Kids With Autism May Benefit From Rare Bacteria

A new study adds to research showing the benefits of L. reuteri for improving social functioning in children with autism. 

The number of children diagnosed with autism spectrum disorder has grown dramatically in the past few decades. Ground Picture/Shutterstock

New evidence is adding to previous research showing that Limosilactobacillus reuteri (L. reuteri) improves the social function of children with autism.

Published in Cell Host and Microbe, the study found that the bacteria—formerly called Lactobacillus reuteri—improved some social function markers related to autistic behavior. Though it involved a small cohort of 43 children, the study was a randomized, double-blind, placebo-controlled trial, considered the gold standard for quality research.

The study builds on previous research showing that oxytocin—often called the “love hormone” that helps with human bonding—delivered intranasally to children with autism may help with social deficits. Manipulating the microbiome specifically by increasing levels of L. reuteri has been shown to be another way to increase oxytocin and improve mental health.

The number of children diagnosed with autism spectrum disorder (ASD) has grown dramatically in the past few decades—up to 2.8 percent of children—and the cost associated with autism care is expected to reach $461 billion by 2025. Difficulties with social interaction is a defining symptom of autism—and is exceptionally challenging to address, though there is a wide array of interventions targeting it.

Those difficulties include establishing and maintaining relationships, reciprocating social interaction, and communicating with others, according to a 2017 article in Patient Related Outcome Measures.

“Lack of social skills may have lifelong implications for children with ASD, affecting their family/community interactions, academic skills, self-worth, and independence,” the article stated.

“Reports on social skills in ASD indicate that these skills are extremely difficult to learn and that educational objectives should be focused on developing social skills because they have lifelong implications.”

This problem calls for effective interventions that can help these children improve their social capabilities, the article noted.

The Overall Effect of L. Reuteri

In addition to looking at social behaviors in children with autism, the new study examined repetitive behaviors, overall microbiome compositions, and the immune profiles of the children. It measured parameters before and after six months of taking either the placebo or two probiotic tablets containing 200 million colony-forming units (CFUs). CFUs are the number of viable bacteria.

The microbiome is the collection of bacteria, viruses, fungi, and other microorganisms that live in the gastrointestinal tract.

The study found that L. reuteri didn’t improve overall symptom severity, nor did it change the microbiome or the immune profile. There were no reported changes to gastrointestinal symptoms from the intervention.

However, the aim of the study was primarily to test the hypothesis that L. reuteri could work as a therapeutic intervention for autism, particularly for social skills. A 2021 meta-analysis published in the National Autistic Society looked at 31 studies and concluded that oxytocin levels were “significantly lower in autistic people.”

A 2021 study published in Cell noted that treating mice with L. reuteri at various developmental stages was able to improve social deficits.

The new study reported improvements in communication but not social motivation or mental state understanding. However, there were significant improvements in adaptive social functioning, which refers to developmentally appropriate skills and abilities necessary to communicate and function in daily living.

‘Still a Success’

Dr. William Davis, cardiologist and author of “Super Gut,” who has researched L. reuteri, told The Epoch Times the study is an important piece of the autism puzzle.

“I applaud what these people did. They did the study I wanted to do but just didn’t have the funding for it,” he said. “I didn’t expect it to be a cure-all. People want to hear, ‘They cured autism.’ If L. reuteri improves some aspect of social behavior, that’s still a success.”

It’s more likely that there will be a collection of several microbes that will prove beneficial for autism. In the meantime, Dr. Davis has witnessed many anecdotes of L. reuteri leading to improvement with autism among his own clients.

One is a mother whose adult daughter with autism was barely functional. Though she was physically capable of working, her social deficits didn’t allow her to hold down a job or engage socially. She began taking L. reuteri and now has a job and friends. It didn’t cure anything, but she became a different person, Dr. Davis explained.

One thing he pointed out was that probiotic manufacturers often have too small of a dose in their products. He teaches clients to culture the bacteria in yogurt to increase a 400 million CFU dose to one with 300 billion CFUs.

“Four hundred million sounds like a lot, but in microbes, it’s a drop in the bucket. My suspicion is you’d see bigger effects in higher doses. In the real world, I see that happen, and I see dramatic improvements,” Dr. Davis said.

Eventually, he said, research will catch up to include more precise dosing. He compares the dosing in many studies to taking half milligrams of aspirin and expecting it to work for a headache when the proper dose is 600 milligrams.

Where Has All the L. Reuteri Gone?

When it was discovered, L. reuteri was found in about 30 percent to 40 percent of the population. A Science Daily article in 2010 noted its presence had shrunk to only 10 percent to 20 percent by then. While specific data are hard to come by, Dr. Davis believes its level is now about 4 percent.

As with many other bacteria that are disappearing from the human microbiome, L. reuteri’s extinction is connected to antibiotic overuse, glyphosate, emulsifiers in processed food, and stomach acid blockers.

“Nearly everybody has lost this gut microbe L. reuteri ... because it’s very susceptible to common antibiotics like amoxicillin and penicillin. We’ve nearly knocked off the reuterin in modern populations,” Dr. Davis said.