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, and emerging studies have suggested that both pathogenic and non-pathogenic 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.