
Human gut bacterial enzyme ingests L-dopa and converts it to dopamine - bookofjoe
https://elifesciences.org/articles/50845
======
eganist
Interesting.

L-dopa appears to have L-Tyrosene as a precursor, which can be found in Casein
(present in cheese) or synthesized from Phenylalanine (a metabolic byproduct
of Aspartame).

[https://en.wikipedia.org/wiki/L-DOPA](https://en.wikipedia.org/wiki/L-DOPA)

[https://en.wikipedia.org/wiki/Tyrosine](https://en.wikipedia.org/wiki/Tyrosine)
\--casein in intro pgh

[https://en.wikipedia.org/wiki/Tyrosine#Biosynthesis](https://en.wikipedia.org/wiki/Tyrosine#Biosynthesis)
\--phenylalanine

Edit: The phe->tyr connection in the context of a gut biome capable of
converting l-dopa to dopamine is dubious, though, because I'd assume phe->tyr
synthesis would likely _not_ take place in the gut, rather beyond it, in
mammals. So uh, maybe just cheese?

Anyway, I'm not an organic chemist. I can't even remotely pretend to be
qualified to connect those dots. But if my anecdotal/personal experience says
anything: breaking my aspartame habit has been an utter nightmare when I
switched to keto, and I still love cheese. I drank well over two liters of
diet coke a day for years, and I still go through cheese like air.

I invite corrections from the experts here. Dead certain I got something
wrong. All I know is I have a hideous addiction to certain foods and anything
minting dopamine in my gut would surely invite my curiosity.

------
CapriciousCptl
Dopamine doesn’t cross the blood brain barrier— sorry to burst the bubble of a
lot of the posts here. In fact, for the dopamine deficient disease,
Parkinson’s, L-dopa is the treatment because it does cross and is the
converted to dopamine after crossing.

~~~
eganist
This doesn't rule out the effect of dopamine on the rest of the nervous
system, including the hundred million neurons wrapping the gut as well as the
neurons modulating heart function.

------
HeavenBanned
The question is: what foods are rich in L-Dopa? Should we therefore avoid
them, eat them in moderation, or bulk up on them?

~~~
twelvechairs
You should do neither right now. Just focus on normal healthy eating habits.

~~~
lactobacillis
That begs the question of course: What are normal healthy eating habits?

Our eating habits have been formed by mass marketing for many decades so I
would not call them normal. Even the fresh fruit and vegetables I see in the
supermarkets (Coles and Woolworths in Australia) do not look normal.

~~~
basch
Greens - spinach, kale, swiss chard, beet greens, parsley, watercress,
mustard, turnip, cress, dandelion

Seeds - sunflower, pumpkin, *

Seafood - Salmon, sardines, mussels

Reds - Tomato, red peppers

Insects - Crickets

Everyone can debate the merits of livestock, cereals, roots, legumes,
extracted seed oils, saturated fat, cholesterol, refined sugar, top feeding
fish, alliums, brassicaceae. But the other things listed above are about as
universally and unequivocally considered healthy with the understanding of
food we have, with regard to commonly available foods in a western diet.

* almond, peanut, walnut, pistachio, pecan, cashew, macadamia too if fodmap issues arent a concern. Same with alliums, brassicaceae, legumes.

------
hinkley
I wonder how many drug studies we'll end up having to eventually re-do to
account for metabolic interference by microbes.

Everyone without this microbe was non-responsive to Drug A. Everyone with this
microbe had negative outcomes from Drug B.

~~~
LARP1234
Likely none.

The paper describes finding an enzyme that can cleave catecholamine
precursors. OK? There's literally only one catecholamine precursor that's used
medically, and that's L-DOPA.

We know Parkinson's medications work, and very effectively. L-DOPA is used
effectively, despite being metabolized by gut flora.

------
steven_is_false
Taking a pill is a somewhat poor way of getting substances into the body
because it must go through the liver anyway. It does have the advantage of
slowly leaking into the body though.

If you read into this subject to avoid processing by the liver or other
problems like this you want an injection, sublingual administration or rectal
administration or a patch/cream. For want of a better word "sensitive" parts
of the body such as the scrotum are more permeable to patches/creams. You
could probably get tipsy by dipping your balls in a drink similar to boofing.

------
daeken
Huh, that's interesting. I wonder what effect this has on the gut and what
advantage this confers to the bacterium. AFAIK, dopamine doesn't cross the
blood-brain barrier, so it can't (directly) have an effect on the brain's
dopaminergic pathways, but who knows what it does to the gut, or follow-on
effects on the brain.

------
mrfusion
Eli5?

~~~
rriepe
The "feel good" chemical in your brain is put together from a building block
version of it.

But sometimes it doesn't get that far, because special types of bugs in your
gut get to the building block version first. They do the same thing your brain
does to it, but it's unclear what the effects are, because it's happening in
your gut before it gets to your brain.

This is a paper confirming and isolating one of those special types of bugs.
The implications could be pretty big: Are these bugs affecting medications?
Moods? Are they stealing our brain's supply of feel good chemical? Can we use
their powers for good?

~~~
LARP1234
Major nitpick: Dopamine isn't the "feel good" chemical.

Endorphins are more accurately "feel good" chemicals.

Dopamine is involved in motivation through reward reinforcement, movement, and
cognition in the human nervous system.

Another nitpick: L-DOPA isn't a building block of dopamine. It's dopamine with
an extra molecule attached to it that makes it "inactive." This molecule gets
snapped off by the AADC enzyme, which "activates" it. L-DOPA is the precursor
to dopamine.

Third nitpick: We can understand how these gut flora affect ingestion of
L-DOPA, and neurotransmitter precursors, by looking at how it's used in
medical treatments. Most notably, Parkinson's patients. Suffice to say, it
really makes no fucking difference, and orally-administered L-DOPA (with a
dehydroxylaze inhibitor) is effective.

Whatever L-DOPA is stolen by gut-flora, can be augmented with a higher dosage.
If for some strange reason, the converted L-DOPA -> Dopamine gets released
into the digestive tract, and absorbed by the body, it's readily broken down
in the blood. L-DOPA converts to dopamine in the blood-stream anyway, so it
makes absolutely no difference.

I wanted this paper to be novel, but after reading it, it's not.

Gut flora have AADC-like enzymes, cool?

~~~
heavyset_go
If we're nitpicking, endorphins act on opioid receptors of GABAergic neurons,
inhibiting the release of GABA, which in turn disinhibits the release of
dopamine in reward pathways.

That dopamine release is what is directly responsible for pleasure and
euphoria associated with endorphin release.

