Correlations of Gut Microbiome, Serum Metabolome and Immune Factors in Insomnia

Abstract

Insomnia is a common sleep disorder of unclear etiology characterized by individuals experiencing the inability to sleep or the difficulty staying asleep. Gut-brain interaction is being explored with the intent of discerning gut microbiota and its role in many brain-related conditions including insomnia. The number and diversity of gut microbiota that colonize the digestive tract could have a significant association with insomnia, given the microbes that colonize the digestive tract integrate with and impact on the central nervous system, the immune system and multiple metabolic pathways. We aim to examine the diversity and to explore the functional impact of gut microbiota in insomniacs by examining fecal microbiome using 16S rRNA gene sequencing, serum metabolome using ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS), and various immune factors. Our results discover altered and distinct gut microbiota in insomniacs, with enriched Desulfovibrio, Lactobacillus and Streptococcus, and decreased abundance of Bifidobacterium, Gardnerella, Sneathia, Aerococcus and Atopobium. Non-targeted metabolomics identify 31 aberrant metabolites and implicate metabolic pathways in insomniacs. Most importantly, correlations across gut microbiome, serum metabolome and inflammatory factors are unraveled. Our study provides a better understanding of gut microbiota’s role in insomnia and new insights into potential novel etiologies for insomnia.