Self-reported sleep quality is associated with gut microbiome composition in young, healthy individuals: a pilot study

Abstract

Objectives: The microbiota-gut-brain axis is an intricate communication network that is emerging as a key modulator of psychological and physiological wellbeing. Recent pioneering work in the field has suggested a possible link between gut microbiome composition with sleep, an evolutionarily conserved behavior demonstrated to play a critical role in health. This study is the first to address relationships between self-reported sleep habits and gut microbiome composition in young, healthy individuals.

Methods: A total of 28 young, healthy subjects (17 males/11 females; 29.8 ± 10.4 years) that were free of metabolic or cardiovascular disease, and that did not take sleep medication or antibiotics within the past six months were included in the study. Relationships between self-reported sleep quality, obtained using the Pittsburgh Sleep Quality Index (PSQI), with microbial diversity (Shannon Index), the Firmicutes/Bacteroidetes (F/B) ratio, and select bacterial taxa were assessed.

Results: Alpha diversity (r = -0.50) and F/B ratio (r = -0.47) were inversely associated (P < 0.05) with the PSQI score. Ten bacterial taxa were associated (P < 0.05) with the PSQI score, including genus-level Blautia (r = -0.57), Ruminococcus (r = -0.39), and Prevotella (r = 0.39).

Conclusions: In young healthy individuals, self-reported sleep quality was positively associated with microbial diversity. We also observed a positive association between sleep quality with F/B ratio, seemingly due to a greater relative abundance of Blautia and Ruminococcus (Firmicutes) and lower proportions of Prevotella (Bacteroidetes) in individuals reporting superior sleep quality. Future studies are encouraged to evaluate mechanistic links between the gut microbiome with sleep, as well as the health implications of this relationship.

Keywords: Blautia; Gut microbiome; Microbiota-gut-brain axis; Prevotella; Sleep.

Figure 1.

Scatterplots showing associations of the global Pittsburgh Sleep Quality Index (PSQI) score with A) Alpha diversity (Shannon’s Diversity Index) and B) Firmicutes/Bacteroidetes ratio. Black dots represent “normal” sleepers, characterized by a global PSQI score between 0–5, whereas white dots represent “poor” sleepers with a PSQI score > 5 [24]. Trendlines consider all data points.

Figure 2.

Theoretical model illustrating the possible down-stream implications of gut microbiome differences observed in normal (PSQI 0–5) vs. poor (PSQI > 5) self-reported sleepers [24]. Compared to poor sleepers, the gut microbiome of normal sleeping individuals exhibited greater microbial diversity and an elevated F/B ratio. At the genus level, normal sleepers possessed a greater relative abundance of the butyragenic genera Blautia and Ruminococcus, which may aid in the attenuation of inflammation. Meanwhile, the gut microbiome of poor sleepers was characterized by a greater relative abundance of the genus Prevotella, which has been implicated in endotoxemia (i.e., increased circulating lipopolysaccharide [LPS]), branch chain amino acid (BCAA) production, and metabolic dysfunction.