Summary of Effects of Gluten on Dyspeptic Symptoms: A Systematic Review and Meta-Analysis of Clinical Trials
Introduction
Dyspeptic symptoms, such as bloating, early satiety, epigastric pain, and nausea, can significantly impact the quality of life for individuals with functional dyspepsia. There has been ongoing debate regarding the effects of gluten on these symptoms, with conflicting results reported in previous studies. To address this controversy, a systematic review and meta-analysis of clinical trials was conducted to evaluate the effects of gluten on dyspeptic symptoms. The aim of this article is to provide a comprehensive summary of the findings from this study and shed light on the potential implications for individuals with functional dyspepsia.
Methodology
The systematic review and meta-analysis included a thorough search of several online databases, including PubMed, ISI Web of Science, Scopus, Cochrane, and Embase. The search was conducted up to May 2022, and both randomized controlled trials (RCTs) and non-RCTs were considered for inclusion. The selected studies examined the impact of a gluten-free diet, a low-gluten diet, or a gluten challenge on dyspeptic symptoms. Two authors independently screened and selected the articles, and the certainty of the evidence was assessed using the GRADE framework. The results were pooled using a random-effects model and expressed as weighted mean differences (WMDs) and 95% confidence intervals (CIs).
Results
A total of 27 articles, comprising 18 RCTs and 9 non-RCTs, were included in the systematic review. Of these, 5 RCTs were eligible for the meta-analysis. The pooled results indicated that a gluten challenge significantly increased the severity of bloating, early satiety, and epigastric pain. However, there was no significant effect of gluten challenge on the severity of nausea.
| Dyspeptic Symptom | Effect Size (WMD) | 95% CI | I2 (%) |
|---|---|---|---|
| Bloating | 0.67 | 0.37-0.97 | 81.8% |
| Early Satiety | 0.91 | 0.58-1.23 | 27.2% |
| Epigastric Pain | 0.46 | 0.17-0.75 | 65.8% |
| Nausea | 0.13 | -0.17 to 0.43 | 0.0% |
Discussion
The findings of this systematic review and meta-analysis suggest that gluten challenge significantly worsens dyspeptic symptoms, including bloating, early satiety, and epigastric pain. These results provide support for the potential benefits of gluten restriction in reducing dyspeptic symptoms in individuals with functional dyspepsia. However, it is important to note that the effect of gluten on dyspeptic symptoms may vary among individuals, and further research is needed to understand the underlying mechanisms and identify specific subgroups that may benefit the most from gluten restriction.
Limitations
It is essential to acknowledge the limitations of this study. The certainty of the evidence was rated as very low for all outcomes, highlighting the need for more high-quality research in this area. Additionally, the heterogeneity among the included studies, such as variations in gluten challenge protocols and duration of interventions, may have influenced the results. Further, the generalizability of the findings may be limited due to the specific populations and settings of the included studies.
Conclusion
In conclusion, this systematic review and meta-analysis provide valuable insights into the effects of gluten on dyspeptic symptoms. The findings suggest that gluten challenge exacerbates bloating, early satiety, and epigastric pain in individuals with functional dyspepsia. These results support the potential benefits of gluten restriction in managing dyspeptic symptoms. However, further well-designed large-scale randomized controlled trials are needed to clarify the effectiveness of gluten restriction on dyspeptic symptoms and identify subgroups that may benefit the most from this dietary intervention.
Future Directions
Moving forward, future research should focus on addressing the limitations highlighted in this study. Well-designed large randomized controlled trials that recruit homogenous groups of patients with functional dyspepsia are needed to provide more robust evidence on the effects of gluten restriction. Additionally, exploring the mechanisms underlying the association between gluten and dyspeptic symptoms can help develop personalized interventions and optimize the management of functional dyspepsia.
References
- Hosseinian SZ, Haghighatdoost F, Hajihashemi P, Adibi P. Effects of gluten on dyspeptic symptoms: a systematic review and meta-analysis of clinical trials. Nutr Rev. 2023 Apr 28:nuad034. doi: 10.1093/nutrit/nuad034. Epub ahead of print. PMID: 37115663.
