Association between gut microbiota and anxiety disorders: a bidirectional two-sample mendelian randomization study.

Area of Science:

• Microbiome research
• Neuroscience
• Genetics

Background:

• Growing evidence suggests a link between intestinal microbiota and anxiety disorders (AD).
• The brain-gut axis is a key area of research, but the precise relationship between gut microbiota and AD remains unclear.
• Bidirectional Mendelian randomization (MR) is employed to investigate potential causal relationships.

Purpose of the Study:

• To investigate the causal relationship between gut microbiota composition and anxiety disorders (AD).
• To identify specific bacterial genera associated with the risk of developing AD.

Main Methods:

• Utilized genetic instrumental variables from a large genome-wide association study (GWAS) for gut microbiota (18,340 participants).
• Employed summary data for AD from a GWAS (158,565 cases, 300,995 controls).
• Applied the inverse variance weighted (IVW) method, with sensitivity analyses (Cochran's Q, MR-Egger, MR-PRESSO) to ensure robustness and test for pleiotropy.

Main Results:

• Identified 9 potential causal connections between bacterial genera and AD risk.
• Five bacterial genera (Eubacteriumbrachygroup, Coprococcus3, Enterorhabdus, Oxalobacter, Ruminiclostridium6) showed a positive correlation with AD risk.
• Four bacterial genera (Blautia, Butyricicoccus, Erysipelotrichaceae-UCG003, Parasutterella) demonstrated a negative association with AD risk, confirmed by sensitivity analyses.

Conclusions:

• Established a causal relationship between specific gut microbiota components and anxiety disorders (AD).
• Findings highlight the potential role of the gut microbiome in AD etiology.
• Further research, including randomized controlled trials on probiotics, is recommended to understand protective mechanisms against AD.