A recent study from Japan shows that eating xylitol works as a probiotic and increases our production of a very useful substance–butyrate. Butyrate is a small molecule that works as a messenger signaling other processes in our bodies. One of the key ones is reducing inflammation. We know that eating meat, especially when it is cooked at high temperatures, increases inflammation. This is a way to reduce that problem.
There is a very good review of GI butyrate on the paleo diet web page if you want more about it. One area not discussed in their review is the argument from Derrick Mac Fabe about the role of small molecule like this in contributing to autism.
Dr. Mac Fabe sees a connection between propionic acid and autism. The connection is easy to see when you inject this small molecule into the brains of lab animals–they behave like autistic children. He argues that the rise in autistic spectrum problems is due both to our increased use of this molecule in preserving our foods, and to using more antibiotics in children, which promotes the growth of harmful bacteria that make more of it in the gut.
That’s where xylitol comes in. The most prevalent of the harmful bacteria is a species of clostridia. It’s not the one that causes so much of a problem with its antibiotic resistance, but all members of that species make lots of propionic acid. And we found out a long time ago that xylitol unhooks these bacteria very effectively. Unhooking them means that they are removed from the GI tract, not by killing them, but just a friendly ‘shape up or ship out”. Butyrate is a better choice that propionic acid and in lowering the amount of the latter we may help our autistic kids as well.