With the help of hydrogen breath test (HRT) the state of small intestina micro flora was studied and the time of transiting chyme in it was defined in 72 patients with chronic biliary-dependent pancreatitis. It was determined that in small intestine of 40% of patients there took place an excessive bacterial growth and chime transiting time increased. After dietary (a standard high-protein diet) and enzyme (Mezim, Creon) therapies, the bacterial semination and HRT were in norm. The use of HRT in gastroetherology permits to evalu ate the efficacy of performed therapy, m particular in patients with body weight deficiency, the character of diarrhea, its possible link with exoennous function of pancreas and excessive bacterial growth in intestine.