Researchers found that cohabiting people share certain microbes regardless of the ‘proximity’ of their relationship. Siblings, parents and children all shared similar numbers of microbial strains. Your flatmates may be living rent-free in your gut, too.
Romantic partners, however, shared more oral microbes, which the researchers attribute to kissing. “Who we decide to share our homes with can have a huge influence on our microbiomes, which has potential consequences for our health,” said Vitor Heidrich of the University of Trento, Italy, first author and computational biologist at the University of Trento, Italy. The team analysed 1,644 paired mouth and stool samples to see how microbes spread between healthy people living together, and how microbes move from the mouth to the gut within the same person.People living together shared 19% of their gut microbiome strains and 26% of their oral microbiome strains, compared to 6% and 0% among people who did not live together.
Romantic partners shared an average of 44% of their oral microbes.
The human gut and oral microbiome are made up of millions of microscopic organisms, including bacteria, viruses, fungi and parasites. They are unique for each person and are determined by a combination of factors, such as birth environment, infant feeding, long-term diet and lifestyle.
The exchange is likely to happen through daily contact and shared environments. People living together prepare and eat food together and share bathrooms, which provides opportunities for microbes to move from one person to another.
“We know that diet and other lifestyle factors can change our microbiome, but these factors are acting on the microbes that are already within us,” said senior author and computational biologist Nicola Segata of the University of Trento, Italy. “It doesn’t solve the question about where the microbes are coming from.”
The researchers also found that the microbes most easily transmitted between people were more likely associated with poor health, particularly type 2 diabetes and more generally, poor cardiometabolic health. In the mouth, the most transmissible species included two microbes that are associated with colorectal cancer and several opportunistic pathogens that can cause serious illness in people with weakened immune systems.
The authors said that these findings may suggest that disease-associated microbes may possess characteristics that allow them to spread more easily or encounter less resistance when colonising new hosts.
The findings could help improve microbiome-based treatments, including probiotic and fecal microbiota transplant therapies, the researchers say. (euronews.)
