A recent study found that a particular garlic supplement (Garsin) works as well as metronidazole without as many side effects.
Source: Iran Red Crescent Med J. 2014 Jul;16(7):e19118. Comparing the therapeutic effects of garlic tablet and oral metronidazole on bacterial vaginosis: a randomized controlled clinical trial.
In a randomized, double-blind, placebo-controlled study involving 82 patients with symptoms of dyspepsia and H. pylori infection, consumption of kefir (250 mL), twice a day, was found to improve the efficacy and tolerability of triple therapy in eradicating H. pylori infection, as compared to treatment with triple therapy (30 mg lansoprazole, 1000 mg amoxicillin, 500 mg clarithromycin) plus a placebo (milk containing a placebo). Forty-five days after beginning treatment, patients completed urea breath tests and results showed significantly more patients who received triple therapy plus kefir achieved eradication of H. pylori (36 of 46, 78%), as compared to patients who received triple therapy plus placebo (18 of 36, 50%). Furthermore, significantly fewer side effects were found among patients who received the kefir.
Source: J Med Food, 2010 Dec 27