Helicobacter pylori are Gram-negative bacteria that inhabit the gastric mucosa and are associated with peptic ulcers and gastric malignancy
Standard treatment of H. pylori overgrowth is a triple therapy: two antibiotics plus a proton-pump inhibitor (PPI) or bismuth.
The most common antibiotics to treat H. pylori are metronidazole, clarithromycin and amoxicillin, but drug resistance is increasingly a problem. Also, even with the PPIs or bismuth to protect the gastric mucosa, gastrointestinal side-effects of triple therapy are problematic.
Berberine is an isoquinoline alkaloid, present in several medicinal plants. Berberine modulates the gastrointestinal flora — both inhibiting the growth of pathogens and promoting the growth of beneficial organisms.
Berberine also regulates smooth muscle contraction by inhibiting the entry of calcium into smooth muscle cells.
Its various mechanisms suggest that berberine might support the eradication of H. pylori while also mitigating some of the side-effects of standard triple therapy.
Several clinical trials have found that berberine enhances the efficacy and reduces the side-effects of triple therapy, so researchers at Guangzhou University conducted a meta-analysis of these trials.
Thirteen randomised controlled trials, including 2048 participants, were pooled for the analysis. The studies compared berberine plus triple therapy to standard triple therapy in patients with H. pylori infection.
Of the 13 studies, eight used berberine, two used berberine hydrochloride and three used compound berberine tablet. Duration of the treatments was 7–14 days.
The primary outcome measure for the meta-analysis was the eradication rate of H. pylori and the secondary outcome measure was the incidence of adverse events.
The meta-analysis found that the eradication rates of berberine combined with triple therapy were 18% higher than triple therapy alone in the urea breath test subgroup (risk ratio=1.18; 95% CI, 1.12-1.24).
Similarly, eradication rates were 23% higher with the addition of berberine compared to the triple therapy alone in the biopsy subgroup (RR=1.23; 95% CI, 1.13-1.34).
The incidence of adverse events was also lower in the berberine group than in the standard therapy group (odds ratio=0.59; 95% CI, 0.46-0.75).
More specifically, the incidence of nausea and diarrhoea were lower in the berberine group, but the incidence of abdominal distention and vomiting were the same.
Overall, this meta-analysis provides evidence that berberine can safely be combined with triple therapy for H. pylori to improve eradication rates and reduce adverse effects.