Transmission of oral and intestinal microbiota, including bacteria, between humans is possible. It occurs at birth but also through social interactions.
- The gut microbiota is the most important microbiota in the body.
- An imbalance between the immune system and the gut microbiota may be one of the causes of Crohn’s disease.
There are over a thousand species in our gut microbiota, according to National Institute of Health and Medical Research (Inserm). Among these micro-organisms, there are bacteria (mostly) but also viruses, parasites and non-pathogenic fungi.
An oral microbiota and an intestinal microbiota
The intestinal microbiota influences a large part of the body, such as the immune, bone, cardiovascular system or even the brain… It is unique to each individual, both qualitatively and quantitatively. Indeed, according to Inserm: “PToOf the 160 species of bacteria found on average in the microbiota of a healthy individual, only half are commonly found from one individual to another. However, there would be a common base of 15 to 20 species present in all human beings, in charge of the essential functions of the microbiota.”
the oral – or buccal microbiota – can be defined as all the micro-organisms present in the oral cavity. These are basically bacteria, about 700 species. According to the Universalis encyclopediaeach individual has its own oral microbiota and there are very few species in common with the intestinal microbiota.
But, between humans, is there a transmission of oral or intestinal microbiota? If yes, how ? These are the questions that researchers wanted to answer. Their work has just been published in the journal Nature.
Transmission of microbiota occurs through social interaction
For this, they analyzed more than 9,000 stool and saliva samples from humans who lived in different places around the world. Thus, the researchers observed that the intestinal microbiota was transmitted at birth, by the mother. This legacy endures because traces of the maternal microbiota have been found in the elderly.
But the most amazing thing is that scientists have discovered that transmission can also occur through human contact, especially when people live or cohabit together. “We found evidence for extensive sharing of gut and oral microbiota related to relationship type and lifestyle, explains Mireia Valles-Colomer, one of the authors. These results suggest that social interactions actually shape the composition of our microbiota.“Obviously, the longer the interaction time, the more bacteria are exchanged.
“The demonstration that the human microbiome is transmissible could suggest that some of these diseases considered non-communicable could, at least to some extent, be transmissible, explains Nicola Segata, who led this work. Additional studies on microbiome transmission may therefore advance the understanding of risk factors for these diseases and, in the future, explore the possibility of reducing this risk with therapies that act on the microbiome or its transmissible components.”