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:
Not all of these are what one would call comprehensive. But some of them are at least approaching the scale of what was done here. And surprisingly, not all of them are cited in the new study. In particular, the papers by Gondalia et al including one on “Molecular Characterisation of Gastrointestinal Microbiota of Children With Autism (With and Without Gastrointestinal Dysfunction) and Their Neurotypical Siblings” is not references despite it doing some similar things. I guess, if you don’t cite other comparable studies, and pretend they don’t exist, then that makes one’s work seem a but more novel right? Weird not to cite that work though – not sure why that happened. And certainly some of the other studies, even though they are cited, seem like they could be referred to as comprehensive. I mean – Ian Lipkin’s study
did metagenomics not just PCR based sequencing. Isn’t metagenomics sort of more comprehensive than PCR?
Anyway – let’s just say this is not the first “comprehensive” study of autism and the microbome.
Moving on in the press release I encountered another painful statement.
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.
Just what exactly does this new study say about prevention or treatment? Actually, as far as I can tell – nothing. So this is a bonus overselling statement just for the PR
Oh but then the PR just get’s worse:
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.
Seriously? We have gone from trying to claim this is the first comprehensive study of the microbiome and autism to now saying it is the first? Fu#*(@@# ridiculous.
Other lines that are troubling are encountered further on including
- “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
Anyway – I kind of wanted to give them an overselling the microbiome award for some of their statements. But in the end I would rather give them an “Overselling ourselves” award. It is a shame too. I think continuing to explore possible connections between autism and the microbiome will be important. Making misleading statements about what you have done and not citing / properly referencing other work will not help.