Diaz Heijtz Laboratory - Research focus
Our research interests are centered on understanding the biological basis of neurodevelopmental disorders, with a focus on attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD).
Research focus
We use different animal model systems to understand the contribution of genetic factors, impact of early adverse life experience (e.g., stress, infections), and gene-environment interactions on the development of motor, affective and cognitive functions, which are impaired in ADHD and ASD. In parallel, we conduct human studies using several cohorts of infants and children (e.g., infants with elevated likelihood of developing ASD, children with ASD and a population-based Swedish twin cohort).
Our work is performed in collaboration with clinicians and psychologists at the Astrid Lindgren Children's Hospital and Karolinska Institutet Center of Neurodevelopmental Disorders (KIND). This optimizes the opportunities for iterative translation from basic to clinical research and back to more fundamental mechanistic studies.
Key subjects of interest:
- Potential role of gut microbiota on early aspects of motor, social and cognitive development in humans
- Influence of gut-derived microbial molecules such as “bacterial peptidoglycan fragments” on typical and atypical brain development
- Role of bacterial peptidoglycans and their sensing molecules in brain and behavior across the life span.
- Potential beneficial effects of psychobiotic diet in early life on motor, social and cognitive development

There are multiple direct and indirect pathways through which gut microbiota may influence the brain, including signals carried by neuronal circuits [e.g., bidirectional vagus nerve-to-brain communication, the enteric nervous system and neuropods; (1)], the production of bacterial fermentation metabolic by-products, such as short chain fatty acids (2), tryptophan metabolites and neurotransmitters (3), release of cytokines by immune cells (4), and gut hormone signaling (5). The gut microbiota has been shown to influence various neurodevelopmental processes such as microglial maturation and function, blood brain barrier formation and integrity, myelination and neurogenesis (7). For more details, see Gonzalez-Santana A, Diaz Heijtz R, Trends Mol Med 2020 08;26(8):729-743.