Exploring the potential causal effects of food preferences on irritable bowel syndrome risk: A two-sample Mendelian randomization study

Objectives

Irritable bowel syndrome (IBS) is a common disorder in gut–brain interaction. Diet plays an important role in the pathophysiology of IBS. Therefore, we aimed to explore the potential causal effects of food-liking on IBS to provide better diet advice for patients.

Methods

Single-nucleotide polymorphisms associated with food-liking were selected as instrumental variables, which were obtained from the latest genome-wide association study (GWAS) conducted on 161 625 participants. The summary data of genetic associations with IBS were obtained from a recent GWAS with 433 201 European controls and 53 400 cases. We used inverse variance weighting as the main analysis. Sensitivity analyses were conducted to detect horizontal pleiotropy and heterogeneity.

Results

Significant evidence revealed the protective effects of a vegetarian diet-liking on IBS, including asparagus, avocadoes, globe artichoke, aubergine, and black olives, while onion-liking showed potential deleterious effects. For meat and fish, preference for sardines and fried fish was marginally associated with IBS risk, but salami and salmon were potential protective factors. In terms of desserts and dairy products, preferences for cake icing, ketchup, and cheesecake were suggestively associated with higher IBS risk, while goat cheese-liking was marginally correlated with lower IBS risk. Additionally and suggestively, significant causal effects of IBS on increased preferences for globe artichoke and salami were also found in a reverse Mendelian randomization (MR) study.

Conclusion

Our study revealed potential causal associations between food preference and IBS from a genetic perspective, which provides a dietary reference for such patients.