Abstract: To investigate whether and how consumption of goats'' milk cheese affects Helicobacter pylori activity in the stomach of infected subjects, a randomized, controlled and blind study was performed. Sixty volunteers consumed 4 × 25 g day−1 “Gouda-type” cheese for 3 weeks, prepared from either goats'' or cows'' milk. The goats'' milk cheese was rich in short- and medium-chain fatty acids. Immediately before the start and thereafter every seven days, H. pylori activity was measured by the 13C-urea breath test, and gastrointestinal well-being was recorded weekly by validated questionnaires. Neither goats'' nor cows'' milk cheese had any significant effect on H. pylori activity. Ingestion of both cheeses improved gastrointestinal well-being but had no effect on stool parameters. The difference of the total symptoms score was significant between day 0 and 21 in each dietary groups, but not between the goats'' and cows'' milk cheese. [Copyright &y& Elsevier]