Effects of Probiotic Supplementation on Circadian Rhythm-Related Gene Expression and Body Weight in Mice with Disturbed Circadian Rhythms.

Given the limited knowledge of probiotic effects on clock genes, this study investigated whether probiotics that regulate gut integrity and microbiota balance influence central circadian clock gene expression. In this study conducted on three groups [control group (CG), shifted group (SG), and shifted and probiotic supplement group (SPG)] of eight BALB/c mice each, Clock, Bmal1, and Per2 gene expressions and weight gain were evaluated. Although body weights at baseline, week 8, and week 16 were similar among groups, weight gain over time was significantly higher in the SG and SPG groups (p<0.05). Significant differences were observed between CG and SG at week 8 and between SG and SPG at week 16. Gene expression analyses revealed no significant differences in Clock expression. However, Bmal1 expression at ZT18 was significantly different between the CG and SPG groups (p = 0.045). These findings demonstrate the regulatory effect of probiotic supplementation on circadian disruption and weight gain, suggesting a potential role in circadian rhythm management. Nevertheless, the results should be interpreted cautiously because they are based on limited gene expression changes and require confirmation in larger studies.