The Stomach and Autism May Be More Closely Related than You Think

The effect of the microbiome on human health is being acknowledged more frequently by the medical and general community. Even more, it is clear that the bacteria inside us do more than assist in food digestion or the movement of our bowels. Dr. Amy Rouse discusses several studies that show connections between the microbiota in the gut and the mental activity of the brain. Furthermore, this “microbiome-gut-brain axis” likely causes some of the behavioral and physical symptoms experienced by people with autism. Rouse stresses that individuals who work with children’s psychiatric health, which certainly includes children with autism, have an obligation to understand this research and be ready to apply it to their practice once there is sufficient evidence supporting these microbiome interactions. 

This article discusses behavioral and physical symptoms of autism and how they may be impacted by the microbiota in the gut. These symptoms include constipation, difficulties in mood moderation and problems with social interaction. While the irregularity of bowel movements is more directly connected to the lack of biodiversity within the guts of those with autism, the connection to autism’s behavioral symptoms may be less apparent. Rouse explains that due to the large amount of bodily serotonin present in the stomach, those with autism may owe a portion of their behavioral symptoms to the reduced functioning of their microbiome-gut-brain axis. Serotonin is a neurotransmitter that moderates mood, sleep, and hunger cycles, as well as the amount of inflammation within the stomach. She supports this idea with studies that gave depressed patients probiotics and monitored their mood, anxiety, and cognition. The decrease in the negative aspects of these side effects gives hope for people with autism since they suffer from similar difficulties. Rouse also discusses anxiety, behavioral, and GI symptom improvements after fecal transplants, which have been shown to effectively treat microbiome disorders. These results give hope for microbiota-focused treatments in treating some symptoms of autism.

Strengths of this article include the optimistic outlook that it provides for future research on the microbiome. Rouse enlightens readers on the many functions and effects that the microbiome has on the body. Her statement on considering all organisms within the microbiome instead of a single, disease-causing one preaches a holistic approach to treatment. Rouse presented evidence from studies that cover different aspects of the symptoms of autism, giving hope for a more holistic approach through microbiome treatments as well.

However, the lack of clarity in a specific mechanism of the microbiome-gut-brain axis may leave readers skeptical of Rouse’s claims. The majority of her paper focuses on explaining how the microbiome causes some symptoms of autism without a clear biochemical explanation of how this occurs. She also considers some studies that were performed on patients without autism, which means that the results of that research can’t necessarily be applied to those with autism. Another point to consider is the studies that showed increases in mental functioning among depressed patients were not standardized and showed only vague, positive outcomes.

In the future, research should focus on understanding the biochemical means by which the bacteria in the stomach communicate with the brain. Overall, studies on this topic need to be repeated and more consistent. Repeatability of results will direct this research towards implementation, at which point the lives of those affected by autism can be positively affected.