Two ecological species Helicobacter pylori. The bacteria, named ‘Hardy’ and ‘Ubiquitous’, coexisted in the stomachs of modern humans before they left Africa, and were dispersed around the world as humans migrated, new research shows. Ta.
Tourette’s others. They discovered that indigenous peoples in Siberia and the Americas were infected with two different types of viruses. Helicobacter pylori. Image credit: sjs.org / CC BY-SA 3.0.
First discovered in 1983, Helicobacter pylori. During long-term colonization of human hosts, it disturbs the stomach lining and causes sequelae such as ulcers and gastric cancer.
Numerous Helicobacter pylori. Virulence factors have been identified and show wide geographic variation.
In the new study, Dr. Elise Tourette and colleagues at the Shanghai Institute of Immunology and Infection used an unprecedented collection of 6,864 individuals. Helicobacter pylori. Genomes from around the world to investigate the prevalence of bacteria.
They unexpectedly discovered a very distinct variant. Helicobacter pylori. They named it the Hardy species, which originated hundreds of thousands of years ago and spread around the world with humans.
They proposed that this species is specialized to live in the stomachs of carnivores whose diet consists mainly of meat and fish.
Therefore, genetic variations found in the bacteria in our stomachs today can tell us what our ancestors ate.
“Our diverse global sample has allowed us to gain a deeper understanding of world history. Helicobacter. This confirmed previous findings that these bacteria were already passengers in our stomachs when we left Africa more than 50,000 years ago,” said Dr. Tourette. .
“But we also identified something surprising, in the form of a new ecological species. Helicobacter. We called it Hardy.”
“It differs by more than 100 genes from the common type we called ubiquitous.”
“Hardy’s ecospecies turned out to be very informative about what bacteria need to do to survive in our stomachs, but more fundamentally, bacterial diversity How it was maintained also turned out to be very informative.”
“Most humans alive today are omnivores or vegetarians, meaning a significant portion of our diet consists of plant material,” said Dr. Daniel Farash, also of the Shanghai Institute of Immunology and Infection. said.
“However, in some parts of the world, plant material was historically unavailable for large parts of the year, and people relied heavily on fish and meat for food.”
“So far, the Hardy ecospecies has only been identified in humans from indigenous populations such as Siberia and northern Canada.”
“Due to ancient host jumps, this virus has also been found in tigers and cheetahs in zoos, with important genetic differences that allow it to adapt to gastric conditions in carnivores.”
“This association is particularly interesting because our analysis also suggests that both ecological species have accompanied humans since our species’ emergence in Africa more than 200,000 years ago.” Because there is.”
“If this species is indeed adapted to being a carnivore, it means that humans who spread around the world often did not eat plants, even if plants were available. .”
By analyzing Helicobacter pylori. By analyzing genomes from around the world, researchers discovered that the first modern humans were infected with two different types of bacteria: M. hardyi and M. ubiquitous.
Both species spread from Africa during early human migrations, reaching as far as South America.
The ubiquitous ecospecies has been found in every human population sampled to date, whereas the Hardy ecospecies has only been sampled from a small number of indigenous populations and may have become extinct at many points along its migratory routes. It suggests that.
However, one strain of the African Hardy strain has shifted hosts to big cats and has been isolated from cheetahs, lions, and tigers in zoos.
Understanding why these species can coexist in some populations but not in others will help us understand the profound implications of our prehistory and the gastric diseases we still suffer from today. It is hoped that this will shed light on the burden.
“Our results also show that very different adaptive strategies can arise and be stably maintained within bacterial populations, even in the presence of continuous genetic exchange between strains.” said the scientists.
of findings. Published in a magazine nature.
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E.Tourette others. ancient ecological species Helicobacter pylori. naturepublished online October 16, 2024. doi: 10.1038/s41586-024-07991-z
Source: www.sci.news
