Search Results (230)

The oral–gut microbiota axis is a relatively new field of research. Although most studies have focused separately on the oral and gut microbiota, emerging evidence has highlighted that the two microbiota are interconnected and may influence each other through various mechanisms shaping systemic health. The aim of this review is therefore to provide an overview of the interactions between oral and gut microbiota, and the influence of diet and related metabolites on this axis. Pathogenic oral bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, can migrate to the gut through the enteral route, particularly in individuals with weakened gastrointestinal defenses or conditions like gastroesophageal reflux disease, contributing to disorders like inflammatory bowel disease and colorectal cancer. Bile acids, altered by gut microbes, also play a significant role in modulating these microbiota interactions and inflammatory responses. Oral bacteria can also spread via the bloodstream, promoting systemic inflammation and worsening some conditions like cardiovascular disease. Translocation of microorganisms can also take place from the gut to the oral cavity through fecal–oral transmission, especially within poor sanitary conditions. Some metabolites including short-chain fatty acids, trimethylamine N-oxide, indole and its derivatives, bile acids, and lipopolysaccharides produced by both oral and gut microbes seem to play central roles in mediating oral–gut interactions. The complex interplay between oral and gut microbiota underscores their crucial role in maintaining systemic health and highlights the potential consequences of dysbiosis at both the oral and gastrointestinal level. Some dietary patterns and nutritional compounds including probiotics and prebiotics seem to exert beneficial effects both on oral and gut microbiota eubiosis. A better understanding of these microbial interactions could therefore pave the way for the prevention and management of systemic conditions, improving overall health outcomes. Full article

Urban expansion fragments once-contiguous forest patches, generating pronounced edge gradients that modulate soil physicochemical properties and biodiversity. We quantified how fragmentation reshaped the soil microbiome continuum and its implications for soil carbon storage in a temperate urban mixed deciduous forest. A total of 18 plots were considered in this study, with six plots for each fragment type. Intact interior forest (F), internal forest path fragment (IF), and external forest path fragment (EF) soils were sampled at 0–15, 15–30, and 30–45 cm depths and profiled through phospholipid-derived fatty acid (PLFA) chemotyping and amino sugar proxies for living microbiome and microbial-derived necromass assessment, respectively. Carbon fractionation was performed through the chemical oxidation method. Diversity indices (Shannon–Wiener, Pielou evenness, Margalef richness, and Simpson dominance) were calculated based on the determined fatty acids derived from the phospholipid fraction. The microbial biomass ranged from 85.1 to 214.6 nmol g⁻¹ dry soil, with the surface layers of F exhibiting the highest values (p < 0.01). Shannon diversity declined systematically from F > IF > EF. The microbial necromass varied from 11.3 to 23.2 g⋅kg⁻¹. Fragmentation intensified the stratification of carbon pools, with organic carbon decreasing by approximately 14% from F to EF. Our results show that EFs possess a declining microbiome continuum that weakens their carbon sequestration capacity in urban forests. Full article

Konjac glucomannan (KGM) is a natural polysaccharide polymer. It is degraded by gut microbiota-derived β-mannanase into small-molecule nutrients, which exert diverse physiological regulatory effects. As a prebiotic, KGM modulates gut microbiota composition. It selectively fosters the proliferation of beneficial commensals and suppresses potential pathogens, thereby alleviating microbiota-related disorders. Moreover, microbiota fermentation of KGM produces metabolites. Short-chain fatty acids (SCFAs) are particularly notable among these metabolites. They exert multifaceted beneficial effects, including metabolic regulation, intestinal barrier strengthening, and neuroprotective functions. These effects are mediated through inhibition of inflammatory pathways (e.g., NF-κB, MAPK), modulation of lipid metabolism genes (e.g., CD36), and regulation of neurotransmitters (e.g., GABA, 5-HT). This highlights KGM’s therapeutic potential for metabolic, inflammatory, and neurodegenerative diseases. Current clinical use is limited by dose-dependent adverse effects and interindividual response variability, which stem from different microbial communities. This necessitates personalized dosage strategies. Despite these limitations, KGM as a prebiotic polysaccharide exhibits multifaceted bioactivity. Current evidence suggests its potential to synergistically modulate metabolic pathways, gut microbiota composition, immune cell signaling, and neuroendocrine interactions. This highlights its promise for developing novel therapeutic interventions. Full article

This article presents a review of several non-exclusive pathways for the sequestration of soil organic carbon, which can be classified into two large classical groups: the modification of plant and microbial macromolecules and the abiotic and microbial neoformation of humic substances. Classical studies have established a causal relationship between aromatic structures and the stability of soil humus (traditional hypotheses regarding lignin and aromatic microbial metabolites as primary precursors for soil organic matter). However, further evidence has emerged that underscores the significance of humification mechanisms based solely on aliphatics. The precursors may be carbohydrates, which may be transformed by the effects of fire or catalytic dehydration reactions in soil. Furthermore, humic-type structures may be formed through the condensation of unsaturated fatty acids or the alteration of aliphatic biomacromolecules, such as cutins, suberins, and non-hydrolysable plant polyesters. In addition to the intrinsic value of understanding the potential for carbon sequestration in diverse soil types, biogeochemical models of the carbon cycle necessitate the assessment of the total quantity, nature, provenance, and resilience of the sequestered organic matter. This emphasises the necessity of applying specific techniques to gain insights into their molecular structures. The application of appropriate analytical techniques to soil organic matter, including sequential chemolysis or thermal degradation combined with isotopic analysis and high-resolution mass spectrometry, derivative spectroscopy (visible and infrared), or ¹³C magnetic resonance after selective degradation, enables the simultaneous assessment of the concurrent biophysicochemical stabilisation mechanisms of C in soils. Full article

Palm oil is a highly versatile natural resource that has gathered significant attention due to its bioactive properties, particularly its antimicrobial and antioxidant effects. Rich in tocotrienols, tocopherols, and carotenoids, palm oil exhibits potent antioxidant activity, while its fatty acid content and other bioactive molecules contribute to its antimicrobial efficacy against various pathogens. The underlying mechanisms of action driving these bioactivities involve intricate molecular interactions, biochemical pathways, and redox processes, which influence microbial cell function and oxidative stress reduction. This review provides a critical analysis of the current mechanistic understanding of palm oil’s biofunctional properties, emphasizing its potential incorporation into engineered biomaterials. Particular focus is given to the chemical composition, reaction pathways, and synergistic potential of palm oil derivatives in material-based formulations. Furthermore, the potential applications of palm oil as a standalone or synergistic agent in novel therapeutic and industrial formulations are explored. By elucidating the mechanistic basis of its bioactivity within material contexts, this review highlights palm oil’s promising role in the development of advanced functional materials for pharmaceutical and dental technologies. Full article

In recent years, gut microbiota has emerged as a critical regulator of gastrointestinal health and disease, with its role in inflammatory bowel disease (IBD)—including Crohn’s disease and ulcerative colitis—being particularly significant. Among the many factors influencing the gut microbiota, dietary components such as fibers, fats, and polyphenols have received substantial attention. However, nitrogen-containing compounds, such as amino acids, nitrates, urea, and even nucleic acids, such as purines, remain underexplored despite their integral role in shaping microbial ecology, host metabolism, and immune responses. Some of these compounds are metabolized by gut bacteria into bioactive molecules such as short-chain fatty acids, ammonia, and nitric oxide, which exert diverse effects on mucosal integrity and inflammation. IBD pathophysiology is characterized by chronic inflammation, microbial dysbiosis, and compromised epithelial barriers. Nitrogen metabolism contributes significantly to these processes by influencing microbial composition, metabolite production, and host immune pathways. The breakdown of various nitrogen-containing compounds in the body leads to the production of byproducts, such as ammonia and hydrogen sulfide, which have been implicated in mucosal damage and immune dysregulation. At the same time, nitrogen-derived molecules, such as short-chain fatty acids and nitric oxide, exhibit protective effects, underscoring the dual role of dietary nitrogen in health and disease. This narrative review highlights the complex interactions between dietary nitrogen sources, gut microbiota, and IBD pathogenesis. We summarize the mechanisms by which nitrogen compounds influence microbial dynamics, identify their contributions to inflammation and barrier dysfunction, and explore their therapeutic potential. Multidisciplinary approaches integrating clinical, metabolomic, and microbiome research are essential to unravel the full scope of nitrogen’s role in gut health and identify novel therapeutic targets. Full article

Dates (Phoenix dactylifera L.) are nutrient-rich fruits with health-promoting properties and broad applications in the food and beverage industries. This study analyzes the chemical properties and volatile profile of fermented date products—juice, alcoholic derivative, and vinegar—to develop a high-quality vinegar with distinct sensory traits. Using HS-SPME-GC-MS, about 50 volatile compounds were identified across six major chemical classes. Juice processing significantly increased volatile release, especially fusel alcohols and furanic aldehydes, due to thermal and mechanical disruption. Fermentation further modified the volatilome, with increased esters and acids in alcoholic and vinegar products. Vinegar was characterized by high levels of acetic acid, fatty acids, phenols, and acetoin (855 mg/L), indicating active microbial metabolism. Ethanol and acidity levels met international standards. Total phenolic content rose from juice (138 mg/L) to vinegar (181 mg/L), reflecting microbial enzymatic activity and acid-driven extraction. These results highlight the metabolic complexity, sensory richness, and functional potential of date-derived fermented products while promoting sustainable use of underutilized fruit resources. Full article

Background: Early neurovascular unit (NVU) impairment plays a critical role in the pathogenesis of diabetic retinopathy (DR), often preceding clinically detectable changes. Butyrate, a short-chain fatty acid (SCFA) derived from gut microbiota, has shown promising metabolic and anti-inflammatory effects. Methods: This study investigated the protective potential of oral butyrate supplementation in a mouse model of early type 2 diabetes mellitus (T2DM) induced by a high-fat diet and streptozotocin. Mice (C57BL/6J) received sodium butyrate (5 g/L in drinking water) for 12 weeks. Retinal NVU integrity was assessed using widefield swept-source optical coherence tomography angiography (WF SS-OCTA), alongside evaluations of systemic glucose and lipid metabolism, hepatic steatosis, visual function, and gut microbiota composition via 16S rRNA sequencing. Results: Butyrate supplementation significantly reduced body weight, fasting glucose, serum cholesterol, and hepatic lipid accumulation. Microbiome analysis demonstrated a partial reversal of gut dysbiosis, characterized by increased SCFA-producing taxa (Ruminococcaceae, Oscillibacter, Lachnospiraceae) and decreased pro-inflammatory, lipid-metabolism-related genera (Rikenella, Ileibacterium). KEGG pathway analysis further revealed enrichment in microbial lipid metabolism functions (fabG, ABC.CD.A, and transketolase). Retinal vascular and neurodegenerative alterations—including reduced vessel density and retinal thinning—were markedly attenuated by butyrate, as revealed by WF SS-OCTA. OKN testing indicated partial improvement in visual function, despite unchanged ERG amplitudes. Conclusions: Butyrate supplementation mitigates early NVU damage in the diabetic retina by improving glucose and lipid metabolism and partially restoring gut microbial balance. This study also underscores the utility of WF SS-OCTA as a powerful noninvasive tool for detecting early neurovascular changes in DR. Full article

Sewage sludge, characterized by its high organic matter and nutrient content, as well as the presence of microbial pathogens and other contaminants, requires proper management due to its significant generation rate. The table olive sector, which is highly significant in Spain as a global leader in production and export, generates various waste streams such the Organic Solid By-Products from Table Olive Processing (OSBTOP), which are mainly derived from the olive pit after the pitting process. The main aim of this study was to enhance the methane production performance of sewage sludge through co-digestion with OSBTOP as a co-substrate. Batch assays demonstrated that employing OSBTOP as a co-substrate increased methane content by 35–41% across all tested mixtures. While the highest methane yield was produced at a 40:60 (sludge:OSBTOP) ratio, a 60:40 mixture proved to be a more advantageous option for scale-up and practical application. This is attributed to factors such as the higher availability of sludge and its inherent buffering capacity, which counteracts the accumulation of volatile fatty acids and promotes process stability, thereby contributing to the study’s objective of significantly enhancing methane production from sewage sludge through co-digestion. In semi-continuous operation, methane yields in the co-digestion scenario exceeded those of mixed sludge digestion, showing a yield of 180 versus 120 LCH₄⁻¹ · kgVS_added⁻¹, representing a 50% improvement. This study highlights the potential of anaerobic digestion as a strategy for valorizing OSBTOP, a by-product with no prior studies, while demonstrating that its co-digestion with sewage sludge enhances methane generation, offering a sustainable approach to organic waste treatment. Full article

Achillea nobilis represents a species of considerable medicinal importance within the Asteraceae family, historically employed in Central Asia and various Eurasian territories for the management of inflammatory, microbial, and gastrointestinal ailments. Notwithstanding its extensive ethnopharmacological significance, the phytochemical profile and pharmacological attributes of its various anatomical components have not been comprehensively investigated. This research endeavor sought to delineate the phytochemical constituents and evaluate the antimicrobial efficacy of ethanol extracts derived from both the aerial and root segments of A. nobilis. Qualitative phytochemical analysis and GC–MS characterization unveiled a diverse array of bioactive compounds, encompassing flavonoids, phenolic compounds, organic acids, lactones, alcohols, and heterocyclic derivatives. In particular, the aerial oil extract exhibited the presence of terpenoids, fatty acids and their esters, sterols, hydrocarbons, and minor organosilicon and cyclobutanone derivatives, with notable compounds such as linoleic acid (8.08%), 6-tetradecyne (14.99%), isopropyl linoleate (14.64%), and E,Z-1,3,12-nonadecatriene (22.25%). In vitro antimicrobial activity was assessed against eight clinically relevant microbial strains employing the broth microdilution technique. The aerial ethanol extract exhibited pronounced antimicrobial properties, particularly against MRSA and C. albicans, with MICs ranging from 0.5 to 2 mg/mL, whereas the root ethanol extract displayed MICs of 1 to 3 mg/mL. Additionally, the aerial oil extract showed moderate inhibitory activity, with MIC values ranging from 1.5 to 3 mg/mL, demonstrating effectiveness particularly against C. albicans, C. neoformans, and MRSA. These findings underscore the therapeutic potential of A. nobilis, particularly its aerial component, as a viable natural source of antimicrobial agents. Full article

Recent advances highlight the crucial role of the gut microbiota in human health and disease, with dietary components emerging as powerful modulators of microbial communities. This review synthesizes current evidence on the effects of olive-derived bioactive compounds, including polyphenols (e.g., hydroxytyrosol, oleuropein or tyrosol), triterpenes and other phytochemicals on gut microbiota composition and function. These compounds have been shown to enhance beneficial bacterial populations such as Lactobacillus and Bifidobacterium, reduce potentially pathogenic taxa, and promote the production of short-chain fatty acids and other health microbial metabolites, reinforcing intestinal barrier integrity. In vitro, in vivo, and clinical studies also reveal the potential of olive bioactives to ameliorate metabolic, inflammatory, and neurocognitive disorders through gut-microbiota-brain axis modulation. Despite promising results, key challenges remain, including interindividual microbiota variability, lack of standardized intervention protocols, and limited human clinical trials. Addressing these gaps through robust translational research could pave the way for microbiota-targeted, personalized nutritional strategies based on olive-derived compounds. Full article

The growing interest in health-promoting diets has brought fermented foods into the spotlight due to their unique microbial compositions and bioactive metabolites. Fermented foods and their beneficial microbiota are expected to stimulate the overall industry’s expansion over the next few years as their beneficial health effects become established. This narrative review explores the evolving dynamics of fermented food microbiota and their interactions with the gut microenvironment, emphasizing strategic pathways to enhance human health. Fermented foods, both industrially produced and traditionally prepared, serve as carriers of beneficial microorganisms such as lactic acid bacteria, yeasts, and certain fungi that transform food substrates into bioactive compounds including short-chain fatty acids (SCFAs), exopolysaccharides, and bioactive peptides. Simultaneously, their bioactive metabolites are the subject of passionate investigation by the scientific community, uncovering novel beneficial aspects that have not been elucidated until now. These metabolites contribute to improved gut barrier function, modulation of immune responses, and overall metabolic health. Notably, microbial fermentation can reshape the intrinsic properties of food, offering therapeutic potential beyond basic nutrition. The interactions between food-derived microbes and the host gut microbiota suggest a synergistic mechanism influencing gastrointestinal and systemic health outcomes. Nevertheless, there remains a significant gap in the comprehensive evaluation of the existing literature in this specific research area. Further research is needed to standardize fermented food formulations, validate the effects of individual microbial strains, and optimize their application in personalized nutrition and functional food development. Accordingly, this review highlights the association between the microbiota of fermented foods and their metabolites with the gut microenvironment, emphasizing their potential health-promoting properties. Full article

Postbiotics, which are non-viable microbial derivatives including short-chain fatty acids (SCFAs), microbial peptides, and cell wall components, are emerging as novel therapeutic agents for Inflammatory Bowel Disease (IBD). Unlike probiotics, postbiotics offer a safer, more stable alternative while retaining potent bioactivity. IBD, encompassing Crohn’s disease and ulcerative colitis, is characterized by chronic gastrointestinal inflammation, epithelial barrier dysfunction, and immune dysregulation. Recent evidence links mitochondrial dysfunction marked by impaired energy metabolism, oxidative stress, and apoptosis with the pathogenesis and persistence of IBD. Postbiotics have shown the ability to modulate mitochondrial health through multiple mechanisms. SCFAs such as butyrate serve as primary energy substrates for colonocytes, enhancing mitochondrial respiration and promoting biogenesis. They improve mitochondrial function and boost ATP production. Moreover, postbiotics reduce oxidative damage by regulating antioxidant defenses. These antioxidant actions limit epithelial apoptosis and preserve cellular integrity. In addition, postbiotics regulate mitophagy and help maintain mitochondrial quality and reduce inflammation. Structural components such as lipoteichoic acid and peptidoglycan have been shown to interact with mitochondrial pathways and modulate inflammatory responses. Collectively, this review explores the interplay between mitochondrial dysfunction, IBD, and preventive approach using postbiotics. Understanding the connections with postbiotics could open up new avenues for therapeutic interventions aimed at mitigating IBD severity in people with IBD. Full article

This randomized, double-blind, placebo-controlled, three-arm clinical trial evaluated the effects of a proprietary bioactive fucoidan-rich extract derived from Saccharina latissima (SLE-F) on gut microbial composition and function in healthy adults. The objective of the study was to assess the potential of SLE-F to beneficially modulate the gut microbiome, with this paper specifically reporting on microbial diversity, taxonomic shifts, and functional pathway outcomes. Ninety-one participants received either a low dose (125 mg), high dose (500 mg), or placebo twice daily for four weeks. The primary endpoint was the microbiome composition assessed via 16S rRNA sequencing (V3–V4 region), with secondary outcomes including surveys, adverse event monitoring, and clinical evaluations. High-dose supplementation resulted in dose-dependent improvements in the microbial diversity; increased abundance of beneficial taxa, including Bifidobacterium, Faecalibacterium, and Lachnospiraceae; and reductions in inflammation-associated taxa, such as Enterobacteriaceae and Pseudomonadota. A functional pathway analysis showed enhancement in short-chain fatty acid biosynthesis and carbohydrate metabolism. The low-dose group showed modest benefits, primarily increasing Bifidobacterium, with limited functional changes. In vitro colonic simulations further demonstrated a dose-dependent increase in short-chain fatty acids and postbiotic metabolite production following SLE-F exposure. SLE-F was well tolerated, with only mild, nonspecific adverse events reported. These findings support the potential of SLE-F as a safe and effective microbiome-modulating agent, warranting further study of the long-term use and synergy with dietary interventions. Full article

Chronic inflammatory enteropathies (CIEs) in companion animals represent a group of idiopathic, immune-mediated gastrointestinal disorders in which the intestinal epithelium can be altered, affecting intestinal functionality, nutrient absorption, and microbiota composition. This review presents an overview of markers that could be used for the assessment of intestinal health, focusing extensively on functional biomarkers, with particular attention to fatty acids (including short-chain fatty acids, SCFAs) and amino acids. Studies have consistently shown reduced concentrations of SCFAs in companion animals with CIEs compared to healthy groups. These alterations occur with varying intensity depending on the type of enteropathy. Alterations in saturated, monounsaturated, and long-chain polyunsaturated fatty acids have also been reported in blood and feces, particularly in omega-3 and omega-6 derivatives, as well as in the elongase and desaturase indices responsible for endogenous synthesis. In addition, amino acids serve as precursors to key metabolites involved in mucosal immunity, oxidative stress regulation, and microbial homeostasis. In CIEs, alterations in systemic and fecal amino acid profiles have been observed, reflecting both host metabolic adaptation and microbial dysbiosis. Integrating fatty acid and amino acid profiles can help distinguish different types of enteropathies, providing additional discriminatory power for determining response to dietary treatment. Future research should aim to elucidate the causal relationships between metabolic alterations and disease pathogenesis, which could lead to novel dietary interventions targeting metabolic interactions between the microbiota and the host. Full article