Gut Microbiota Diversity and Composition Across Shift Types
Shift workers are at increased risk of chronic diseases due to circadian rhythms disruption, suboptimal lifestyle behaviors, and possibly altered gut microbiota (GM). This study aimed to analyze variations in GM diversity and composition across three types of weekly shifts in rotating shift workers. Using a within-person design, we compared GM diversity and composition in 13 shift workers during morning, afternoon and night shifts. Following a three-week observational period, participants added a daily serving of walnuts to their habitual diet for three additional weeks. GM was analyzed via 16S rRNA sequencing, comparing diversity and bacterial composition across shift types and between the observational and interventional phases. Overall microbiota composition did not differ between the beginning and end of the shift, by shift type, or after walnut supplementation. Bacterial diversity was stable, except for a significant decrease at the end of the night shift during the observation phase (p=0.03), which was not observed during walnut supplementation. GM strongly clustered by subject regardless of shift type or walnut supplementation. Across the study period, a healthier diet was associated with a greater mean GM diversity (r = 0.64, p=0.02). Despite stability in GM composition and diversity across most shift types, the decline in diversity during night shifts suggests targeted nutritional strategies—such as walnut supplementation—may support gut health in shift workers. Promoting healthy eating remains essential, particularly during night shifts.
Shift workers are at increased risk of chronic diseases due to circadian rhythms disruption, suboptimal lifestyle behaviors, and possibly altered gut microbiota (GM). This study aimed to analyze variations in GM diversity and composition across three types of weekly shifts in rotating shift workers. Using a within-person design, we compared GM diversity and composition in 13 shift workers during morning, afternoon and night shifts. Following a three-week observational period, participants added a daily serving of walnuts to their habitual diet for three additional weeks. GM was analyzed via 16S rRNA sequencing, comparing diversity and bacterial composition across shift types and between the observational and interventional phases. Overall microbiota composition did not differ between the beginning and end of the shift, by shift type, or after walnut supplementation. Bacterial diversity was stable, except for a significant decrease at the end of the night shift during the observation phase (p=0.03), which was not observed during walnut supplementation. GM strongly clustered by subject regardless of shift type or walnut supplementation. Across the study period, a healthier diet was associated with a greater mean GM diversity (r = 0.64, p=0.02). Despite stability in GM composition and diversity across most shift types, the decline in diversity during night shifts suggests targeted nutritional strategies—such as walnut supplementation—may support gut health in shift workers. Promoting healthy eating remains essential, particularly during night shifts.