Safety and tolerance of L. reuteri in healthy adult male subjects.

A prospective, double blind, placebo-controlled study in which 30 healthy males, aged 18–75, consumed L. reuteri ATCC 55730 in a daily dose of 10¹¹ CFU, or placebo, for 21 days. The subjects made a daily note of any symptoms from the gastrointestinal tract, and samples were taken on days 0, 7, 14, 21 and 28 for analysis of serum, blood, urine and stools. L. reuteri colonized the subjects in the active group within one week, as shown by a significantly higher number of L. reuteri in their stools compared with the control group.

The colonisation persisted for at least one week after intake had stopped, apart from in one individual, who remained colonized for up to 2 months after the end of the L. reuteri intake period. A tendency was observed for slightly increased, though transient, gas formation in a few subjects taking L. reuteri. No significant differences were shown in regard to blood and urine analyses or in regard to tolerance of bacterial intake.

Conclusion: The daily consumption of L. reuteri at the dosage of 10¹¹ CFU for 21 days was shown to be safe and without any side-effects for healthy male adults.

Reference

Safety and tolerance of Lactobacillus reuteri in healthy adult male subjects.
Wolf BW, Wheeler KB, Ataya DG, Casas IA. (1995) Microb Ecol Health Dis. 8:41-50.