Autism and the Brain-Gut Health Connection

Ever since Rachel of PaleoFreedom announced her success with a Paleo diet in treating her daughter Scarlett's autism, it seems like stories about autism and Paleo are coming out of the woodwork.  But one of the most interesting and coincidental articles came to me from Lisa Jo Rudy, the Autism Guide at About.com.

Though Ms. Rudy does not mention the Paleo lifestyle or diet per se in her articles for this particular newsletter, it's interesting to note that the entire newsletter is dedicated to the connection between brain function and proper gut health.  Rudy points out a study from McMaster University where researchers looked at the effects of gut bacteria on the behavior of mice, noting that those with lower levels of probiotic bacteria had both behavior changes and reduced levels of a key behavioral-based marker in the brain (as noted in the Newswise article that Rudy used as a reference):

Working with healthy adult mice, the researchers showed that disrupting the normal bacterial content of the gut with antibiotics produced changes in behaviour; the mice became less cautious or anxious. This change was accompanied by an increase in brain derived neurotrophic factor (BDNF), which has been linked, to depression and anxiety.

And anxiety, as those familiar with autism know, is a key trait for those on the ASD spectrum.

But here's the really interesting part of this:

To confirm that bacteria can influence behaviour, the researchers colonized germ-free mice with bacteria taken from mice with a different behavioural pattern. They found that when germ-free mice with a genetic background associated with passive behaviour were colonized with bacteria from mice with higher exploratory behaviour, they became more active and daring. Similarly, normally active mice became more passive after receiving bacteria from mice whose genetic background is associated with passive behaviour.

This would seem to indicate that even those individuals (mice, in this case) who had a lower level of probiotics in their intestines by nature could have behavioral issues reduced or removed by the introduction of proper bacteria into their guts.  And this is where successes like Scarlett's, above, seem to take over.

As those who follow a Paleo diet know, removing grains, legumes, and dairy from the diet promotes gut health.  Chris Kresser addresses this and the connection to brain health in his podcast (The Healthy Skeptic Podcast – Episode 9).

It's great to see all the evidence pointing to yet another positive effect of the Paleo lifestyle, and the amount keeps growing every day.  As Emily Deans pointed out in an article about Autism for Psychology Today, too many high-level researchers and groups are denying a connection between diet and autism, despite stories like Scarlett's and all the evidence for the success of diet-based treatments such as DAN and the common gluten-free/casein-free diet.

Hopefully researchers will begin to address this more closely as the evidence mounts to support the need for the research!