Retraction of: Scientific Reports https://doi.org/10.1038/s41598-018-35367-7, published online 17 January 2019

The Authors have retracted this Article.

Recent probiotic use was an exclusion criterion for participation in the randomised clinical trial (RCT) reported in the Article. Following publication, the authors identified via dietary data collected concomitantly, but outside the study protocol, that 26% of the trial participants may have been using probiotics despite reporting no use at the time of inclusion. While there had been no deliberate violation of the protocol, if these participants are retrospectively excluded the statistical power of the RCT falls below 80%.

All authors agree to this retraction.