The Cardiff Tracking Study
Use of colony-based bacterial strain typing for tracking the fate of Lactobacillus strains during human consumption
This double-blind, placebo-controlled study examines the role of probiotic administration in the prevention of C. difficile-associated diarrhoea (CDAD) in elderly patients receiving antibiotic therapy.
Results showed that Lab4 probiotics reduced the incidence of Clostridium difficile diarrhoea in these patients.
46% of patients supplemented with Lab4 probiotics were positive for Clostridium difficile toxin compared to 78% of patients in the placebo group
Detection of Lactobacillus salivarius CUL61 and Lactobacillus acidophilus CUL21 in faecal samples of a healthy volunteer on day 7:
Image (A) shows L. salivarius CUL61 colonies from faecal sample grown on plate. The colonies are labelled as No. 6 and No. 7.
Image (B) shows L. acidophilus CUL21 colonies from faecal sample grown on plate. These colonies are labelled as No. 3, 4 and 5.
Image (C) shows the RAPD fingerprint technique results, as follows:
Lanes 6, 7 – the fingerprints of the L. salivarius CUL61 from colonies are the same as the original L. salivarius CUL61 control (Lane 1)
Lanes 3, 4, 5 – the fingerprints of the L. acidophilus CUL21 from colonies are the same as the original L. acidophilus CUL21 control (Lane 2)
Lane numbers correspond to the number labels for the colonies in the faecal samples (Images A and B).
Lane M – the marker fingerprint that checks that the reactions work.
Lane 1 – the fingerprint for the original control for L. salivarius CUL61.
Lane 2 – the fingerprint for the original control for L. acidophilus CUL21.
Probiotic strains Lactobacillus acidophilus CUL21 (from Lab4) and Lactobacillus salivarius CUL61 (from Lab4b) remained viable and can be ‘tracked’ through the gut passage during probiotic consumption by healthy volunteers.