The effects of probiotics on mental health and hypothalamic–pituitary–adrenal axis: A randomized, double-blind, placebo-controlled trial in petrochemical workers
Authors: Zohre Adab
Shima Jazayeri
Zatollah Asemi
Nakisa Mohammadpour
Zahra Solati
Ali Akbar Mohammadi
Mahmoud Djalali
Kianoush Khosravi-Darani
Shahryar Eghtesadi
Mehdi Tehrani-Doost
Mostafa Hosseini
Journal: Nutritional neuroscience (2016)
Discipline: NEUROSCIENCE & BEHAVIOR
Keywords: Hypothalamic–pituitary–adrenal axis; Mental health; Petrochemical workers; Probiotics.
Affiliations: a Department of Nutrition, School of Public Health , Iran University of Medical Sciences , Tehran , Iran., b Research Department of Food Technology Research , National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences , Tehran., c School of Nutritional Sciences and Dietetics , Tehran University of Medical Sciences , Iran., d Research Center for Biochemistry and Nutrition in Metabolic Diseases , Kashan University of Medical Sciences , Iran., e Department of Psychiatry, Roozbeh Hospital , Tehran University of Medical Sciences , Iran., f Department of Epidemiology and Biostatistics, School of Public Health , Tehran University of Medical Sciences , Iran.

Abstract:  Objective: The aim of this study was to determine effects of probiotic yogurt and multispecies probiotic capsule supplementation on mental health and hypothalamic-pituitary-adrenal axis in petrochemical workers. Methods: The present randomized double-blind, placebo-controlled trial was conducted on 70 petrochemical workers. Subjects were randomly divided into three groups to receive 100 g/day probiotic yogurt + one placebo capsule (n = 25) or one probiotic capsule daily + 100 g/day conventional yogurt (n = 25) or 100 g/day conventional yogurt + one placebo capsule (n = 20) for 6 weeks. Mental health parameters including general health questionnaire (GHQ) and depression anxiety and stress scale (DASS) scores were measured. Fasting blood samples were obtained at the beginning and 6 weeks after the intervention to quantify hypothalamic-pituitary-adrenal axis. Results: After 6 weeks of intervention, a significant improvement of GHQ was observed in the probiotic yogurt (18.0 ± 1.5 vs. 13.5 ± 1.9, P = 0.007) and in the probiotic capsule group (16.9 ± 1.8 vs. 9.8 ± 1.9, P = 0.001), as well as a significant improvement in DASS scores in the probiotic yogurt (23.3 ± 3.7 vs. 13.0 ± 3.7, P = 0.02) and the probiotic capsule group (18.9 ± 3.2 vs. 9.4 ± 4.0, P = 0.006). However, there was no significant improvement in the conventional yogurt group (P = 0.05 for GHQ and P = 0.08 for DASS). Discussion: The consumption of probiotic yogurt or a multispecies probiotic capsule had beneficial effects on mental health parameters in petrochemical workers. 

Retracted: No

PubPeer comments:
 There are many concerns about the integrity of 172 publications by this research group, including this one. Some of the concerns are published 1. Anaesthesia 2020;75:1683u201392, see Supplementary data. This paper is A63 2. Account Res 2020;28:149-61. 3. J Clin Epidemiol 2021;131:22-29. Journals and publishers were notified of these concerns in July 2019. 23 publications have an expression of concern. To our knowledge there has been no public response about any of the concerns. We think these publications are unreliable , 
 Apologies, this paper is A68 in the Supplementary data at Anaesthesia 2020;75:1683u201392 ,