Association between gut microbiota and common overlapping gastrointestinal disorders: a bidirectional two-sample...

Area of Science:

• Gastroenterology
• Microbiome Research
• Genetics

Background:

• Functional gastrointestinal disorders (FGIDs), including functional dyspepsia (FD) and irritable bowel syndrome (IBS), often share symptoms with gastroesophageal reflux disease (GERD).
• The gut microbiota's role in FGIDs and GERD is recognized but not fully understood.
• Establishing a causal relationship between gut microbiota and these conditions is crucial for effective diagnosis and treatment.

Purpose of the Study:

• To investigate the potential causal relationship between gut microbial composition and functional dyspepsia (FD), irritable bowel syndrome (IBS), and gastroesophageal reflux disease (GERD).
• To utilize bidirectional two-sample Mendelian randomization (MR) analysis for exploring these associations.

Main Methods:

• Genetic data for 211 gut microbial taxa were sourced from the MiBioGen consortium and the Dutch Microbiome Project.
• Genome-wide association study (GWAS) data for FD and IBS were obtained from the FinnGen consortium, and for GERD from the IEU OpenGWAS project.
• Bidirectional two-sample Mendelian randomization (MR) analysis, primarily using the inverse-variance weighted (IVW) method, with sensitivity analyses and reverse MR were performed.

Main Results:

• The analysis identified 8 gut microbial taxa associated with FD, including the genera *Lachnospiraceae NK4A136 group* and *Terrisporobacter*.
• Eight gut microbial taxa were associated with IBS, notably the family *Prevotellaceae* and species *Clostridium leptum*.
• Five gut microbial taxa were associated with GERD. Reverse MR analysis revealed associations between specific microbial taxa and FD (2), IBS (5), and GERD (21).

Conclusions:

• The study provides evidence for potential causal effects of specific gut microbial taxa on FD, IBS, and GERD.
• These findings may offer new perspectives for the clinical diagnosis and therapeutic strategies for these prevalent gastrointestinal conditions.