Search Results (547)

Background/Objectives: Selective serotonin reuptake inhibitors (SSRIs), widely prescribed for anxiety disorders, may negatively impact the gut microbiota, contributing to dysbiosis. Considering the gut–brain axis’s importance in mental health, probiotics could represent an effective adjunctive strategy. This study evaluated the effects of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 on microbiota composition, metabolic activity, and immune markers in fecal samples from patients with anxiety on SSRIs, using the SHIME^® (Simulator of the Human Intestinal Microbial Ecosystem) model. Methods: The fecal microbiotas of four patients using sertraline or escitalopram were inoculated in SHIME^® reactors simulating the ascending colon. After stabilization, a 14-day probiotic intervention was performed. Microbial composition was assessed by 16S rRNA sequencing. Short-chain fatty acids (SCFAs), ammonia, and GABA were measured, along with the prebiotic index (PI). Intestinal barrier integrity was evaluated via transepithelial electrical resistance (TEER), and cytokine levels (IL-6, IL-8, IL-10, TNF-α) were analyzed using a Caco-2/THP-1 co-culture system. The statistical design employed in this study for the analysis of prebiotic index, metabolites, intestinal barrier integrity and cytokines levels was a repeated measures ANOVA, complemented by post hoc Tukey’s tests to assess differences across treatment groups. For the 16S rRNA sequencing data, alpha diversity was assessed using multiple metrics, including the Shannon, Simpson, and Fisher indices to evaluate species diversity, and the Chao1 and ACE indices to estimate species richness. Beta diversity, which measures microbiota similarity across groups, was analyzed using weighted and unweighted UniFrac distances. To assess significant differences in beta diversity between groups, a permutational multivariate analysis of variance (PERMANOVA) was performed using the Adonis test. Results: Probiotic supplementation increased Bifidobacterium and Lactobacillus, and decreased Klebsiella and Bacteroides. Beta diversity was significantly altered, while alpha diversity remained unchanged. SCFA levels increased after 7 days. Ammonia levels dropped, and PI values rose. TEER values indicated enhanced barrier integrity. IL-8 and TNF-α decreased, while IL-6 increased. GABA levels remained unchanged. Conclusions: The probiotic combination of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 modulated gut microbiota composition, metabolic activity, and inflammatory responses in samples from individuals with anxiety on SSRIs, supporting its potential as an adjunctive strategy to mitigate antidepressant-associated dysbiosis. However, limitations—including the small pooled-donor sample, the absence of a healthy control group, and a lack of significant GABA modulation—should be considered when interpreting the findings. Although the SHIME^® model is considered a gold standard for microbiota studies, further clinical trials are necessary to confirm these promising results. Full article

The fungal component of microbiota, known as the mycobiome, inhabits different body niches such as the skin and the gastrointestinal, respiratory, and genitourinary tracts. Much information has been gained on the bacterial component of the human microbiota, but the mycobiome has remained somewhat elusive due to its sparsity, variability, susceptibility to environmental factors (e.g., early life colonization, diet, or pharmacological treatments), and the specific in vitro culture challenges. Functionally, the mycobiome is known to play a role in modulating innate and adaptive immune responses by interacting with microorganisms and immune cells. The latter elicits anti-fungal responses via the recognition of specific fungal cell-wall components (e.g., β-1,3-glucan, mannan, and chitin) by immune system receptors. These receptors then regulate the activation and differentiation of many innate and adaptive immune cells including mucocutaneous cell barriers, macrophages, neutrophils, dendritic cells, natural killer cells, innate-like lymphoid cells, and T and B lymphocytes. Mycobiome disruptions have been correlated with various diseases affecting mostly the brain, lungs, liver and pancreas. This work reviews our current knowledge on the mycobiome, focusing on its composition, research challenges, conditioning factors, interactions with the bacteriome and the immune system, and the known mycobiome alterations associated with disease. Full article

Background: As a well-known environmental hazard, ambient fine particulate matter (PM_2.5, aerodynamic diameter ≤ 2.5 µm) has been positively correlated with an increased risk of digestive system diseases, including appendicitis, inflammatory bowel disease, and gastrointestinal cancer. Additionally, PM_2.5 exposure has been shown to alter microbiota composition and diversity in human and animal models. However, its impact on goblet cells and gut mucus barrier integrity remains unclear. Methods: To address this, 8-week-old male and female interleukin-10 knockout (IL10^−/−) mice, serving as a spontaneous colitis model, were exposed to concentrated ambient PM_2.5 or filtered air (FA) in a whole-body exposure system for 17 weeks. Colon tissues from the PM_2.5-exposed mice and LS174T goblet cells were analyzed using H&E staining, transmission electron microscopy (TEM), and transcriptomic profiling. Results: The average PM_2.5 concentration in the exposure chamber was 100.20 ± 13.79 µg/m³. PM_2.5 exposure in the IL10^−/− mice led to pronounced colon shortening, increased inflammatory infiltration, ragged villi brush borders, dense goblet cells with sparse enterocytes, and lipid droplet accumulation in mitochondria. Similar ultrastructure changes were exhibited in the LS174T goblet cells after PM_2.5 exposure. Transcriptomic analysis revealed a predominantly upregulated gene expression spectrum, indicating an overall enhancement rather than suppression of metabolic activity after PM_2.5 exposure. Integrated enrichment analyses, including GO, KEGG, and GSEA, showed enrichment in pathways related to oxidative stress, xenobiotic (exogenous compound) metabolism, and energy metabolism. METAFlux, a metabolic activity analysis, further substantiated that PM_2.5 exposure induces a shift in cellular energy metabolism preference and disrupts redox homeostasis. Conclusions: The findings of exacerbated gut barrier impairment and goblet cell dysfunction following PM_2.5 exposure provide new evidence of environmental factors contributing to colitis, highlighting new perspectives on its role in the pathogenesis of colitis. Full article

Acne is a highly prevalent skin condition with multifactorial pathophysiology, where Cutibacterium acnes (C. acnes) overgrowths generate inflammation. C. acnes can grow and adhere, through the formation of biofilms, to almost any surface, which enables chronic infections. Acne treatment with antibiotics can induce topical antimicrobial resistance, impair microbiome biodiversity and cause cutaneous dysbiosis. In this study, we assess the effect of a standardized propolis extract (PE) from Greece against C. acnes, whilst maintaining skin’s microbiome biodiversity, and we investigate its effect against genes related to the attachment and colonization of C. acnes, as well as against biofilm formation. The extract has been chemically characterized by GC-MS and was additionally tested for its antioxidant properties by the Folin–Ciocalteu method and the 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) assay and its regulatory activity on the expression of antimicrobial and anti-inflammatory genes in normal human epidermal keratinocytes (NHEKs). The suggested efficacy of PE in targeting pathogenic C. acnes biofilm, via downregulation of virulence genes, represents an alternative strategy to modulate the behavior of skin microbiota in acne, paving the way for next-generation acne-targeting products. Full article

The gut microbiota has emerged as a key area of biomedical research due to its integral role in maintaining host health and its involvement in the pathogenesis of many systemic diseases. Growing evidence supports the notion that gut dysbiosis contributes significantly to diseases and their progression. An example would be inflammatory bowel disease (IBD), a group of conditions that cause inflammation and swelling of the digestive tract, with the principal types being ulcerative colitis (UC) and Crohn’s disease (CD). Another notable disease with significant association to gut dysbiosis would be colorectal cancer (CRC), a malignancy which typically begins as polyps in the colon or rectum, but has the potential to metastasise to other parts of the body, including the liver and lungs, among others. Concurrently, advances in nanomedicine, an evolving field that applies nanotechnology for disease prevention, diagnosis, and treatment, have opened new avenues for targeted and efficient therapeutic strategies. In this paper, we provide an overview of the gut microbiota and the implications of its dysregulation in human disease. We then review the emerging nanotechnology-based approaches for both therapeutic and diagnostic purposes, with a particular focus on their applications in IBD and CRC. Full article

Probiotics, as live microbial agents, play a pivotal role in modulating host microbiota balance, enhancing immunity, and improving gastrointestinal health. However, their application is hindered by critical challenges, such as inactivation during processing, storage, and gastrointestinal delivery, as well as low colonization efficiency. This article comprehensively reviews recent advances in probiotic delivery systems, focusing on innovative technologies, including hydrogels, nanocoatings, emulsions, and core–shell microgels. It provides an in-depth analysis of natural polyphenol-based nanocoatings and metal–phenolic network (MPN) single-cell encapsulation strategies for enhancing bacterial survival rates while highlighting the unique potential of microalgae-based bio-carriers in targeted delivery. Research demonstrates that well-designed edible delivery systems can effectively preserve probiotic viability and enable controlled intestinal release, offering novel strategies to reshape a healthy gut microbiome. While these systems show promise in maintaining probiotic activity and gut colonization, challenges remain in safety, scalable production, and clinical translation. Overcoming these barriers is crucial to fully harnessing probiotics for human health. Full article

Plastics pollution is a critical global environmental issue, with growing concern over the increasing presence of nanoplastic particles. Plastics are major environmental pollutants that adversely affect human health, particularly when plastics from food sources enter the body and pose potential risks to reproductive health. Echinacea purpurea is an immunologically active medicinal plant containing phenolic acids and alkylamides. Nanoparticles present a promising approach to enhance the effectiveness, stability, and bioavailability of Echinacea purpurea ethanol extract (EE) active components. This study aimed to determine the protective effects of chitosan-silica-Echinacea purpurea nanoparticles (CSE) against reproductive injury induced by polystyrene nanoplastics (PS-NPs) in male rats. The results showed that CSE dose-dependently reduced oxidative damage and protected intestinal and reproductive health. Furthermore, CSE improved gut microbiota dysbiosis, preserved barrier integrity, and attenuated PS-NPs-induced inflammation in the colon, brain, and gonads. Inflammatory factors released from the gut can enter the bloodstream, cross the blood–brain barrier, and potentially modulate the hypothalamic–pituitary–gonadal (HPG) axis. CSE has also been shown to elevate neurotransmitter levels in the colon and brain, thereby repairing HPG axis dysregulation caused by PS-NPs through gut–brain communication and improving reproductive dysfunction. This study enhances our understanding of CSE in modulating the gut–brain and HPG axes under PS-NPs-induced damage. CSE demonstrates the capacity to provide protection and facilitate recovery by mitigating oxidative stress and inflammation, restoring gut microbiota balance, and preserving hormone levels in the context of PS-NPs-induced injury. Full article

Human milk (HM) is a complex biological fluid that plays a significant role in infant health, influenced by maternal dietary habits and body composition. This study aimed to explore how maternal diet and nutritional status affect the microbial composition of HM. In this pilot study, 15 mothers were recruited from a maternity ward and assessed for dietary habits through a semi-structured food frequency questionnaire and a 3-day dietary record. Maternal body composition was evaluated using bioelectrical impedance analysis. HM samples were collected for microbiota analysis, focusing on the diversity and composition of bacterial communities via 16S rRNA sequencing. The study identified that maternal nutrient intake significantly correlated with the composition of HM microbiota. Specifically, Firmicutes abundance showed positive correlations with animal protein (τ = 0.39; p = 0.043), total carbohydrates (τ = 0.39; p = 0.043), and vitamin A (τ = 0.429; p = 0.026). Bacteroidota was positively correlated with retinol (τ = 0.39; p = 0.043). Higher consumption of dietary fiber (>24 g/day) did not yield significant differences in bacterial composition compared to lower intake (<24 g/day) (p = 0.8977). Additionally, no significant differences were found in overall bacterial abundance across different maternal characteristics such as age, mode of delivery, or breastfeeding type. This study underscores the importance of maternal diet in shaping the HM microbiota, which may have implications for infant health. Dietary modifications during lactation could be a strategic approach to promote beneficial microbial colonization in HM. Further research is warranted to confirm these findings and explore the underlying mechanisms. Full article

Histamine intolerance is a condition that occurs when there is an imbalance between the accumulation and degradation of histamine within the body. Excess histamine is metabolized and then degraded by two enzymes, of which the most abundant is the vesicular diamine oxidase (DAO). An imbalance or a state of dysbiosis of the intestinal microbiota has been observed in patients with histamine intolerance compared to healthy individuals. Studies indicate that the administration of bifidobacteria or lactobacilli alone or in mixtures can alter colonic microbiota populations and metabolic activities. The present study has evaluated the ability of a probiotic bacterial strain to stimulate the release of cellular DAO from an in vitro model of the human intestinal epithelial barrier. The results indicate that, under the experimental conditions used, probiotic strain Lactiplantibacillus plantarum LP115 has a significant stimulatory effect on DAO secretion in adenocarcinoma cell line HT-29. Full article

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. Full article

Fucoidans have demonstrated a wide range of bioactivities including immune modulation and benefits in gut health. To gain a deeper understanding on the effects of fucoidan from Undaria pinnatifida (UPF) on the colonic microbiome, the short-term Simulator of the Human Intestinal Microbial Ecosystem^®, a validated in vitro gut model, was applied. Following a three-week intervention period on adult faecal samples from three healthy donors, microbial community activity of the colonic microbiota was assessed by quantifying short-chain fatty acids while composition was analysed utilising 16S-targeted Illumina sequencing. Metagenomic data were used to describe changes in community structure. To assess the secretion of cytokines, co-culture experiments using Caco-2 and THP1-Blue™ cells were performed. UPF supplementation over a three-week period had a profound butyrogenic effect while also enriching colonic microbial diversity, consistently stimulating saccharolytic genera, and reducing genera linked with potentially negative health effects in both regions of the colon. Mild immune modulatory effects of UPF were also observed. Colonic fermentation of UPF showed anti-inflammatory properties by inducing the secretion of the anti-inflammatory cytokines IL-6 and IL-10 in two out of three donors in the proximal and distal colon. In conclusion, UPF supplementation may provide significant gut health benefits. Full article

Precision nutrition-targeted gut microbiota (GM) may have therapeutic potential not only for age-related diseases but also for slowing the aging process and promoting longer healthspan. Recent studies have shown that restoring a healthy symbiosis of GM by counteracting dysbiosis (DYS) through precise nutritional intervention is becoming a major target for extending healthspan. Microbiota-accessible borate (MAB) complexes, such as boron (B)–pectins (rhamnogalacturonan–borate) and borate–phenolic esters (diester chlorogenoborate), have a significant impact on healthy host–microbiota symbiosis (HMS). The mechanism of action of MABs involves the biosynthesis of the autoinducer-2–borate (AI-2B) signaling molecule, B fortification of the mucus gel layer by the MABs diet, inhibition of pathogenic microbes, and reversal of GM DYS, strengthening the gut barrier structure, enhancing immunity, and promoting overall host health. In fact, the lack of MAB complexes in the human diet causes reduced levels of AI-2B in GM, inhibiting the Firmicutes phylum (the main butyrate-producing bacteria), with important effects on healthy HMS. It can now be argued that there is a relationship between MAB-rich intake, healthy HMS, host metabolic health, and longevity. This could influence the deployment of natural prebiotic B-based nutraceuticals targeting the colon in the future. Our review is based on the discovery that MAB diet is absolutely necessary for healthy HMS in humans, by reversing DYS and restoring eubiosis for longer healthspan. Full article

Pyracantha fortuneana, an underutilized wild plant, has been found to have a high nutritional value. This study used simulated digestion and fecal fermentation models to investigate the digestive properties of the purified acidic pectin polysaccharide of Pyracantha fortuneana and its impact on the gut microbiota and metabolites. Pyracantha fortuneana polysaccharide (PFP) is mainly composed of rhamnose (Rha), galacturonic acid (GalA), glucose (Glc), galactose (Gal), and arabinose (Ara), with a molecular weight (Mw) of 851.25 kDa. Following simulated digestion, the Mw of PFP remained consistent. The reduced sugar content showed minimal change, suggesting that PFP exhibits resistance to gastrointestinal digestion and can effectively reach the colon. Following fecal fermentation, the molecular weight, monosaccharide, and carbohydrate contents of PFP decreased, while the short-chain fatty acid content increased. This suggests that PFP is susceptible to degradation by microorganisms and can be metabolized into acetic acid and n-butyric acid, contributing to the regulation of intestinal health. Meanwhile, PFP promotes the reproduction of beneficial bacteria such as Bacteroides, Dialister, and Dysgonomonas, inhibits the growth of harmful bacteria like Proteus, and generates metabolites such as thiamine, leonuriside A, oxoadipic acid, S-hydroxymethylglutathione, and isonicotinic acid, which exert beneficial effects on human health. These results indicate that PFP has great potential in regulating the gut microbiota and generating beneficial metabolites to promote intestinal functional health and can be used as a prebiotic to prevent diseases by improving intestinal health. Full article

Background/Objectives: Alginate and its oligosaccharides (AOS) are widely used in the food industry all over the world. However, how they are fermented by the human gut microbiota has not been fully elucidated. Here, we aim to explore the structure–property relationships of the fermentation of these carbohydrates by the human gut microbiota. Methods: High-performance liquid chromatography, 16S rRNA gene amplicon high-throughput sequencing, whole genome sequencing, and metabolome analysis were used to study the fermentation of alginate and AOS by the human gut microbiota. Results and Conclusions: Low-molecular-weight alginate and AOS were more fermentable than alginate. Moreover, fermentation of AOS with a molecular weight (Mw) of 0.8 kDa produced higher amounts of acetate and butyrate than that with a Mw of 0.3 kDa. B. xylanisolvens was a keystone species responsible for the fermentation. Additionally, each B. xylanisolvens strain was characterized with a unique capability for AOS fermentation. Specifically, B. xylanisolvens P19-10, a bacterium isolated from healthy human colon, exhibited the best fermentation capacity. Genomic analysis suggested that B. xylanisolvens P19-10 was armed with a plethora of carbohydrate-active enzymes. Additionally, the polysaccharide lyase family 6_1 was identified as a candidate enzyme responsible for the utilization of AOS. Moreover, fermentation of AOS by B. xylanisolvens P19-10 was associated with significant changes in bacterial metabolites and metabolic pathways. Future perspectives: Our study provides novel mechanistic insights into the fermentation of alginate and AOS by human gut microbiota, which has applications for the development of new carbohydrate-based nutraceuticals and foods. Full article

Background: Staphylococcus spp. and Mammaliicoccus sciuri (M. sciuri) are Gram-positive cocci that inhabit mammals’ and birds’ skin and mucous membranes, part of the microbiota. An imbalance in local immunity can increase colonization, resulting in various infections. Inappropriate use of antimicrobials leads to Staphylococci and M. sciuri becoming resistant to conventional treatments. The transmission of methicillin-resistant staphylococci and M. sciuri (MRS and MRMs, respectively) between humans and animals is still underreported in Brazil. Objectives: this study aimed to describe the frequency, distribution, resistance pattern, and evaluation of potential sharing of MRS and MRMs in isolates from asymptomatic dogs and their owners in Rio de Janeiro. Methods: Samples from 50 asymptomatic dogs and 34 from their owners were collected. Isolates were identified by mass spectrometry. The mecA gene was confirmed by conventional PCR. Antimicrobial activity of samples that carried the mecA gene was evaluated by disk diffusion method. Results: In this study, MRS and MRMs were analyzed in 50 dogs and their owners (34) by identifying strains carrying the mecA gene. A total of 185 strains were isolated. The mecA gene was found in 33.5% of the isolates. The most prevalent species carrying the mecA gene was S. epidermidis (33.9%). MRMs showed 14.5%. Fourteen dogs had the same strain carrying the mecA gene as their owners. Of these, 50% exhibited the same antimicrobial resistance pattern, determined by the disk diffusion. The highest percentage of resistance observed in the MRS isolated from dogs and the owners was to Erythromycin (51.3% and 56.5%, respectively). Conclusions: The presence of methicillin-resistant staphylococci is worrisome because there is the potential to transfer these strains between dogs and humans. These strains may act as a reservoir of resistance genes. Full article