Gut bacteria metabolize nutrients from plants with known health benefits differently in healthy and diseased people, according to research that could help create health-promoting diets tailored for a particular individual.
Large-scale systematic mapping showed that gut microbial enzymes were able to biotransform hundreds of dietary, plant-derived food compounds—or phytonutrients—according to the study in Nature Microbiology.
However, this metabolic potential varied according to the health of a person and suggested that biotransformational potential was affected by disease.
It also underscored the central role of gut microbiota in mediating the health effects of diet, reported Lu Zhang, PhD, from Leibniz Institute for Natural Product Research and Infection Biology in German, and colleagues.
“This should open avenues for optimizing the nutritional value of plant-based diets through targeted microbial engineering and inform the development of next-generation probiotics, functional foods and personalized nutrition,” they suggested.
Using multiple databases relating to enzymatic reactions and food health benefits, the team integrated information on more than 3000 global microbiomes and more than 1300 phytonutrients.
This revealed that an estimated 775 phytonutrients—including several with known bioactivities—were metabolized by gut microbes, based on genomic content. The team found that 1388 phytonutrients were linked with 4678 enzymes.
Overall, 67% of gut microbial enzymes were potentially involved in phytonutrient biotransformation. Phytonutrient biotransformation by gut bacteria varied among phyla and was widespread.
Studies in mice revealed that the benefits of a healthy diet largely depended on the presence and transcriptional activity of particular microbial enzymes.
The full-spectrum anti-inflammatory effect of strawberries, for example, occurred only in mice with healthy microbiota, with the researchers identifying key gut bacterial enzymes potentially biotransforming specific health-promoting phytonutrients.
Using public gut metagenomics datasets for inflammatory bowel disease, colorectal cancer and non-alcoholic fatty liver disease that included healthy control individuals, the team identified a corresponding 608, 1038, and 517 phytonutrient-associated enzymes for the three diseases.
The ability of gut bacteria to biotransform healthy foods differed between health and disease, suggesting that, once a dysbiotic microbiota is established, broad “one-size-fits-most” dietary recommendations might have limited value.
“Our results underscore the importance of revisiting the concept of a ‘healthy diet’, as the diet’s effectiveness may be significantly boosted by the presence of a healthy microbiome,” the researchers elaborated.
“Consuming edible plants with demonstrated health benefits may be insufficient for someone with an imbalanced microbiome capacity to biotransform health-associated phytonutrients.”
They added: “This suggests a new direction for developing functional foods through fermentation with selected bacterial species, identified via mechanistic links between phytonutrients and gut bacteria.”
The team further proposed: “Consuming foods fermented by gut bacteria after rigorous safety testing could be extremely valuable for populations whose intestines may be unable to perform the modifications necessary to harness foods’ full nutritional value, including aged individuals and those with reduced microbiome diversity.”
