Studies using supplementation with L. reuteri in both symptomatic and non-symptomatic H. pylori-infected subjects show a clear reduction of infection load after 4 weeks of use and this was concomitant with a reduction in symptoms associated with the infection (Imase et al. 2007; Francavilla et al. 2007, unpublished data). Further, dietary supplementation with L. reuteri during and after the period of H. pylori eradication therapy has also been shown to reduce the side effects of this therapy without affecting the degree of eradication (Lionetti et al., 2007). It is also feasible, through the inhibitory action of L. reuteri on H. pylori, that pre-exposure to L. reuteri may weaken H. pylori and make it more susceptible to antibiotic attack during eradication.