Disrupted Rhythms, Disrupted Microbes: A Systematic Review of Shift Work and Gut Microbiota Alterations

Area of Science:

• Microbiome research
• Chronobiology
• Occupational health

Background:

• Shift work disrupts circadian rhythms, increasing risks for metabolic, gastrointestinal, cardiovascular, and neurocognitive disorders.
• Gut microbiota may play a mediating role in these adverse health outcomes.
• Understanding the gut microbiome's response to shift work is crucial for public health.

Purpose of the Study:

• To systematically review and assess alterations in gut microbiota composition due to shift work.
• To explore potential mediating roles of gut microbiota in shift work-related health consequences.

Main Methods:

• Systematic literature search of PubMed, Scopus, and ScienceDirect up to March 2025.
• Inclusion of studies on adult shift workers reporting gut microbiota changes.
• Risk of bias assessment using NIH Quality Assessment Tool and ROBINS-E framework.

Main Results:

• Four observational studies and one Mendelian randomization study were included.
• Observational studies indicated reduced gut microbial diversity and increased pro-inflammatory bacteria in night shift workers.
• Preliminary evidence suggests a causal link between circadian misalignment, gut dysbiosis, and cardiovascular risk.

Conclusions:

• Shift work is linked to significant gut microbiota alterations, potentially contributing to adverse health outcomes.
• Current evidence is limited and heterogeneous, requiring further investigation.
• High-quality longitudinal and interventional studies are needed to establish causality and develop preventive strategies.