a A simple salad of crisp lettuce and onions topped with juicy tomatoes sits on the same plate as an army of ingredients invisible to the human eye: a world where microscopic life thrives. Researchers explained the microorganisms in food as follows: yogurt, cheeseand meatmicrobial communities in diverse foods remained uncharacterized. 1-3
Currently, a team of researchers has carefully selected Largest database ever Examine more than 2,500 types of foods for microorganisms.4 collection published in cellcontains over 500 new microbial species and provides researchers with a resource to study how food-associated microorganisms impact human health.
Microorganisms are present throughout the food lifecycle, from enhancing flavor to extending shelf life to promoting spoilage. “Food microbiologists have been studying microorganisms in food for hundreds of years.” Nicola Segataa computational microbiologist at the University of Trento and co-author of the study. “But with modern technology, we actually have the opportunity to look at all microorganisms, not just those that are easy to grow, and we can even check for microorganisms that are present in less-studied foods.”
use shotgun metagenomicsIn one such modern method for sequencing all the genetic material in a sample, Segata’s team analyzed microbial DNA from food products from 50 countries.5 They combined that data with existing sequence data to create a food microbiome database.
The researchers used computational methods to assemble metagenomics from sequence data, reconstructing more than 10,000 genomes of food-related microorganisms and classifying them into more than 1,100 species. Segata discovered that about half of these species were previously unknown. Most of the newly identified microorganisms were found in unusual foods, such as an alcoholic drink called pulque from Mexico, palm wine from Africa, and fermented fish from South Korea, but new species have also been found in common items such as vegetables and coffee. was lurking. When Segata and his team compared the genomes of these newly identified microorganisms with those of other unknown species found in animals, soil, water, and plants, they found that unknown species related to food Almost half of them were found to be absent in other environments.
The researchers also identified less desirable species in some food samples, demonstrating that metagenomic studies can be useful in food safety investigations. Although known disease-causing microorganisms such as listeria monocytogenes and Clostridium perfringens Their samples contain other potentially pathogenic microbial strains, including: Staphylococcus aureus was more common. Microorganisms associated with spoilage were also detected in some samples.
“[Now] “We have an idea of what microorganisms we should expect to find in a particular food,” Segata said, adding that this is used to test food for potential spoilage and quality control. He added that it will be the basis of
“The more you know about good bacteria, the more you can control the bad bacteria.” Josephine Wiea food microbiologist at Pennsylvania State University. This knowledge could also have an impact on extending the shelf life of food and avoiding waste by understanding the microorganisms that cause spoilage, she added.
The researchers then investigated whether these food-associated microorganisms can be found in the human microbiome by comparing the new database with previously sequenced human metagenomes. In adults, 3 percent of microbial species were found to have overlap.
However, Segata cautioned that this does not necessarily mean that the microbes in the human gut come from food. “At some point in human history, some microorganisms found in food may have colonized our intestines and subsequently adapted to our intestines,” he explained. “And these microbes were exchanged not directly from food, but by direct contact between individuals, similar to pathogens.”
Wie agreed. “But the potential association is very interesting because it means we can protect ourselves from certain things,” she said. “we can [potentially] Our diet alone shapes the human microbiome. ”
“Although the strength of this study lies in the 2,500 foods, I think there are significant limitations. [food source] It’s diversity,” she said. She noted that the majority of the foods tested were from Europe. She suspects that fermented foods from older civilizations such as Asia and the Middle East may have more biodiversity than those from Europe and America.
“We need to look at more countries, continents, and communities,” Segata says. “They harbor a huge variety of food microorganisms that are very important to investigate.”
