Mapping the ‘food microbiome'

While there has been a significant amount of research into the microbiomes of human beings, the microbiomes of food itself has been largely neglected. Until now.

A new study published in the journal Cell looks closer at food’s microbes. They sequenced a wide range of food metagenomes, the genetic content of a community of organisms within a given sample, to develop a ‘food microbiome,’ looking at a total of 2,533 metagenomes from 50 countries.

Secrets of food

The study used shotgun metagenomics, a technique that sequences an entire sample simultaneously, without the need for culturing. This saved the researchers a lot of time and allowed them to find out more about their subjects.

Around 65% of the food sequenced was dairy, 17% was fermented beverages, and 5% was fermented meat, although the study also included non-fermented fish, non-fermented meat, and fermented seeds.

Out of the 10,899 food-associated microbes found from the study, around half were previously unknown. These spanned all categories, although were especially found in fermented fish. These, the study suggested, can be an object for future research.

Researchers found a greater similarity between the metagenomes of similar products (for example, a metagenome of a fermented beverage was likely to be closer to another fermented beverage than fermented meat). Non-fermented products had a higher microbial diversity than fermented products.

However, there was a more striking variety between dairy products, likely due to the wider array of such products sequenced. The highest diversity was found in cheese and cheese brine.