19 May 2014 - MedicalXpress - Can chemicals produced by gut microbiota affect children with autism?

"Most gut bacteria are beneficial, aiding food digestion, producing vitamins, and protecting against harmful bacteria. If left unchecked, however, harmful bacteria can excrete dangerous metabolites or disturb a balance in metabolites that can affect the gut and the rest of the body, including the brain," says Dae-Wook Kang of the Biodesign Institute of Arizona State University, an author on the study.

Increasing evidence suggests that children with ASD have altered gut bacteria. In order to identify possible microbial metabolites associated with ASD, Kang and his colleagues looked for and compared the compounds in fecal samples from children with and without ASD. They found that children with ASD had significantly different concentrations of seven of the 50 compounds they identified.

"Most of the seven metabolites could play a role in the brain, working as neurotransmitters or controlling neurotransmitter biosynthesis," says Kang. "We suspect that gut microbes may alter levels of neurotransmitter-related metabolites affecting gut-to-brain communication and/or altering brain function."

"Correlations between gut bacteria and neurotransmitter-related metabolites are stepping stones for a better understanding of the crosstalk between gut bacteria and autism, which may provide potential targets for diagnosis or treatment of neurological symptoms in children with ASD," says Kang.