None listed
Conditions
Brief summary
In this randomised, double-blind, placebo-controlled study, 60 adults presenting with depressive symptoms will be randomly assigned to receive probiotic capsules containing (1) Bifidobacterium adolescentis (5 billion colony-forming units a day), or (2) Lacticaseibacillus rhamnosus LGG and Bifidobacterium BB-12 (1 billion colony-forming units a day), or (3) a placebo for 12 weeks. We will assess changes in mood and sleep using self-report questionnaires. Changes in blood markers associated with inflammation (tumour necrosis factor-alpha, interleukin -1beta, interleukin-6, interferon-gamma, and high-sensitivity C-reactive protein), intestinal barrier integrity (lipopolysaccharide-binding protein and intestinal fatty acid-binding protein), and brain-derived neurotrophic factor (important for the survival of brain cells) will be assessed over time. We will also assess changes in cortisol (blood and hair), heart rate variability, and the gut microbiome over time.
Interventions
Probiotic capsules containing Bifidobacterium adolescentis (1 capsule taken orally, once daily in the morning, delivering 5 billion colony-forming units a day for 12 weeks) or Probiotic capsules containing Lacticaseibacillus rhamnosus LGG and Bifidobacterium BB-12 (1 capsule taken orally, once daily in the morning, delivering 1 billion colony-forming units a day for 12 weeks). Adherence to capsule intake will be measured by capsule return at weeks 6 and 12.
Sponsors
Clinical Research Australia
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
1. Generally healthy adults (male and female) 18 to 65 years 2. Currently experience mild to moderate depressive symptoms as indicated by a score of between 20 and 40 on the BDI-II at both the screening and baseline visit 3. Body mass index (BMI) between 18.5 and 30.0 kg/m2 4. Non-smoker 5. No plan to change dietary or exercise habits during the study period 6. No recent history (within 3 months) or plan to commence new treatments over the study period 7. Willing and able to take probiotic/placebo regimen for 12 weeks 8. Understand, willing and able to comply with all study procedures 9. Willing to provide a personally signed and dated informed consent form detailing all pertinent aspects of the trial.
Exclusion criteria
1. Suffering from recently diagnosed or unmanaged medical conditions including but not limited to: diabetes, hyper/hypotension, cardiovascular disease, a gastrointestinal disease requiring regular use of medications, gallbladder disease, autoimmune disease, endocrine disease, acute or chronic pain condition, or cancer/malignancy 2. Diagnosis of psychiatric or neurological conditions including but not limited to: psychiatric disorders other than mild-to-moderate depression and/or anxiety disorder, or neurological disease (e.g., Parkinson’s, Alzheimer’s disease, intracranial hemorrhage, head or brain injury) 3. Regular medication intake, including but not limited to anticholinergics, anti-epileptics, acetylcholinesterase inhibitors, benzodiazepines, antipsychotics, opioids, or corticosteroids. 4. Within 2 months before screening, the use of pharmaceutical medications, including but not limited to immunosuppressant drugs, antibiotics, and steroids 5. Change in medication (dose or type) in the last 3 months or an expectation to change during the study duration. Permitted medications include, but are not limited to, pharmaceutical antidepressants such as selective serotonin reuptake inhibitors (SSRIs), and serotonin and norepinephrine reuptake inhibitors (SNRIs), cholesterol-lowering medications, antihypertensives, proton pump inhibitors, and thyroid medications, 6. Use of probiotics or mood support supplement up to 4 weeks before study commencement 7. Current or 12-month history of illicit drug abuse 8. Alcohol intake greater than 14 standard drinks per week 9. Any significant surgeries over the last year 10. Women who are pregnant, breastfeeding or intend to fall pregnant
Outcome results
None listed