Extended cut and early access: Gut Microbiome part 1- mental health! (Patreon)

Video transcript:

What do you need to know about your gut microbiome? Part 1 of… several: How does your gut influence your mental health? Scientists sifted through shit– yes,literally, but also lots of really bad research papers— to get you some answers.

Let me start by saying I’ve been skeptical of these studies because the vast majority of them don’t even bother to ask participants about their diet or medications, or even exclude participants who used antibiotics recently. They also tend to have a high risk of bias (Sanada et al, 2020).

Frankly, we don’t know *how* a connection between gut bacteria and your mental health *really* works: in science we call this the mechanism of action. To be honest, from what I can tell this field is all over the fucking place. There are multiple theories (Cryan and Dinan, 2012;), but to my knowledge none of them have been determined to be necessary or sufficient to create changes in behavior.

The current dominating theory is that these bacteria consume different nutrients and digest them into smaller metabolites that then may do up to a thousand different beneficial things to various targets in your body. Gut bacteria, feeding on the stuff you can’t digest, may either directly produce– or indirectly activate—various little molecules that *maybe act on your brain. or, *maybe act directly on the nerves lining your gut. and those nerves *maybe signal *STRESS* back up to your brain.

(wait but that one can’t be it alone because severing the vagus nerve doesn’t stop us from observing the microbiota-behavior effects!)

There *is* good evidence (Sanada et al, 2020) that certain bacteria are disturbed in people with depression. People with major depression had less Coprococcus, Faecalibacterium, Ruminococcus, Bifidobacterium, and Escherichia bacteria (like e.coli), and more Paraprevotella bacteria. However, we don’t know if that might be a diet thing, a stress thing, or a causing-your-depression thing.

But here’s what you really need to know: A meta-analysis of multiple, randomized controlled clinical trials (love) determined that taking a probiotic containing BOTH lactobaccili and bifidobacterium for more than one month created a moderate to large improvement in depression symptoms, and to a lesser degree, anxiety symptoms as well.  (Liu, Walsh, and Sheehan, 2019). And y’know, that’s good enough for me. If you have depression or anxiety, and *especially* if you *also* have IBS, I’d say giving this a shot is in your best interest.