Effects of a probiotic preparation on the human faecal microflora and biochemical and haematological parameters

The aim of this study was to investigate the effects of supplementation of a probiotic preparation PROBIO-C containing Lactobacillus acidophilus, Bifidobacterium longum, L. rhamnosus, and Streptococcus thermophilus on the intestinal microflora of healthy volunteers and the effects on biochemical and haematological measurements. In vitro analyses, which included acid and bile salts tolerance and adhesion tests, were performed first. Probiotic bacteria in PROBIO-C demonstrated adhesion to human intestinal Caco-2 cells. An intervention study was conducted in a single-blind, random, and placebo-controlled trial. Twenty-four healthy volunteers were randomly assigned to one of three treatment groups, one provided with the placebo powder excluding the probiotic, one with 3 g of PROBIO-C with a targeted dose of 1.5 × 10¹¹ CFU of probiotic bacteria, and one with 6 g of PROBIO-C with a targeted dose of 3 × 10¹¹ CFU of probiotic bacteria. The experiment comprised three phases: the control period (week 1) during which no supplementation was given; the test period (weeks 2-4) during which volunteers were given either the placebo sample or PROBIO-C each day; the post-test period (week 5) during which no supplementation was given. The faecal samples were collected once every week throughout the study. The abundances of Bifidobacterium and Lactobacillus species increased significantly during the test period in both PROBIO-C supplemented groups. In addition, the probiotic supplementation did not result in any significant change in clinical chemistry and haematological parameters. The results from this pilot study indicated that PROBIO-C is well-tolerated and safe.