to confirm the increase of intestinal probiotics was due to oral administration of ProBioPCC, we further demonstrated that L. fermentum P.C.C. strain was resistant against simulated gastric acid and bile in vitro. Conclusions: Our data indicate that ProBioPCC is effective in decreasing C. perfringens and increasing ratio of Bifidobacterium spp. to total anaerobic bacteria in healthy humans.
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