[The dietary features of diarrhea predominant irritable bowel syndrome patients with small intestinal bowel overgrowth].

Objective: To explore the diet features of diarrhea predominant irritable bowel syndrome (IBS-D) with small intestinal bacterial overgrowth (SIBO). Methods: IBS-D patients were enrolled in outpatient department of Peking University Third Hospital from March 2015 to April 2016. Healthy volunteers were recruited as controls (HC). All the subjects completed screening examinations, clinical and food investigation, and lactulose methane and hydrogen breath test (LMHBT). The high fat diet is defined as the daily total calories supplying from fat is more than 50%. Results: Eighty-eight IBS-D patients and 32 HC were finally enrolled. The positive rate of LMHBT in IBS-D was significantly higher than that of HC[39.8% (35/88) vs 12.5%(4/28), P =0.005]. The 28 HC with negative LMHBT were enrolled in the follow-up analysis. (1) The BMI of IBS-P (IBS-D with positive LMHBT) was significantly lower than IBS-N (IBS-D with negative LMHBT) [(21.57±0.54) vs (23.30±0.53)kg/m(2,) P =0.032]. IBS-D patients with SIBO had higher scores of abdominal pain assess. (2) The proportion of dietary protein and carbohydrate in IBS-D was significantly higher than that of HC (14.39% vs 12.22%, P =0.001; 53.94% vs 46.25%, P =0.003, respectively). The proportion of diet fat was significantly higher in IBS-P than IBS-N[(47.19±2.62)% vs (40.74±1.66)%, P =0.038]. (3) The baseline of breath methane in IBS-P was significantly higher than that of in IBS-N[(8.69±0.39) ×10(-6) vs (6.39±0.47) ×10(-6,) P =0.002]. IBS-D patients with high fat diet had higher LMHBT positive rate than that of non-high fat diet patients[54.2% (13/24) vs 17.2% (11/64), P =0.001]. Breath methane peak value was positively correlated with the fat proportion of diet ( r =0.413, P =0.022). Conclusions: About 39.8% IBS-D patients diagnosed by Rome Ⅲ are combined with SIBO. SIBO may affect IBS-D patients' nutritional status. High fat diet might be one of the risk factors for IBS-D with SIBO. Proper diet structure might reduce the prevalence of IBS-D, especially for IBS-D with SIBO.