A randomized crossover study in twenty-one patients (18F, age 50 ± 13 years) with overlapping GERD-IBS was conducted to evaluate the effects of rice noodles (low FODMAPs) vs. wheat noodles (high FODMAPs) on typical GER symptoms, and the correlation between GERD symptoms and intestinal gas production. Results: Heartburn and regurgitation scores were highest in most patients (19/21) during the first 15 min after meals. At 15 min after lunch, wheat was significantly associated with more regurgitation and heartburn than rice. Also, at 15 min after breakfast, wheat aggravated more regurgitation than rice. Wheat ingestion was significantly associated with higher H2 and CH4 levels after lunch compared to rice, whereas gas levels before lunch were similar (p > 0.05). The area under the curve of H2 and CH4 concentration 15 min after a lunch of wheat moderately correlated with the regurgitation severity at 15-min (r = 0.56, p < 0.05). Conclusion: Wheat induced more GERD symptoms than rice in patients with overlapping GERD-IBS. This effect, immediately developed after lunch, was associated with more intestinal gas production. Thus, a low FODMAPs diet may relieve postprandial GERD symptoms in GERD patients with overlapping IBS. Wheat inducing more regurgitation than rice after breakfast suggests other mechanism(s) besides gut fermentation.
Keywords: GERD; fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs); fermentation; intestinal gas; irritable bowel syndrome; rice; wheat.