Gut microbiota profile can discriminate between paradoxical and objective insomnia in post-menopausal women

Insomnia remains one of the most common sleep disorders among middle-aged and older adults heavily affecting quality of life and predisposing to age-related diseases. Insomnia is classified into objective insomnia (O-IN) or paradoxical insomnia (P-IN), with the latter characterized by a discrepancy between subjective and objective sleep assessments. Currently the two groups of patients are treated with the same drug therapy often with unsatisfactory results, and thus there is an urgent need to explore the neurophysiological mechanisms of P-IN versus O-IN to establish new precision therapeutic interventions. Due to the emerging role of gut microbiota in influencing sleep physiology via the gut-brain axis, in the present study we characterized the gut microbial profiles of a well-characterized cohort of 96 Italian post-menopausal women (54 insomniac patients (18 O-IN and 36 P-IN) and 42 controls) by 16S rRNA amplicon sequencing. We then tested for associations with general and clinical history, sleep, stress and psychological evaluation, anthropometric and hematobiochemical measurements. Nutritional patterns and other health-related parameters were also assessed. Results showed that Coriobacteriaceae family and its genera Collinsella and Adlercreutzia were distinctive of O-IN patients, along with Erysipelotrichaceae, Clostridium and Pediococcus. As for P-IN patients, they were mainly discriminated by Bacteroides, Staphylococcus, Carnobacterium, Pseudomonas and their respective families, along with Odoribacter. This is the first study identifying distinct profiles in the gut microbiota of O-IN and P-IN patients, which could pave the way for improved stratification criteria and the design of integrated microbiota-based therapeutic strategies.