Autism & Developmental

Molecular characterisation of gastrointestinal microbiota of children with autism (with and without gastrointestinal dysfunction) and their neurotypical siblings.

Gondalia et al. (2012) · Autism research : official journal of the International Society for Autism Research 2012
★ The Verdict

Gut bacteria look the same in autistic and neurotypical siblings, so shift your GI work-up to diet and anxiety.

✓ Read this if BCBAs treating autistic kids with tummy trouble in clinic or school.
✗ Skip if Practitioners focused on non-GI behavior only.

01Research in Context

01

What this study did

Scientists swabbed the stool of the kids. Half had autism, half were their neurotypical brothers or sisters.

They read the DNA of every bug in the sample. The goal: see if autistic kids carried a different gut zoo.

02

What they found

The bug list was almost identical. Autism, tummy pain, or diarrhea made no clear difference.

In plain words: the microbiome is probably not the villain behind GI complaints in autism.

03

How this fits with other research

Esteban-Figuerola et al. (2019) pooled 29 diet studies and found autistic kids eat less dairy, calcium, and omega-3. Low intake, not bad bugs, may trigger constipation or reflux.

Tonnsen et al. (2016) double-blind tested gluten and casein snacks. Behavior stayed flat, just like V et al. found flat microbiota. Both papers weaken the “diet-toxin” story but for different reasons—one shows no reaction, the other no bacterial shift.

Çıtar Dazıroğlu et al. (2024) went further, measuring antioxidant capacity. Autistic kids scored lower, hinting that poor nutrient variety, rather than microbes, drives GI pain.

04

Why it matters

Stop chasing stool tests and miracle probiotics. Start asking about food refusals, liquid intake, and mealtime anxiety. A simple three-day food diary plus a hydration log often reveals the real culprit—and you can fix that today.

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→ Action — try this Monday

Run a 72-hour food and drink log before recommending any probiotic.

02At a glance

Intervention
not applicable
Design
other
Sample size
104
Population
autism spectrum disorder, neurotypical
Finding
null
Magnitude
negligible

03Original abstract

Many children with autism spectrum disorders (ASDs) suffer from gastrointestinal problems such as diarrhoea, constipation and abdominal pain. This has stimulated investigations into possible abnormalities of intestinal microbiota in autistic patients. Therefore, we designed this study to identify differences (and/or similarities) in the microbiota of children with autism (without gastrointestinal dysfunction: n = 23; with gastrointestinal dysfunction: n = 28) and their neurotypical siblings (n = 53) who share a similar environment using bacterial tag-encoded FLX amplicon pyrosequencing. Regardless of the diagnosis and sociodemographic characteristics, overall, Firmicutes (70%), Bacteroidetes (20%) and Proteobacteria (4%) were the most dominant phyla in samples. Results did not indicate clinically meaningful differences between groups. The data do not support the hypothesis that the gastrointestinal microbiota of children with ASD plays a role in the symptomatology of ASD. Other explanations for the gastrointestinal dysfunction in this population should be considered including elevated anxiety and self-restricted diets.

Autism research : official journal of the International Society for Autism Research, 2012 · doi:10.1002/aur.1253