Eleni Dalaka

Edible insects have drawn increasing interest from researchers as sustainable sources of protein with potential functional ingredients for feed and food applications. However, the intestinal effects of digestion-derived fractions remain insufficiently characterized. The present research combined INFOGEST 2.0 in vitro digestion with a polarized Caco-2 monolayer model to examine the potential intestinal effects of digestates produced from Tenebrio molitor and Alphitobius diaperinus. Neither digestate affected cell viability at the tested concentrations. Transepithelial electrical resistance also remained comparable to the control treatments, indicating the preservation of monolayer integrity. Nevertheless, both insect-derived digestates moderately increased Lucifer Yellow apparent permeability. At the molecular level, both treatments significantly upregulated genes associated with epithelial differentiation and tight junctions, including claudins and intestinal alkaline phosphatase, while A. diaperinus digestate additionally increased the mRNA expression of tight junction protein 1 and sucrase-isomaltase. Both digestates also enhanced the expression of antioxidant-related genes, including NAD(P)H quinone dehydrogenase 1, glutathione-disulfide reductase, and heme oxygenase 1, with A. diaperinus eliciting a broader transcriptional response than T. molitor by additionally increasing the expression of NFE2-like bZIP transcription factor 2 and superoxide dismutase 1. Overall, these results indicate that digestion-derived components from these edible insects can modulate selected intestinal epithelial and antioxidant-related transcriptional responses in differentiated Caco-2 cells under the conditions tested.

Lignocellulosic agricultural residues are abundant yet underutilized despite their potential for sustainable bioconversion. This study evaluated spent mushroom substrate (SMS) from Pleurotus ostreatus cultivation and roots of leafy vegetables (RLV) as alternative substrates for Pleurotus production, using wheat straw as a control. Two species, P. ostreatus and P. citrinopileatus, were cultivated on different SMS/RLV ratios and the immunomodulatory potential of harvested mushrooms was assessed. Specifically, protein (PE-D-P3 < 3 kDa) and carbohydrate (CE-D) fractions obtained after in vitro digestion were applied to LPS-challenged THP-1 cells and immune-related gene expression was analyzed by qPCR. Both species significantly modulated immune responses. The PE-D-P3 showed a more pronounced immunomodulatory effect, significantly downregulating IL1B, IL6 and TNF, whereas the CE-D reduced only TNF expression. Substrate composition influenced bioactivity: PE-D-P3 from SMS 80-RLV 20% resulted in the greatest reduction in IL1B, IL6 and TNF, while CE-D from SMS 60-RLV 40% reduced IL1B and CXCL8. These findings provide insights that both fungal species and substrate composition influence immunomodulatory compound production. Valorizing lignocellulosic residues through optimized mushroom cultivation represents a sustainable strategy for producing functional ingredients with applications in human and animal health, particularly for preventing inflammation-related disorders.

Polyunsaturated fatty acids, particularly γ-linolenic acid, are recognized for their therapeutic and nutritional properties. Zygomycetes, such as Cunninghamellaelegans, represent a promising microbial platform for sustainable gamma-linolenic acid (GLA) production as an alternative to conventional sources. Despite this potential, the immunomodulatory activity of metabolites from C. elegans has not been previously explored. In this study, C. elegans was cultivated on hydrolysates from discarded residues of Pleurotus spp. cultures (DRPC-HL), optimized to release assimilable compounds, promoting valorization of low-value biomass within a circular bioeconomy. Dry mycelial biomass, lipid-free biomass, and intracellular lipids from these cultures, alongside previously reported C. elegans cultures grown under nitrogen-excess (N-Xs) and nitrogen-limited (N-Lim) conditions, were tested on THP-1-derived macrophages, under lipopolysaccharide (LPS)-induced inflammatory conditions. Following in vitro gastrointestinal digestion, dry biomass and lipid-free dry biomass fractions upregulated the anti-inflammatory cytokine IL10 and downregulated IL1B and TNF, particularly from N-Xs and DRPC-HL cultures. Lipids mainly enhanced IL10 expression, especially when derived from N-Xs cultures. No changes were observed in upstream regulators (TLR2, TLR4, NFKB1, RELA), suggesting a feasible post-receptor immunomodulatory action. Overall, these findings highlight the dual value of fungal bioproducts derived from agro-industrial residues, combining sustainable bioprocessing with bioactive compound generation, supporting environmentally friendly microbial platforms for industrial applications.

The objective of the present study is to evaluate the effects of lactation stage, age, somatic cell count (SCC), and daily milk yield on plasmin–plasminogen (PL–PG) system activity and physicochemical milk traits in intensively reared Chios and Frizarta ewes. A total of 52 purebred ewes (26 ewes per breed and farm) were randomly selected and prospectively monitored during the 3rd, 5th, and 6th month post-lambing. Daily milk yield and body condition score (BCS) were recorded, and individual milk samples were collected for the assessment of PL–PG activities using enzymatic assays, SCC, electrical conductivity (EC), refractive index (RI), and pH. Correlation analysis and mixed linear regression models were used for the assessment of the effects. Lactation stage significantly affected PL–PG system traits in both breeds, but in opposite direction; plasmin and plasminogen plus plasmin declined toward late lactation in Chios ewes, whereas it increased in Frizarta ewes. Lower SCC was associated with reduced plasmin system activity in Chios ewes, whereas no effect was observed in Frizarta ewes. The plasminogen-to-plasmin ratio remained stable across lactation, breeds, and SCC classes, indicating coordinated regulation of the system. BCS was positively associated with plasmin activity during late lactation, suggesting a stage-dependent metabolic modulation. EC and pH were closely associated with SCC, while RI mainly reflected compositional variation. Our findings underline that, although the PL–PG system is primarily affected by lactation stage and mammary health status in sheep, there are breed-specific regulatory patterns which should be further investigated.

Probiotics have emerged as an important strategy to achieve improved feed efficiency and carcass quality. To evaluate the effects of a probiotic combination based on Weizmannia faecalis (formerly Bacillus coagulans) and Bacillus licheniformis on broiler performance, carcass, and intestinal health, a study was conducted. As-hatched ROSS 308 broilers were purchased from a local hatchery at day 0 and were randomly allocated to two treatments (160 birds per treatment; 8 replicates of 20 birds each): the control, which was fed a standard commercial diet throughout the experiment, and the probiotics group, where the standard diet was further supplemented with the probiotic combination. Feed and water were offered for ad libitum consumption while the feeding schedule was as follows: Starter, 1–10 days, mash; Grower, 11–24 days, mash; Finisher, 25–42, mash. The birds were challenged using re-used litter as bedding and the application of increased stocking density and mild heat stress. The final body weight of the probiotics’ supplemented group was higher than the control at 42 days of age (2822.7 g vs. 2575.4 g, respectively) (p < 0.05), and the overall feed conversion ratio was significantly reduced. The weight of all the commercial parts increased, along with the thigh and drumstick yield, thus indicating an improvement of carcass composition (p < 0.05). The European Poultry Efficiency Factor significantly improved following the probiotic dietary supplementation (409.7 vs. 344.9 of the control), while the probiotic fed birds had higher antibody titers for Bursal disease at 42 days and lower serum concentration of fatty acid binding protein 2 at 24 days (p < 0.05). Overall, the dietary supplementation of broilers with the probiotic mixture, under challenging rearing conditions, enhanced growth performance and improved carcass composition.

In recent years, insect-derived peptides have attracted attention for their potential biological activities, particularly antioxidant properties. This study assessed the antioxidant activity of two widely consumed edible insects, T. molitor and A. diaperinus larvae, using cell-free and cell-based approaches. Whole lyophilized larvae, digestion products from the oral, gastric, and intestinal phases, as well as the A. diaperinus D-P3 was associated with increased mRNA expression of genes related to antioxidant defense, including NFE2-like bZIP transcription factor 2 (NFE2L2, also known as Nrf2), glutathione-disulfide reductase (GSR), superoxide dismutase 1 (SOD1), and catalase (CAT), whereas T. molitor D-P3 preferentially modulated nuclear factor kappa B p50 subunit (NFKB1) and nuclear factor kappa B p65 subunit (RELA). Overall, these findings indicate that gastrointestinal digestion enhances the bioaccessibility of antioxidant components in both edible insect species while revealing species-specific transcriptional responses under in vitro inflammatory conditions. This multilevel assessment provides mechanistic insight into the antioxidant-related biological activity of digestion-derived insect peptides and supports their further investigation as functional ingredients in food and feed systems.

Microbial bioconversion of agro-industrial by-products into high-value-added metabolites such as polysaccharides or lipids serves a dual purpose: mitigating environmental pollution through waste reduction and supporting the development of novel bioproducts. In this study, a non-conventional, poorly studied Cryptococcus albidus strain was initially assessed for its ability to grow on semi-defined media containing lactose, glycerol, or glucose under three distinct nitrogen availability conditions at C/N equal to 20, 80, and 160 mol/mol in shake flask cultures. The goal was to evaluate biomass production and synthesis of valuable metabolites under these conditions. C. albidus demonstrated robust growth on all commercial carbon sources, particularly under nitrogen-rich conditions, producing more than 25.0 g/L of microbial biomass with a high intracellular polysaccharide content (>45%, w/w). Additionally, mannitol production was detected in cultures with glycerol and glucose (9.1 and 13.1 g/L, respectively), especially after nitrogen depletion. Subsequently, C. albidus and a Cutaneotrichosporon curvatus strain were batch-cultivated using pretreated secondary cheese whey (SCW) as a carbon-rich waste substrate. When cultivated on SCW, both yeast strains partially metabolized lactose and produced polysaccharide-rich biomass, dominated by β-glucans (>29% of total biomass), compounds known for their functional and bioactive properties. The cellular polysaccharides (cPS extracted from C. albidus exhibited cytotoxic effects against cancer cells, suggesting their potential use as biological response modifiers. In contrast, the cPS from C. curvatus did not affect cell viability, indicating their promise as ingredients for applications in the food, feed, pharmaceutical, or cosmetic sectors.