Search Results (204)

This study presents an integrated metabolite-centered framework for the comparative evaluation of plant-based substrates through the simultaneous profiling of fermentation-associated short-chain fatty acids (SCFAs) and neuroactive compounds within a single in vitro experimental platform. Unlike conventional studies focusing on individual metabolite classes, the present approach combines in vitro gastrointestinal digestion with simplified bacterial fermentation to characterize substrate-dependent metabolic responses under controlled experimental conditions. Concurrent evaluation of SCFA production and neuroactive compound formation enabled multidimensional assessment of fermentation-associated metabolite profiles and their potential biochemical interrelationships. Significant differences (p < 0.05) were observed among substrates in both SCFA production and neuroactive compound formation. Hemp seed flour exhibited the highest acetate concentration (4.67 mg/100 g) and γ-aminobutyric acid (GABA) level (114.00 µg/g), whereas lentil and corn flour showed elevated propionate levels. Chickpea and bulgur produced the highest butyrate concentrations. Among neuroactive compounds, bulgur exhibited the highest dopamine and serotonin levels, while lentil demonstrated a more balanced metabolite profile. Correlation analysis suggested exploratory associations between SCFA production and neuroactive compound formation. A strong positive correlation between acetate and GABA (r = 0.89) indicated potential co-variation between carbohydrate fermentation and neuroactive metabolite formation, whereas divergent dopamine and serotonin patterns suggested substrate-dependent metabolic differences. Functional mapping further classified substrates into SCFA-oriented, neuroactive compound–dominant, and mixed metabolic profile groups. Collectively, these findings support a metabolite-centered framework for comparative assessment of plant-based substrates based on fermentation-associated metabolite profiles obtained under controlled in vitro conditions. Although the simplified two-strain fermentation model does not reproduce the complexity of the human colonic microbiota, the observed substrate-dependent metabolic differences may provide preliminary insights into biochemical outputs potentially relevant to gut–brain axis-associated pathways. Further studies employing complex microbial communities and in vivo validation are required to confirm the physiological relevance of these findings. Full article

Gastrointestinal digestion and colonic fermentation determine phenolic transformation and reciprocal microbiome modulation, influencing the generation of gut-derived metabolites associated with epithelial integrity, inflammatory regulation, and metabolic homeostasis. Baby spinach phenolics possess antioxidant and microbiome-modulating potential; however, their functional efficacy is constrained by storage-induced degradation and limited gastrointestinal bioaccessibility. This study investigated phenolic transformation in fresh and stored baby spinach (4 °C and 25 °C) during simulated gastrointestinal digestion and subsequent colonic fermentation. Standardized in vitro digestion revealed limited phenolic bioaccessibility (10–15%), with storage at 25 °C accelerating oxidative degradation and reducing antioxidant capacity. Storage at 25 °C reduced TPC from approximately 465 to 265 µg GAE/g and decreased antioxidant activity by nearly 30%, whereas refrigerated storage (4 °C) better preserved phenolic stability and antioxidant capacity throughout the storage period. LC–MS/MS–based untargeted metabolomics characterized digestion-driven structural remodeling and identified diverse colonic metabolites generated during human fecal fermentation. Despite storage-induced alterations in precursor phenolics, 16S rRNA sequencing demonstrated microbiome relative microbial stability, with fermentation time exerting a stronger influence on community assembly than storage conditions. Microbial metabolism produced shared downstream metabolites, particularly phenylpropionic and flavonoid-derived intermediates. These results suggest that storage modifies phenolic availability during digestion, while gut microbial metabolism sustains the production of functionally relevant metabolites. Full article

The association between dietary fiber and phenolic compounds allows the latter to reach the colon, where most polysaccharides undergo fermentation. This bioprocessing weakens the matrix and promotes the release of the phenolic compounds, which then exert beneficial effects on intestinal function. Although this notion is widely accepted, supporting evidence remains scarce. In this study, we subjected grape pomace skin to in vitro digestion to obtain an indigestible fraction suitable for SHIME bioreactors. Throughout these stages, we observed a sequential increase in the release of phenolic compounds, with colonic fermentation playing an important role. Although we did not observe an increase in short-chain fatty acid (SCFA) production by the gut microbiota, we performed a repeated-challenge design on differentiated Caco-2 monolayers. With this approach, we found that the phenolic-rich ferment prevented the transepithelial electrical resistance (TEER) drop on the second challenge and modulated the transcriptomic profile assessed by RNA-seq. Our findings indicate that the Caco-2 cellular responses mentioned above were SCFA-independent and likely due to the differential impact of phenolic compound load after colonic fermentation of grape pomace skin. Full article

Lentils (Lens culinaris; family: Fabaceae) are increasingly recognized as functional legumes with potential benefits for gut health because they provide bioactive peptides, resistant starch, and polyphenol-rich fractions within a shared food matrix. However, most existing studies have focused on individual lentil-derived compounds, and their matrix-dependent complementary interactions during digestion and fermentation remain insufficiently resolved. This review synthesizes current evidence on lentil-derived peptides, resistant starch, and polyphenols, with particular emphasis on their matrix-dependent complementary relationships, digestion-dependent transformation, microbial co-metabolism, and implications for intestinal barrier function. During gastrointestinal digestion and colonic fermentation, lentil proteins, resistant starch, and phenolic compounds undergo sequential transformation, yielding bioactive peptides, fermentable substrates, short-chain fatty acids (SCFAs), and phenolic metabolites that may collectively influence microbial composition and metabolic activity. Emerging evidence suggests that these interconnected processes may support gut health through microbiota–host crosstalk by modulating tight junction-related markers, reducing intestinal permeability, and maintaining epithelial homeostasis. Mechanistically, these effects have been associated with SCFA-mediated G protein-coupled receptor (GPCR) signaling, suppression of TLR4–NF-κB/MAPK inflammatory cascades, and activation of Keap1–Nrf2 antioxidant defenses, thereby attenuating oxidative stress and pro-inflammatory responses. Current evidence is more consistent with matrix-dependent complementary or convergent actions than with demonstrated synergy. At present, phenolic-rich fractions provide clear pathway-level evidence, whereas fermentation-linked carbohydrate effects are more strongly supported by microbiota- and in vivo-associated outcomes, and protein- or peptide-related mechanisms remain comparatively underdefined. Nevertheless, the evidence base remains limited by the scarcity of integrated studies, well-controlled human intervention trials, and factorial experimental designs capable of distinguishing complementary, additive, and truly synergistic effects among lentil bioactives. This review therefore highlights the need to move from describing coexisting beneficial effects toward formally testing interaction effects within physiologically relevant lentil matrices. Full article

This study investigates the effects of N-acetylneuraminic acid (Neu5Ac) on intestinal microbial composition and metabolic activity in piglets using two complementary approaches: in vitro fermentation and in vivo dietary supplementation with coated Neu5Ac. In vitro fermentation results demonstrated that Neu5Ac stimulates higher production of formate and acetate by piglet intestinal microbiota compared with other human milk-derived monosaccharides (p < 0.05). In vivo feeding trials showed that dietary coated Neu5Ac significantly increased microbial α-diversity and altered the overall microbial composition in both the jejunum and colon (p < 0.05). For instance, coated Neu5Ac reduced the relative abundances of ASV1 Clostridium and ASV17 Clostridium in the jejunum, while raising the relative abundances of ASV3 Veillonella, ASV4 Veillonella, ASV7 Lactobacillus salivarius, ASV11 Actinobacillus porcitonsillarum in the jejunum, and ASV41 Xylanibacter in the colon (p < 0.05). Furthermore, coated Neu5Ac significantly elevated formate and acetate concentrations in the jejunum (p < 0.05) and exhibited a trend toward increased acetate levels in the colon (0.05 < p < 0.1). Collectively, using piglets as a model, this study demonstrates that Neu5Ac facilitates the intestinal colonization of beneficial microbes (e.g., Lactobacillus), leading to enhanced production of microbial metabolites, particularly formate and acetate, which may contribute to improved gut homeostasis in early life. Full article

Modulation of the gut microbiota represents a promising approach to counteract diet-induced metabolic alterations, with microalgae emerging as potential interventions. Building on our previous in vivo evidence that dietary supplementation with the marine microalga Tisochrysis lutea F&M-M36 (T. lutea) positively modulates selected metabolic alterations under high-fat feeding, the present study aimed to identify potential associations between these metabolic changes and coordinated modifications of the gut microbiota. Animals were fed normal-fat (NF), high-fat (HF), or HF supplemented with 5% T. lutea (HFTiso) diets for three months. Gut microbial profiles were analyzed by 16S rRNA sequencing and correlated with plasma lipids, glucose, blood pressure, fecal lipid excretion, and adiponectin levels. T. lutea supplementation was associated with significant modulation of selected metabolic parameters and coherent alterations in gut microbial communities. Multivariate analyses revealed treatment-dependent clustering of metabolic profiles, with HFTiso forming an intermediate group between HF and NF diets. Beta-diversity analyses showed marked treatment-specific shifts, while alpha-diversity remained stable. Linear discriminant analysis identified 31 discriminative genera, with the HFTiso group enriched in taxa associated with fermentative metabolism and lipid-related metabolic pathways including Anaerotruncus, Marvinbryantia, and Eubacterium coprostanoligenes, while the HF group was linked to Clostridium sensu stricto 1 and Terrisporobacter. Positive correlations between HFTiso-associated taxa and adiponectin levels were consistent with microbiota-associated metabolic signatures. In parallel, T. lutea supplementation was associated with downregulation of colonic Niemann-Pick C1-like 1 (NPC1L1) mRNA expression, a key mediator of intestinal cholesterol uptake. The bioactivity of T. lutea likely reflects its content of polyunsaturated fatty acids, oleic acid, phytosterols, and fucoxanthin; however, whether these components act synergistically or whether specific bioactive compounds are primarily responsible remains to be clarified. Together, these findings indicate that T. lutea supplementation is associated with coordinated changes in gut microbiota composition and transcriptional modulation of the intestinal cholesterol transporter NPC1L1 in the context of selected early-stage metabolic alterations under high-fat feeding. While direct extrapolation to humans remains limited, these results suggest potential translational relevance of T. lutea as a nutraceutical approach targeting early-stage metabolic dysregulation. Future studies will be required to determine the mechanistic contribution of individual bioactive components and to assess whether microbiota- and gene expression-associated changes play a causal role in mediating the observed metabolic outcomes, thereby informing the rational development of T. lutea-derived interventions. Full article

Faced with the challenge of reducing food waste, transforming discarded fruit into functional ingredients useful for the food industry is a valuable solution. Ingredients from fruit such as persimmons, which are rich in indigestible carbohydrates and bioactive compounds with antiradical capacity, could positively impact on the health of certain population groups due to their potential prebiotic effect. This study aimed to select the most suitable drying conditions and milling intensity for obtaining powdered persimmon ingredients with a prebiotic-like effects observed in vitro for postmenopausal women, and to evaluate this effect by considering the stimulation of health-promoting bacterial growth and short-chain fatty acids (SCFAs) production. First, the effect of the drying method (hot air drying at 60 and 70 °C, and freeze-drying) and grinding intensity on antiradical capacity, particle size, and the release of bioactive antiradical components into the intestinal lumen after an in vitro gastrointestinal digestion was determined. Next, the effect of these conditions on the microbiota composition of postmenopausal women was preliminary assessed in a batch colonic fermentation experiment for 24 h. The results showed that the ingredient dried with air at 70 °C had the highest phenol and flavonoid content, suffered the least degradation during in vitro gastrointestinal digestion and promoted the differential growth of fiber-degrader genera. Consequently, this was the ingredient selected as the most suitable. Lastly, the impact of this ingredient on the microbiota composition of 4 postmenopausal women has been evaluated in a long-term study using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME^®) coupled to high throughput sequencing. The growth stimulation of health-associated bacteria, such as Akkermansia muciniphila, Faecalibacterium prausnitzii or Phascolarctobacterium faecium, and the promotion of beneficial metabolic pathways, such as the sugar uptake-specific phosphotransferase system, sugar metabolism and propionate and isobutyrate production, were detected along 14 days of persimmon powder supplementation. A holistic framework for promoting human health while advancing environmental sustainability is represented by the combination of sustainable by-product valorization and microbiota-targeted functional food development. Full article

The escalating global incidence of ulcerative colitis (UC) underscores the demand for novel therapeutic strategies. This study investigated the fermentation of Periplaneta americana (PA) powder using two conventional dairy starter strains, Lactobacillus delbrueckii subsp. bulgaricus SN22 and Streptococcus thermophilus SN05, to enhance its functional properties, particularly anti-inflammatory activity, via microbial processing. Both strains demonstrated favourable safety and antimicrobial activity. Untargeted metabolomics revealed that fermentation significantly altered the metabolite profile of the PA supernatant, enriching compounds with potential bioactivities, notably anti-inflammatory (e.g., 3-anisic acid) and antioxidant (e.g., vitamin U) properties. In the DSS-induced mouse colitis model, treatment with the fermented supernatant alleviated intestinal inflammation compared to the unfermented group. This was demonstrated by significantly reduced levels of the pro-inflammatory cytokines IL-1β and TNF-α, along with improved maintenance of intestinal barrier integrity. Further in vitro assays showed that the fermented supernatant significantly suppressed proliferation and clonogenicity in human HT-29 colon cancer cells, while also inducing reactive oxygen species accumulation and apoptosis. Results demonstrate these strains are multifunctional starters possessing superior antimicrobial and anti-inflammatory efficacy. This study employed LAB fermentation of insect-derived matrices to derive bioactive components. The fermentation products exhibited anti-inflammatory potential, offering a potential microbial transformation strategy for developing functional products for adjunctive UC intervention. Full article

Fructose dietary intake is one of the most common risk factors for hyperuricemia, which is a critical threat to human health, and the lack of an effective biological intervention method is the main problem in preventing hyperuricemia caused by fructose intake. Lacticaseibacillus rhamnosus Fmb14 (L. rhamnosus Fmb14) has a fructose-metabolizing ability to produce extracellular polysaccharides (EPSs), and the yield of EPSs reached 0.50 and 0.42 g/L after 48 h of fermentation in liquid media of glucose-MRS and fructose-MRS. Six pure polysaccharide components were obtained after purification. A hyperuricemic mouse model was subsequently established by feeding a 60% high-fructose diet with potassium oxyazinate for 8 weeks, and the results revealed that L. rhamnosus Fmb14 and fructose-derived EPS (F-EPS) intervention significantly reduced the serum uric acid level of the model mice from 133.6 μmol/L to 106.7 to 111.0 μmol/L. The content of XOD in the liver decreased from 2188.1 ng/L in the model group to 1797.9 ng/L in the H-Fmb14 group and 1906.6 ng/L in the H-F-EPS group, alleviating fatty liver degeneration and improving intestinal barrier (increasing OCLN and ZO1 expression in colon). The abundances of allobaculum, bacteroides, Lactobacilli prevotella, and clostridium, the new potential biomarkers of fructose-induced hyperuricemia, were found to be modulated after Fmb14 and F-EPS intervention. The effects of Fmb14 and F-EPS in reducing uric acid synthesis and protecting the intestinal tract are very promising as food intervention agents in the prevention of hyperuricemia caused by fructose dietary. Full article

Cheese is a complex fermented dairy food containing bioactive nutrients and microorganisms that can influence host physiology. However, most existing evidence of its health effects derives from observational studies or investigations of isolated components rather than the whole food matrix. The present study examined the impact of low-fat Cheddar cheese as a whole food on the gut microbiota using a human microbiota–associated (HMA) mouse model. Germ-free C57BL/6 mice were colonized with human fecal microbiota and randomly assigned to either a control diet or a diet supplemented with low-fat Cheddar cheese (7.5% w/w) for six weeks. Fecal samples were collected longitudinally and analyzed by 16S rRNA gene (V3–V4 region) amplicon sequencing. Human microbiota transplantation successfully established a stable, human-like gut microbial community in the mice. Cheese supplementation significantly increased alpha diversity (Shannon and Chao1 indices) and altered microbial composition, characterized by a higher relative abundance of Firmicutes and a reduction in Bacteroidetes (p < 0.001). At the genus level, Lactococcus and Streptococcus were enriched in cheese-fed mice, reflecting potential viable transfer of cheese-derived lactic acid bacteria. These findings provide experimental evidence that low-fat Cheddar cheese can beneficially influence the human-derived gut microbiota in an animal model and highlight the need for further clinical research to validate these effects in humans. Full article

Jackfruit (Artocarpus heterophyllus Lam.) phenolic compounds are chemically diverse. Previous studies have predominantly focused on easily extractable free polyphenols, with limited attention on bound (conjugated) polyphenols. The transformation mechanisms of these polyphenols during maturation, digestion, and colonic fermentation remain unclear, limiting the full utilization of jackfruit resources. This study provides a comprehensive portrait of how jackfruit polyphenols shift in abundance, chemical composition, and bioactivity throughout maturation, in vitro digestion, and colonic fermentation. It also quantifies their selective reshaping of the human gut microbiota and their enhancement of short-chain fatty acid production. The results indicate a significant conversion of bound to free polyphenols during maturation, with distinct behaviors observed across different digestion stages. More importantly, jackfruit polyphenols selectively enrich beneficial gut bacteria, promote short-chain fatty acid production, and positively regulate gut health. Full article

Plastic pollution, particularly the widespread presence of microplastics, has emerged as a global environmental threat. Conventional plastics are highly resistant to degradation and can persist in ecosystems for decades, posing a serious long-term risk to wildlife, habitats, and human health. Increasing evidence suggests that insects and their gut microbiota may play a significant role in the degradation of these plastics. This review examines the mechanisms by which insects and their associated microorganisms contribute to microplastic biodegradation. Plastivorous insect larvae such as Spodoptera frugiperda, Galleria mellonella, Tenebrio molitor and Zophobas atratus have demonstrated the ability to ingest and partially degrade diverse polymers. The initial mechanical breakdown caused by insect mandibles increases the surface area, which allows gut microbes to colonize the material. Once these microbes are established, they form biofilms that help with adhesion, create localized redox environments, and concentrate degradative enzymes at the polymer interface. The enzymatic machinery of insect-associated microbes plays a crucial role in breaking down polymers. Oxidative enzymes, including DyP-type peroxidases, multicopper oxidases, alkane monooxygenases, and laccases, initiate the oxidation of polymers, while hydrolases and esterases further break down the resulting fragments. Co-metabolic processes and microbial consortia improve degradation efficiency by primary degraders by producing oxidized intermediates, which are then consumed and mineralized by secondary fermenters. Despite significant progress, the complete biochemical pathways of microplastic mineralization remain unclear. Degradation rates are slow, and scalability challenges hinder practical applications, with incomplete mineralization in insect biodegradation potentially causing secondary microplastics. Understanding these mechanisms will lay the groundwork for developing insect-microbe systems as potential biotechnological solutions to mitigate plastic pollution in terrestrial environments. Full article

Traditional dry-cured and fermented foods are part of the diet of many countries all over the world. These products are a source of lactic acid bacteria (LAB). Some of the LAB isolated from these products have a variety of probiotic effects on the consumers, among others, maintaining gastrointestinal homeostasis, enhancing immunity, providing antioxidant effects, preventing vaginal and urinary tract infections, and treating obesity. In addition, LAB has antagonistic properties against human pathogens and foodborne bacteria. This review summarizes methods for isolation, characterization, and selection of LAB with probiotic effects. Besides the effect of the selected probiotic LAB, focusing on gastrointestinal adhesion and colonization, and the described mechanisms of action, emphasizing their potential to advance nutritional innovations, will also be discussed. Furthermore, the advantages of the application of selected probiotic LAB in traditional dry-cured and fermented foods and in plant-based analogues will also be reviewed. Full article

Background/Objectives: Consuming apples regularly has positive effects on human health due to their anti-inflammatory and antioxidant properties, which have been associated with their phenolic composition. To enhance the bioactive properties of apple phenolic compounds, high-pressure processing (HPP) has been studied as a tool to improve their extraction during gastrointestinal digestion with the aim of increasing their bioaccessibility and the amount that reaches the colon unchanged, which can serve as substrates for bacterial fermentation. This study aimed to analyze the impact of an HPP-apple ingredient on the metabolism of human gut microbiota using an in vitro dynamic simulator of gastrointestinal digestion and colonic fermentation (GID-CF) that allowed us to study the three colon regions separately (ascending—AC; transverse—TC; and descending—DC). Methods: Apples were HPP-treated (400 MPa/5 min) and lyophilized to obtain an HPP-apple ingredient in powder form. A GID-CF was employed to study the continuous intake of the HPP-apple ingredient for 14 days at 37.5 g/day. Results: The HPP-apple ingredient produced a significant accumulation of phenolic metabolites mainly in the DC, with benefits on human health. The main phenolic metabolites formed were phloroglucinol, 4-hydroxyphenylacetic acid, 4-hydroxy-3-methoxyphenylacetic acid, 3-(3-hydroxyphenyl)-propionic acid, and 3-(4-hydroxyphenyl)-propionic acid. A PCA revealed a perfect separation of the three colon regions based on the phenolic precursors and metabolites. The microbiota-modulatory effects were attributed to the increase in Bifidobacterium spp. and Lactobacillus spp. populations and the butyric acid (SCFA) concentration. Conclusions: The results obtained highlight the health benefits and potential prebiotic-like effect of the HPP-apple ingredient on the gut microbiota. Full article

Fructose malabsorption is characterized as the incomplete absorption of fructose in the small intestine. Fructose is one of the most common monosaccharides in the human diet. The purpose of this review is to provide an updated overview of insights into the relationship between high-fructose diet, fructose malabsorption, gut microbiota and clinical consequences. Incomplete absorption of fructose causes accumulation in the colon, which leads to fermentation by gut microbiota and abdominal symptoms such as bloating and excessive gas production. Malabsorption may result from exceeding the absorptive capacity of GLUT5 or insufficient upregulation, with incidence increasing with age and higher dietary fructose concentrations. High-fructose diets generally promote an increase in inflammatory bacterial groups such as Desulfovibrio and Deferribacteraceae, while reducing beneficial Bacteroidetes. These microbial alterations may impair intestinal barrier function, modify short-chain fatty acid profiles, and contribute to systemic inflammation, metabolic disorders, and potentially mental health issues. Animal studies using fructose malabsorption models present inconclusive results regarding the impact of fructose on the composition of gut microbiota. Additional research is essential to fully comprehend the complex relationship between diet, fructose malabsorption and gut microbiota, to develop personalized, effective dietary approaches for managing symptoms of fructose malabsorption. Full article