Baylor College of Medicine

Study to investigate connection between antibiotic use and autism symptoms

Dana Benson


Houston, TX -
Media Component
Dr. Ruth Ann Luna, assistant professor of pathology & immunology at Baylor and director of medical metagenomics at the Texas Children’s Microbiome Center at Texas Children’s Hospital.

Baylor College of Medicine is launching a study that will investigate why some children with autism spectrum disorder experience changes in their autism symptoms when taking antibiotics.

The study will follow children over a two-year period, with the intent to capture information anytime antibiotics are prescribed during that time by their regular healthcare providers. Researchers will compare the gut microbiome (bacteria, yeasts and fungi found in the gut) and metabolome (small biological molecules produced by the microbes) of those who experience a change in symptoms during antibiotic use to those who do not. The study may provide valuable insight into when and why these changes occur and how this information can be harnessed for future interventions.

“We’re interested in tracking changes in children with autism while on antibiotics, looking specifically at the microbiome and metabolome and changes in behavior,” said Dr. Ruth Ann Luna, assistant professor of pathology & immunology at Baylor and director of medical metagenomics at the Texas Children’s Microbiome Center at Texas Children’s Hospital. “Research suggests that antibiotic use can have a measurable effect on behavior in some children, which is supported by anecdotal evidence from parents of children with autism who have noticed either improvements or worsening of symptoms while their child was on various antibiotics.”

The aims of the study are:

To characterize changes in behavior, including communication, anxiety, social interaction and more, and in gastrointestinal symptoms such as constipation, diarrhea and incontinence and abdominal pain while taking antibiotics.

To characterize changes in the gut microbiome across three time points: baseline, initiation of antibiotics and discontinuation of antibiotics, and determine which antibiotics had the most significant positive or negative effects on symptoms, and to compare these changes to children who do not have autism spectrum disorder.

The study is funded by N of One Autism Research Foundation, which was founded by John Rodakis, the parent of a child with autism. Rodakis observed his child’s autism symptoms improve while taking a routine antibiotic, and he embarked on a journey to discover what was behind this commonly reported phenomenon. This path led him to Luna, also the parent of a child with autism. She also had seen changes in her son’s autism symptoms while on antibiotics, although his symptoms worsened.

“Both of these scenarios support the same hypothesis – that changes in the gut microbiome related to antibiotic use elicit changes in autism-related behaviors,” Luna said. “Because both of us have witnessed the antibiotic effect in our own children, we knew this was a natural starting point targeting a gap in published autism research. Our goals reach far beyond this first study and include using this initial data to more effectively subtype autism and develop and deliver more effective microbial-based interventions.”

“Working with Dr. Luna has been very energizing because as a fellow affected parent, we share a real passion to get this right for our children as well as millions of others,” Rodakis said.

The study will enroll children nationally ages 2 to 17 with autism, and after collection of baseline data, will monitor the children’s microbiome, metabolome and behavior during any course of antibiotics prescribed by their regular physician over the two-year study period. For more information visit the study website and to enroll, please contact Dr. Ruth Ann Luna at

Back to topback-to-top