The effect of probiotics on mood and sleep quality in postmenopausal women: A triple-blind randomized controlled trial

Symptoms associated with menopause could be a public health issue in the world, characterized by a permanent cessation of menstruation due to lack of ovarian follicular activity 12 months after menopause. It leads to mood swings, sleep disturbances and hot flashes. Modification of lifestyle and proper nutrition program are involved in improving mood and sleep quality. Thus, the aim of present study was to evaluate the effect of probiotics on mood and sleep quality (primary outcomes), quality of life, satisfaction with the intervention and side effects (secondary outcomes) in postmenopausal women.This triple-blind randomized controlled trial was conducted on 66 postmenopausal women aged 45-55 years in Behbahan city-Iran in 2020-2021. Women were randomly assigned to the intervention and control groups. Intervention group received 100 g of yogurt containing probiotics and control group received 100 g of ordinary yogurt daily after lunch for 6 weeks. Before the intervention and 6 weeks after the intervention, the participants completed the Pittsburgh sleep quality scale, DASS-21 (Depression, Anxiety, and Stress Scale-21 items), and the menopause quality of life (MENQOL) questionnaire. Independent t-test, Mann-Whitney U and ANCOVA tests were used for data analysis.There was no statistically significant difference between the two groups in terms of socio-demographic characteristics and baseline values. Six weeks after the intervention, based on ANCOVA test and by adjusting the baseline score, the mean anxiety score (adjusted mean difference (AMD): -0.56, 95% confidence interval (95% CI): -0.01 to -1.12; P = 0.044), mean stress score (AMD: -0.76, 95% CI: -0.01 to -1.52; P = 0.046) and mean quality of life score (AMD: -4.86, 95% CI: 3.06 to -6.66; P < 0.001) in the group receiving probiotic yogurt were significantly lower than those in the control group. However, in terms of mean scores of depression and sleep quality, there was no statistically significant difference between the two groups.The results of this study suggest the effects of consuming probiotic yogurt on improving anxiety, stress and quality of life in postmenopausal women. However, further studies are needed to obtain a definite conclusion in this regard.Iranian Registry of Clinical Trials (IRCT): IRCT20120718010324N57; Date of registration: 30/06/2020. URL: https://en.irct.ir/user/trial/47177/view; Date of first registration: 21/07/2020.