By sequencing over 2,500 food samples from around the world, researchers have identified more than 10,000 metagenome-assembled genomes (MAGs), shedding light on how microbes in our food could influence human health: the food-to-gut microbiome connection.
The adage "you are what you eat" may hold more truth than previously thought, according to a study published in the October edition of the journal Cell. The research uncovers the largely unexplored microbial diversity within our food.
Despite the growing interest in the gut microbiome, the microbial communities in our food have remained relatively uncharted territory. The new research fills this gap, showing the potential for microbes not only to impact the quality and safety of our food but also to play a role in shaping our gut microbiome.
The researchers identified a vast array of microbial species across the sampled foods, categorising them into 1,036 prokaryotic species-level genome bins (SGBs) and 108 eukaryotic SGBs. Remarkably, 320 of these species were previously unknown to science, underscoring the sheer diversity of food microbiomes.
The study found that fermented foods, dairy products, and other fermented beverages harbour particularly complex microbial communities. Most of the identified microbes belonged to the Lactobacillaceae and Streptococcaceae families, which are commonly associated with dairy products. However, the research also highlighted unique microbial profiles in other food types, such as fermented seeds and non-fermented fish.
This diversity suggests that food microbiomes are much more complex than previously thought, with different foods supporting distinct microbial ecosystems. For instance, the study revealed that dairy products, particularly those involving fermentation processes, are rich in microbial diversity. Notable examples include the species Lactococcus lactis and Streptococcus thermophilus, which are vital in cheese production.
In contrast, less common food categories such as fermented seeds and non-fermented fish also exhibited distinct microbial profiles. These findings suggest that food microbiomes could have significant implications for food quality, safety, and even the sensory properties of food, such as taste and texture.
One of the study's most intriguing findings is the overlap between food and human microbiomes. The researchers discovered that, on average, microbes from food constitute about 3% of the adult gut microbiome. This overlap suggests that our diet plays a crucial role in shaping our gut microbiome, with certain microbial strains potentially being transferred from the foods we eat to our digestive systems.
For example, strains of Lacticaseibacillus paracasei – a probiotic often found in fermented foods – were detected in both food and human samples. This indicates that consuming certain foods may introduce beneficial microbes into our gut, where they can colonise and contribute to a healthy microbiome.
Moreover, the study found that this microbial transmission is not limited to adults. In fact, the overlap between food and human microbiomes was even more pronounced in infants, where food-associated microbes constituted a larger fraction of the gut microbiome. This suggests that diet during early life stages could be particularly influential in establishing a healthy microbiome, potentially setting the foundation for long-term health benefits.
The findings from this research also open up new possibilities for improving food safety and quality control. The study's authors suggest that metagenomic data could be used to develop new methods for tracing the origin of food products and ensuring their authenticity.
By identifying specific microbial signatures associated with different food types, it may be possible to create microbial fingerprints that can verify the source and quality of food products. For example, the distinct microbial profiles found in various dairy products could be used to authenticate cheeses and other dairy items, ensuring that they meet specific quality standards.
Additionally, the study's findings could help identify food safety risks. By understanding the microbial content of different foods, it may be possible to detect harmful pathogens more effectively and prevent foodborne illnesses. This could lead to the development of more robust food safety protocols that leverage the power of metagenomics to monitor and control microbial contamination in the food supply.
The frontier of unexplored species
While the study has significantly expanded our knowledge of food microbiomes, it also highlights the vast number of microbial species in food that remain unexplored. The researchers identified 320 previously uncharacterised microbial species, many of which are specific to certain food types. These species represent a significant area for future research, with the potential to uncover new roles for these microbes in food production, preservation, and human health.
For instance, some of these newly discovered species may play crucial roles in fermentation processes or contribute to the nutritional value of foods. Others may have potential applications in the development of new probiotics or other functional foods designed to promote health. Understanding the functions of these microbes could offer new opportunities for innovation in the food industry, leading to the creation of healthier, safer, and more sustainable food products.
Furthermore, the presence of these unexplored species in food microbiomes highlights the need for continued research into the microbial ecosystems of our food. As scientists dig deeper into this microbial frontier, they may discover new ways to harness the power of these microbes to improve food quality, enhance human health, and address some of the most pressing challenges facing the global food system.
