Search Results (229)

Candida spp. are ubiquitous yeasts that are part of most mammals’ microbiota and can become opportunistic pathogens under predisposing conditions. Interestingly, recent studies in human medicine report an increased abundance of Candida spp. in association with inflammatory bowel disease (IBD). Gastrointestinal candidiasis has been primarily reported in neonatal foals, but not in adult horses. The aim of this study is to describe the morphological, histopathological, and microbiological features of gastric lesions associated with Candida infiltration in five horses referred to two tertiary hospitals for different reasons. Clinical features, findings from gastroscopy, gastric, and duodenal biopsies, as well as fungal and bacterial cultures obtained from gastric lesions will be reported. Macroscopically, gastric lesions showed a characteristic yellow/white pseudo-membranous appearance, similar to lesions reported in foals. The presence of Candida spp. was confirmed by positive culture and/or histopathological evidence of fungal infiltration on the gastric epithelium. Three out of five horses showed histopathological changes in duodenal biopsies, potentially suggesting IBD. These results demonstrate that gastric candidiasis can occur in adult horses. Further research is needed to elucidate the pathogenesis, predisposing factors, and clinical relevance of Candida spp. infections in the equine stomach, as well as their potential impact on gastrointestinal health and overall performance. Full article

Roux-en-Y gastric bypass (RYGB) surgery induces profound gut microbiota alterations that may impact metabolic outcomes. This study investigated site-specific effects of a multicomponent bovine colostrum-honey-serviceberry (CHJ) complex on post-RYGB microbiome changes in obese rats. Twenty-nine Wistar rats underwent RYGB surgery with CHJ supplementation, followed by mucosal-associated microbiota analysis from five gastrointestinal segments using 16S rRNA sequencing and serum metabolite profiling. RYGB caused regional-specific changes: decreased alpha diversity, systematic Proteobacteria increases (31.2 ± 5.1% in duodenum), and reductions in SCFA-producing bacteria (Romboutsia, Roseburia). CHJ supplementation exhibited dual effects on the microbiome: restoration of beneficial bacteria (Lactobacillus, Bifidobacterium) in distal segments while concurrently promoting Enterobacteriaceae growth in proximal regions. CHJ also maintained alpha diversity levels of the mucosa-associated microbiota comparable to those observed in the control group. Disconnects emerged between predicted microbial functions and systemic metabolites: thiamine pathway activation accompanied 78.5% serum vitamin B1 reduction, indicating severe absorption deficits. Three distinct patterns emerged: pro-inflammatory (proximal), decolonization (widespread Helicobacteraceae loss), and restorative (selective CHJ-mediated recovery). Results demonstrate that post-RYGB dysbiosis exhibits profound regional heterogeneity requiring segment-specific interventions and highlight complex interactions between nutritional supplementation and surgically altered gut ecology in determining metabolic outcomes. Full article

Background: Constipation is a common gastrointestinal disorder with a significant impact on quality of life. Methods: Constipation was induced in male ICR mice via 25% cotrimoxazole gavage (20 mL/kg/day for 7 days). Mice were divided into prevention (pre-MBSFL), treatment (MBSFL), and control groups. MBSFL was prepared by fermenting mung bean starch with Lactobacillus plantarum (1:3 w/v ratio, 37 °C for 48 h), and administered via daily oral gavage (250 mg/kg bw) for 14 days. Fecal parameters (water content and first black stool latency), gastrointestinal motility (gastric emptying and small intestinal propulsion), serum biomarkers (NO, VIP, SP, and 5-HT), and intestinal gene expression (5HTR₄, SERT, and MAO_A) were analyzed. Results: MBSFL intervention restored fecal water content by 38%, reduced first black stool latency from 6.2 h to 3.1 h, and improved small intestinal propulsion by 64%. Additionally, it downregulated serum NO (25%) and VIP (32%) while upregulating SP (49%) and 5-HT (78%) levels. Intestinal 5HTR4 and SERT expression increased by 78% and 71%, respectively, with MAOA suppression (25%). Microbial analysis revealed a 140% increase in Dubosiella and 49% in Lactobacillus abundance, alongside a 62% reduction in Mucispirillum. MBSFL contained polysaccharides (12.3% w/w) and organic acids, including hydroxy butyric acid (4.2 mg/mL). Conclusions: MBSFL alleviates constipation through dual mechanisms: modulating 5-HT pathway activity and restoring gut microbiota homeostasis. Full article

Background: The oral microbiome differs in obese patients compared to normal-weight subjects. Microbiologic shifts very often appear after surgical interventions such as bariatric surgery (BS) and in immunocompromised patients. However, the oral microbiome composition and load in subjects after bariatric surgery are unclear. Aim: The aim of this review is to summarize the current state of the art related to the oral microbiome shift induced by bariatric surgery and to discuss its implications on oral cavity health. Methods: Electronic databases: PubMed/Medline, Web of Science, and Cochrane Library were searched for articles published up to March 30, 2025, describing prospective studies focused on changes in the oral microbiota of patients who underwent bariatric surgery. Results: Eight studies measuring the oral microbiome with different approaches—16S ribosomal RNA (16S rRNA) sequencing, polymerase chain reaction (PCR), culture, and matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI TOF MS)—were included in this review. The following bariatric techniques were used: sleeve gastrectomy, Roux-en-Y gastric bypass, Omega loop gastric bypass, and laparoscopic gastric plication. The follow-up period ranged from 3 to 12 months. The results of microbiologic studies were unequivocal. There was an increment in Streptococcus mutans reported, high levels of Candida species, and increased rates of some periodontitis-associated bacteria (Porphyromonas gingivalis) in the post-bariatric surgery period, though some studies suggested a shift towards non-pathogenic composition of the oral microbiome in prospective observations. Conclusions: The local oral microbial homeostasis becomes strongly impacted by the bariatric surgical treatment itself as well as its consequences in the further post-operative period. Therefore, obese patients undergoing BS require very careful dental observation. Full article

Global warming represents one of the most pressing environmental challenges to cold-water fish farming. Heat stress markedly alters the mucosal symbiotic microbiota and intestinal microbial metabolites in fish, posing substantial barriers to the healthy artificial breeding of rainbow trout (Oncorhynchus mykiss). However, the relationship between mucosal commensal microbiota, intestinal metabolites, and host environmental adaptability under heat stress remains poorly understood. In this study, rainbow trout reared at optimal temperature (16 °C) served as controls, while those exposed to maximum tolerated temperature (24 °C, 21 d) comprised the heat stress group. Using 16S rRNA amplicon sequencing and ultra-high-performance liquid chromatography–mass spectrometry (UHPLC-MS), we analysed the mucosal commensal microbiota—including gastrointestinal digesta, gastrointestinal mucosa, skin mucus, and gill mucosa—and intestinal metabolites of rainbow trout under heat stress conditions to explore adaptive and regulatory mechanisms. Analysis of microbial composition and diversity revealed that heat stress exerted the greatest impact on the diversity of gill and skin mucus microbiota, followed by gastrointestinal digesta, with relatively minor effects on the gastrointestinal mucosa. At the phylum level, Proteobacteria, Firmicutes, and Bacteroidetes were predominant in the stomach, intestine, and surface mucosa. At the genus level, Acinetobacter showed the greatest increase in abundance in skin and gill mucosa under heat stress, while Enterobacteriaceae exhibited the most pronounced increase in intestinal digesta, gastric digesta, and gastric mucosa. Differential metabolites in the intestinal digesta under heat stress were predominantly enriched in pathways associated with amino acid metabolism, particularly tryptophan metabolism. This study provides a comprehensive characterisation of microbiota and metabolic profile alterations in rainbow trout under heat stress condition, offering a theoretical foundation for understanding the response mechanisms of fish commensal microbiota to thermal stress. Full article

Background/Objectives: Probiotics are increasingly recognized for their role in managing gastrointestinal disorders through modulation of gut microbiota. Restoring microbial balance remains a therapeutic challenge. Recent strategies combine probiotics, inulin, and sodium butyrate as synergistic agents for gut health. This study aimed to evaluate the effects of milk supplementation with inulin and sodium butyrate on physicochemical properties, sensory characteristics, and the survival of selected probiotic strains during in vitro simulated gastrointestinal digestion. Methods: Fermented milk samples were analyzed for color, pH, titratable acidity, and syneresis. A trained sensory panel evaluated aroma, texture, and acceptability. Samples underwent a standardized in vitro digestion simulating oral, gastric, and intestinal phases. Viable probiotic cells were counted before digestion and at each stage, and survival rates were calculated. Results: Physicochemical and sensory attributes varied depending on probiotic strain and supplementation. Inulin and the inulin–sodium butyrate combination influenced syneresis and acidity. Lacticaseibacillus casei 431 and Lactobacillus johnsonii LJ samples showed the highest viable counts before digestion. Two-way ANOVA confirmed that probiotic strain, supplementation type, and their interactions significantly affected bacterial survival during digestion (p < 0.05). Conclusions: The addition of inulin and sodium butyrate did not impair probiotic viability under simulated gastrointestinal conditions. The effects on product characteristics were strain-dependent (Bifidobacterium animalis subsp. lactis BB-12, L. casei 431, L. paracasei L26, L. acidophilus LA-5, L. johnsonii LJ). These findings support the use of inulin–butyrate fortification in dairy matrices to enhance the functional potential of probiotic foods targeting gut health. Full article

Background/Objectives: Bariatric surgery improves weight and metabolic health in individuals with severe obesity; however, challenges like gut dysbiosis and nutrient deficiencies persist postoperatively. Probiotic supplementation may enhance recovery by modulating gut microbiota. This updated meta-analysis aimed to assess the effects of probiotics/synbiotics on metabolic, anthropometric, and nutritional outcomes after bariatric surgery. Methods: A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted using PubMed, SCOPUS, Web of Science, and CENTRAL through December 2024. Studies comparing probiotics/synbiotics (which contain both probiotics and prebiotics) versus a placebo in adults post-bariatric surgery were included. Meta-analyses were conducted, with subgroup analyses by surgery type, the timing of the intervention, and probiotic formulation (PROSPERO ID: CRD420251019199). Results: Thirteen RCTs involving 809 patients were included in the analysis. Probiotic use significantly reduced BMI (MD = 0.67, 95% CI: 0.33 to 1.00), HbA1c (MD = −0.19%, 95% CI: −0.36 to −0.01), triglycerides (MD = −16.56 mg/dL), and AST levels (MD = −3.68 U/L), while increasing ALP (MD = 8.12 U/L) and vitamin D (MD = 13.68 pg/mL). Ferritin levels were significantly lower (MD = −18.89 µg/L) in the probiotic group. A subgroup analysis showed enhanced benefits in patients undergoing mini-gastric bypass, with perioperative or synbiotic interventions specifically improving triglycerides, total cholesterol, and HbA1c. Conclusions: Probiotics may offer modest but significant improvements in BMI, glycemic control, lipid profile, liver enzymes, and vitamin D levels after bariatric surgery. These findings support the potential role of probiotics/synbiotics as an adjunct therapy, though further large-scale trials are warranted to confirm long-term benefits. Full article

Equine gastric disease (EGD) is a common condition in performance horses (Equus caballus), potentially compromising behaviour, performance, and welfare. EGD is often attributed to high-starch, high-sugar feeds and limited forage. Evidence for diet-induced changes on digestive microbiota is lacking. Nine elite showjumping horses were housed at the same performance yard with standardised diet and management throughout the study. Horses were transitioned from a high-sugar and -starch (31%) feed to a low-starch and -sugar (16.5%) concentrate feed. Gastroscopies, blood, and faecal samples were taken pre- and 12 weeks post-diet change. Squamous and glandular ulceration was blindly graded a posteriori using 0–4 scores and faecal microbiota profiled using 16S rRNA gene amplicon sequencing. Total (t_(1,8) = −6.17, p < 0.001; Pre: 4 [0–5], Post: 1 [0–2]), squamous (t_(1,8) = −5.32, p < 0.001; Pre: 1 [0–3], Post: 0 [0–1]), and glandular (t_(1,8) = −2.53, p = 0.04; Pre: 2.5 [0–4], Post: 0 [0–2]) disease improved following the introduction of a low-starch diet. Diet change did not impact microbiota communities (PERMANOVA: F_(1,16) = 1.37, p = 0.15, r² = 0.08), but Firmicute to Bacteroidota (F/B) ratio reduced (t_(1,8) = −3.13, p = 0.01; Pre: 2.07 ± 0.21 vs. Post: 1.29 ± 0.14). Lower F/B ratios were associated with reduced total EGD scores (ChiSq_(1,17) = 3.83, p = 0.05). Low-starch diets did not influence faecal microbiota diversity but aided gastric disease healing and reduced F/B ratios in elite showjumpers during a competition season without medication. Full article

Lactobacillus plantarum exhibits probiotic effects, including regulating the balance of the intestinal microbiota and enhancing immune function. However, this strain often experiences viability loss upon ingestion due to harsh conditions within the human digestive tract. This study aimed to evaluate the efficacy of metal–phenol networks (MPNs) fabricated via three polyphenols—tannic acid (TA), tea polyphenol (TP), and anthocyanin (ACN)—combined with Fe(III) coatings in protecting Lactobacillus plantarum during simulated digestion and storage. The results demonstrated that MPNs formed a protective film on the bacterial surface. While TA and ACN inhibited the growth of Lactobacillus plantarum YJ7, TP stimulated proliferation. Within the MPNs system, only Fe(III)-TA exhibited growth-inhibitory effects. Notably, ACN displayed the highest proliferation rate during the initial 2 h, followed by TP between 3 and 4 h. All MPN-coated groups maintained high bacterial viability at 25 °C and −20 °C, with TP-coated bacteria showing the highest viable cell count, followed by TA and ACN. In vitro digestion experiments further revealed that the Fe(III)-ACN group exhibited the strongest resistance to artificial gastric juice. In conclusion, tea polyphenol and anthocyanin demonstrate superior potential for probiotic encapsulation, offering both protective stability during digestion and enhanced viability under storage conditions. Full article

Helicobacter pylori (H. pylori) infection is a leading cause of gastritis, peptic ulcers, and gastric cancer, affecting more than half of the global population. Its persistence in the acidic gastric environment and its ability to evade host immunity present major treatment challenges. Although antibiotics remain the standard therapy, rising antimicrobial resistance has reduced treatment efficacy, prompting the search for alternative and adjunct approaches. Emerging therapies include probiotics, antimicrobial peptides (AMPs), and plant-derived compounds, which target H. pylori through membrane disruption, immunomodulation, or direct antimicrobial activity. Novel drug delivery systems and microbiota-sparing interventions are also being investigated. Additionally, vaccine development offers a promising strategy for long-term protection, though challenges related to antigenic variability and host-specific responses remain. Despite these advances, treatment variability and the limited clinical validation of alternatives hinder progress. A multifaceted approach integrating microbiome research, host–pathogen interactions, and new therapeutic agents is essential for future success. Full article

Gastric cancer (GC) remains a major global health burden, with high morbidity and mortality rates, particularly in regions with prevalent Helicobacter pylori (H. pylori) infection. While H. pylori has long been recognized as a primary carcinogenic agent, recent research has underscored the broader contribution of the gastric microbiota to gastric carcinogenesis. Alterations in the microbial community, or dysbiosis, contribute to chronic inflammation, immune modulation, and epithelial transformation through a range of mechanisms, including disruption of mucosal integrity, activation of oncogenic signaling pathways (e.g., PI3K/Akt, NF-κB, STAT3), and epigenetic alterations. Furthermore, microbial metabolites, such as short-chain fatty acids, secondary bile acids, and lactate, play dual roles in either promoting or suppressing tumorigenesis. Oral and gut-derived microbes, translocated to the gastric niche, have been implicated in reshaping the gastric microenvironment and exacerbating disease progression. The composition of the microbiota also influences responses to cancer immunotherapy, suggesting that microbial profiles can serve as both prognostic biomarkers and therapeutic targets. Emerging strategies, such as probiotics, dietary interventions, and fecal microbiota transplantation (FMT), offer new avenues for restoring microbial balance and enhancing therapy response. This review synthesizes current knowledge on the complex interplay between microbiota and gastric cancer development and emphasizes the potential of microbiome modulation in both preventive and therapeutic frameworks. Full article

Helicobacter pylori (H. pylori) is regarded as a significant risk factor for gastritis, peptic ulcer disease, and gastric cancer. However, the increasing resistance of H. pylori strains has resulted in low eradication rates and ineffective treatments. Herein, we report on identification of a new quipazine derivative—compound 9c (N-(3-chlorobenzyl)-2-(piperazin-1-yl)quinolin-4-amine), which displayed antibacterial properties (MIC range 2–4 µg/mL) against H. pylori CagA-positive reference strains associated with an increased risk of gastric cancer, including metronidazole-resistant ATCC 43504, clarithromycin-resistant ATCC 700684 and susceptible J99 strain, as well as clinical, multidrug-resistant isolate (3CML, resistant to clarithromycin, metronidazole and levofloxacin). Compound 9c showed bacteriostatic activity (MBC/MIC ratio > 4), demonstrated antibiofilm-forming properties and prevented auto-aggregation of microbial cells. It also displayed an additive effect in ½ MIC (2 µg/mL) when administered with clarithromycin and/or metronidazole. Compound 9c had no impact on gut microbiota reference strains of S. aureus, E. coli, E. faecalis and L. paracasei as well as no hemolytic activity against sheep erythrocytes. Finally, by reducing the viability of the SNU-1 human gastric cancer cell line (IC₅₀ = 3.28 μg/mL), compound 9c might offer important implications regarding the oncogenic characteristics of cagA+ H. pylori strains. Full article

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the human stomach and is associated with several gastric diseases, including gastritis, peptic ulcer disease, and gastric cancer. The bacterium’s ability to thrive in the harsh gastric environment is due, to some extent, to its stress response mechanisms, with its heat shock proteins (HSPs) playing a putative, yet not fully understood, role in these adaptive processes. HSPs are a family of molecules, highly conserved throughout phylogenesis, that assist in protein folding, prevent aggregation, and ensure cellular homeostasis under stressful conditions. In H. pylori, HSPs contribute to survival in the stomach’s acidic environment and oxidative stress. Furthermore, they aid in the bacterium’s ability to adhere to gastric epithelial cells, modulate the host immune response, and form biofilms, all contributing to chronic infection and pathogenicity. The role of microbial HSPs in antibiotic resistance has also emerged as a critical area of research, as these proteins help stabilize efflux pumps, protect essential proteins targeted by antibiotics, and promote biofilm formation, thereby reducing the efficacy of antimicrobial treatments. Among bacterial HSPs, GroEL and DnaK are probably the major proteins that control most of the H. pylori’s functioning. Indeed, both proteins possess remarkable acid resistance, high substrate affinity, and dual roles in protein homeostasis and host interaction. These features make them critical for H. pylori’s adaptation, persistence, and pathogenicity in the gastric niche. In addition, recent findings have also highlighted the involvement of HSPs in the crosstalk between H. pylori and gastric epithelial cells mediated by the release of bacterial outer membrane vesicles and host-derived exosomes, both of these extracellular vesicles being part of the muco-microbiotic layer of the stomach and influencing cellular signalling and immune modulation. Considering their critical role in the survival and persistence of bacteria, microbial HSPs also represent potential therapeutic targets. Strategies aimed at inhibiting microbial HSP function, combined with conventional antibiotics or developing vaccines targeting microbial HSPs, could provide new avenues for the treatment of H. pylori infections and combat antibiotic resistance. This review explores the multifaceted roles of microbial HSPs in the pathogenesis of H. pylori, highlighting their contributions to bacterial adhesion, immune evasion, stress response, and antibiotic resistance. Full article

Obesity, insulin resistance, type 2 diabetes mellitus (T2DM) and metabolic syndrome have been largely correlated to a reduction in bacterial load and diversity, resulting in a condition known as intestinal dysbiosis. The recent emergence of novel antidiabetic medications has been demonstrated to exert a favourable influence on the composition of the intestinal microbiota. Incretin-based therapy exerts a multifaceted influence on the composition of the gut microbiota, leading to alterations in bacterial flora. Of particular significance is the capacity of numerous metabolites produced by the gut microbiota to modulate the activity and hormonal secretion of enteroendocrine cells. This review examines the effects of dipeptidyl peptidase 4 (DPP-4) inhibitors, glucagon-like peptide 1 (GLP-1) receptor agonists and GLP-1/gastric inhibitory polypeptide (GIP) receptor dual agonists on the composition of the gut microbiota in both mice and human subjects. The nature of this interaction is complex and bidirectional. The present study demonstrates the involvement of the incretinic axis in modulating the microbial composition, with the objective of providing novel preventative strategies and potential personalised therapeutic targets for obesity and T2DM. Full article

The gut microbiota significantly impacts the development and progression of upper gastrointestinal (GI) cancers, including esophageal and gastric cancers. Microbial dysbiosis contributes to carcinogenesis through mechanisms such as inflammation, immune modulation, and direct DNA damage. Techniques for sampling oral, esophageal, and gastric microbiota vary, with standardization being essential for reliable results. Barrett’s esophagus (BE) and esophageal adenocarcinoma (EAC) are associated with an enrichment of Gram-negative bacteria, promoting inflammation and cancer progression. Esophageal squamous cell carcinoma (ESCC) also shows distinct microbial patterns, with reduced diversity and increased harmful bacteria like Porphyromonas gingivalis and Fusobacterium nucleatum. In gastric cancer (GC), Helicobacter pylori (HP) and non-HP gastric microbiota play significant roles, with diverse microbial communities contributing to cancer development through nitrate reduction, immune modulation, and inflammation. Emerging evidence highlights the role of non-HP bacteria in promoting carcinogenesis, with specific taxa like Fusobacterium nucleatum and Lactobacillus influencing tumor growth and immune evasion. Further research is needed to elucidate the complex interactions between gut microbiota and upper GI cancers, paving the way for novel diagnostic and therapeutic approaches. Understanding these microbial dynamics offers potential for microbiota-based interventions, improving the early detection, prognosis, and treatment of upper GI cancers. This comprehensive review summarizes the available evidence on the role of microbiota in upper GI oncology and the need for continued exploration in this field. Full article