A case report of improvement on ADHD symptoms after fecal microbiota transplantation with gut microbiome profiling pre- and post-procedure

Background Recent studies demonstrate the association of the gut microbiome in regulating interactions between the central nervous system and intestinal function. Individuals with attention-deficit hyperactivity disorder (ADHD) have been shown to have unique gut microbial signature, with depletion of beneficial commensal microbes. Fecal microbiota transplant (FMT) restores the imbalanced gut microbiome and may replete missing microbes to increase production of hormones and neurotransmitters regulating human behavior and cognition.Research design & methods Here, we present an interesting case of a 22-year-old woman treated with FMT primarily to treat recurrent Clostridioides difficile infection, which coincidentally alleviated her ADHD symptoms. We also present the pre- and post-FMT gut microbiota profiles conducted using shotgun metagenomic sequencing on the patient's fecal samples to thereby highlight potential microbial-associated mechanisms associated with the relief of ADHD symptoms.Results & conclusions Our case report provides preliminary evidence regarding the use of FMT in a patient with C. difficile and ADHD. We speculate that gut microbiome modulation, in particular the gain or loss of specific microbial species and pathways involving the metabolism of SCFAs, tryptophan and GABA, may merit further exploration as a potential therapeutic strategy for ADHD.