Researchers look at the link between gut bacteria and autism

New research looks to the gut microbiome to try to address some of the symptoms associated with autism, but this investigation comes with its own set of problems.

The National Institute of Neurological Disorders and Stroke explain that "autism spectrum disorder (ASD) refers to a group of complex neurodevelopment disorders characterized by repetitive and characteristic patterns of behavior and difficulties with social communication and interaction." They also point out that specialists use the term "spectrum," as autism is different in different individuals. The condition can incorporate a "wide range of symptoms, skills, and levels of disability in functioning."

Research has also found that autistic children often experience chronic gastrointestinal problems a lot more frequently than children without autism. This has led scientists from Arizona State University in Tempe to explore whether a fairly new form of therapy — microbiota transfer therapy (MTT) — can help solve gastrointestinal issues in autistic children. Also, they wanted to see whether this intervention could affect other autism markers. MTT involves collecting, processing, and freezing the fecal material of healthy people, and then administering it — orally or rectally — to the person receiving the treatment. Thus, the healthy bacteria should re-establish a balance in the gut microbiome of the person experiencing gastrointestinal problems.

The researchers explain that at the start of the study, autistic children had poorer bacterial diversity in the gut, compared with neurotypical children with healthy and balanced microbiota. More specifically, two beneficial bacterial strands — Bifidobacteria and Prevotella — were lacking in the microbiota of children on the spectrum. Following the initial MTT intervention, the autistic children experienced more gut bacterial diversity, including increased levels of Bifidobacteria and Prevotella. In the new clinical trial, which measured bacterial diversity in the gut after 2 years from the intervention, the children had even more bacterial diversity and a steady presence of healthful bacteria.



As for the health effects, the children saw a 58 percent decline in symptoms tied to gastrointestinal problems. Also, the authors write that the children involved in this study showed "a slow but steady improvement in core ASD symptoms," with a 45 percent improvement in measurements related to language, social interaction, and behavior. According to Dr. Thomas Borody, the gastroenterologist who pioneered MTT, "This is a world first discovery that when we treated the gut bacteria in these children during our clinical trial 2 years ago to reset their microbiome with [fecal microbiota transplant], positive results are still continuing to be improving 2 years from the original treatments." "I," adds Dr. Borody, "would call it the highest improvement in a cohort that anyone has achieved for autism symptoms."

My Take:
This study has been criticized for several reasons. The study was small with only 18 participants and was funded by a company that provides fecal microbiota transplant therapy. While I agree with those criticisms, the connection between the gut microbiota and autism spectrum is well worth further investigation.

Add this study to several others that have expanded the concept of the HPA (hypothalamus pituitary adrenal) axis to the new title HPA gut axis. Gut microbes have an intimate relationship with the brain and endocrine system of our body.

Bottom Line:
If a child is not born through vaginal delivery, the lack of that initial inoculation with the mother’s microbes can never be replaced. However, there are several techniques now available to help mitigate this loss. Clinically, I begin with oral Lactobacillus bulgaris supplementation, but vaginal smear and now fecal implant are viable options.

Source: April 11, 2019 NIH