Autism and Probiotics

This is a three part post, first review of actual published studies, second review of probiotic suggested by published studies on microbiome shifts with autism, third review of probiotics created from a composite off all autism-tag microbiome on my site.

“Probiotics have been thought to alleviate the progression of autism and reduce cognitive and behavioural deficits.” [2020 Study]

1-Published Studies

I restricted to actual human studies. Many of these studies appear to be sponsored or assisted by product manufacturers.

  • ” In conclusion, the favourable effect of probiotic supplementation on cognitive function in children and adolescents was observed in one study with Lactobacillus rhamnosus GG (LGG) 1×1010 cfu supplementation by a risk reduction of developing ADHD or AS (i.e. autism). ” [2019 Study]
  • ” 6 strains of bacteria; each strain has 1 billion CFU/gram. The dosage is 6 g per day (36 billion CFU in total)…Probiotics treatment can reduce the magnitude ASD-related and gastrointestinal symptoms” [2019 Study] – have emailed authors for details
  • “Following Bimuno® galactooligosaccharide (B-GOS®) ® intervention, we observed improvements in anti-social behaviour, significant increase of Lachnospiraceae family, and significant changes in faecal and urine metabolites.” [2018 Study]
  • ” VSL#3, a multi-strain mixture of ten probiotics… reduced the severity of abdominal symptoms as expected but an improvement in Autistic core symptoms was unexpectedly clinically evident already after few weeks from probiotic treatment start” [2016 Study]

Conclusion: galactooligosaccharide supplements, 36 BCFU/day of Lactobacillus Probiotics (No Bifidobacterium — ASD is often high/very high in them). LGG has not been demonstrated to help after ASD occurs, just before (risk reduction).

2-Published studies on microbiome shifts

This data comes from MicrobiomePrescription site, A Priori Adjustment page

Given the goal of 36 BCFU per day, the best cost option would likely be CustomProbiotics that sells these in pure bulk form powder.

  • L. Gasseri US$ 120 for 50gm or 500 servings of 20 BCFU.
  • $240 for 250 days of dosages, or a dollar a day.
  • I have no financial interest in Custom Probiotics – and I often order from them

3-Composite using all autism-tag microbiomes

This is done by using the average value from 90+ microbiome samples marked with an official diagnosis of autism. This composite is in the Demo Login (so you can explore it in other ways).

Logon with Demo / 1234567 at

Running several different scenarios on this composite

I first did a hand picked against Autism and ended up with:

There is a list of probiotics to avoid

Bifidobacterium is dominate in the avoid

Playing around (lots of choices), the only significant one to add was lactobacillus kefiri (NOT KEFIR) – which is unfortunately only available in Italy.

Bottom Line

The short of the above is a daily dosage of at least 36 BCfu of Lactobacillus species with L.Reuteri and L.Gasseri being the strongest choices. L. Kefiri if you happen to know someone in Italy. lactobacillus paracasei (probiotics) showed off frequently in some scenarios.


  • Any addition of probiotics should be reviewed by your physician, the above is “academic” and “educational”
  • Start off with a small dosage and slowly increase to the goal
  • Do not be surprised if: (and cited in some studies reviewed)
    • Diarrhea happens for a few days – it is dislodging some nasty customers
    • Die-off or Herxheimer effect –

I was personally hoping for better clarity / course of action when I started this post then when I am closing it. If your MD gives the go ahead, please post a report as a comment every 2 weeks for the benefits of others.

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