•

Urban Diets Lead to Decline in Gut Bacteria That Digest Plants

Urban humans have lost much of their ability to digest plants

https://arstechnica.com/science/2024/03/human-gut-bacteria-that-can-digest-plant-matter-probably-came-from-cows/

Rural populations still have lots of the gut bacteria that break down cellulose.

Urban humans have lost much of their ability to digest plants

This article discusses a new study on the link between gut bacteria and diet, particularly the ability to digest cellulose, a major component of plants.

Key Points:

Humans have gut bacteria that can break down cellulose, but the amount varies depending on diet.
Rural populations and hunter-gatherers have more of these bacteria compared to urban dwellers.
The decline is likely due to modern, processed diets low in fiber.
Some cellulose-digesting bacteria may have come from our primate ancestors, while others were acquired from domesticated herbivores like cows.
These bacteria, though digesting cellulose for themselves, may provide benefits to human health through byproducts and immune system interaction.

The study identified:

Four distinct groups of cellulose-digesting bacteria in humans.
A historical decline in these bacteria with dietary changes.
Potential benefits to gut health from these bacteria, even if they contribute minimally to direct food processing.

1 comments

autotldr

•

🤖 I'm a bot that provides automatic summaries for articles: ::: spoiler Click here to see the summary It's responsible for the properties of materials like wood and cotton and is the primary component of dietary fiber, so it's hard to overstate its importance to humanity.

Given its ubiquity and the fact that it's composed of a bunch of sugar molecules linked together, its toughness makes it very difficult to use as a food source.

The animals that manage to extract significant calories from cellulose typically do so via specialized digestive tracts that provide a home for symbiotic bacteria—think of the extra stomachs of cows and other ruminants.

"Our evolutionary analysis strongly suggests that [these strains] likely originated in the ruminant gut and later transferred to humans, possibly during domestication," the researchers conclude.

For example, the strains found in primate guts often had genes that enabled the digestion of chitin, a different polymer that is a major component of insect exoskeletons.

By contrast, some human-specific strains had enzymes that can efficiently break down the cell walls of plants like rice, wheat, and corn.

Saved 82% of original text. :::