A Cultural Context for Human-Microbe Symbiosis 9
are now eating store-bought food and in general adopting a more Western
lifestyle.
One group of Canadian researchers compared the gut microbiota composi-
tion of urban-living individuals from Montreal to that of the Inuit. Surpris-
ingly, they discovered that the two groups had very similar gut microbiomes.
One interesting observation was the abundance of Prevotella species in both
Montrealers and the Inuit. High numbers of Prevotella species are usually seen
in traditional diets with high fiber intake. Researchers also noted that Mon-
treal samples were enriched with Faecalibacterium prausnitzii, while some
Inuit samples were enriched with the methanogen Mehtanosphaera (see chap-
ter 2 for more information on these species).
Although traditional diets are usually associated with higher levels of micro-
bial diversity, the Inuit microbiomes weren’t much more diverse than those of
the Montrealers. As the Inuit switch from their traditional hunter-gather diet
to a Western one, the incidence of obesity among this indigenous group is
increasing. The researchers theorize that lower level of microbe diversity may
be driven by increasing body weights, as obesity tends to promote significant
shifts in gut microbiota composition. They also speculate that lower diversity
may reflect lower fiber intake. Inuit of Nunavut consume around 13–14 grams
of fiber per day—significantly lower than other hunter-gatherer diets previ-
ously mentioned, which can contain over 100 grams of daily dietary fiber.
Transition into Agriculture: Early Farming to Industrial Food
Production
The “First Agricultural Revolution” occurred in the final period of the Stone
Age, during the Neolithic Era. This marks the historical beginning of human
agriculture and animal husbandry. Archeologists find clear evidence that
foraging societies began to cultivate wild foods approximately 10,000 years
ago. Although this cultural change allowed humans to create settlements and
become less nomadic, historical ecologists continue to debate the exact moti-
vations for this shift. It might seem that hunter-gatherers saw farming as a
more efficient means of subsistence, but these early agricultural practices were,
in fact, very labor-intensive and time-consuming. Given that for thousands
of years, early hominins were well sustained by foraging, why did hunter-
gatherers begin to invest such time and effort into plant cultivation?
Most archeologists agree that human population density increased with the
emergence of agriculture. However, the question remains as to whether popu-
lation pressure led to food cultivation or cultivation caused population growth.
The idea of population pressure suggests that foraging societies experienced
nutritional stress due to insufficient food sources. Yet archeologists have failed
to find evidence of significant nutritional stress in human skeletal remains
are now eating store-bought food and in general adopting a more Western
lifestyle.
One group of Canadian researchers compared the gut microbiota composi-
tion of urban-living individuals from Montreal to that of the Inuit. Surpris-
ingly, they discovered that the two groups had very similar gut microbiomes.
One interesting observation was the abundance of Prevotella species in both
Montrealers and the Inuit. High numbers of Prevotella species are usually seen
in traditional diets with high fiber intake. Researchers also noted that Mon-
treal samples were enriched with Faecalibacterium prausnitzii, while some
Inuit samples were enriched with the methanogen Mehtanosphaera (see chap-
ter 2 for more information on these species).
Although traditional diets are usually associated with higher levels of micro-
bial diversity, the Inuit microbiomes weren’t much more diverse than those of
the Montrealers. As the Inuit switch from their traditional hunter-gather diet
to a Western one, the incidence of obesity among this indigenous group is
increasing. The researchers theorize that lower level of microbe diversity may
be driven by increasing body weights, as obesity tends to promote significant
shifts in gut microbiota composition. They also speculate that lower diversity
may reflect lower fiber intake. Inuit of Nunavut consume around 13–14 grams
of fiber per day—significantly lower than other hunter-gatherer diets previ-
ously mentioned, which can contain over 100 grams of daily dietary fiber.
Transition into Agriculture: Early Farming to Industrial Food
Production
The “First Agricultural Revolution” occurred in the final period of the Stone
Age, during the Neolithic Era. This marks the historical beginning of human
agriculture and animal husbandry. Archeologists find clear evidence that
foraging societies began to cultivate wild foods approximately 10,000 years
ago. Although this cultural change allowed humans to create settlements and
become less nomadic, historical ecologists continue to debate the exact moti-
vations for this shift. It might seem that hunter-gatherers saw farming as a
more efficient means of subsistence, but these early agricultural practices were,
in fact, very labor-intensive and time-consuming. Given that for thousands
of years, early hominins were well sustained by foraging, why did hunter-
gatherers begin to invest such time and effort into plant cultivation?
Most archeologists agree that human population density increased with the
emergence of agriculture. However, the question remains as to whether popu-
lation pressure led to food cultivation or cultivation caused population growth.
The idea of population pressure suggests that foraging societies experienced
nutritional stress due to insufficient food sources. Yet archeologists have failed
to find evidence of significant nutritional stress in human skeletal remains
