UCL study into probiotics

Dr Simon Gaisford of University College London (UCL) School of Pharmacy carried out an independent study on eight well-known probiotics.

The eight products selected to be tested in this study were:

  • Actimel
  • Align
  • Bio-kult
  • Symprove
  • Biobalance
  • Probio7
  • Yakult
  • VSL#3

They study's aim was to establish if they safely arrive, survive stomach acids and thrive in the target area of the gut. Symprove was the only one to meet all three challenges.

The study was published in Beneficial Microbes journal in 2015.

Watch Dr Simon Gaisford talking about the study in the video below.

Symprove was the only product to arrive alive, survive transit through the stomach and thrive in the target area of the gut

Study abstract from Beneficial Microbes journal

The large number of probiotic products now available makes the decision about which product to choose difficult both for the consumer and for the specialist providing dietary/nutritional advice. Data on the viability of the bacteria in these products, in an in vivo situation, are therefore important. This study was designed to explore the comparative health and survival of probiotic species in various commercial formulations, using more realistic test systems. This might allow further understanding of factors that must be controlled to optimise the delivery of live healthy bacteria to the lower gut.

A total of eight commercially available probiotic preparations were selected for enumeration tests and in vitro gastric tolerance tests. Tolerance assays were conducted in porcine gastric fluid (PGF) fed and fasted state (pH 3.4±0.04), simulated gastric fluid (SGF, pH adjusted to 1.2 and 3.4) and fasted state simulated gastric fluid (FaSSGF, pH adjusted to 1.6 and 3.4). Isothermal microcalorimetry was also used to measure real-time growth of probiotics after exposure to simulated gastric fluid.

Results from the enumeration tests indicated that recovery of viable organisms per dose is the same as or better than the stated label claims for liquid-based formulations, but lower than the stated claim for freeze-dried products. Results from the in vitro tolerance tests overall suggest that the PGF provided a harsher environment than the simulated systems at similar pH.

In general, liquid-based products tested tended to give superior results in terms of survival compared with the freeze-dried products tested. Results from tests in the fed state in PGF suggested that food greatly affects viability. Microcalorimetric data showed that for some products probiotic species were able to grow following exposure to gastric fluid, suggesting that viable bacteria reach the gut in vivo.

Read the full publication