they also have many inconsistencies. Some studies found that microbes only affect the brains of young mice; others that adolescents and adults are also affected. Some found that bacteria make rodents less anxious; others, more so. Some show that the vagus nerve is vital; others emphasise that microbes can produce neurotransmitters like dopamine and serotonin, which carry messages from one neuron to another.43 These contradictions aren’t unexpected – when two things as fiendishly complex as the microbiome and the brain collide, it would be naïve to expect clean results.
Inconsistency
