The interactions among the intestinal tract, the gut microbiome, food systems, and nutrition are intricately linked and, together, contribute to overall health and well-being. Various axes, such as the gut-brain axis and the gut-skin axis, have been identified that extend the gut’s influence far beyond simple nutrient processing. Similarly, dysbiosis of the gut microbiome and hence an imbalance in available metabolites, has been linked to various disease states, most prominently inflammatory bowel disease and detrimental mental states.
The Topic’s overall theme is based on the following lead article published in Frontiers in Science: Harnessing agri-food system microbiomes for sustainability and human health.
New approaches to food processing and nutrition, such as precision fermentation, dietary supplements, and personalized diets, aim to optimize the gut-microbiome balance and stability. Other strategies directly modulate the gut microbiome by inhibiting specific pathogens or undesirable microorganisms. Precise and efficient delivery of such nutrients, modulatory compounds, and enzymes can be challenging due to exposure to varying pH, digestive enzymes, bile salts, and local gut microbiome composition during gastrointestinal transit. Although encapsulation is a well-known methodology for transit and fast or slow release, it is not always suitable nor specific.
Biological, functionalized nano- and micro-particles offer a tantalizing new opportunity for protecting, storing, and releasing compounds, including enzymes. Upon ingestion, these particles may interact directly with members of the gut microbiome or host tissues such as the gut lining to deliver payloads directly to the desired targets. Beyond delivery applications, functionalized particles may also serve as reusable biocatalysts for the enzymatic synthesis of high-value nutrients and bioactive compounds, or as selective platforms for the isolation and purification of such compounds from complex food matrices. Such particles may be comprised of short-chain fatty acids (e.g., polyhydroxyalkanoates), proteins or conjugates thereof, and often originate from naturally occurring vesicles. Another class of emerging biological nanoparticles, virus-like particles (VLPs), has attracted attention due to their stable physical properties and ability to store and release compounds in a controlled manner. In contrast to anorganic nanoparticles and due to their natural prevalence, these organic structures may be free of (cyto-)toxicity and be additionally suitable as dietary supplements, food additives, and/or processing aids.
However, challenges remain in food-grade scaling of particle production and tailoring size and composition to respective food applications. Delivery-related challenges include controlled payload uptake and release, target specificity, mechanisms of biodegradation, and cytotoxicity studies. For biocatalytic and purification applications, biocatalytic efficiency and reusability, as well as selective binding and recovery of target compounds, require further development. Additionally, interactions with food matrices and changes in organoleptic properties must be carefully managed.
This Research Topic welcomes Original Research, Methods, and Reviews that advance the development of food-grade production processes, surface and payload functionalization of biological particles and VLPs that can serve to enhance food structures, gut health, and well-being. Emphasis is placed on understanding underlying biological mechanisms and experimentally testing clearly formulated hypotheses. Descriptive work and sole community analyses are not considered.
Subtopics of interest include:
o Food-grade materials and functionalization
Biopolymer, lipids, and protein-based carriers; surface functionalization with peptides, polysaccharides, prebiotics/postbiotics, or plant bioactives.
o Fermentation-enabled and bioengineered particle production
Microbial and cell-free production systems for biological nano- and microparticles; metabolic and genetic engineering of production hosts; production of extracellular vesicles, protein cages, and polyhydroxyalkanoate (PHA)-based particles, upstream and downstream production.
o Immune stimulation and mucosal defense
Interactions with gut-associated lymphoid tissue; modulation of innate immune signaling; support of barrier integrity and mucus layer function.
o Mechanisms of Microbiome-targeted delivery
Targeted release in the small intestine vs. colon; shaping microbial metabolism; promoting beneficial taxa and short-chain fatty acid production.
o Stability, bioaccessibility, and controlled release
Protection from oxidation and gastric degradation; triggered release by pH or cell binding, enzymes, bile salts, or microbial activity.
o Biocatalytic synthesis and isolation of high-value compounds
Enzyme immobilization and biocatalytic efficiency; reusable particle-based synthesis of bioactive nutrients, vitamins, antioxidants, or prebiotics/postbiotics; selective binding and extraction of health-promoting compounds from food matrices.
o Safety, efficacy, and translation
– Dose–response, biodistribution, particle fate during digestion, allergenicity risk, and validated biomarkers in human studies.
– Regulatory and safety frameworks for food-grade biological particles
o Scalable production, downstream processing, and formulation
Compatibility with industrial processing (e.g. heat, shear), and shelf-life requirements; formulation strategies, sensory effects; scalable manufacturing and quality control for commercial translation.
Article types and fees
This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:
- Editorial
- FAIR² Data
- FAIR² DATA Direct Submission
- General Commentary
- Hypothesis and Theory
- Methods
- Mini Review
- Opinion
- Original Research
- … View all formats
Articles that are accepted for publication by our external editors following rigorous peer review incur a publishing fee charged to Authors, institutions, or funders.
Keywords: Functionalized nanoparticles, Biological microparticles, Food-grade delivery systems, Immune modulation, Gut microbiota, Bioactive compound encapsulation, Nutraceuticals, Bioavailability, Colloidal food systems
Important note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.

