The correlation between gut microbiota and sleep quality changes in breast cancer patients receiving postoperative chemotherapy: a longitudinal study.

[STUDY OBJECTIVES] Sleep problems are common in breast cancer patients undergoing postoperative chemotherapy. The association between gut microbiota dysbiosis and impaired sleep quality has been demonstrated in some cross-sectional studies. However, their longitudinal and temporal associations remain unclear.

[METHODS] A longitudinal study was conducted among breast cancer patients undergoing postoperative chemotherapy in two East China hospitals. Data collection included the general information form, the General Sleep Disturbance Scale, and fecal samples for 16S rRNA sequencing analysis. Repeated measures ANOVA examined sleep quality trajectories, growth mixture models (GMM) identified latent trajectory classes, and logistic regression explored class predictors. Cross-lagged panel models examined the temporal association between gut microbiota and sleep quality.

[RESULTS] Sleep quality initially declined and subsequently improved during chemotherapy, remaining lower than pre-chemotherapy levels. Distinct sleep trajectory classes were identified: persistent sleep disorder (23.81%), post-chemotherapy sleep disorder (45.24%), no sleep disorder (30.95%). Age, exercise frequency, mental stress, probiotic product consumption and chemotherapy regimen were significant predictors of trajectory class membership. Cross-lagged analyses indicated a lower Shannon index can affect a subsequent sleep quality decline. Faecalibacterium and Butyricicoccus abundance predicted improved subsequent sleep quality, while Intestinibacter abundance negatively predicted it. Ruminococcus demonstrated bidirectional temporal associations with sleep quality.

[CONCLUSION] Specific butyrate-producing gut bacteria, rather than overall microbial diversity, showed temporal associations with sleep quality in breast cancer patients undergoing chemotherapy. These findings suggest that targeted microbiota interventions warrant further investigation as potential strategies for improving sleep quality during cancer treatment.