A double blind, placebo controlled, randomised pilot trial examining the effects of probiotic administration on mood and cognitive function

Abstract

4Cultech Limited, Christchurch Rd Port Talbot, Neath Port TalbotThere is a growing body of evidence indicating that the gut microbiota communicates with the CNS influencing mood and behaviour (1)(2)(3)(4)(5)(6)(7) and a role for the microbiota in the development of brain plasticity and the subsequent physiological response has been suggested (2) . Furthermore treatment with probiotics has been shown to alter functional task-related brain activity and changes in midbrain connectivity 9 . To date no study has demonstrated cognitive modification in response to probiotic treatment. The aims of the study were i) To examine the mood effects of probiotic supplementation at rest and in response to psychological stressors ii) To examine the effects of probiotic administration on cognitive functioning.In this pilot study, healthy participants (n = 50) were recruited to take part in a double blind, randomised, controlled trial. Participants were randomized to receive either a probiotic preparation comprising two strains of Lactobacillus acidophilus CUL60 (NCIMB 30157) and CUL21 (NCIMB 30156), Bifidobacterium lactis CUL34 (NCIMB 30172) and Bifidobacterium bifidum CUL20 (NCIMB 30153) at a total of 2.5 × 10 10 cfu/capsule or a placebo for 6 weeks. The sample population comprised 18 males and 32 females, mean age 23.22 years (range 19-38, SD 3.846), with a BMI <30. Participants underwent morphometric measurements (height, weight, % total body fat, hip and waist measurement) and completed mood, stress and depression questionnaires (Bond Lader Mood Scales, Stait Trait Anxiety Inventory and NASA Task Load Index). Participants also were required to perform a battery of computerised cognitive test (COMPASS) measuring attention, executive function, working memory and episodic memory.In terms of mood measures, a significant interaction showed that 'trait' anxiety levels decreased in the active probiotic condition whilst increasing in the placebo condition over the course of the 6 week intervention (p = 0.042). A significant interaction was also observed for tasks of attention; 'continuity of attention increased in response to the probiotic treatment and decreased with the placebo group (p = 0.035). No morphometric changes between the two treatment conditions were recorded during the intervention period. The findings of this pilot trial provide a justification for further studies to characterise the potential cognitive and mood enhancing benefits of probiotics in healthy populations.

Interoceptive dysfunction: Toward an integrated framework for understanding somatic and affective disturbance in depression.

“…For example, a recent study reported significant gut microbiome abnormalities in clinically depressed persons compared to healthy age- and gender-matched controls (Naseribafrouei et al, 2014). Probiotics also appear to improve anxiety and symptomatology in IBS and chronic fatigue syndrome (Rao et al, 2009; Silk, Davis, Vulevic, Tzortzis, & Gibson, 2008); they have been found to improve depression and anxiety in nonclinical samples (Messaoudi et al, 2011; Owen et al, 2014) and mood in a general population sample, specifically in participants who displayed low mood upon entering the study (Benton, Williams, & Brown, 2007). In another line of research, altered gut–brain feedback in Crohn’s disease (CD)—an inflammatory bowel disease with high anxiety and depression comorbidity (Graff, Walker, & Bernstein, 2009)—has been found to up-regulate the intensity of negative emotions (Vianna, Weinstock, Elliott, Summers, & Tranel, 2006).…”

Probiotic-based strategies for therapeutic and prophylactic use against multiple gastrointestinal diseases

“…However, there are a growing number of studies providing data on effects of probiotic bacteria on the human immune system and on microflora of the GIT ( Holzapfel and Schillinger, 2002 ; Foligne et al, 2007 ; Verdú et al, 2009 ; Wen et al, 2012 ). Increasingly, reports of the human/animal microbiome playing a central role in other key aspects of health functionality are emerging, including beneficial impacts on the treatment of metabolic disorders, such as obesity and type 2 diabetes, improvement of bowel function in patients with colorectal cancer, potential cognitive, and mood-enhancing benefits, antidepressant, and anxiolytic (antianxiety) activity ( Desbonnet et al, 2008 ; Bravo et al, 2011 ; DiBaise et al, 2012 ; Lee et al, 2014a ; Owen et al, 2014 ). The latter anxiolytic effect has even led to the emergence of the new term, psychobiotic, coined by Dinan et al (2013) as a “live organism that, when ingested in adequate amounts, produces a health benefit in patients suffering from psychiatric illness.”…”

The Microbiome and Mental Health: Looking Back, Moving Forward with Lessons from Allergic Diseases

“…There have been a number of human intervention studies involving beneficial microbes and mood-related outcomes. 129 – 137) To the best of our knowledge, there has yet to be an intervention study involving microbes and patients with MDD or anxiety disorders. However, the benefits observed in the available clinical studies suggest that a movement toward trials involving patients with depression, anxiety, or subsyndromal disorders is warranted.…”