Pilar Gómez-Cortés

Microalgae and cyanobacteria represent an emerging and sustainable source of bioactive compounds for the food, cosmeceutical, and pharmaceutical sectors. In this study, the potential of two microalgae-cyanobacteria consortia, consortium 1 (C1) consisting of Chlorella vulgaris and Arthrospira platensis, and consortium 2 (C2) consisting of Kamptonema sp., Nannochloropsis oculata, Tetraselmis suecica, and Chlorella vulgaris, as a source of bioactive peptides was evaluated. Firstly, protein extraction from both biomasses was optimized by testing different protein solubilization and precipitation pHs, with pH 10 and pH 5 providing the best results in terms of protein recovery in both cases. Selected protein extracts, with protein contents of 28.50 ± 2.69% (C1) and 8.46 ± 0.45% (C2), were further hydrolyzed with Alcalase, evaluating the impact of the incubation time on peptide release and the antioxidant capacity of hydrolysates. A total of 1 h of hydrolysis proved to be enough for antioxidant capacity increase. In addition, in silico hydrolysis of the proteins identified with Alcalase in C1 and C2 (data are available via ProteomeXchange with identifier PXD077201 and PXD077149 for C1 and C2, respectively) was evaluated, assessing the potential bioactivity of the peptides produced, more specifically their antioxidant capacity. Our findings demonstrate that both microalgae-cyanobacteria consortia are valuable sources of bioactive compounds with antioxidant capacity, with potential interest as functional ingredients for the food, cosmeceutical, and pharmaceutical industries.

Microalgae represent sustainable sources of bioactive compounds with potential health benefits. This study conducted a comprehensive proteomic analysis of Tetraselmis chuii (T. chuii) biomass to identify proteins capable of generating bioactive peptides (BAPs) through simulated orogastric digestion. In silico digestion and bioinformatic predictions indicated the release of antioxidant, anti-inflammatory, and antibacterial peptides. Molecular docking demonstrated strong interactions with targets implicated in oxidative stress, inflammation, and Helicobacter pylori (H. pylori) virulence. Biochemical assays and cell-based models confirmed antioxidant and anti-inflammatory activities in both the biomass and its digest, although no significant antibacterial effect against H. pylori was observed under the tested conditions. Considering the role of chronic inflammation in H. pylori-associated pathologies, these findings suggest that T. chuii may serve as a candidate for mitigating tissue damage driven by oxidative and inflammatory stress. Further research is required to address compound stability and optimize delivery strategies.

This study aims to provide a first step into understanding the digestion process and potential bioactivity of fresh cheese made from ultrafiltered milk (UFC), focusing on the effects of enrichment with ω-3 polyunsaturated fatty acids (FAs) and a milk fat globule membrane (MFGM) concentrate. To this end, simulated gastrointestinal digestion following the harmonized INFOGEST protocol was carried out on four types of UFC (C: control, W: ω-3 FA enriched, M: MFGM concentrate enriched, and WM: enriched in both ω-3 FA and MFGM concentrate). Neither protein nor lipid digestibility was negatively affected by ω-3 FA or MFGM enrichment, as bioaccessible nutrients were detected after gastrointestinal digestion. Among the cheeses studied, WM exhibited the highest antioxidant capacity, which was associated with the total number of small size peptides and ω-3 FA. Overall, enrichment with ω-3 FA and MFGM concentrate produces cheeses with digestibility similar to that of the control but significantly enhances their antioxidant capacity.

Tetraselmis chuii is a microalga commercialized because of its richness in health-beneficial molecules. Previous studies have profusely demonstrated the biological properties of compounds isolated from T. chuii, but data are not yet available on the impact that gastrointestinal digestion could exert. This article describes the passage of T. chuii through the gastrointestinal tract, combining the INFOGEST procedure and in vitro colonic fermentation to examine potential effects on the human colonic microflora composition and its metabolic activity. Microbial plate counting was conducted to determine the different groups of microorganisms. Amplification of the 16S ribosomal RNA gene was performed via polymerase chain reaction to examine in detail the main genera of bacteria, and its metabolic activity was evaluated by measuring of short-chain fatty acids (SCFAs) by gas chromatography. The presence of T. chuii modified the fecal microbiota. Although the evolution of lactic acid bacteria and Enterococcus spp. content during 72 h showed that the use of T. chuii, compared to fructopolysaccharides such as inulin, would not provide nutritional advantages, the microalgae extract contributed to a significant decrease in Clostridium, Staphylococcus, and Enterobacteriaceae. Furthermore, T. chuii increased the relative abundance of Akkermansia and Butyricimonas, genera considered highly beneficial. In correlation with the presence of these microorganisms, the results show that the presence of T. chuii favored the release of SCFA, such as acetic (20 mM), propionic (>5 mM), isovaleric (0.3 mM), isobutyric (0.15 mM), and, mainly, butyric (>2 mM), after 72 h colonic fermentation, being indicators of gut health. These findings suggest that T. chuii has potential as a functional ingredient for promoting health through its modulatory effects on the intestinal microbiota.

Chlorella vulgaris is a source of potential bioactive compounds that can reach the large intestine and interact with colonic microbiota. However, the effects of consumption of this microalga on gastrointestinal function have scarcely been studied. This paper simulates, for the first time, the passage of C. vulgaris through the gastrointestinal tract, combining the INFOGEST method and in vitro colonic fermentation to evaluate potential effects on the human colonic microbiota composition by 16S rRNA gene sequencing and its metabolic functionality. The results show that the presence of this microalga increased the release of short-chain fatty acids (SCFAs), such as acetic, propionic, butyric, and isobutyric fatty acids, after 48 h colonic fermentation, being indicators of gut health. In correlation with the release of SCFAs, a significant reduction in bacterial groups causing intestinal imbalance, such as Enterobacteriaceae, Enterococcus spp., and Staphylococcus spp., was observed. In addition, digests from C. vulgaris favored intestinal health-related taxa, such as Akkermansia and Lactobacillus. C. vulgaris is, therefore, a promising food ingredient for good intestinal health and the maintenance of a balanced colonic microbiota.

The impact of the world’s growing population on food systems and the role of dietary patterns in the management of non-communicable diseases underscore the need to explore sustainable and dietary protein sources. Although microalgae have stood out as alternative sources of proteins and bioactive peptides, some species such as Nannochloropsis gaditana remain unexplored. This study aimed to characterize N. gaditana’s proteome and evaluate its potential as a source of bioactive peptides by using an in silico approach. A total of 1955 proteins were identified and classified into functional groups of cellular components, molecular functions, and biological processes. In silico gastrointestinal digestion of identified proteins demonstrated that 202 hydrophobic and low-molecular-size peptides with potential bioactivity were released. Among them, 27 exhibited theorical antioxidant, antihypertensive, antidiabetic, anti-inflammatory, and/or antimicrobial activities. Seven of twenty-seven peptides showed ≥20% intestinal absorption, suggesting potential systemic effects, while the rest could act at local level. Molecular docking demonstrated strong affinities with key enzymes such as MPO, ACE, and DPPIV. Resistance to the digestion, capacity to be absorbed, and multifunctionality were demonstrated for peptide FIPGL. This study highlights N. gaditana’s potential as a sustainable source of novel potential bioactive peptides with promising local and systemic biological effects.

The connection between gut microbiota and factors like diet is crucial for maintaining intestinal balance, which in turn impacts the host’s overall health. Nannochloropsis gaditana microalgae is a sustainable source of bioactive compounds, mainly known for its used in aquaculture and extraction of bioactive lipids, with potential health benefits whose effects on human gut microbiota are still unknown. Therefore, the goal of this work was to assess the impact of N. gaditana on human gut microbiota composition and derived metabolites by combining the INFOGEST protocol and in vitro colonic fermentation process to evaluate potential effects on human gut microbiota conformation through 16S rRNA gene sequencing and its metabolic functionality. The results have demonstrated the ability of the digests from N. gaditana to significantly modify gut microbiota composition, promoting an increase in beneficial bacterial genera such as Akkermansia, Butyricicoccus, Eisenbergiella, Lachnoclostridium, and Marvinbryantia, in contrast to inulin, after 48 h of colonic fermentation. Additionally, the digests increased the levels of both major and minor short-chain fatty acids (SCFAs), particularly butyric and valeric acids, considered as intestinal biomarkers, and increased ammonium production. This research has demonstrated, for the first time, the potential of N. gaditana microalgae as a sustainable agent for influencing the composition and functionality of human gut microbiota.

The impact of the world’s growing population on food systems and the role of dietary patterns in the managing of non-communicable diseases underscore the need to explore sustainable and dietary protein sources. Although microalgae have stood out as alternative sources of proteins and bioactive peptides, some species such as Nannochloropsis gaditana remain unexplored. This study aimed to characterize N. gaditana’s proteome and evaluate its potential as a source of bioactive by using an in silico approach. A total of 1955 proteins were identified and classified into functional groups of cellular component, molecular function, and biological process. In silico gastrointestinal digestion of identified proteins demonstrated that 202 hydrophobic and low molecular size-peptides with potential bioactivity were released. Of them, 27 exhibited theorical antioxidant, antihypertensive, antidiabetic, antiinflammatory, and/or antimicrobial activities. Seven of 27 peptide showed ≥20% intestinal absorption, suggesting potential systemic effects, while the rest could act at local level. Molecular docking demonstrated strong affinities with key enzymes such as MPO, ACE, and DPPIV. Resistance to the digestion, capacity to be absorbed and multifunctionality were demonstrated for peptide FIPGL. This study highlights N. gaditana's potential as a sustainable source of novel potential bioactive peptides with promising local and systemic biological effects.