Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Modern city dwellers have lost about half their gut microbes

science.org

Post reply on HN
Print view View original

161–170 of 318 posts

Re: Modern city dwellers have lost about half their gut microbes

#161

Post by mulmen »

This article is mostly cliche popsci trash that isn’t worth reading. Good for a game of logical fallacy bingo.

The only interesting development seems to be the methodology but that only gets a passing mention.

The rest is basically fearmongering.

> In humans, for example, gut bacteria influence how the immune system responds to pathogens and allergens, or interact with the brain, affecting mood.

Ok. But what does that have to do with diversity? Humans have not been an emotionally rational species at any point in the past. Arguably the relationship between gut biome diversity and civilization is inverse. Maybe we want fewer microbes.

Lifespan has also increased with decreased gut biome diversity.

This is why correlation alone is uninteresting. You can find it anywhere.

> Splitting the difference, people in less developed parts of the world have between 60 and 65 of those bacterial groups, an observation that ties the decrease in microbial diversity to urbanization.

Oh come on. How does a line like this get published? This is fine if you define “ties” as “moves with” but not “is connected to”. IOW correlation doesn’t imply causation.

> Kyle Meyer, a microbiologist at UC Berkeley, argues such losses are not necessarily a problem. “Maybe we don’t need them,” he points out. But Moeller is worried. “We are really doing some scary stuff to our microbiomes,” he warns.

Why is it “scary”? Nothing in this article established any cause for concern.

The guy that developed the methodology is now in search of a problem his solution fits.

Re: Modern city dwellers have lost about half their gut microbes

#162

Post by ssnistfajen »

AussieWog93 wrote: post #151
ssnistfajen wrote: post #149

Earlier quoted context omitted.

Lactase persistence is regulated by genetic mutations, not gut microbes. The negative symptoms of lactose intolerance is exactly due to lactose being able to reach the gut and making the microbes there flourish by digesting lactose, creating large quantities of gas and other metabolic byproducts that cause flatulence, diarrhea, etc. People don't spontaneously become lactose intolerant just because they stopped eating…

Holy shit, that is the most over-the-top, aggressive response to a guy being factually incorrect about yoghurt that I've ever read.

Can you point exactly which part was "over-the-top" or "aggressive"? Or is calling out that factually incorrect things are, well, factually incorrect somehow unacceptable nowadays? The world needs less pseudoscience misinfo, not more.

Re: Modern city dwellers have lost about half their gut microbes

#163

Post by haimez »

easytiger wrote: post #126
GuB-42 wrote: post #118

Earlier quoted context omitted.

It seems that lactose tolerance is the new thing here. Lactose intolerance is normal, but for a few people, presumably dairy animal farmers, something happened to their genes and they became tolerant, and it was an evolutionary avantage because they had access to all that milk. But because access to farmed milk is relatively recent from an evolutionary standpoint and people can live with lactose intolerance, the trai…

Or people who worked out they were tolerant to it, farmed it, and the high density nutrients allowed faster more reliable development of healthy children in adverse conditions. i.e. North Western Europe.

Also that smallpox resistance via cowpox exposure can’t have hurt survival rates in general

Re: Modern city dwellers have lost about half their gut microbes

#164

Post by ssnistfajen »

etiam wrote: post #95
giardini wrote: post #82

Earlier quoted context omitted.

Eating yogurt or sauerkraut will not render you (once again) lactose tolerant. Lactase (the enzyme that breaks down lactose) production is regulated by a human gene; how would a probiotic like yogurt alter a gene? https://biologydictionary.net/lactase/

Well, as you probably know, genes are regulated more or less according to environmental cues all the time, including being very much subject to presence and behavior of commensals/parasites/symbionts. I don't know any specific data whatsoever about inducing lactase, but it seems perfectly plausible that microorganisms such as lactic acid bacteria could interact with the system.

You can't say something is "perfectly plausible" right after admitting you don't know any data supporting that hypothesis.

The negative symptoms of lactose intolerance is exactly due to microbes in the gut digesting lactose and producing metabolic byproducts such as gas. People who aren't lactose intolerant are free of such symptoms because lactose is digested with enzymes produced by the body before it reaches the gut thus depriving gut microbes of sufficient quantities of lactose to cause negative symptoms.

Re: Modern city dwellers have lost about half their gut microbes

#165

Post by jancsika »

AussieWog93 wrote: post #151
ssnistfajen wrote: post #149

Earlier quoted context omitted.

Lactase persistence is regulated by genetic mutations, not gut microbes. The negative symptoms of lactose intolerance is exactly due to lactose being able to reach the gut and making the microbes there flourish by digesting lactose, creating large quantities of gas and other metabolic byproducts that cause flatulence, diarrhea, etc. People don't spontaneously become lactose intolerant just because they stopped eating…

Holy shit, that is the most over-the-top, aggressive response to a guy being factually incorrect about yoghurt that I've ever read.

Yet they are all reasonable questions.

I'd be interested in knowing how asdff arrived at the idea that a sizable portion of lactose intolerance comes from people neglecting to fertilize their microbes with sauerkraut, pickled cabbage, or yogurt.

Re: Modern city dwellers have lost about half their gut microbes

#166

Post by lemming »

steve_adams_86 wrote: post #141
lemming wrote: post #137

Earlier quoted context omitted.

There is a wealth of other research showing that most people in North America should dramatically reduce their sodium intake. The evidence for this seems much less conclusive than most people think: https://examine.com/nutrition/awful-nutrition-myths/#summary... . The tl;dr is that most of that salt comes from crappy food, and that’s what you want to fix - it’s not the salt as such.

It really is the salt though, and examine says as much: > Some myths contain a grain of truth. Studies have associated excess salt with hypertension (high blood pressure),[54] kidney damage,[55] and an increased risk of cognitive decline.[56][5 The thing is, a lot of people have no idea that their salt intake is way too high. You’re right that the salt tends to come from processed foods, but the salt is still a probl…

To be fair, that says "a grain of truth", and that's contained within a section entitled: "Myth 6: Salt is bad for you". The summary says:

But a drastic decrease in salt intake has not shown uniform benefit in clinical trials. Most people will benefit more from a diet of mostly unprocessed foods than from micromanaging their salt intake.

As an example, salt-sensitive hypertension is a condition which some people have, but most people don't. If you don't, then salt will generally not affect your blood pressure adversely (it will go up temporarily if you eat a whole Domino's pizza, but will quickly go down again).

Re: Modern city dwellers have lost about half their gut microbes

#167

Post by justsomeguy123 »

ssnistfajen wrote: post #162
AussieWog93 wrote: post #151

Earlier quoted context omitted.

Holy shit, that is the most over-the-top, aggressive response to a guy being factually incorrect about yoghurt that I've ever read.

Can you point exactly which part was "over-the-top" or "aggressive"? Or is calling out that factually incorrect things are, well, factually incorrect somehow unacceptable nowadays? The world needs less pseudoscience misinfo, not more.

I re-read your post and while it's not overly aggressive it's the difference in tone and approach that get you. The original poster was like the hippie encouraging home-made yogurt and you were like the school principal saying 'this is bull, store yogurt has scientifically the same benefits'.

PS: I also learned while writing this I can't spell yogurt. Thanks spellchecker!

Re: Modern city dwellers have lost about half their gut microbes

#169

Post by [deleted] »

hackerlight wrote: post #159
steve_adams_86 wrote: post #62

Earlier quoted context omitted.

One tricky part with fermented foods is that the salty ones appear to increase rates of colon and stomach cancer as I recall. I read something years ago about how as the Japanese population adapted a more western diet, heaps of ailments came upon them as you’d expect, but their salt intake declined so dramatically that they stopped experiencing stroke and GI tract cancers nearly as much. I think you’d need to pin dow…

Salt tolerance varies a lot with blood pressure

[deleted]

Re: Modern city dwellers have lost about half their gut microbes

#170

Post by hinkley »

HeyLaughingBoy wrote: post #67
kaycebasques wrote: post #66

I had to use oral antibiotics about a year ago for reasons that could have been avoided. I was pretty upset about it precisely because it probably wreaked havoc on all the beneficial gut microbes that I had built up over the years.

I had a couple courses of IV antibiotics to fight a severe tooth infection. All the oral surgeons who came in to check on me recommended picking up a few bottles of probiotic drinks on my way home.

And some cheddar cheese. https://en.wikipedia.org/wiki/Lacticaseibacillus_casei is theorized to be a sort of a halo probiotic - it doesn't do the work, but it makes you GI tract more hospitable to the bacteria that do.

There are cheddar cheeses though that barely rank the name. Quality over quantity here. Buy the small block of fancy cheddar, not whatever name the food megacorporations are using locally.

Post reply on HN