Shift work, gut dysbiosis, and circadian misalignment: The combined impact of nighttime light exposure, nutrients, and microbiota rhythmicity

Disruption of circadian rhythms, particularly in shift workers, has been increasingly associated with a wide range of adverse health outcomes, including metabolic, immune, cardiovascular, and neurobehavioral impairments. This review explores the intricate bidirectional interactions between the circadian clock and the gut microbiota, highlighting how nighttime exposure to artificial light and irregular nutritional timing affect microbial composition, rhythmicity, and microbial-derived metabolite production. We summarize current evidence linking circadian misalignment to gut dysbiosis, inflammation, and metabolic dysfunction, and discuss emerging strategies such as chrononutrition, light modulation, and targeted microbial interventions (e.g. targeted probiotics). Understanding this complex network of light exposure, food intake, circadian regulation, and microbial dynamics could pave the way for personalized preventive and therapeutic strategies in populations vulnerable to circadian disruption, such as night shift workers. These strategies have the potential to mitigate health risks and improve overall well-being in affected individuals.