A small study suggests a novel treatment for kids with autism: Give these young patients a fresh supply of healthy gut bacteria via a fecal transplant.

After the procedure, the children experienced a 25 percent reduction in symptoms related to language, social interaction and repetitive behaviors, said study co-author James Adams, an autism researcher at Arizona State University.

Not only that, the kids also became less hyperactive, irritable and lethargic, Adams said.

“It’s not a cure for autism, but in 10 weeks we were able to make a substantial dent,” he said.

Many children with autism suffer from chronic gastrointestinal problems like diarrhea and constipation, often from infancy, Adams explained. That may be because they either carry harmful gut bacteria or lack many healthy strains.

“Most people have about a thousand different species of bacteria in their gut, mostly beneficial,” he said. “In previous studies, we found kids with autism were missing several hundred of those species.”

Earlier studies showed that powerful antibiotics can temporarily improve autism symptoms, but the symptoms returned when the drugs wore off, Adams said.

“It’s not just wiping out the bad bacteria, but allowing the good bacteria to regrow so they fight off the bad bacteria,” he said.

Adams and his colleagues decided to see whether giving children a brand new gut ecosystem could provide longer-term relief of autism symptoms.

Special antibiotics were given to 18 children diagnosed with autism spectrum disorder, to wipe out their gut bacteria, Adams said. The children also fasted for half a day and underwent a bowel cleanse.

“Then we gave them a fecal transplant of very healthy gut bacteria from very, very healthy, carefully screened donors,” he said.

A laboratory purified the samples to remove nearly all waste material, leaving a “super probiotic” that was 99 percent healthy bacteria, Adams said.

The kids took high oral doses of the “super probiotic” for two days, and then lower doses daily for eight weeks, he said. They also took a stomach acid suppressant to make sure more of the bacteria made its way into their gut.

Five weeks into the study, the children had experienced an average 80 percent reduction in the GI symptoms most had experienced for years, Adams said.

Slowly but surely, the kids also experienced a steady improvement in their autism symptoms.

“By the end of the treatment, there was about a 25 percent reduction in autism symptoms,” Adams said.

Follow-ups conducted eight weeks later showed that their new gut bacteria were still healthy, and that both their GI and autism symptoms were stable, he said.

Mathew Pletcher is vice president and head of genomic discovery at Autism Speaks, an advocacy group. He said the study’s results “are encouraging but need to be repeated on a larger group of individuals before we can be confident that there is a positive benefit to be had from fecal transplant for individuals with autism.

“Digestive issues are common in individuals with autism and effectively addressing them through medical treatments have been shown to impact behavioral and social issues associated with autism,” Pletcher acknowledged.

“So, if changing the microbiome environment in the stomach and intestines through fecal transplant can reproducibly restore digestive health of individuals with autism, there is the potential to ease some neurological symptoms of autism as well.”

The researchers have received funding to proceed with a much larger trial, Adams said.

Adams hopes the larger trial’s results will lead to FDA approval of fecal transplants for people with autism. Currently, the agency only allows the procedure to treat infections of C. difficile, a dangerous bacteria that can cause life-threatening diarrhea.

There are several theories that could explain an interaction between gut bacteria and autism.

First, the gut releases a number of substances that affect the brain, said senior study author Rosa Krajmalnik-Brown, an associate professor of fundamental and applied biomics at Arizona State’s Swette Center for Environmental Biotechnology.

These include vitamins like folic acid and biotin, substances like short-chain fatty acids, and neurochemicals like serotonin, tryptophan and GABA, Adams and Krajmalnik-Brown said.

In addition, certain harmful bacteria can produce toxins that interfere with the immune system and potentially disrupt thinking, Adams added.

But it might just wind up being a simple matter of profound relief for these children.

“These kids have had GI problems like diarrhea or constipation for years, since infancy,” Adams said. “I think just relieving that discomfort makes them feel better, makes them be more sociable, less irritable and better able to learn.”

The study was published Jan. 23 in the journal Microbiome.

More information

For more about autism, visit Autism Speaks.

Source: HealthDay