There is no information that connects the workings of a brain to the production of consciousness. We don't understand the connection in the least.
This is not to say there is not evidence connecting the consumption of certain drugs with changes in human consciousness.
Those drugs work by altering neural activity, such as by binding to chemical receptors. That is evidence that consciousness is a property of neural activity.
Consciousness is one of the things that the brain 'can do', which is why we can alter consciousness by altering the brain.
Saying a "brain does consciousness" does not tell us what consciousness is in the least.
It is not an understanding of consciousness in the least.
It tells us that consciousness is a property of the brain.
And without an understanding of what consciousness is you cannot make statements about what can't possibly affect it.
Since we have a (very basic) understanding of what consciousness is, we can make statements about what can't possibly affect it.