Johnson did a little reading and, like Chinitz, came across Trichuris suis therapy. He brought it to his son’s doctor, Eric Hollander, the director of the Autism and Obsessive Compulsive Spectrum Program at Albert Einstein College of Medicine in New York City. Hollander started Lawrence with a three-month dose, having the boy swallow the eggs in a drink every two weeks. The effects were rapid and striking, Johnson says: “It was just remarkable; it was back to all the good stuff that we saw.” Hollander, too, recalls a marked improvement in terms of Lawrence’s aggression, self-injury, and openness to changes in his routine, adding that “it was easier for the family to travel with him.”
Last year, Hollander and his colleagues published a small trial of helminth therapy in 10 autistic adults. To increase their odds of seeing a response, they selected participants with a personal or family history of autoimmune problems, such as allergies. After 12 weeks of the treatment, they measured the therapy’s effect on certain autism traits. Overall, the participants showed fewer repetitive behaviors and less behavioral rigidity and irritability. The next step, Hollander says, is to identify biomarkers to group the people and traits that are most likely to respond to these therapies.
Inflammatory pathways do not play a role in all autistic people, Hollander says, but it may be that repetitive behaviors and rigidity, for example, are particularly amenable to modifications of the microbiome or the immune system in some people. “It’s possible that there may be different therapeutics for the repetitive behaviors than there might be for social communication,” he says.
If these lines of research pan out, doctors may one day be able to treat autism with a combination of drugs, some targeting the microbiome.
A plethora of biotech companies are trying to engineer or cultivate the perfect mix of gut microbes or even small molecules that manipulate gut microbes as treatments for autism and other conditions. In February, for example, Boston-based Axial Biotherapeutics, co-founded by Mazmanian, raised $25 million in a second round of funding to develop gut-targeted small molecules to treat Parkinson’s disease and autism.
To date, though, pharmaceutical companies have not shown much interest, perhaps because questions of regulation bedevil such therapies. And although the Food and Drug Administration has approved fecal transplants under close supervision to treat people with deadly Clostridium difficile infections, it has yet to rule on stool for other purposes, such as IBD. Krajmalnik-Brown and her colleagues hope to develop microbial cocktails that can be administered orally, which might make the approach easier to deliver and regulate.
The challenge of standardization also makes helminths harder to bring to market. Companies have shown little interest in parasites since a clinical trial of Trichuris suis ova to treat Crohn’s disease, a type of IBD, fizzled out in 2014. The German biotech entrepreneur Detlev Goj, who was involved with those trials and co-founded the Thai helminth distributor Tanawisa, is attempting to get the eggs regulated as a medical food in Europe. If he succeeds, the eggs would be available in supermarkets there, alongside probiotic drinks. Eventually, Goj hopes to have the helminth eggs regulated as a supplement in the United States.