Pre-Incubation of Probiotics Before Intake: A Reasonable Recommendation?

Abstract

Abstract Background Protecting the bacteria contained in probiotics against the effects of low pH is one of the key issues for the development and production of such products. In earlier research we demonstrated that the inactivation of bacteria in probiotics by low pH can be prevented by an effective enteric coating formulation of the product. Objective The present study aimed to evaluate whether the producer’s recommended pre-incubation step for its probiotic product A prior to intake is having an effect on the survival rate of the product’s bacteria in low pH solutions. Method For the investigated product A (and an enteric coated reference product B) amounts of colony forming units (CFU) before and after pre-incubations for 0, 1 and 30 min followed by exposure to 0.1 N HCl (pH 1.2) at 37°C for 90 min were determined. The loss of living bacteria was calculated using the CFU1/CFU0-ratio, with CFU1 and CFU0 being the amount of CFU at the end and at the beginning of the experiment, respectively. Results The exposure of the product A to a low pH (1.2) resulted in a strong reduction of the amount of CFU (about -99.9%). Pre-incubation of product A neither for one nor for 30 min had a significant effect on the strong loss of viability of the probiotic bacteria contained in product A when compared to the loss without the pre-incubation process. In contrast, exposing the enteric coated product B to low pH resulted only in a minor loss (about -7%) of living bacteria. Conclusions The pre-incubation before intake recommended by the producer of product A is not having a significant influence on a major reduction of CFU caused by the exposure to low pH. However, the observed considerable loss of CFU in a solution that mimics the condition in the human stomach triggers doubts about product A. We strongly suggest basing probiotic product related statements on scientific data.