Short report

A randomized, double-blind, placebo-controlled pilot study of a probiotic in emotional symptoms of chronic fatigue syndrome

A Venket Rao¹ , Alison C Bested^2,3 , Tracey M Beaulne³ , Martin A Katzman^4,5 , Christina Iorio⁵ , John M Berardi⁶ and Alan C Logan³

¹  Department of Nutritional Sciences, University of Toronto, 50 College Street, Toronto, Ontario M5S 3E2, Canada

²  Environmental Health Clinic, Women's College Hospital, 76 Grenville Street, Toronto, Ontario M5S 1B2, Canada

³  Integrative Care Centre of Toronto, 3600 Ellesmere Road, Unit 4, Toronto, Ontario M1C 4Y8, Canada

⁴  Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario M5T 1R8, Canada

⁵  START Clinic for Mood and Anxiety Disorders, 790 Bay Street, Toronto, Ontario M5G 1N8, Canada

⁶  Precision Nutrition, 1665 Gregory Road, St Catharines, Ontario L2R6P9, Canada

author email corresponding author email

Gut Pathogens 2009, 1:6doi:10.1186/1757-4749-1-6

Published:	19 March 2009

Abstract

Chronic fatigue syndrome (CFS) is complex illness of unknown etiology. Among the broad range of symptoms, many patients report disturbances in the emotional realm, the most frequent of which is anxiety. Research shows that patients with CFS and other so-called functional somatic disorders have alterations in the intestinal microbial flora. Emerging studies have suggested that pathogenic and non-pathogenic gut bacteria might influence mood-related symptoms and even behavior in animals and humans. In this pilot study, 39 CFS patients were randomized to receive either 24 billion colony forming units of Lactobacillus casei strain Shirota (LcS) or a placebo daily for two months. Patients provided stool samples and completed the Beck Depression and Beck Anxiety Inventories before and after the intervention. We found a significant rise in both Lactobacillus and Bifidobacteria in those taking the LcS, and there was also a significant decrease in anxiety symptoms among those taking the probiotic vs controls (p = 0.01). These results lend further support to the presence of a gut-brain interface, one that may be mediated by microbes that reside or pass through the intestinal tract.