The composition of the intestinal microbiota could have an impact on the risk of attention deficit hyperactivity disorder in children.
- Attention Deficit Disorder, with or without hyperactivity, manifests as impulsiveness, difficulty concentrating and inattention.
- According to a new study, the composition of the gut microbiota may impact ADHD risk.
- This could be linked to the passage of certain bacteria in the blood, responsible for brain inflammation.
Attention deficit disorder, with or without hyperactivity (ADHD), is characterized by difficulty concentrating, impulsivity and restlessness. The first symptoms appear during childhood and can evolve later. According to Insermthis disorder is linked to a “accumulation of genetic and environmental factors”, such as in utero exposure to alcohol, premature or low birth weight. But according to a new study published in Journal of Child Psychology and Psychiatrythe composition of the intestinal microbiota could also have an impact on the risk of ADHD in children.
ADHD: why should we be interested in the intestinal microbiota?
“The human gastrointestinal tract hosts a large population of microorganisms such as bacteria, viruses and fungi“, remind the authors of this study, Taiwanese researchers. These can have different impacts on human health and have “a role in digestive, metabolic, immune and neurological functions“, precise Inserm. “Consequently, dysbiosis, i.e. the qualitative and/or functional alteration of the intestinal microbiota, is a serious lead to explain certain diseases, in particular among those underpinned by autoimmune or inflammatory mechanisms., explains the French research organization. In this study, Taiwanese scientists were specifically interested in the links between dysbiosis and ADHD.
Gut microbiota and ADHD: differences in the levels of certain gut microbes
The researchers therefore compared fecal samples from 35 children with ADHD and 35 healthy controls. They found that samples from children with ADHD had higher levels of some fungal species and lower levels of other species. “The ADHD group had a significantly higher abundance of Ascomycota and a significantly lower abundance of Basidiomycota than the healthy control groupthey point out. At the genus level, the abundance of Candida (especially Candida albicans) was significantly increased in ADHD patients compared to healthy controls.“
ADHD: what is the link with the composition of the intestinal microbiota?
In a second step, the scientists carried out experiments with cells cultured in the laboratory. The abundant presence of Candida albicans in samples from children with ADHD increased the “permeability of the cells lining the intestine“.”This could create a ‘leaky gut’ which allows bacteria to enter the bloodstream, eventually leading to inflammation throughout the body and brain“, believe the authors of the study. This inflammation could be one of the explanations for the onset of ADHD. In France, these disorders affect approximately 5.9% of children under 18 and 2.8% of adults.
