> What about people in the US who are not in cities? That's the more interesting comparison to me. Why would that be left out?
At least in the US, my lay-intuition is that you wouldn't see much of a difference between average Americans between urban, suburban, and rural settings. That's perhaps worth testing, but I think the much more interesting test would be between wealth and class groups.
(Again, wild speculation: it's easy to imagine that most gut biota don't care about the difference between dollar-store knockoff sodas and brand-name sodas, but definitely do care about $14 free-range, organic eggs.)
> but definitely do care about $14 free-range, organic eggs
Can you elaborate on why you think this is the case? Intuitively to me, most folks’ diets are going to be mostly cooked eggs which would reduce any effect on bacteria in the gut.
Sorry, I meant that as a proxy for “families that have the purchasing power to buy premium goods.” My intuition is that there’s a weak inverse relationship between food processing and food price, with less processing corresponding to healthier gut biota. But you’re right that the $14 eggs themselves probably don’t matter.
"Processing" is meaningless and largely a naturalistic fallacy; your biome definitely cares about what you eat, but not if it's been sliced up first, which is a kind of processing.
I don’t disagree. You can substitute “processed” for the “ultra processed” category in the NOVA scheme[1]. I don’t think there’s anything wrong with chopping up your apples before eating them.
>At least in the US, my lay-intuition is that you wouldn't see much of a difference between average Americans between urban, suburban, and rural settings.
It wouldn't surprise me, but that would call into question the entire notion that the article is attempting to create -- that urban (and therefore non-urban) is the key factor in the differences it mentions in gut flora.
I'm curious why that comparison is more interesting to you?
I can see great value in having both data points when trying to formulate a hypothesis about what causes the decline in gut-microbes in us city folks, but I find it hard to think of a use-case for solely a urban/rural comparison without other context.
(Update: I was thinking about this from a scientific perspective, ignoring the idea that people might be interested in what it means for them personally (facepalm) )
I shouldn't say more overall, but the difference among people who have a similar diet and circumstances, but differ by housing culture, would be interesting to observe. I'd like to see apples to apples, if indeed the theorized reason of where gut differences come from is strictly (or mostly) urban vs. rural. Is it that country people are around more dirt, or that city people have different stressors, or maybe both are included? It'd be easier to tell if other differences are eliminated, imo. I've long preferred country life, having spent roughly half of my life in cities and the other half in the country, so maybe some personal interest is there too, to be honest. I do feel a lot healthier living in the countryside, perhaps my gut has something to do with that.
Even from a scientific perspective, it would be more interesting to see the effect of each variable independently (cities vs rural, US vs somewhere else) rather than bundling them together.
What about people in the US who are not in cities? That's the more interesting comparison to me. Why would that be left out?