I want to discuss a really important paper from December 2013 published in Cell by the Mazmanian lab at Cal Tech that links the microbiome to autism spectrum disorders (ASD). We already know that there is link that is becoming well-established between the gut and behavior. It has also been shown by other researchers that humans with autism also have high levels of IBD and other intestinal disorders. This suggests microbiome dysbiosis may be linked to autism, and was the motivation for this research.
In the paper the researchers induced ASD symptoms in mice by using a known method in which a mother is infected with a virus-like molecule, and the offspring of that mouse have a high likelihood of having ASD symptoms. After doing this procedure they directly demonstrated that those mice with ASD symptoms had reduced GI tract integrity, and had elevated levels of some metabolites in their blood when compared to offspring mice from the same mothers without ASD symptoms. Furthermore, some of the metabolites that were elevated are thought to be biomarkers for autism in humans (they are also elevated in humans with autism). Finally, when the offspring mice with ASD symptoms were given a probiotic, their symptoms were reduced, and those same metabolites were also reduced.
This research is especially exciting given that the probiotics were therapeutic for mice already displaying ASD symptoms, suggesting a possible cure for autism, but obviously let's not get ahead of ourselves.
A nice round-up of the article, which was co-authored by our friend Rob Knight, has a great summary of research, and I suggest anyone with further interest to read it.