[Aurornis]

> 1. I stopped drinking heavily and using other drugs, i.e. marijuana

Heavy alcohol use and marijuana are both known to impact memory and recall directly.

Discontinuing both of those explains changes in memory. Attributing this to microbiome changes does not follow.

[uxhacker]

This paper actually surveys research on humans and not mice.

The association between gut microbiota and cognitive decline: A systematic review of the literature

https://www.sciencedirect.com/science/article/pii/S027153172...

It shows ”Gut microbiota modulation improves cognition in adults with early impairment. Diet, probiotics, and fecal microbiota transplantation share mechanistic pathways and that evidence clarifies how microbiota-targeted strategies support cognitive health.”

The action could be explained due to an anti inflammatory action by the gut biome.

[Aurornis]

Yes, there are some interesting potential mild modulations that can occur with microbiome change.

That paper commits one of the major sins of many microbiome papers which is to attribute all benefits of diet change to the microbiome. Like the parent commenter it gets drawn to the idea that all changes in the body can be traced back to the microbiome and assumes that it explains everything, but that’s obviously not true.

However, when someone is taking two powerful substances with direct brain action and known modulators effects on memory, blaming anything else in the body is bad logic.

[coldtea]

>Heavy alcohol use and marijuana are both known to impact memory and recall directly.

And who said they don't do this (long term) exactly through their affecting the gut microbiome?

[Aurornis]

Both alcohol and marijuana have direct actions on the brain. That’s why people consume them.

They do not exert their primary effects via microbiome modulation. This is obvious because the effects occur nearly immediately upon consumption, whereas microbiome change from what you consume is a gradual process.

The question I have is: Why has microbiome become the explanation for everything? What would lead you to believe that microbiome would be the explanation for this, when the direct action upon the brain is so much more direct and obvious? Microbiome is an interesting area of research but how did we get to this point where some are ignoring the obvious and trying to construct alternative microbiome based explanations for things like alcohol and marijuana impairing memory?

[coldtea]

>Both alcohol and marijuana have direct actions on the brain. That’s why people consume them.

Which is orthogonal as to whether those direct actions also affect long term memory.

>They do not exert their primary effects via microbiome modulation.

Who said anything about primary effects?

[metalman]

a great deal of alcohol, weed, etc, is consumed ,very specifcly, to forget. to the point that users, often workers doing labour, or other jobby jobs, get fairly aggetated by days, and especialy weeks end, wrapped up in an overload of the realities of serving others interests, and ends. drugs provide a crude function similar to the processing that occurs durring sleep and dreaming. That this has effects on the gut, is hardly unexpected ,but that the system will recover with due care, is. Treating the gut as a self maintaining biological digester, which it is, then suggests looking at how various industrial digestors operate and malfunction.

[red75prime]

Or by affecting the kidneys, or by affecting the enteric nervous system, or through some other pathway for which we have no substantial evidence of influencing memory (yet). It just seems like a baseless prioritization of a hypothesis. For some reason, people are specifically fascinated by the gut–brain axis.

[coldtea]

>For some reason, people are specifically fascinated by the gut–brain axis.

Might the reason be that we're constantly finding new important ways it affects things, or that we see major changes to seemingly orthogonal issues from targetting the gut microbiome directly?

[wk_end]

I think the appropriate response here is some combination of Russell's Teapot and Occam's Razor: they might, but some kind of hard evidence is necessary before humouring that theory, particularly since there's a vastly simpler explanation on hand.

[jb1991]

It has been well recognized that alcohol significantly disrupts the bacteria in your gut.

[PeterStuer]

Anecdotal. I have never drank much alcohol, but an evening Trappist helped me turn off after a day's work.

Since I stopped that habit, I do notice memory getting worse. Not saying it is THE EXPLANATION, but it is an observation non the less.

[fwip]

Also, getting better sleep (by fixing heartburn and meals) will mean you're more rested, and improve functioning during the day.

[sfpotter]

It could easily be both.