Bacteria can be harmful or helpful. While we have seen deadly pathogenic bacteria cause massive endemics, we have also seen the numerous auto-immune diseases in patients who have minimal exposure to bacteria. Companies have been selling probiotics for a long time now. What we really need to ask is are these helpful enough?
Neurologists, in particular, have always been sceptic of the idea that a healthy gut can give you a healthy mind. While they have had reason to deny this observation in the past, they cannot do so now.
The US Institute of Mental Health that targeted the microbiome – brain connection which was presented at the annual meeting of the Society of Neurosciences. How do we relate the bacteria in our gut to our brain? The gut is a breeding ground for all sort of bacteria. We already know how some bacteria are good and produce substances that are helpful for our body, in the same way, these bacteria produce noxious material that harms us. Scientists know of two bacteria that produce GABA (γ-aminobutyric acid) which is one of the most important neurotransmitters in the brain. Hence what the bacteria produce, its affects and the implications are too profound for us to understand at this stage.
There have been previous studies that note this particular relationship in neurological disorders like autism, depression and even anxiety. In his study, pharmacologist John Cryan reveals how babies born out of a caesarean section tend to be more depressed than those born of normal delivery. He believes this to be due to lack of exposure to the vaginal bacteria newborns encounter during birth. This lack may be an important factor since this is the first thing babies come in contact with.
Sarkis Mazmanian is a microbiologist at the California Institute of Technology in Pasadena and he presented a mouse model in 2013, where mice had features that are remarkably similar to those of autism. These mice were found to have lower levels of the bacteria Bacteroides fragilis in their guts and higher levels of a metabolite 4-ethylphenylsulphate (4EPS) in their blood. When healthy mice were injected with 4EPS, they developed autism like features.
Although these are results of a basic research, they have neuroscientists thinking about many diseases like these from a different angle.