Study Highlights Person-to-Person Microbiome Transmission

An investigation into how person-to-person interactions affect gut and oral microbiomes is reported in Nature this week, revealing extensive sharing of microbes based on relationships and lifestyle. The human microbiome is an integral component of the human body and a co-determinant of several health conditions, yet little is known about how interpersonal relations shape the individual genetic makeup of the microbiome and its transmission within and across populations. In the new study, an international team led by scientists from the University of Trento in Italy analyzed the microbe composition of more than 9,700 stool and saliva samples from individuals in 20 countries, uncovering extensive bacterial strain sharing across individuals with distinct mother-to-infant, intra-household, and intra-population transmission patterns. Mother-to-infant microbiome transmission was particularly robust, remaining detectable well past infancy. Social interactions also drove microbe acquisition in adults, especially among cohabitating individuals. Notably, the researchers also found that, unlike with the gut microbiome, the transmission of oral microbiomes occurred mostly horizontally and increased with the amount of time people spent together. The findings, the study's authors write, suggests that person-to-person microorganism transmission may be involved in microbiome-associated diseases currently believed to be noncommunicable and should be considered in future microbiome studies.