Study Links Gut Microbiota to Predicting Autism Spectrum Disorder

Stool samples have shown a high level of accuracy in differentiating autism, and early detection is linked to better outcomes.

As a young mother, Lyndsy Moffatt was unfamiliar with autism but voiced concerns about her son’s behavior to his pediatrician multiple times.

Dominic displayed poor eye contact, delayed speech, loss of emotional responses, obsessive behaviors, and irregular behavior and play. His symptoms progressed to constipation lasting up to nine days, rashes, picky eating, and nose bleeds.

“They would assure me, ‘He’s fine. He looks healthy. He’ll start talking,'” Moffatt shared with The Epoch Times. “He began having severe hour-long meltdowns at age 3. He would scream, and it was unclear what triggered it. He had trouble sleeping at night, and after researching online, I connected the dots with autism.”

Despite being informed that it would take 10 months for Dominic to be evaluated and diagnosed, Moffatt, disappointed yet undeterred, initiated her research, conducted independent tests for food allergies and heavy metals, and adopted a healing diet known as GAPS to help his symptoms. This diet has proven beneficial for individuals with autism spectrum disorders (ASD).

The diet and other interventions significantly improved Dominic’s condition. He was eventually diagnosed with ASD and is now a 14-year-old who is social, happy, well-behaved, musically gifted, kind, considerate, healthy, and enthusiastic about learning and school.

“Every day, I am thankful because I never knew if he would speak. He had one of the most severe cases I had ever seen,” Moffatt, who later became an autism specialist and certified GAPS coach, stated. “He will conquer any challenge he faces. I no longer worry about him.”

Commencing Early

Timely intervention is crucial for successful ASD treatment. However, accurate and quick diagnosis can be hindered by various challenges. Apart from long specialist waiting times, misdiagnoses in children with autism, particularly with co-occurring conditions like attention deficit hyperactivity disorder (ADHD), could complicate matters. Symptoms are frequently unrecognized until children reach school age, missing the window for evidence-based early interventions.

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Biomarkers could play a crucial role in not only diagnosing ASD but also identifying individuals at risk prenatally and determining those who should undergo screening for diagnosis. Biomarkers could also aid in understanding the fundamental causes of autism and monitoring treatment, as per the article.

Nevertheless, the authors cautioned that biomarkers should not replace the current screening tests for ASD, which rely on clinical observation.

The study identified a panel of 31 biomarkers consistently exhibiting superior diagnostic precision among 1,627 children aged 1 to 13 years.

Moffatt highlighted the potential value of such a test for toddlers not reaching developmental milestones. It could help identify those who would benefit most from early intervention. Moreover, owing to the close connection between gut microbiota and diet, it could help healthcare providers determine which patients might benefit from dietary changes.

“This assessment is crucial. Given that the current diagnosis is solely based on behavior and lacks available lab tests, it would be incredibly beneficial, especially with the numerous root causes, types, and symptoms of autism,” she remarked.

Many Aspects to the Puzzle

Some companies are already leveraging microbiome testing to identify children at risk of autism—a practice that Beth Lambert, author and founder of the autism support group Epidemic Answers, finds useful among various tools that can help in diagnosing many childhood diseases.

“Administering a gut microbiome test to children in early life could help determine the relative risk of developing various conditions, not just autism. It could assess the risk of allergic diseases, autism, autoimmune conditions, and more. The microbiome offers a crucial insight into an individual’s health,” she mentioned in an email to The Epoch Times.

Lambert, however, suspects that many other children might exhibit autism symptoms but lack identifiable markers of gut dysbiosis or microbial imbalances common in autism.

She described autism as a developmental interruption that affects infants, toddlers, and young children facing stressors that affect their growing bodies and brains. It is characterized by deficits in social and communication skills, restricted interests, and repetitive behaviors.

The stressors at play could originate from toxic bacteria or fungal metabolites in the gut, for instance, or heavy metals that might also impact gut microbes, Lambert explained.

“These two scenarios [pathogenic gut issues and heavy metals] will have distinct gastrointestinal microbial ‘signatures,’ and this microbial ‘signature’ fluctuates continuously based on what the child consumes, drinks, and experiences in their environment,” she elaborated. “It’s incredibly intricate.”

In either scenario, the body’s resources are redirected to combat inflammation, regulate an imbalanced nervous system, and eliminate cellular toxins, causing impacts or halts in development and resulting in symptoms affecting sensory, motor, and behavioral systems.

Exploring the Microbiome

Prior research has revealed that individuals with autism possess a distinct microbial signature identified through stool samples. However, whereas most studies concentrate on bacteria, the recent study also examined the fungi and viruses that were either diminished or enriched in individuals with ASD. It also identified 14 archaea that were depleted in individuals with ASD. Additionally, there were differences in 51 bacteria, seven fungi, 18 viruses, 27 microbial genes, and 12 metabolic pathways. 

The study in Nature Microbiology disclosed that children with ASD displayed an overall reduction in the diversity of archaea, bacteria, and viruses compared to neurotypical children. Notably, neurotypical children achieve developmental milestones at the expected ages.

Specifically, children with autism presented a significantly decreased relative abundance in 80 of the 90 identified microbial species, with the most noticeable decrease observed in bacteria, where 50 species were depleted in children with autism.

Another unique aspect of the study was the evaluation of microbial pathways and genes that offer insights into the function of gut microbiota—a methodology employed in metagenomics studies, which examine the DNA in a sample to identify the microbial components of a microscopic community.

Su explained in an email to The Epoch Times that by counting genes linked to pathways, researchers can estimate the activity levels of those pathways.

A “pathway” denotes a biochemical process of interconnected reactions wherein one molecule transforms into another, or compounds undergo a series of processes to transport a specific substance to a particular location in the body. The study identified two pathways significantly reduced in children with ASD—ubiquinol-7 and thiamine diphosphate.

According to the study, ubiquinol has an antioxidant function associated with alleviating autism symptoms. The impairment of thiamine diphosphate is linked to ASD and mental health issues in both animal and human studies.

Verified Findings

The discovery segment of the study involved 709 children with ASD and a control group of 374 neurotypical children.

The results were then validated using fecal samples from a hospital, encompassing 82 children with ASD and 90 neurotypical children. Furthermore, these findings were compared with published datasets.

Lastly, the results were compared with samples from children with ADHD and atopic dermatitis—two conditions also associated with variations in gut microbiota.

In the case report, a boy diagnosed with complex ADHD exhibited neglected social challenges that led to a comorbid ASD diagnosis at age 14. The authors emphasized the necessity of ASD screening in scenarios where symptoms persist despite other treatments. Comorbid conditions present one of many diagnostic complexities.

“Given the growing body of research concerning the connection between ADHD and ASD, children diagnosed with ADHD should undergo screening or assessments for autism in appropriate clinical settings, such as the persistent presence of impaired social interaction despite ADHD treatment,” the authors noted.

The authors indicated that methylphenidate and atomoxetine are frequently prescribed to manage ADHD and exhibit varying levels of efficacy in children with concurrent ASD and ADHD.

“The findings suggest that children diagnosed with ADHD before ASD may exhibit distinct dimensional traits that could skew clinicians towards an ADHD diagnosis,” the authors wrote.

His study also confirmed a microbial signature exclusive to autism. Morton told The Epoch Times that the differing analytical tools utilized could explain the lack of overlapping data.

“The data presents a melange of information, and we’re trying to piece together what could be there, but there are various ways to interpret the data,” Morton stated. Importantly, there is no standardized method for identifying microbes based on sequencing data.

“These genomes are quite complex. Imagine you have an entire library of encyclopedias, and you blend them all together and then try to read the shreds and reconstruct the encyclopedias from an entire library,” he illustrated.

Even within species, there can be variations, and not all technologies can differentiate the nuances that demonstrate distinctions between similar bugs.

Morton mentioned Escherichia coli (E. coli) as an example, pointing out its numerous variants, including one known as shigella that “encodes a toxin” harmful to humans. Other E. coli strains are harmless, and distinctions can sometimes boil down to a single gene.

Morton believes that microbial technology is nearing its limitations and will necessitate validation through alternative means. Advancements in science are swiftly addressing gaps, yet numerous unknowns remain, he noted.