Neurological Effects of Manipulating the Microbiome
In fact, it is now thought that the microbiome plays a role in many neurological conditions such as obsessive compulsive disorder and autism; and also emotions like anxiety, aggression and sadness.4 Therefore, an understanding of the vast influence the microbiome has will undoubtedly open up new and exciting opportunities to diagnose and treat patients.
Recently, there has been interest in looking at the connection between the microbiome and autism spectrum disorder (ASD). The suggestion that a connection exists between the microbiome and ASD stems from the observation that many children with ASD suffer from increased inflammatory bowel disease and other gastrointestinal (GI) disorders compared to neurotypical children.8 Furthermore, studies have shown that the extent of GI dysfunction and severity of ASD exhibited are strongly correlated.9 Stronger evidence comes from a recent small open-label clinical trial which examined the impact of a 7-8 week long Microbiota Transfer Therapy (MTT) on GI and ASD symptoms.10 ASD-diagnosed children went through a two-week antibiotic treatment and a bowel cleanse followed by a fecal microbiota transplant course to re-populate their gut microbiota using a standardized source prepared from healthy individuals. Following the MMT the children showed significant improvements in both GI and ASD related symptoms, which persisted for at least 8 weeks after treatment ended. Looking at the microbiota composition of the children with ASD, the MMT shifted their microbiota to be more similar to that of neurotypical children. These findings support the idea that microbiota play a significant role in ASD symptoms.
The Microbiome as a Future Drug Delivery System
Pushing the boundaries even further, synthetic biologists are working to engineer bacteria and mammalian cells so the cells themselves are able treat certain diseases and act as therapeutic agents or “living pills.”11 For instance, scientists have already engineered a cell to be a “biomedical biosensor” which can detect a flare-up of the skin disease psoriasis and respond by releasing anti-inflammatory cytokines to sooth inflammation and provide on-the-spot treatment.12 Another area of research involves using the academic information obtained from studies on the microbiome to influence the interplay between our microbiota, the immune system and a the mechanism of action of disease to create a therapeutic bacterial cocktail. This bacterial cocktail would contain specifically selected commensal microbial species in order to remodel the gut microbiome and treat the disease.13 One major concern of modulating the microbiome is the importance of looking for unintentional global effects as much or even more than focusing on the intended ones. This is similar to the concerns mentioned in a previous article discussing editing genes with the CRISPR-Cas9 system; when dealing with influencing large scale complex systems like the microbiome or genome, minimizing uncertainties is paramount