Nurahmad Habibi, Gusnedi Gusnedi, Ricvan Dana Nindrea, Rina Hasniyati, Renita Afriza, Riska Rusydi, Defniwita Yuska, Sri Darningsih, Zulkifli Zulkifli, Ismanilda Ismanilda, Marni Handayani, Citra Tristi Utami, Hermita Bus Umar, Defriani Dwiyanti, Eva Yuniritha
Background: Psychobiotics, including probiotics, prebiotics, and synbiotics, have been proposed to improve mental health through modulation of the gut–brain axis. However, findings from randomized controlled trials (RCTs) remain inconsistent, Objectives: To systematically review and synthesize evidence on the effects of probiotics, prebiotics, and synbiotics on depression, stress, and mood in adult populations. Methods: A comprehensive search was conducted in PubMed, yielding 531 articles, of which 14 RCTs met the inclusion criteria. Risk of bias was assessed using the Cochrane Risk of Bias Tool. Meta-analyses were performed using both fixed- and random-effects models in RevMan. The study protocol was registered in PROSPERO (CRD420251103338). Discussions: Ten RCTs (n = 881) assessing depression did not show consistent benefits (SMD = –0.72; 95% CI: –1.42 to –0.01; p-value = 0.05; I² = 96%). Six RCTs (n = 444) evaluating stress also showed non-significant effects (MD = –1.35; 95% CI: –3.70 to 1.01; p-value = 0.26; I² = 73%). Conversely, six RCTs (n = 376) demonstrated significant improvements in mood (MD = 0.73; 95% CI: 0.25 to 1.20; p-value = 0.003; I² = 75%). Meta-regression indicated that larger sample sizes were associated with more consistent improvements in mood (p-value = 0.04). Sensitivity analyses confirmed the stability of the findings, and no evidence of publication bias was detected. Conclusions: Probiotic, prebiotic, and synbiotic supplementation may provide beneficial effects on mood and could serve as a potential nutritional intervention to enhance psychological health. However, effects on depression and stress inconsistent. © 2025 Faculty of Public Health Universitas Airlangga.
Jurusan Gizi, Poltekkes Kemenkes Padang, Padang, Indonesia; Fakultas Kedokteran, Universitas Negeri Padang, Padang, Indonesia; Prodi Ilmu Gizi, Departemen Gizi, Universitas Andalas, Padang, Indonesia
