While their motives might lead them to say something, that doesn't mean it can't be true or partially true sometimes. The gut bacteria/fecal transplant thread elsewhere raises the possibility that something that changes the bacteria could lead to autism. Perhaps in some people milk or vaccines do provoke that change. I would imagine there are many other possible causes to change in gut bacteria.
Certainly some of the anti-vaccine/anti-milk/anti-whatever crowd act like quacks, cranks and charlatans. But this gut bacteria stuff will keep the argument going for a while.
I just did quick Google and found this from 2011, note 2011. The blogger is slamming some anti-vaccine quack for the ridiculous theory that doesn't look so ridiculous for the moment. GAPS in a doctor's reasoning
Here is an excerpt:
In the next part of the interview, Dr. Campbell-McBride gets to the heart of her ?treatment? for autism by describing what she thinks is the cause of autism. Basically, she does not believe there is a genetic component to autism, at least not in the way that real scientists do. Instead, she expresses an absolute certainty that autistic children are born with ?perfectly normal brain and perfectly normal sensory organs and they are supposed to function normally.? So what disrupts this normal functioning?
This, apparently:
What happens in these children, they do not develop normal gut flora from birth, from the beginning of their life. Gut flora is a hugely important part of our human physiology. Recently research in Scandinavia has demonstrated that 90% of all cells and all genetic material in a human body is our own gut flora. We are just a shell. We are only 10%. We are a habitat for this mass of microbes inside us. We ignore them at our peril.
What happens in these children they develop very abnormal gut flora from the beginning of their lives. So as a result their digestive system instead of being a source of nourishment for these children becomes a major source of toxicity. These pathogenic microbes inside their digestive tract damage the integrity of the gut wall.
So all sort of toxins and microbes flood into the bloodstream of the child and get into the brain of the child. That usually happens in the second year of life in children who were breast fed because breastfeeding provides a protection against this abnormal gut flora.
Recognize this? It wasn?t so long ago that I wrote about detoxification quackery. What Dr. Campbell-McBride is talking about here is nothing more than a variant of the ancient concept of autointoxication, whereby our own human waste products ?poison? us. The difference is that she?s attributing it to bacteria living in our gut. But where do many of the bacteria living in your gut end up? In your poop, of course! In any case, Campbell-McBride even has a name for her invented autism syndrome: Gut and Psychology Syndrome (GAPS). She?s even developed a whole cottage industry of dietary woo to treat it, which can be found on various websites, including Gut and Psychology Syndrome, The GAPS Diet, and in her book Gut and Psychology Syndrome Book: Natural Treatment For: Autism, ADD, ADHD Depression, Dyslexia, Dyspraxia, Schizophrenia. And, of course, she has her own website Doctor-Natasha.com, and if you check it out you?ll see that she claims to be able to treat anything from acne to depression to diabetes to autism to ADHD to schizophrenia to tummy pain. Yes, tummy pain. (I always thought that a good shot of Pepto-Bismol would take care of your basic tummy pain much of the time.) Here is her pseudoscience explained: