Exploring Dietary- and Disease-Related Influences on Flatulence and Fecal Odor Perception in Inflammatory Bowel Disease

Background/Objectives: Inflammatory bowel disease (IBD) affects gastrointestinal function and may alter fecal and flatulence odor (intestinal odor) due to changes in inflammation, the gut microbiome, and metabolism. Investigating the relationship between dietary habits and intestinal odor in IBD is critical given the relationship between diet, gut health, and microbiome diversity. Methods: We performed a cohort analysis of a monocentric, cross-sectional study at a tertiary referral center and compared the perception of fecal and flatulence odor in 233 IBD patients (n = 117 women) with that of 96 healthy controls (HCs) (n = 67 women). In addition to a short screening questionnaire on highly processed foods (sQ-HPF), dietary behavior (Food Frequency Questionnaire (FFQ)), clinical (HBI, PMS) and biochemical (CRP, fecal calprotectin) parameters of disease activity, and adherence to a Mediterranean diet were assessed. Results: A notable predisposition towards elevated levels of intestinal malodor was identified in the IBD cohort when compared to the HC group. The analysis of dietary behavior in conjunction with intestinal malodor revealed more pronounced associations in the HC collective than in the IBD collective. The data further indicated that, in comparison to those in remission, IBD individuals with an active disease status exhibited a higher prevalence of intestinal malodor. In an adjusted logistic regression analysis of the influence of disease- and diet-specific factors on flatulence and fecal malodor in IBD, male sex was identified as a significant risk factor. Conclusions: This study highlights the significance of dietary factors in the management of IBD symptoms, with a particular focus on flatulence and fecal odor. Individuals with IBD demonstrated a higher propensity for intestinal malodor compared to HC, with active disease status further amplifying this prevalence. Dietary behavior showed stronger associations with malodor in the HC group than in IBD individuals, suggesting distinct interaction patterns between diet and gut health in these populations.