The potential development of human brain evolution could be rooted in the gastrointestinal system.
Study Reveals Gut Microbes May Fuel the Evolution of Large Brains
A recent study published in Microbial Genomics by researchers from Northwestern University in the U.S. suggests that gut microbes could play a significant role in the evolution and energy demands of large-brained animals.
Despite accounting for only around 2% of the body's weight, the human brain consumes approximately 20% of the body's energy. This high energy requirement has long puzzled scientists, as it puts a significant strain on the body's resources.
However, this study is the first to show that gut microbes from different animals can shape their biology and evolution, potentially offering an answer to this puzzle.
By implanting microbes from various primates into mice and measuring their physiology over a 60-day period, the researchers discovered that mice with human and squirrel monkey microbes produced and used more energy compared to those with microbes from macaque, a smaller-brained primate.
"When humans and squirrel monkeys both separately evolved larger brains, their microbial communities changed in similar ways to help provide the necessary energy," says first author Katherine Amato, Associate Professor of Anthropology at Northwestern University.
The research supports the idea that gut microbes may have facilitated the evolution of large brains by mitigating their energetic costs. For instance, these microbes can ferment dietary fibers into short-chain fatty acids, providing a valuable energy source for the host.
The study also hints at the possibility of an evolving relationship between gut microbes and their hosts, with microbial communities adapting to specific diets and environments over time. This adaptation may have co-evolved with humans to optimize energy extraction and support complex biological functions necessary for large brain maintenance.
Amato and her team plan to conduct further studies with additional primate species and a variety of brain sizes, as well as exploring the microbes themselves and their functions and behaviors.
This research aligns with broader concepts that gut microbial communities shape health outcomes and may have played an integral role in human evolution by enhancing energy efficiency and supporting complex biological functions necessary for large brain maintenance.
- This finding suggests that altered gut microbial communities in larger-brained animals, like humans and squirrel monkeys, might have evolved to help mitigate the high energy demands associated with medical-conditions such as large brains.
- As gut microbes are involved in health-and-wellness aspects like energy efficiency and might have co-evolved with humans, future research could uncover more details about their functions and behaviors, potentially leading tonew insights in medical-conditions and wellness.
