Author(s): Gomes, Andreia ; Siopa, Carlos ; Pestana, Pedro Câmara ; Novais, Filipa
Date: 2025
Persistent ID: http://hdl.handle.net/10400.14/54563
Origin: Veritati - Repositório Institucional da Universidade Católica Portuguesa
Subject(s): ADHD; Adults; Efficacy assessment; Gut microbiota modulation; Probiotics; Synbiotics
Purpose of Review: To critically assess the effectiveness of gut microbiota modulation (GMM) as a complementary approach for managing Attention Deficit Hyperactivity Disorder (ADHD) in adults. Methods: A systematic review was conducted following the JBI Manual for Evidence Synthesis, with searches in PubMed, Web of Science, Cochrane Database, ClinicalTrials.gov, EMBASE/Ovid, and APA PsycInfo. Results: Among 3,591 identified studies, only three randomized controlled trials met the inclusion criteria. One study reported improvements in inattention, while another found benefits in hyperactivity. Additionally, synbiotics and probiotics showed positive effects on emotional dysregulation, inflammatory markers, and gastrointestinal symptoms, reinforcing the link between gut microbiota and ADHD. However, the evidence remains inconsistent, and the studies are heterogeneous in methodology and outcomes. Summary: This review highlights the potential of GMM, particularly to enhance the management of refractory ADHD or for patients who experience significant side effects from conventional treatments. However, due to the very limited evidence, further high-quality, standardized trials are needed to determine its effectiveness, identify optimal bacterial strains and dosages, and develop more personalized treatment approaches, for better patient outcomes and functioning.
