The Gut/Brain Link and Autism
Hardly a week goes by that the gut microbiome doesn’t figure in breaking medical news. As my faithful readers will know, it’s become increasingly clear in recent years that the collection of beneficial bacteria species living in the human digestive system—the gut microbiome—has a profound impact on various aspects of health. Gut microbes influence everything from how many and what types of nutrients we’re able to extract from our food, to how well our immune systems function, to how our brains work.
It’s that relationship between the gut microbiome and the brain that has researchers wondering if gut microbes play some previously unsuspected role in autism. Autism—or autism spectrum disorders (ASD)—are a collection of conditions characterized by varying degrees of difficulty with social interaction and verbal and non-verbal communication. ASD is also often accompanied by repetitive or restricted behaviors.
Although it was once rare, the condition is becoming increasingly common. In fact, the number of children affected in the United States increased by a startling 30% in the brief period between 2012 and 2014. Presently, one in 68 children are born with the disorder here. Clearly, something is going on, and it’s rapidly getting worse. While scientists know that genetics plays a role, they think that certain unknown environmental factors must also play a role in triggering symptoms.
Studies have shown that the makeup of microbes living in the guts of patients with autism are markedly different than that of healthy people. Investigators speculate that these changes may either cause, or at least be somehow associated with, the disease itself. “Mounting evidence shows us that there is a link between the gut and brain; that the gut may have previously under-recognized influences on cognition and possibly even behavior,” said Dr. Dr. Richard E. Frye, Director of Arkansas Children’s Hospital autism research program.
Frye and colleagues convened a conference last year, where attendees discussed various opportunities and avenues for future research into this promising area of inquiry. “If the gut microbiome truly plays a causative or even contributory role in ASD, then we could be potentially talking about a new therapeutic approach to improve ASD symptoms,” said John Slattery, CCRP.
Given that modern antibiotics were first developed and widely used in the mid-20th century, is it unreasonable to wonder if we may be experiencing the effects of unintended—and previously unsuspected—consequences from their enthusiastic, widespread use? Many common antibiotics are “broad spectrum,” meaning they kill all sorts of microbes, more or less indiscriminately. While we still have more questions than answers, I think this finding underscores, once again, the importance of maintaining a healthy gut microbiome. One way to achieve that is to eat plenty of plant-based foods, and consume probiotic foods, such as yogurt, on a regular basis. And think twice before asking your doctor for antibiotics.
Richard E. Frye, John Slattery, Derrick F. MacFabe, Emma Allen-Vercoe, William Parker, John Rodakis, James B. Adams, Rosa Krajmalnik-Brown, Ellen Bolte, Stephen Kahler, Jana Jennings, Jill James, Carl E. Cerniglia, Tore Midtvedt. Approaches to studying and manipulating the enteric microbiome to improve autism symptoms. Microbial Ecology in Health & Disease, 2015; 26 (0) DOI: 10.3402/mehd.v26.26878