PRO-DEMET Randomized Controlled Trial on Probiotics in Depression-Pilot Study Results

Area of Science:

• Psychiatry and Neuroscience
• Gastroenterology and Hepatology
• Metabolic Medicine

Background:

• Depression frequently co-occurs with metabolic disorders, sharing potential pathophysiological links like inflammation and altered gut microbiota.
• Probiotic interventions offer a potential adjunctive therapy for depression, particularly in patients with partial response to standard pharmacologic treatments.
• Investigating the interplay between depression, metabolic syndrome, and microbiota is crucial for developing novel therapeutic strategies.

Purpose of the Study:

• To assess the feasibility of a randomized controlled trial (RCT) investigating probiotic supplementation in adult patients with depressive disorders.
• To evaluate the impact of a specific probiotic formulation on psychometric, anthropometric, metabolic, and inflammatory markers.
• To determine the feasibility of recruiting and retaining participants with and without metabolic syndrome for a full-scale RCT.

Main Methods:

• A four-arm, parallel-group, prospective, randomized, double-blind, controlled pilot study involving 60 participants over 60 days.
• Participants received a probiotic containing *Lactobacillus helveticus* Rosell®-52 and *Bifidobacterium longum* Rosell®-175 or a placebo.
• Assessments included depressive/anxiety symptoms, quality of life, anthropometrics, blood markers (inflammation, metabolic health), and liver fibrosis indices.

Main Results:

• The study design was generally feasible, with an eligibility rate of 52% and an 80% study completion rate.
• No significant baseline differences were observed between probiotic and placebo groups in sociodemographic, anthropometric, or laboratory findings.
• A key limitation was the insufficient proportion of recruited participants meeting the criteria for metabolic syndrome.

Conclusions:

• The overall protocol for a full RCT on probiotics for depression with or without metabolic syndrome is feasible, requiring minor modifications to timepoint procedures and recruitment strategies.
• Recruitment methods need enhancement to ensure adequate representation of participants with metabolic syndrome.
• This pilot study provides a foundation for a larger RCT exploring the therapeutic potential of probiotics in comorbid depression and metabolic conditions.