3 ms·

Whenever I see these gut biome results, I can't help thinking that there are so many common causes that can explain both biome and diagnosis/behavior: region, e

Whenever I see these gut biome results, I can't help thinking that there are so many common causes that can explain both biome and diagnosis/behavior: region, ethnography, socioeconomic class, etc. Has anyone gone deep enough into the studies to know if/how that is controlled for?

thereticent 3y ago
I appreciate the scientific question. These posts tend to launch wild takes on HN that confuse correlation with causation and attempt to reduce disease to just one foundational factor. It just doesn't work like that for a lot of illnesses.
roywiggins 3y ago
By my reading of the paper, they didn't see an effect when they compared siblings...
mtsr 3y ago
Fair point. But once you start comparing regions that differ in one way (say food between Western European countries), they most likely differ in so many other ways that the analysis becomes very very hard.
marginalia_nu 3y ago
It's also worth questioning in which direction the causality flows. If it's reasonable to expect diet and activity levels to have microbial effects, and it is reasonable to expect the psychopathology in question to have an effect on activity levels and diet; then whatever microbial differences you find between sufferers and non-sufferers could just as easily be the consequence as the cause of the pathology.
- 2OEH8eoCRo0 3y ago
  Is there anything that flows both ways? When it comes to human behavior I've read that faking it and smiling more makes you feel happier, and happier people smile more. Almost like your brain goes, "I'm smiling so I must be happy right now."
  - marginalia_nu 3y ago
    Yeah sure, it's pretty common in physics and everywhere. The notion of cause and effect is closer to a legal concept than a physical one. If you kick a ball, it begins to roll not only because it was kicked, but because it was round, solid, not made out of lead, etc. Further the presence of the ball may have induced you to kick it. Surely you don't go around kicking empty air. But we tend to have a sort of simplified view where there is an active cause acting on a passive world to have an effect.

thereticent 3y ago

I appreciate the scientific question. These posts tend to launch wild takes on HN that confuse correlation with causation and attempt to reduce disease to just one foundational factor. It just doesn't work like that for a lot of illnesses.

roywiggins 3y ago

By my reading of the paper, they didn't see an effect when they compared siblings...

mtsr 3y ago

Fair point. But once you start comparing regions that differ in one way (say food between Western European countries), they most likely differ in so many other ways that the analysis becomes very very hard.

marginalia_nu 3y ago

It's also worth questioning in which direction the causality flows. If it's reasonable to expect diet and activity levels to have microbial effects, and it is reasonable to expect the psychopathology in question to have an effect on activity levels and diet; then whatever microbial differences you find between sufferers and non-sufferers could just as easily be the consequence as the cause of the pathology.

2OEH8eoCRo0 3y ago
Is there anything that flows both ways? When it comes to human behavior I've read that faking it and smiling more makes you feel happier, and happier people smile more. Almost like your brain goes, "I'm smiling so I must be happy right now."
- marginalia_nu 3y ago
  Yeah sure, it's pretty common in physics and everywhere. The notion of cause and effect is closer to a legal concept than a physical one. If you kick a ball, it begins to roll not only because it was kicked, but because it was round, solid, not made out of lead, etc. Further the presence of the ball may have induced you to kick it. Surely you don't go around kicking empty air. But we tend to have a sort of simplified view where there is an active cause acting on a passive world to have an effect.