Microorganisms, such as bacteria, fungi or viruses are everywhere on the planet, from the interior of living beings to the arctic ice. The term microbiome refers to a community of different microorganisms that occupies a particular setting and how they relate to each other and to the environment. The term microbiota refers to the universe of microorganisms living together in a habitatFor example, in the intestines of humans. The relationship between, for example, the gut microbiota and general health of a person has been gaining relevance in recent decades. One of the recent contributions in this field based on studies with thousands of people from all over the world, raises the possibility that diseases related to microbiome dysfunction, such as cancer, diabetes and obesity, may be partially transmissible.
This is a study led by Italian scientists, in which the Higher Council for Scientific Research (CSIC) and that you have published Nature Recently. “This study is the most comprehensive look to date at when and why microbes are transmitted to gut and oral microbiomes,” he says. Katherine Xue, microbiome researcher at Stanford University in California, United States. “New microbes may continue to reshape our microbiomes throughout our lives.”
According to collect Nature, most studies on how humans acquire their microbiomes have focused on people’s first contact with microbes: through their mothers. “Providing a microbial starter kit is key,” he says Hillary Browne, microbiologist at the Wellcome Sanger Institute in Hinxton (UK). To examine how and why this starter kit changes throughout life, a team led by microbiome researchers Mireia Valles-Colomer Y Nicola Segata, from the University of Trento (Italy), analyzed the DNA from nearly 10,000 stool and saliva samples from people around the world, from rural villages in Argentina to a city in China, passing through towns in Europe and North America. Next, the researchers looked for matches in the strains of microbes present in the intestines and mouths of family members, partners, roommates and other social contacts.
They analyzed the DNA of 10,000 stool and saliva samples from around the world
The analysis confirmed the close relationship between the microbiomes of mothers and those of their children, especially in the first years of life. During the first year of a baby’s life, half of the microbial strains in her intestines were shared with her mother. The degree of overlap decreased as the children aged, but did not disappear. Older people, ages 50 to 85, continued to have gut microbial strains in common with their mothers.
Taking advantage of more than 9,700 human metagenomes and computational strain profiles, we have detected a wide exchange of bacterial strains between individuals (more than 10 million cases) with different patterns of mother-to-child, intrafamilial, and intrapopulation transmission. Transmission of the gut microbiome from mother to child was considerable and stable during infancy (about 50% of the same strains between species shared (strain exchange rate)) and remained detectable at later ages.
Instead, oral microbiome transmission largely occurred horizontally and was favored by length of cohabitation. Cohabiting individuals shared many strains, with mean rates of 12% and 32% for gut and oral microbiomes, and time since cohabitation affected strain sharing more than age or genetics. As the conclusions of this work indicate, the exchange of bacterial strains recapitulated the structures of the host population better than the profiles at the species level.
Finally, different taxa emerged as efficient spreaders through modes of transmission and were associated with different predicted bacterial phenotypes related to off-host survivability. The extent of transmission of microorganisms that we describe underscores its importance in studies on the human microbiomeespecially those related to non-infectious diseases associated with the microbiome.
