Search Results (468)

Fusobacterium nucleatum (Fn) has been increasingly recognized as a crucial mediator of colorectal cancer (CRC) biology, particularly in microsatellite-stable (MSS) tumors, where immune checkpoint inhibitors (ICIs) have shown limited efficacy. Rather than representing a passive microbial passenger, Fn actively shapes tumor behavior by adhering to epithelial cells, activating oncogenic signaling, and promoting epithelial–mesenchymal transition (EMT). At the same time, it remodels the tumor microenvironment, driving immune suppression through inhibitory receptor engagement, accumulation of myeloid-derived cells, and metabolic reprogramming of tumor-associated macrophages. These mechanisms converge to impair cytotoxic immunity and contribute to both intrinsic and acquired resistance to ICIs. Beyond immune escape, Fn interferes with conventional chemotherapy by sustaining autophagy and blocking ferroptosis, thereby linking microbial colonization to multidrug resistance. Most of these mechanisms derive from preclinical in vitro and in vivo models, where causal relationships can be inferred. In contrast, human data are mainly observational and provide correlative evidence without proving causality. No interventional clinical studies directly targeting Fn have yet been conducted. Its enrichment across the adenoma–carcinoma sequence and consistent detection in both tumor and fecal samples highlight its potential as a biomarker for early detection and patient stratification. Importantly, multidimensional stool assays that integrate microbial, genetic, and epigenetic markers are emerging as promising non-invasive tools for CRC screening. Therapeutic strategies targeting Fn are also under exploration, ranging from antibiotics and bacteriophages to multifunctional nanodrugs, dietary modulation, and natural microbiota-derived products. These approaches may not only reduce microbial burden but also restore immune competence and enhance the efficacy of immunotherapy in MSS CRC. Altogether, current evidence positions Fn at the intersection of microbial dysbiosis, tumor progression, and therapy resistance. A deeper understanding of its pathogenic role may support the integration of microbial profiling into precision oncology frameworks, paving the way for innovative diagnostic and therapeutic strategies in CRC. Full article

Background/Objectives: There is a constant increase in the incidence of food allergies. Short-chain fatty acids (SCFAs), responsible for maintaining the intestinal barrier and immune balance, are produced by the intestinal microbiota through the fermentation of dietary fibre. The aim of this systematic literature review was to analyse the association of SCFAs with the occurrence of food allergies. Methods: The analysed data were obtained by searching the PubMed and Scopus databases with the keywords “short-chain fatty acids and allergy”, “SCFA and allergy”, “SCFA and food allergy”, and “acetic acid or propionic acid or butyric acid or 3,4-methylvaleric acid and allergy”. Exclusion criteria were as follows: retracted articles, articles not freely accessible, and incomplete/insufficient data (conference reports). Two authors independently searched the literature. Results: Patients with food allergies show lower levels of SCFAs, especially acetic, butyric and propionic acids. 3,4-methylvaleric acid may be associated with intestinal inflammation in infants and intestinal leakage. Conclusions: Based on studies, there appears to be an association between lower stool levels of SCFAs—particularly butyric, propionic, acetic, and isovaleric acids—and the occurrence of food allergies in both children and adults. A proper diet that strengthens fibre, probiotics, and prebiotics and limits antibiotics, xenobiotics, pesticides is crucial for maintaining adequate SCFA levels and thus reducing allergy-related symptoms. 3,4-Methylvaleric acid and the activation of inflammatory processes contributing to intestinal leakage may provide a new diagnostic path. Full article

Background: This pilot study aimed to investigate the relationship between the breast tissue microbiota and breast cancer in Turkish women. We compared cancerous and adjacent normal breast tissues, as well as stool samples, obtained during breast-conserving surgery. Methods: In this prospective study, paired tumor and normal breast tissue samples, together with preoperative stool samples, were analyzed using 16S rRNA sequencing. Diversity indices and relative abundance differences were calculated, with effect sizes, 95% confidence intervals, and false discovery rate (FDR) corrections reported where appropriate. Results: A total of 22 patients with early-stage breast cancer were included (mean age 58.3 ± 12.7 years, mean BMI 28.9 ± 3.1 kg/m²). Distinct compositional shifts were observed between tumor and normal tissues, with Ruminococcus, Eubacterium, Actinobacteria (phylum), and Stenotrophomonas enriched in tumor samples, while Lactobacillus, Staphylococcus, Bifidobacterium, and Faecalibacterium were more abundant in normal tissues. No consistent associations were identified between fecal and breast tissue microbiota. Limitations: The small sample size, absence of healthy tissue or stool controls, and reliance on 16S rRNA sequencing limit the generalizability and functional interpretation of these findings. Conclusions: Despite these limitations, this study demonstrates localized microbial differences between tumor and adjacent normal breast tissues. Larger, multi-center studies with healthy controls and functional omics approaches are warranted to clarify the biological relevance and potential clinical implications. Full article

Colorectal cancer (CRC) is one of the most common cancers worldwide and a significant global health issue. The human gut microbiota, a complex ecosystem hosting numerous microorganisms such as bacteria, viruses, fungi, and protozoa, plays a crucial role. Increasing evidence indicates that gut microbiota is involved in CRC pathogenesis. In this study, the gut microbiota profiles, short-chain fatty acids, zonulin, and lipopolysaccharide-binding protein levels of newly diagnosed CRC patients were analyzed along with healthy controls to elucidate the relationship between CRC and the gut microbiota. The study included 16 newly diagnosed CRC patients and 16 healthy individuals. For microbiota analysis, DNA isolation from stool samples was performed using the Quick-DNA™ Fecal/Soil Microbe Miniprep Kit followed by sequencing using the MinION device. Data processing was conducted using Guppy software (version 6.5.7) and the Python (3.12) programming language. ELISA kits from Elabscience were utilized for analyzing LBP and zonulin serum levels. Fecal short-chain fatty acids were analyzed using GC-MS/MS equipped with a flame ionization detector and DB-FFAP column. Microbial alpha diversity, assessed using Shannon and Simpson indices, was found to be lower in CRC patients compared to healthy controls (p = 0.045, 0.017). Significant differences in microbial beta diversity were observed between the two groups (p = 0.004). At the phylum level, Bacteroidota was found to be decreased in CRC patients (p = 0.027). Potential biomarker candidates identified included Enterococcus faecium, Ruminococcus bicirculans, Enterococcus gilvus, Enterococcus casseliflavus, Segatella oris, and Akkermansia muciniphila. Serum zonulin levels were higher in CRC patients (CRC = 70.1 ± 26.14, Control = 53.93 ± 17.33, p = 0.048). There is a significant relationship between gut microbiota and CRC. A multifactorial evaluation of this relationship could shed light on potential biomarker identification and the development of new treatment options for CRC. Full article

(1) Background: Chronic enteropathy (CE) in canines is associated with persistent microbiome dysbiosis, and conventional therapies (e.g., special diets, antimicrobials, and immunosuppressive drugs) are sometimes ineffective. Currently, fecal microbiota transplantation (FMT) has proven successful in treating CE in canines via invasive methods (e.g., enemas or endoscopy) or via oral frozen liquid capsules, which must be stored at −80 °C. However, due to the invasiveness of the administration methods and the storage constraints of the liquid capsules, FMT is not widely used in veterinary clinical practice. (2) Methods: The case of a four-year-old Siberian Husky with a three-year history of CE following canine parvovirus infection received lyophilized FMT capsules for thirty days. Stool samples were collected for metagenomic sequencing and quantification of fecal short-chain fatty acids (SCFAs), both pre- and post-FMT. Blood samples were analyzed using complete blood count (CBC) and biochemical testing. Ultrasound was used to assess the wall thickness of the stomach, duodenum, jejunum, and colon. (3) Results: Post-FMT, improvements in clinical outcomes were observed: fecal scores improved from 6 (unformed stools with mucus) to 2 (formed stool), and body weight increased by 8.3% (from 24.2 kg to 26.2 kg). Abnormal CBC and biochemical parameters were restored to reference ranges, including hematocrit (from 60.6% to 55.7%), hemoglobin (from 208 g/L to 190 g/L), creatinine (from 167 μmol/L to 121 μmol/L), and urea (from 11.9 mmol/L to 7.1 mmol/L). Ultrasound results showed that colonic wall thickness decreased from 0.23 ± 0.03 cm (pathological) to 0.18 ± 0.01 cm (physiological). Metagenomic analysis revealed that microbial richness (operational taxonomic units (OTUs) from 151 to 183) and diversity (Shannon and Simpson indices from 3.16 to 4.8 and from 0.87 to 0.94, respectively) all increased. The microbiota composition of the recipient exhibited a decline in the relative abundance of Firmicutes, falling from 99.84% to 35.62%, concomitant with an increase in Actinobacteria (from 0.08% to 4.78%), indicating a convergence toward a donor-like profile. Fecal SCFAs analysis revealed a 251.4% increase in propionate (from 0.0833 to 0.2929 mg/g) and elevated acetate (from 0.4425 to 0.4676 mg/g). These changes are functionally linked to enriched propanoate metabolism (Z = 0.89) in KEGG pathways. (4) Conclusions: Oral lyophilized FMT capsules resolved clinical signs of CE, enhanced microbial diversity and richness, and restored donor-like abundances of gut microbiota, particularly SCFA-producing taxa. Microbial restructuring increased microbial metabolite output, notably SCFA concentrations, and enriched functional metabolic pathways. Importantly, lyophilized FMT overcomes storage limitations and administration barriers, demonstrating its high clinical viability for treating canine CE. Full article

Background: Oral probiotic intake is suggested to have positive effects on skin. We aimed to elucidate the effects of oral Bifidobacterium breve M-16V intake on skin by analyzing facial images, the skin myco/microbiota, and the gut microbiota. Methods: We conducted a randomized, double-blind, placebo-controlled study in Japan. Healthy women aged over 30 years were randomly allocated to either the B. breve (1 × 1010 colony-forming units (CFU)/sachet, two sachets daily) or the placebo group and consumed the corresponding study food for 12 weeks. Facial images were taken at weeks 0, 4, 8, and 12 using VISIA evolution. Stool and skin samples were collected at weeks 0 and 12. The primary outcome was the change in the total VISIA score from baseline. Results: A total of 120 females aged 30–79 years were assigned to the B. breve (n = 59) or placebo (n = 61) group. The total VISIA score worsened in the placebo group at week 8 (p = 0.029) but not in the B. breve group. Compared with that of the placebo group, the VISIA brown spot score of the B. breve group improved at weeks 4 (p = 0.013) and 8 (p = 0.041). The VISIA pore score improved at weeks 4 (p = 0.013), 8 (p = 0.041), and 12 (p = 0.004) within the B. breve group. Genus-level analysis of the gut microbiota revealed a significant increase in Blautia abundance in the B. breve group. The frequency of adverse events was not different between the groups. Conclusions: Oral B. breve M-16V administration may suppress skin deterioration, including the appearance of brown spots, on the faces of adult females. Full article

Background/Objectives: Sleep is essential for children’s well-being, yet insufficient sleep duration and quality are common among preschoolers. The brain–gut microbiota axis, a bidirectional communication network connecting the brain, the gastrointestinal tract, and the microorganisms living there, known as the gut microbiota, influences sleep regulation, but its role in children remains largely unexplored. Here, we examined the association between gut microbiota and sleep in preschoolers from Étude Longitudinale Française depuis l’Enfance (ELFE) birth cohort study. Methods: This study included 597 children (51.2% boys) with available stool samples and sleep data at 3.5 years. The gut microbiota data was analyzed using bacterial 16S rRNA sequencing. Data on day and night sleep durations and frequencies of sleep onset difficulties and night waking were collected through telephone questionnaires and grouped into ‘optimal’ and ‘suboptimal’ clusters using Latent Class Analysis. Statistical analyses involved multivariate logistic regressions or multivariate permutation analysis of variance, controlling for confounders. Results: In total, 25% of the included children were in the suboptimal sleep cluster. No significant associations were found between gut microbiota diversity and composition and sleep clusters at age 3.5 years. Similarly, no differences were found in the abundance of specific microbiota genera between the two sleep clusters. Conclusions: While emerging evidence suggests correlations between gut microbiota and sleep in preschool children, our results do not confirm such correlations. The data used in this study were obtained from a homogeneous, high socioeconomic population, which must be considered when interpreting the findings. Further research is needed to validate the results of this study. Full article

Background: Rhamnogalacturonan-I (RG-I) is a pectic polysaccharide with emerging prebiotic and immunomodulatory potential. This randomised, double-blind, placebo-controlled trial (ID: NCT06081972) evaluated the effects of carrot-derived RG-I (cRG-I) supplementation, compared to placebo (maltodextrin), on gut microbiota composition and immune cell activation in healthy adults. Methods: A total of 54 participants (18–70 years old) were randomised in a double-blind manner to receive either 500 mg/day of cRG-I or placebo for four weeks. Pre-screening ensured balanced randomisation based on habitual fibre intake and faecal Bifidobacterium counts. Questionnaires assessed potential gut health and well-being effects, while in vitro and ex vivo models were used to evaluate effects on intestinal permeability. Results: cRG-I was well tolerated with excellent compliance. Faecal Bifidobacterium counts increased significantly, peaking at week 3. Isobutyric acid levels rose, though no other SCFAs differed. Immunologically, cRG-I enhanced the percentage of circulating myeloid dendritic cells expressing activation markers (CD86, HLA-DR) on. Stool consistency improved slightly. Preclinical models further showed that cRG-I and its fermentation products protected intestinal barrier integrity under stress. Conclusion: These results support cRG-I as a safe, low-dose dietary intervention capable of beneficially modulating gut microbiota, immune responses, and barrier function in healthy adults within a short supplementation period. Full article

Background: The gut–muscle axis is believed to influence training adaptations through microbiota-derived signals and the regulation of inflammation, but evidence in elite swimmers is limited and mixed. This study aims to determine whether synbiotic supplementation (probiotics + omega-3) combined with ultra-short race-pace training (USRPT) improves sprint-related upper-body strength. Methods: In a randomized, double-blind, 8-week trial of male elite sprint freestyle swimmers, participants completed USRPT and were allocated to either synbiotic supplementation or its single-component arms (probiotic or omega-3) or placebo. Primary outcomes indexed dynamic/explosive strength (isokinetic shoulder torque and power at 180°/s, rate of force development, time-to-peak torque); secondary outcomes included maximal strength (MVIC; 60°/s) and field/strength-endurance tests (dead-hang, handgrip, medicine-ball throw). Analyses reported p-values with effect sizes. Results: The synbiotic group showed greater improvements in high-velocity, sprint-relevant measures versus comparators—higher 180°/s torque and power, increased rate of force development, and shorter time-to-peak torque (Time × Group p < 0.05 across domains; effects in the medium–large range). Changes in handgrip and medicine-ball throw were small and not different between groups (p > 0.05). Conclusions: Synbiotic supplementation concurrent with USRPT preferentially enhances dynamic (explosive) upper-body strength in elite sprint swimmers, whereas non-stroke-embedded field tests show limited added value. Any reference to gut–muscle-axis modulation is hypothesis-generating, as stool sequencing and metabolite profiling were not performed. Larger, sex-inclusive trials incorporating in-water, stroke-embedded assessments and microbiome/metabolomic profiling are warranted. Full article

Background: Symptomatic uncomplicated diverticular disease (SUDD) is a common condition in older adults, primarily managed through symptom control. Emerging evidence highlights the role of gut microbiota in symptom modulation and disease progression. Butyrate supplementation offers anti-inflammatory benefits and supports gut barrier integrity; when combined with specific probiotic strains, it may further promote microbiota balance. Objectives: To evaluate the clinical and microbiological effects of an oral formulation combining microencapsulated sodium butyrate with probiotic strains from four probiotic strains (Lacticaseibacillus rhamnosus, Lactiplantibacillus plantarum, Limosilactobacillus reuteri, and Bifidobacterium longum subsp. infantis) in patients with SUDD. Methods: This prospective, preliminary observation enrolled 23 patients. To control for high interindividual variability in microbiota composition, each participant served as their own control. The intervention lasted 12 weeks and included five scheduled visits, incorporating a 3-week washout period. Symptom severity and quality of life were assessed using validated questionnaires. Faecal microbiota composition was evaluated using 16S rRNA sequencing and strain-specific colonisation was monitored with qPCR. Results: Significant improvements were observed in seven out of nine reported symptoms, including reductions in abdominal pain, bloating, and discomfort. Overall symptom burden decreased, especially symptoms related to gas and stool consistency. Quality of life scores improved notably. qPCR confirmed colonisation by the administered probiotic strains. Microbiome analysis demonstrated individualized but meaningful improvements in microbial profiles. Conclusions: The combined use of microencapsulated sodium butyrate and selected probiotic strains led to measurable clinical improvements and the positive modulation of gut microbiota in patients with SUDD. This formulation was well tolerated and may represent a promising adjunct or standalone approach in the dietary management of SUDD. Full article

This randomized, double-blind, controlled trial evaluated the effects of 4-week dietary fiber supplementation on gut microbiota, bowel-related quality of life, and secondary outcomes, including sleep and skin condition. A total of 105 healthy adults received either low-fiber foods (2.2 g/day total fiber, 1.2 g/day fermentable fiber) or high-fiber foods (8.2 g/day total fiber, including 6.4 g/day fermentable fiber). Gut microbiota was analyzed by 16S rRNA sequencing. Outcomes included stool diary, JPAC-QOL (Japanese version of the Patient Assessment of Constipation Quality of Life), OSA-MA (Oguri-Shirakawa-Azumi sleep inventory MA version), skin questionnaires, and fecal organic acids. The high-fiber group showed significant improvements in JPAC-QOL and increases in SCFA-associated genera such as Anaerostipes, Bifidobacterium, and Fusicatenibacter. These taxa positively correlated with other beneficial bacteria, including Faecalibacterium, suggesting ecological cooperation. The effects on sleep and skin were limited but correlated with beneficial bacteria, implying possible gut–brain and gut–skin axes involvement. This study demonstrated that short-term fiber supplementation meaningfully improved the bowel-related quality of life and beneficially modulated the gut microbiota in healthy adults. Although the systemic effects were modest, microbial shifts suggest that higher fiber intake may provide broader health benefits with longer interventions. This study was registered in the UMIN Clinical Trial Registry (UMIN000054712). Full article

The gut microbiota plays an essential role in human health, influencing gut–brain communication. Imbalances in this microbial ecosystem, termed dysbiosis, have been associated with increased gut permeability and gastrointestinal symptoms commonly reported in autism spectrum disorder (ASD), without implying a direct causal role in ASD itself. This study aimed to determine whether alterations in gut microbiota exist in individuals with Fragile X Syndrome (FXS), with or without ASD, compared to ASD patients and neurotypical controls, and to identify microbiota biomarkers associated with these disorders. Stool samples from Caucasian individuals aged 3–18 years belonging to four groups (ASD, FXS, FXS + ASD, and controls) were analysed by amplifying the V3–V4 region of the bacterial 16S rRNA gene to characterize microbiota composition. Significant differences were found among patient groups compared to neurotypical controls, with notable similarities between the ASD and FXS + ASD groups. Additionally, specific microbiota biomarkers were identified for each patient group. These findings suggest that distinct microbiota alterations are associated with FXS and ASD, which may contribute to a more accurate characterization of symptoms in these disorders and could serve as potential biomarkers for assessing neurodevelopmental risk. Full article

Background/Objectives: The complementary feeding period is a critical window for shaping infant diet, gut microbiota, and immune development. While allergic symptoms often emerge in the first year of life, the effects of specific foods, such fruits, on infant allergy symptoms, inflammation, immunity and associated microbiota remain unclear. This study aimed to assess the impact of daily blueberry consumption during the complementary feeding period on allergy-related symptoms, immune biomarkers, and gut microbiota in breastfed U.S. infants. Methods: In a double-blind, randomized, placebo-controlled trial, infants from the Denver metro area were assigned to receive up to 10 g/day of freeze-dried blueberry powder or an isocaloric placebo from 5 to 12 months of age. Stool, blood, and caregiver-reported allergy-related symptom data were collected at baseline and study end. Results: Of the 76 infants enrolled, 61 completed the study (Blueberry: n = 30; Placebo: n = 31). While more infants in the blueberry group had allergy-related symptoms at baseline, they had significantly different longitudinal symptom trajectories than the placebo (p = 0.05), showing a greater resolution rate of symptoms by study end. Pro-inflammatory serum IL-13 levels were significantly reduced (p = 0.035) and anti-inflammatory IL-10 levels borderline increased (p = 0.052) in the blueberry group. However, changes in allergy symptoms were not significantly associated with IL-10 or IL-13. The relative abundances of Lacticaseibacillus, Blautia, and Peptostreptococcaceae at 12 months were negatively correlated with IL-10, while Lactobacillus, Clostridiaceae, and Megasphaera were positively associated. IL-13 was positively associated with Citrobacter and negatively associated with Anaerostipes and Blautia. Conclusions: The consumptio9n of blueberries as an early complementary food may improve resolution of allergy symptoms, modulate immune biomarkers, and promote beneficial shifts in gut microbiota during infancy. Future research should aim to identify the specific bioactive components of blueberries responsible for these effects and explore the potential of other complementary foods to favorably influence developing biological systems involved in microbiota and immune development. Full article

Background: Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by social communication deficits, repetitive behaviors, and frequent gastrointestinal comorbidities. Emerging research suggests gut microbiota alterations contribute to ASD symptoms and gastrointestinal dysfunction, but detailed microbial profiles and clinical correlations remain underexplored. Methods: This study analyzed gut microbiota in 45 children aged 2–18 years diagnosed with ASD. Stool samples underwent 16S rRNA gene sequencing. Clinical assessments included ASD diagnostic subtype, adaptive functioning using the Vineland Adaptive Behavior Scale, gastrointestinal symptoms as per the Rome IV criteria, dietary patterns, and demographic variables. Statistical analyses correlated microbiota profiles with clinical features. Results: Gut microbiota composition was significantly influenced by delivery mode, age, sex, and diet. Vaginally delivered children had higher beneficial SCFA-producing bacteria, whereas Cesarean section was linked to increased pathogenic Clostridiales. High-calorie and protein-rich diets correlated with shifts toward pro-inflammatory taxa. Microbial diversity and specific genera correlated with adaptive behavior domains (communication, socialization, motor skills) and severity of gastrointestinal symptoms. Both pro-inflammatory and anti-inflammatory bacteria variably impacted neurodevelopmental outcomes. Conclusions: Gut microbiota composition in children with ASD is shaped by multifactorial influences and connected to neurobehavioral and gastrointestinal phenotypes. The findings of this study support the potential of microbiota-targeted interventions to ameliorate ASD-associated symptoms and improve quality of life. Full article

It is mostly known which microorganisms make up the intestinal microbiota and what their role is in the digestive tract. Moreover, there is evidence about the influence of these microorganisms, especially bacteria, on the functioning of the human body in general. Intestinal microbiota is metabolically active and synthesizes numerous molecules that are an important part of biochemical processes in the human body, as well as signaling pathways. Some of these molecules are of lipid origin, which is why new knowledge in the field of lipidomics can help in their more precise identification. It is now clear that the lipid profile of the stool depends on the composition and metabolic activity of the microbiota. Therefore, under changed conditions, such as the existence of an infection, there are changes in the lipid profile of the stool. One of the epidemiologically most important and most studied infections of the digestive tract is Clostridioides difficile infection. This infection is recurrent in a large number of cases; it is related to resistance to antibiotics and their irrational use, and because of that, further research in this area would bring insight into possibly new knowledge that would help in more effective suppression of this infection. Full article