Autism is increasing at rapid rates, and researchers may be looking in the wrong places for the answer as to why.
An extensive meta-analysis of 25 autism studies could shift the focus of research into the cause of autism from genetics to environmental triggers. That shift could open up new, revolutionary avenues for potential treatments.
The research ties the disorder to changes in the gut microbiome, a community of microbes that live in the colon and are responsible for creating metabolites and other compounds crucial to our health and wellness.
Many influences outside of the human body are killing these beneficial microbes, which aren’t genetically part of us but live in symbiosis with humans. The new study, published June 26 in Nature Neuroscience, has linked autism spectrum disorders (ASD) to a distinct microbial signature that’s dysbiotic, or unnaturally out of balance. As in an ecosystem, too much of certain problematic species can destroy the overall ecology or lead to problematic consequences, such as too many of certain metabolites and not enough of others.
Meanwhile, autism rates are increasing at a speed that defies improved screening and diagnostic practices, as well as genetic patterns. The Centers for Disease Control released statistics in April that show the latest autism rate was 1 in 36 children in 2020, up from 1 in 44 in 2018, and 1 in 150 in 2000.
Taken together, the evidence suggests that it’s time to direct resources to pinpoint exactly what it is in our environment that appears to “turn on” autism development, according to doctors who are treating patients with ASD.
“Genetic diseases aren’t responsible for epidemics,” Dr Arthur Krigsman, a specialist who treats children with ASD around the world, told The Epoch Times. “There’s something in the environment that’s triggering a gene that otherwise would be silent. There is no gene responsible for an epidemic.”
Our genes are wound up tightly in DNA spirals—many of them never being used—similar to blueprints that never make their way to the manufacturer. But cues in our environment can trigger epigenetic processes that trigger some genes to get turned on or others to get turned off, dramatically changing our likelihood of developing certain diseases or attributes.
The new research suggests that autism is linked to epigenetic triggers, which are influenced by the microbiome and modifiable over the course of our lifetime.
Researchers will undoubtedly keep trying to tease out some of the genetic links to the neurological disorder, which is largely diagnosed in childhood. Autism has been connected to more than 100 genes so far. But the puzzle has gotten more complex with environmental associations that seem to keep growing. And the heterogeneity of ASD makes it impossible to accuse one single factor as the cause.
Many doctors believe that autism arises when “toxic” environmental pressures are applied and trigger epigenetic changes, Dr. Mark Cannon, a professor at Northwestern University, told The Epoch Times.
Toxicities can be biological and chemical but also emotional and social, and they can interfere with physiology. Examples include air pollutants, artificial food ingredients, glyphosate, medications, viruses, and even stress, which causes a biochemical cascade of changes in the body. All exert influence by changing the microbiome.
This community of trillions of bacteria, viruses, and fungi is responsible for breaking down food into metabolites, especially short-chain fatty acids (SCFAs) that communicate vital information to the whole body to perform digestive, neurological, and other functions. The main roles of these gut bugs are metabolism, nutrient absorption, and immune function.
Microbiomes are constantly in flux, and it’s becoming impossible to define exactly what a healthy microbiome looks like because our industrial world has already altered our microbiome in severe ways. We’re only learning how to study them in detail now. That said, patterns are emerging, and studies are offering powerful clues about how diseases are linked to certain microbiome patterns.
Dr. Cannon pointed to an autism study published in 2012 in Microbial Ecology in Health and Disease that showed the epigenetic nature of autism. Rats were given SCFAs from a subject with autism.
The rats displayed abnormal motor movements, repetitive behaviour, cognitive deficits, impaired social interactions, and other traits common in autism. The brain tissue of treated rats also showed neurochemical changes—such as innate neuroinflammation, increased oxidative stress, and glutathione depletion—consistent in patients with ASD.
“Conceptually, it is the author’s opinion that the pathophysiology of ASDs may be more completely understood as being similar to conditions such as ethanol intoxication, or diabetes, and the resultant complex interactions between diet, genetics, metabolism, host microbiome, and behaviour, that are well known to exist in these treatable disorders throughout the life cycle,” Dr Derrick F. MacFabe, the study’s author, wrote.
He suggested that SCFAs are the trigger of ASD or ASD behaviour. SCFAs are derived from the fermentation of nondigestible polysaccharides, such as resistant starches and dietary fibres. Among their physiological functions, SCFAs are important to intestinal epithelial cell growth, which protects the gut barrier, and to inflammation regulation.
“Yes, you can turn autism on,” Dr. Cannon said. “I can’t tell you how many times I’ve sat at a conference and heard, ‘I always thought that was genetic,’ when in fact the data has never supported that.”