Citric acid inhibits growth of Helicobacter pylori in vitro: a new strategy for eradication

BACKGROUND: About 50% of the world population is infected with Helicobacter pylori. The association of peptic ulcer disease with Helicobacter pylori is well documented. Therefore eradication is obligatory. However, the high costs of multidrug therapy, the resistance of Helicobacter pylori to antibiotics as well as the sometimes present drug intolerance are limiting factors. METHODS: The inhibitory effect of 3% hydrogen peroxide, 8.4% sodium bicarbonate, 2% ascorbic acid, citric acid in combination with sodium citrate, 7% and 14% citric acid solutions, respectively, on nine Helicobacter pylori strains were tested in vitro. RESULTS: Citric acid showed a potent inhibitory activity on growth of Helicobacter pylori strains in vitro. This was observed not only when citric acid was applied alone but also if citric acid was given together with low concentration of sodium citrate. Two percent ascorbic acid inhibited three, sodium bicarbonate two and hydrogen peroxide one of the nine tested Helicobacter pylori strains, respectively. CONCLUSIONS: Citric acid is a cheap substance present in many fruits and produced by food industry, and it demonstrated powerful inhibitory effect on the growth of Helicobacter pylori strains. On the basis of our findings citric acid should be further evaluated for the eradication of Helicobacter pylori.