Is the microbiome shaped by nature or nurture?

The link between the gut microbiome and a person’s overall health has been well established, but is this purely due to genetic factors? According to a study, the answer is no; nurture has far more of an impact on the gut microbiome than nature.

The gut microbiome is the community of organisms in the digestive tract, and it can influence several aspects of a person’s health, from their mood to their weight. Previous studies have focused heavily on how genes influence the environment our microbiome occupies, with different environments allowing certain bacterial strains to thrive. However, a study by the Weizmann Institute of Science found that genes only account for 2% of microbiome variation between populations, and other environmental factors are largely overlooked.

The study was based on a unique database of 1046 Israelis “with several distinct incestral origins who share a relatively common environment” who had participated in a longitudinal study of personalised nutrition.

Taking into account their genetic data, microbiome composition, dietary habits, lifestyle, medications and additional measurements, the researchers concluded that the most significant factors shaping our microbiome composition are diet and lifestyle.

“There is significant similarity among the microbiomes of genetically unrelated individuals who share a household, but no significant microbiome similarity among relatives who do not have a history of household sharing,” the authors explained in an article.

“Over 20% of the inter-person microbiome variability is associated with factors related to diet, drugs and anthropometric measurements,” it continued.

The researchers also looked at the link between microbiome and the measurements of cholesterol, weight, blood glucose levels and other clinical parameters to establish how microbiome populations interact with our genes to modify our health.

They found that for most of these clinical measures, the association with bacterial genomes was as strong, if not stronger, than the association with the host’s human genome.

The findings of this study highlight the importance of understanding the factors that shape our microbiome, and how this knowledge can be applied to treating many common health problems.

“We cannot change our genes, but we now know that we can affect — and even reshape — the composition of the different kinds of bacteria we host in our bodies. So the findings of our research are quite hopeful; they suggest that our microbiome could be a powerful means for improving our health,” said Professor Eran Segal of the Computer Science and Applied Mathematics Department.

However, they emphasised that more research needs to be done to further confirm the relationship between the microbiome, genetics, environmental factors and health.

The article was published in the journal Nature.

Image credit: ©iStockphoto.com/LesCunliffe