Probiotics as a Tool for the Management of Helicobacter pylori
contribute to the maintenance of low densities of H. pylori and decreased intensities of gastric inflammation, thus reducing the risk for gastric pathologies?
An interesting third question that has not yet been explored is whether the consumption of probiotics by children living in areas with high incidence of H. pylori delays their colonization.
In relation to the first question, a meta-analysis evaluating the effect of probiotics on eradication rates and adverse effects during H. pylori antibiotic treatment and incorporating 14 randomized trials (1,671 subjects), was recently published.37
Pooled eradication rates were 83.6%
(95% confidence interval [CI] 80.5–86.7%) for patients receiving probiotics and 74.8% (95% CI 71.1–78.5%) for patients not in receipt of probiotics (odds ratio [OR] 1.84, 95% CI 1.34–2.54). Probiotics also significantly decreased the total adverse effects of the therapy compared with the controls (24.7%, 95% CI 20–9.4% versus 38.5%, 95% CI 33.0–44.1%; OR 0.44, 95% CI 0.30–0.66). Although this study suggests that probiotic administration may be useful in improving eradication rates while decreasing adverse effects, caution has to be exerted in its interpretation. There is considerable diversity between the studies in this meta-analysis, particularly in relation to the treatments used and the strains, dosages, frequency, and administration duration of the probiotics. Some studies were carried out in children and others in adults, and not all of them were placebo- or double-blind-controlled, an important factor when the outcome, including the adverse effects, may be subjective.
Seven clinical trials with the same aim have been subsequently published (see Table 1).38–44
double-blind, controlled studies.38,40,42
Only three of the studies were randomized, The main probiotics used in these
studies were L. reuteri ATCC 55730 and S. boulardii. Probiotics were administered, together with pharmacologic therapy and, in some cases, their intake was maintained after the antibiotic treatment had been completed. In only one study the probiotic was administered prior to the triple therapy.42
Finally, it has been shown that other foodstuffs exert anti-H. pylori activities. The investigation in this field has focused on the possible use of cranberry juice or extracts, due to their high concentrations of pro-anthocyanidins capable of inhibiting H. pylori growth and adhesion to human gastric mucus and epithelial cells.55
These in vitro studies have
been confirmed by a clinical trial showing that the administration of cranberry juice (500ml per day) for 90 days to colonized subjects eradicated the pathogen in 14.3% of them.56
cranberries inhibit H. pylori through different mechanisms (bacteriocins and proanthocyanidins, respectively), it is interesting to postulate that the simultaneous intake of both foodstuffs might result in an additive or synergistic inhibition of H. pylori in colonized subjects.
To confirm this hypothesis, we recently realised a multicenter, randomized, controlled, double-blind trial in 295 asymptomatic colonized children using L. johnsonii NCC533 as the probiotic.57
Children
Of these seven studies, lower rates of adverse effects were observed in four, while they increased in one and remained unchanged in two. Eradication rates were unaffected by probiotics in five studies and improved in two open studies. These results confirm the importance of randomized, double-blind, controlled clinical trials and the need to homogenize the experimental protocols in order to reach more solid conclusions.
Of these only three were randomized, double-blind, and placebo-controlled and six had a low sample size (<50). In seven studies (four of them with L. johnsonii NCC533) significant decreases of 13C excretion in the 13C–UBT or in H. pylori stool antigen excretion was observed, suggesting a lower gastric density of H. pylori after probiotic treatment.27,47–51
using S. boulardii in children.52
An eradication rate of 12% of was observed in one study The UBT was carried out immediately
after the end of the treatment period with the probiotic, perhaps favoring false-negative results. A decrease in the severity of gastric
US GASTROENTEROLOGY & HEPATOLOGY REVIEW
In relation to whether probiotic intake contributes to the maintenance of low densities of H. pylori and decreased intensities of gastric inflammation, the results of 10 clinical trials with probiotics alone carried out in colonized adults and children have recently been reviewed.45
were allocated into four groups to receive a daily amount of 200ml of cranberry juice (or its placebo) and 80ml of a product containing NCC533 (or its placebo) for three weeks. H. pylori detection was carried out by UBT before treatment and after treatment. We observed that the eradication rates significantly differed in the four groups: 1.5% in the control group compared with 14.9, 16.9, and 22.9% in the NCC533, cranberry, and cranberry/NCC533 groups, respectively. In comparison with the cranberry group and the NCC533 group, the eradication rate in the group receiving both foodstuffs was increased, but not significantly. The results using foodstuffs containing different bioactive compounds useful against H. pylori are promising and deserve further investigation.
Conclusions
The use of probiotics in H. pylori-colonized subjects with gastric inflammation is supported by many observations. Some specific strains of Lactobacillus and Bifidobacterium inhibit H. pylori through the production of bacteriocins or organic acids, and/or inhibit its adhesion to epithelial cells in vitro and animal models. Some clinical trials have evaluated the effect of probiotics in colonised adults and children, showing that they contribute to maintaining low levels of H. pylori in the stomach and to decreasing gastric inflammation. In association with antibiotic treatments, some probiotics increased eradication rates and/or decreased adverse effects. These findings confirm that, as suggested by the 2000 Maastricht Consensus Conference on H. pylori, probiotic micro-organisms may be used as a possible tool for the management of H. pylori infection and its associated gastric inflammation. n
25 As probiotics and
The anti-inflammatory activity of probiotics was confirmed by two recent studies. The first was a randomized, double-blind, controlled study in 79 subjects who received B. bifidum YIT 4007 or a placebo for 12 weeks; the results of the UBT were significantly lower at the end of the treatment while serum pepsinogen I/II levels, a biomarker of inflammation, decreased slightly.53
inflammation after the probiotic treatment was observed in three studies.48,50,51
In another study in 12 patients
receiving L. rhamnosus GG, L. rhamnosus LC705, P. freudenreichii ssp. shermanii JS and B. lactis Bb12 for eight weeks, UBT values decreased significantly after treatment, as did levels of serum gastrin-17, another marker of gastric inflammation.54
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