A study in Spain reveals that high intake of proline-rich foods may increase depression risk, influenced by gut bacteria.
BARCELONA: A groundbreaking study by researchers at the Girona Biomedical Research Institute (IDIBGI) and Pompeu Fabra University (UPF) in Spain has uncovered a potential dietary link to depression. The research, published in Cell Metabolism, points to the amino acid proline—commonly found in foods like beef, fish, and gelatin—as a possible contributor to depressive symptoms.
Led by Dr. José Manuel Fernández-Real and Dr. Jordi Mayneris-Perxachs of IDIBGI and CIBEROBN, along with Dr. Rafael Maldonado of UPF, the study assessed the dietary intake of amino acids in participants and evaluated their mood through standardised surveys. Surprisingly, proline stood out as the amino acid most significantly associated with increased depression risk.
Blood tests revealed that individuals with higher levels of proline in their plasma were more likely to report depressive symptoms. Interestingly, gut microbiota played a major role in this link—those with certain bacterial compositions in their digestive tract appeared less affected by proline, showing fewer symptoms even with high intake.
Animal trials further supported the human data, with mice and fruit flies demonstrating depression-like behaviour when their proline metabolism was disrupted. The findings suggest that proline may impact mood regulation and mental health through complex metabolic and gut-brain interactions.
Researchers believe this study opens the door to new dietary interventions for mental health. They also stress the importance of personalised nutrition, considering how gut microbiota diversity can alter the impact of certain nutrients on emotional wellbeing.
