So when we sleep and we have an empty stomach then the activity, the contractile activity
of our gut changes to a very unique pattern.
It’s a 90-minute cycle, very powerful waves of contractions migrate from the esophagus
all the way down to the end of our large intestine.
And they move very slowly.
So this has been referred to as the intestinal housekeeper that sort of cleans the gut from
any residue that’s present.
And the rhythm for that is generated by the brain so it’s dependent on the input of
the vagus nerve on the second brain in the gut.
And this has been something that also should occur when during daytime when in between
meals when our stomach and intestinal system is empty.
However with the sort of modern habit of snacking in between meals so a lot of people don’t
have that during the day but have it during sleep.
If you add the microbes into this now it’s quite likely, not really proven.
I mean the microbes obey some kind of a Circadian rhythm by themselves so they’re different
during sleep and during daytime.
But it’s quite possible to assume that this powerful wave that sort of cleans everything
out will also affect the microbes, the composition of the microbes because if we don’t have
it – so people that don’t have that for some reason they will develop abnormal colonization,
for example, of their small bowel with a lot of microbes that don’t really belong there.
So clearly an important role in regulating the populations and the regional distribution
of these microbes in our gut.
What happens during sleep, so during REM sleep when we have a lot of activity going on within
the autonomic nervous system circuits within the brain and the signals are being sent to
the gut.
So our body is inhibited but not our intestinal activity.
So in many ways emotions that we experience usually in our dreams have their mirror image
in terms of gut activity – contractions, secretions.
And again I mean like everything that goes on within our brain emotionally always is
reflected just like our facial expression reflects our emotions, everything reflects
our emotional state either during waking time or sleep time at the gut level.
And the microbes who live in that environment are affected by it.
So it’s an area that’s not studied in great detail but very important for an understanding
of how the microbes, the gut and the brain interact and maintain health.
So sleep is a very important ingredient for health regulation of the immune system but
for the also regulation of gut function and particularly gut microbial integrity and wellbeing.
We know quite a bit about what happens during sleep and during dreaming.
In psychoanalysis this is a big window into our emotional lives so Jungian or Freudian
psychoanalysts have spent a lot of time interpreting dreams and getting an access to this process.
A big portion is probably the processing and consolidation of memories that have been experienced
during the day.
Many of these memories have a gut feeling component because every time we have an emotion
during the day there’s always a counterpart at the gut level that is then through these
sensory pathways goes back to the brain.
We may not experience it during the daytime but it’s encoded in this vast database within
the brain.
So what happens then during sleep there is this retrieval and then processing and consolidation
of these memories including all the gut feelings that are associated with those experiences
that we had during the day.
I think it’s a very important point to emphasize that emotions have an intricate component
of gut activity and gut feelings regardless if you feel it like the butterflies in the
stomach or the knot in the stomach.
Every emotion has a component that the brain engages gut activity and that’s being reported
back to the brain.
And so you have to look at an emotion really as a circular process within the brain-gut
access.
And during sleep and during dreaming there’s almost certainly a consolidation processing
of this myriad of gut feelings that are generated throughout the day.