Microbial fermentation is a key biotechnological tool for producing bioactive metabolites such as alkaloids, carotenoids, essential oils, and phenolic compounds, among others, with applications in human health, agriculture, and food industries. This review comprehensively reviews recent information on the synthesis of valuable compounds and enzymes through fermentation processes. Here, we discuss the advantages of the different types of fermentation, such as submerged and solid-state fermentation, in optimizing metabolite production by bacteria, fungi, and yeast. The role of microbial metabolism, enzymatic activity, and fermentation conditions in enhancing the bioavailability and functionality of these compounds is discussed. Integrating fermentation with emerging biotechnologies, including metabolic engineering, further enhances yields and specificity. The potential of microbial-derived bioactive compounds in developing functional foods, pharmaceuticals, and eco-friendly agricultural solutions positions fermentation as a pivotal strategy for future biotechnological advancements. Therefore, microbial fermentation is a sustainable tool to obtain high-quality metabolites from different sources that can be used in agriculture, animal, and human health.

Tortillas are an essential food staple in the Mexican diet due to their nutritional value. Blue corn tortillas have been reported as a source of bioactive compounds, such as phenolic compounds and flavonoids. Likewise, the blue corn tortillas have been studied to enhance the nutritional and nutraceutical composition. In this sense, Quelites are a large family of plants with macronutrient and micronutrient content, as well as a source of phenolic compounds, flavonoids, and carotenoids. Among these, Amaranthus hybridus L. could fortify the blue corn tortilla composition. Therefore, this study aims to fortify blue corn tortillas with different concentrations of Quelites flours. The total flavonoid and phenolic compounds content, as well as the antioxidant capacity and identification of phenolic compounds, were evaluated on tortillas fortified with Quelites. The addition of Quelites to blue corn tortillas reduced the lipid and protein content, carbohydrate, and flavonoid content, and enhance the antioxidant capacity of tortillas as measured by FRAP, ORAC, and TEAC assays. Also, caffeic acid, chlorogenic acid, ferulic acid, and sinapic acid were identified on blue corn tortillas fortified with Quelites. These results support the use of A. hybridus L. as an ingredient to improve the nutrient and nutraceutical composition of foods.

The gut microbiota is a dynamic ecosystem shaped by dietary factors, lifestyle factors, environmental exposures, and host characteristics, with important implications for metabolism, immune regulation, intestinal barrier function, and host–microbiota interactions. This narrative review examines how dietary patterns, specific food components, physical activity, sleep and circadian rhythms, aging, and medication exposure modulate gut microbial composition and function, with particular emphasis on interindividual variability and personalized nutrition. A literature search was conducted in Scopus, ScienceDirect, PubMed, and Google Scholar for publications from 2000 to 2026, with emphasis on recent peer-reviewed evidence. Current evidence indicates that dietary patterns and individual food components can modify microbial community structure, metabolic pathways, and bioactive metabolite production, although responses vary substantially across individuals. Physical activity may modify microbial ecology, intestinal physiology, barrier function, and microbial metabolism, whereas sleep disruption and circadian misalignment may alter microbial rhythmicity and host metabolic regulation. Aging and antibiotic exposure are associated with context-dependent changes in microbial composition, function, resilience, and, with antibiotics, the gut resistome. Across these determinants, interindividual variability emerges as a central feature driven by host characteristics, habitual diet, lifestyle, medication history, baseline microbiota, and microbial functional capacity. Personalized nutrition therefore represents a promising but evolving framework in which microbiome data may be integrated with host and environmental characteristics to predict differential responses. Future research should prioritize longitudinal human studies, standardized methodologies, multi-omics integration, and prospective validation of microbiome-informed interventions to establish clinically meaningful benefits.

Microbial fermentation is a key biotechnological tool for producing bioactive metabo-lites such as alkaloids, carotenoids, essential oils, and phenolic compounds, among others, with applications in human health, agriculture, and food industries. This re-view comprehensively reviews recent information on the synthesis of valuable com-pounds and enzymes through fermentation processes. Here, we discuss the advantages of the different types of fermentation, such as submerged and solid-state fermentation, in optimizing metabolite production by bacteria, fungi, and yeast. The role of microbial metabolism, enzymatic activity, and fermentation conditions in enhancing the bioa-vailability and functionality of these compounds is discussed. Integrating fermentation with emerging biotechnologies, including metabolic engineering, further enhances yields and specificity. The potential of microbial-derived bioactive compounds in de-veloping functional foods, pharmaceuticals, and eco-friendly agricultural solutions positions fermentation as a pivotal strategy for future biotechnological advancements. Therefore, microbial fermentation is a sustainable tool to obtain high-quality metabo-lites from different sources that can be used in agriculture, animal, and human health.

Tortillas are an essential food staple in the Mexican diet due to their nutritional value. Blue corn tortilla has been reported as a source of bioactive compounds such as phenolic compounds and flavonoids; likewise, the blue corn tortilla has been studied to enhance the nutritional and nutraceutical composition. In this sense, Quelites are a large family of plants with macronutrients and micronutrients content, as well as a source of phenolic compounds, flavonoids, and carotenoids; among these, Amaranthus hybridus L. could fortify the blue corn tortilla composition. Therefore, this study aims to fortify blue corn tortillas with different concentrations of Quelites flours. The total flavonoid and phenolic compounds content, as well as the antioxidant capacity and identification of phenolic compounds were evaluated on tortillas fortified with Quelites. The addition of Quelites to blue corn tortillas reduced the lipid content, increased the protein, carbohydrate, and flavonoid content, and maintained the antioxidant capacity of tortillas as measured by FRAP, ORAC, and TEAC assays. Also, caffeic acid, chlorogenic acid, ferulic acid, and synapic acid were identified on blue corn tortillas fortified with Quelites. These results support the use of A. hybridus L. as an ingredient to improve the nutrient and nutraceutical composition of foods.