The role of gut health in the development of autism has taken a new turn, with scientists now confirming major imbalances in people with the condition. They are reported to be considering revolutionary ways to treat the problem.
According to an Arizona State University study, different concentrations of certain metabolites, which are chemicals produced by bacteria, have been found in the faeces of children with autism that do not exist in children without the condition.
Dae-Wook Kang, of the university’s Biodesign Institute and lead author of the study, explained: “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.”
One treatment Kang is reported to be considering is whether transplanting fecal material from healthy people to children with autism might help. The move would require permission from several groups, including the Food and Drug Administration in the US.
The Arizona University study was small, involving 23 children with autism and 21 without. The researchers discovered that children with ASD had at least seven of the 50 gut germs different than the second group. Some of these bacteria act as message-carrying chemicals called neurotransmitters.
The children with ASD were shown to have reduced amounts of metabolites homovanillate and N,N-dimethylglycine. The percentage of glutamine/glutamate was higher in the group. The imbalance of glutamate and gamma-aminobutyric acid (GABA) transmission has been linked to hyper-excitation in children with autism.
According to Kang, the metabolites could play a role in the brain, working as neuro-transmitters or controlling neurotransmitter biosynthesis.
The study concluded that, overall, children with autism had a less diverse bacterial composition in the gut.
Kang said that the correlations between gut bacteria and neurotransmitter-related metabolites were “stepping stones for a better understanding of the link between gut bacteria and autism, which may provide potential targets for diagnosis or treatment of neurological symptoms in children with ASD”.
Other recent studies have raised questions about the gut health of children with autism. In 2013, scientists at Arizona State University found children with autism had lower levels of the gut bacteria Coprococcus, Veillonellaceae and Prevotella.
Elsewhere, a London study at Imperial College in 2010 found that children with autism have a different chemical fingerprint in their urine than non-autistic children and indication of gut bacteria differences.
The researchers are pictured above. From left: Dae-Wook Kang, Zehra Esra Ilhan, Rosa Krajmalnik-Brown, Joshua LaBaer, Garrick Wallstrom and Jin Gyoon Park. Photo by The Biodesign Institute at Arizona State University.
Published: 22 May 2014
