Uggh. Just saw a bunch of stories about autism and the microbiome. Many of the comments in the news stories I read seemed, well, not so good. So I decided to sniff around. Seems that many of the comments and stories are based on a new PLOS One paper and the comments and press release from the group behind the paper.
Here is the press release I found: Clues about autism may come from the gut. From Arizona State University. So I read it. But I had a hard time getting past paragraph 2:
In new research appearing in the journal PLOS ONE, a team led by Rosa Krajmalnik-Brown, a researcher at Arizona State University’s Biodesign Institute, present the first comprehensive bacterial analysis focusing on commensal or beneficial bacteria in children with autism spectrum disorder (ASD).
This did not sound true and sounded a bit overblown as I could have sworn I had seen other “comprehensive” studies of the microbiome in children with ASD. So first I decided to look at the paper. And – thanks a lot – there was no link in the PR or the stories I had seen. So I had to go to PLOS One and do a little searching and I found it:
Reduced Incidence of Prevotella and Other Fermenters in Intestinal Microflora of Autistic Children
Kang D-W, Park JG, Ilhan ZE, Wallstrom G, LaBaer J, et al. (2013) Reduced Incidence of Prevotella and Other Fermenters in Intestinal Microflora of Autistic Children. PLoS ONE 8(7): e68322. doi:10.1371/journal.pone.0068322
So – first I asked – did they make the same claim in the paper or was this just in the PR? Usually such things are just in the PR but amazingly they have this claim in the paper too, with lines like:
“previous studies describing the relationship between autism and gut microbes have either mostly focused on the emergence of harmful bacteria or mainly paid attention to already-known beneficial bacteria”
So I decided to then look at Pubmed and Google Scholar for other papers on autism and the microbiome. Here are some that I found:
- Pyrosequencing study of fecal microflora of autistic and control children from 2010.
- The Gut Microbiome: A New Frontier in Autism Research
- Molecular Characterisation of Gastrointestinal Microbiota of Children With Autism (With and Without Gastrointestinal Dysfunction) and Their Neurotypical Siblings
- Gastrointestinal microbiology in autistic spectrum disorder: a review
- Faecal microbiota of individuals with autism spectrum disorder
- Gastrointestinal flora and gastrointestinal status in children with autism–comparisons to typical children and correlation with autism severity
- Analysis of Small Intestinal Microbiome in Children with Autism
- A microbial association with autism
- Impaired carbohydrate digestion and transport and mucosal dysbiosis in the intestines of children with autism and gastrointestinal disturbances.
The work also offers hope for new prevention and treatment methods for ASD itself, which has been on a mysterious and rapid ascent around the world.
Their new study is the first to approach autism from a different angle, by examining the possible role of so-called commensal or beneficial bacteria.
- “The authors stress that bacterial richness and diversity are essential for maintaining a robust and adaptable bacterial community capable of fighting off environmental challenges.”. Hmm. What is the difference between richness and diversity? And what is the evidence that they are essential for such functions?
- “The species is a common component in normal children exhibiting more diverse and robust microbial communities.” Again – what makes that robust?
- Michael Polan’s recent New York Times Magazine story on the microbiome points to the fact that he is proud that his gut microbiome is rich in Prevotella regarding it as a possible sign of a healthy non-Western diet. Really? They brought Michael Pollan (with a mis-spelling that might be on purpose so that Pollan does not see this) into their PR? Uggh

I can feel the steam coming out of your ears!
This post (which should be sent to the authors) may calm you a bit:
http://blog.dansimons.com/2013/07/six-simple-steps-scientists-can-take-to.html
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I just found your blog post. I am hoping to understand your angle on it. I am a parent of a child on the autism spectrum who came out of autism three weeks into the Specific Carbohydrate Diet. It was snubbed by many doctors, so when I find research like this I feel somewhat validated, perhaps an explanation why he got better on this diet. I do feel frustrated that six years later this type of research is getting an ever so slight notice, this could have helped so many so much sooner. Well, I will guess it's only looked at in the research peer groups and not yet on the radar of pediatricians. My brother and mother are also on the spectrum so the biology of autism has been fascinating to me. I will have to check out more of your blog, seems interesting.
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P.S.- Thanks for the list of links!
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