Systematic review and meta-analysis: plant based therapy for functional dyspepsia

Introduction: Functional dyspepsia (FD) is characterized by symptoms such as bloating, early satiety, epigastric pain, and burning, with a global prevalence ranging from 11% to 29%. The causes are multifactorial, including motility disturbances, visceral hypersensitivity, immune activation and psychosocial factors. FD is classified according to the Rome IV criteria into postprandial distress syndrome and epigastric pain syndrome. It is associated with reduced quality of life and comorbid psychiatric disorders, highlighting the need for effective treatment. Many FD patients prefer herbal preparations to pharmaceutical medication. However, the efficacy of this form of therapy is uncertain.

Aim: The aim of this systematic review is to check the evidence supporting the efficacy and safety of use of phytotherapeutics in the treatment of FD.

Methods: A systematic review and meta-analysis were conducted to synthesize current evidence on phytotherapy for FD. Literature searches were performed in three electronic databases (Medline via PubMed, Web of Science, and Cochrane Library) until June 2023. Studies were excluded based on predefined criteria (homeopathic medicines,<10 participants, non-English or German publications). Efficacy was assessed using dichotomous ratings of symptom improvement, applying a 95% confidence interval and a random-effect model. The I² statistic for heterogeneity was classified as follows: 0-24%=none, 25-49%=low, 50-75%=moderate and>75%=high heterogeneity.

Results: A total of 2490 studies were identified, of which 53 (46 RCTs) were eligible, comprising 6450 participants. Meta-analysis was performed for any form of phytotherapy (21/46 (45%) studies included absolute or relative key figures relating to symptom improvement). Sufficient data was available to assess the effect of STW-5/Iberogast (2 studies), Rikkunshito (2 studies), and peppermint and caraway oil (4 studies). Further meta-analyses could not be conducted due to insufficient data. The results are displayed in the following Forest-Plots ([Fig. 1] [2] [3]). A Funnel-Plot indicated that publication bias may be present.

Fig. 1  Forest-Plot of Meta-analysis of STW-5

Fig. 2  Forest-Plot of Meta-analysis of Rikkunshito

Fig. 3  Forest-Plot of Meta-analysis of Peppermint and Caraway oil

Conclusion: This study demonstrates that certain phytotherapeutics are effective in treating FD. Peppermint and caraway oil, along with Rikkunshito, showed significant efficacy compared to placebo. The quality and reporting of many studies was limited. High-quality RCTs are needed to confirm the benefits of phytotherapy in this condition.