Similar foods have different effects on microbiome, study says
Foods that look the same on nutrition labels can have significantly different effects on an individual’s microbiome, according to a new study published in the journal Cell Host & Microbe.
In the study, 34 participants recorded everything they ate for 17 days. Stool samples were collected daily, and researchers performed shotgun metagenomic sequencing, analyzing at a very high resolution how different participant's microbiomes, as well as the enzymes and metabolic functions that they influence, were changing from day to day in response to what they ate. This provided a resource for analyzing the relationships between dietary changes and how the microbiome changes over time.
Researchers observed a close correspondence between changes in the diet and the microbiome when they considered how foods were related to each other rather than only their nutritional content. For example, two different types of leafy greens like spinach and kale may have a similar influence on the microbiome, whereas another type of vegetable like carrots or tomatoes may have a very different impact, even if the conventional nutrient profiles are similar, according to the study abstract. The researchers then developed a tree structure to relate foods to each other and share statistical information across closely related foods.
Two people in the study consumed nothing but Soylent, a meal replacement drink that is popular with people who work in technology. Although it was a very small sample, data from these participants showed variation in the microbiome from day to day, suggesting that a monotonous diet doesn't necessarily lead to a stable microbiome, according to the study, which was funded in part by General Mills.
The results suggest that the correlation between what we eat and what's happening with our gut microbes might not be as straightforward as we thought. This adds an increased level of complexity to research focused on improving health by manipulating the microbiome, said Dan Knights, PhD, assistant professor at the Department of Computer Science and Engineering and the BioTechnology Institute at the University of Minnesota.
"The microbiome has been linked to a broad range of human conditions, including metabolic disorders, autoimmune diseases, and infections, so there is strong motivation to manipulate the microbiome with diet as a way to influence health," Knights said in a statement. "This study suggests that it's more complicated than just looking at dietary components like fiber and sugar. Much more research is needed before we can understand how the full range of nutrients in food affects how the microbiome responds to what we eat."