Ulcerative colitis (UC) is a chronic inflammatory disease of the gastrointestinal tract. Candida albicans, a common commensal fungus in the human gut, has been increasingly implicated in UC pathogenesis. Qi-Huang decoction (QHD), a traditional Chinese herbal formula known for its spleen-invigorating and purgative properties, is commonly used to restore gastrointestinal function.

This study investigates the therapeutic potential of QHD in treating colitis exacerbated by C. albicans and explores the underlying mechanisms of action.

A mouse model of colitis was induced using dextran sulfate sodium combined with gavage of C. albicans. Following QHD treatment, colitis severity was evaluated by measuring survival rate, body weight, disease activity index, colon length, and fungal burden, and through histopathological analysis using hematoxylin-eosin staining. The expression of proinflammatory genes IL-1β and TNF-α was quantified, alongside protein levels of key molecules involved in Dectin-1 signaling, including Syk, CARD-9, NLRP-3, Raf-1, and NF-κB. Barrier integrity markers, such as Occludin and Claudin-1, were also examined. To further elucidate QHD's mechanisms, Dectin-1 was inhibited using laminarin. In vitro experiments assessed QHD's antifungal activity against three Candida strains through microdilution, spot assays, and time-kill tests. RAW 264.7 macrophages were employed to study the exposure of fungal cell wall β-glucan and subsequent phagocytosis. Molecular docking simulations predicted interactions between QHD's active compounds and the Dectin-1 receptor.

QHD significantly mitigated colitis severity and reduced fungal burden in vivo. QHD enhanced β-glucan exposure on the fungal cell wall, thereby stimulating phagocytosis by RAW264.7 macrophages. QHD effectively activated Dectin-1-mediated signaling pathways and increased proinflammatory levels in RAW 264.7 cells. In colitis mice, QHD treatment markedly reduced inflammation and Dectin-1 signaling following fungal clearance. However, Dectin-1 inhibition with LAM neutralized QHD's therapeutic effects, highlighting the pathway's importance in mediating QHD's efficacy. Interestingly, QHD alone elevated Dectin-1, NF-κB, TGF-β, and IL-10 levels, whereas reduced IL-1β and TNF-α expression, suggesting a dual modulatory role in inflammation. Molecular docking confirmed a potential direct interaction between QHD's bioactive components and the Dectin-1 receptor.

QHD demonstrates promising therapeutic potential for managing Candida colitis by modulating immune responses and targeting Dectin-1 signaling pathways in clinical settings.

Ulcerative colitis is a chronic disease that has not well-established etiology. The role of microbial dysregulation in its pathogenesis has been recently highlighted. Overall, microbiome alterations concern the reduction of bacterial abundance and diversity, resulting in gut microbiome imbalance negatively affecting immunological aspects. There is a link between ulcerative colitis and the oral microbiome. The changes of oral microbiome are found at many levels, from gently dysbiotic composition to the presence of the main periodontal microbes. The analysis of oral microbiome can be a part of personalized medicine due to the fact that it is a potential biomarker. Patients with ulcerative colitis may manifest dental symptoms/problems, such as periodontitis (strongly related to the red-complex pathogens-Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and bacteria belonging to the other complexes, such as Fusobacterium nucleatum and Aggregatibacter actinomycetecomitans), dental caries, oral ulcerations, leukoplakia, halitosis, and others. Notably, the DMFT (Decayed, Missing, Filled Teeth) index is higher in these patients compared to healthy subjects. According to some data, oral lichen planus (which is a disease with an immunological background) can also be observed in ulcerative colitis patients. It seems that deep understanding of ulcerative colitis in association with oral microbiome, immunology, and dental manifestations may be crucial to provide complex treatment from a dental point of view.

While there is increasing interest in microbiome-directed therapies for patients with ulcerative colitis (UC), the identification of microbial targets remains elusive, underlining the need for novel approaches.

Utilizing metagenomic data from the Study of a Prospective Adult Research Cohort with Inflammatory Bowel Disease (SPARC IBD), available via the IBD Plexus Program of the Crohn's & Colitis Foundation, we used a tree-based dichotomous approach to assemble distinct clusters of species-level bacterial co-abundance groups (CAGs). We evaluated the abundance of bacterial CAGs and fungal taxa during remission (n = 166) and activity (n = 46). We examined if the bacterial CAGs identified in our cohorts were conserved in 2 healthy cohorts and a Korean UC cohort.

CAG3 and CAG8, dominated by bacteria from the family Lachnospiraceae, were associated with remission. Low abundance of CAG8 and elevated abundance of Candida genus were predictive of active UC. Constituents from CAG8 were influential hub species of the remission-associated microbial UC network, including Ruminococcus gnavus, Erysipelatoclostridium ramosum, Blautia, and Dorea species. These hub species interactions were preserved in 2 healthy cohorts and were partially recapitulated in a Korean UC cohort. CAG8 abundance correlated with the secondary bile acid production pathway. Bacterial CAGs did not correlate with Candida; however, Bifidobacterium adolescentis and Alistipes putredinis were negatively associated with Candida.

Lachnospiraceae-dominated bacterial CAGs were associated with remission in UC, with key bacterial interactions within the CAG also observed in 2 healthy cohorts and a Korean UC cohort. Bacterial CAG-based analyses may aid in designing candidate consortia for microbiome-based therapeutics.

Although the role of fungi in gut inflammation in IBD has been suggested, data are still limited in ulcerative colitis (UC). Our aim was to describe the gut fungal profile in a pediatric UC in Saudi Arabia.

Fecal samples from children with UC and control samples provided by healthy school children were collected. The fungal DNA was analyzed using Shotgun metagenomic procedures. Shannon alpha diversity, beta diversity, differential abundance, random forest classification algorithm, and area under the curve were analyzed.

There were 20 children with UC and 20 healthy school children. The median age and range were 13 (0.5-21) and 13 (7-16) years for children with UC and controls, respectively. Male subjects were 40% and 35% for UC and controls, respectively. At diagnosis, the UC extent was E4 (38%); E3 (25%); E2 (37%) and 35% had a PUCAI ≥65. The reduction of alpha diversity and the significant dissimilarity in children with UC were similar to those of most published studies. However, a significant difference was found at all taxa levels with a remarkable enhancement of Candida genus and Saccharomyces cerevisiae in children with UC. Three species were identified as fungal signatures and an area under the curve of 98.4% (95.1-100% CI), indicating an association with UC that has not been reported thus far.

We report significant fungal dysbiosis in children with UC consistent with published literature. However, the report of potential fungal signature and a strong association with UC deserves further studies with a bigger sample size from other populations.

The gut microbiome plays a key role in the pathogenesis and disease activity of inflammatory bowel disease (IBD). While research has focused on the bacterial microbiome, recent studies have shifted towards host genetics and host-fungal interactions. The mycobiota is a vital component of the gastrointestinal microbial community and plays a significant role in immune regulation. Among fungi, Candida species, particularly Candida albicans (C. albicans), have been extensively studied due to their dual role as gut commensals and invasive pathogens. Recent findings indicate that various strains of C. albicans exhibit considerable differences in virulence factors, impacting IBD's pathophysiology. Intestinal fungal dysbiosis and antifungal mucosal immunity may be associated to IBD, especially Crohn's disease (CD). This article discusses intestinal fungal dysbiosis and antifungal immunity in healthy individuals and CD patients. It discusses factors influencing the mycobiome's role in IBD pathogenesis and highlights significant contributions from the scientific community aimed at enhancing understanding of the mycobiome and encouraging further research and targeted intervention studies on specific fungal populations. Our article also provided insights into a recent study by Wu et al in the World Journal of Gastroenterology regarding the role of the gut microbiota in the pathogenesis of CD.

Crohn's disease (CD) and intestinal tuberculosis (ITB) are gastrointestinal (GI) inflammatory disorders with overlapping clinical presentations but diverging etiologies. The study aims to decipher CD and ITB-associated gut dysbiosis signatures and identify disease-associated co-occurring modules to evaluate whether this dysbiosis signature is a disease-specific trait or is a shared feature across diseases of diverging etiologies.

Disease-associated gut microbial modules were identified using statistical machine learning and co-abundance network analysis in controls, CD and ITB patients recruited as part of this study. Module reproducibility was reinvestigated through meta-network analysis encompassing >5400 bacteriomes and ~900 mycobiomes. Subsequently, >1600 Indian gut microbiomes were analyzed to identify a central-core gut microbiome of 46 taxa, whose abundances aided in the formulation of an India-specific Core Gut Microbiome Score (CGMS) to measure the degree of core retention.

Both diseases witness similar patterns of alterations in [alpha]-diversity, characterized by a significant reduction in gut bacterial (i.e., bacterial/archaeal) diversity and a concomitant increase in the fungal [alpha]-diversity. Specific bacterial taxa, along with the diverging mycobiome enabled distinction between the diseases. Co-abundance network analysis of these taxa, validated by integrated meta-network analysis, revealed a 'disease-depleted' module, consistent across multiple cohorts, with >75% of this module constituting the central-core Indian gut microbiome. CGMS robustly assessed the core-microbiome loss across different stages of gut inflammatory disorders, in Indian and international cohorts.

While the disease-specific gain of detrimental bacteria forms an important component of gut dysbiosis, loss of the core microbiome is a shared phenomenon contributing to various GI disorders.

Hesperetin (HT) is a type of citrus flavonoid with various pharmacological activities, including anti-tumor, anti-inflammation, antioxidant, and neuroprotective properties. However, the role and mechanism of HT in ulcerative colitis (UC) have been rarely studied. Our study aimed to uncover the beneficial effects of HT and its detailed mechanism in UC. Experimental colitis was induced by 2.5% dextran sodium sulfate (DSS) for seven days. HT ameliorated DSS-induced colitis in mice, showing marked improvement in weight loss, colon length, colonic pathological severity, and the levels of TNFα and IL6 in serum. A combination of informatics, network pharmacology, and molecular docking identified eight key targets and multi-pathways influenced by HT in UC. As a highlight, the experimental validation demonstrated that PTGS2, a marker of ferroptosis, along with other indicators of ferroptosis (such as ACSL4, Gpx4, and lipid peroxidation), were regulated by HT in vivo and in vitro. Additionally, the supplement of HT increased the diversity of gut microbiota, decreased the relative abundance of Proteobacteria and Gammaproteobacteria, and restored beneficial bacteria (Lachnospiraceae_NK4A136_group and Prevotellaceae_UCG-001). In conclusion, HT is an effective nutritional supplement against experimental colitis by suppressing ferroptosis and modulating gut microbiota.

Intestinal fungi have been implicated in the pathogenesis of ulcerative colitis (UC). However, it remains unclear if fungal composition is altered during active versus quiescent disease.

We analyzed clinical and metagenomic data from the Study of a Prospective Adult Research Cohort with Inflammatory Bowel Disease (SPARC IBD), available via the IBD Plexus Program of the Crohn's & Colitis Foundation. We evaluated the fungal composition of fecal samples from 421 patients with UC during clinical activity and remission. Within a longitudinal subcohort (n = 52), we assessed for dynamic taxonomic changes across alterations in clinical activity over time. We examined if fungal amplicon sequence variants and fungal-bacterial relationships were altered during activity versus remission. Finally, we classified activity in UC using a supervised machine learning random forest model trained on fungal abundance data.

During clinical activity, the relative abundance of genus Candida was increased 3.5-fold (P-adj < 1 × 10-4) compared with during remission. Patients with longitudinal reductions in clinical activity demonstrated parallel reductions in Candida relative abundance (P < .05). Candida relative abundance correlated with Parabacteroides diastonis, Faecalibacterium prausnitzii, and Bacteroides dorei relative abundance (P < .05) during remission; however, these correlations were disrupted during activity. Fungal abundance data successfully classified patients with active or quiescent UC (area under the curve ∼0.80), with Candida relative abundance critical to the success of the model.

Clinical activity in UC is associated with an increased relative abundance of Candida, cross-sectionally and dynamically over time. The role of fecal Candida as a target for therapeutics in UC should be evaluated.

Reduced butyrate-production capacity has been reported in fecal microbial communities in patients with active ulcerative colitis. However, the butyrate-production capacity of the mucosal microbiome from active vs quiescent mucosa in ulcerative colitis has been unexplored. We sought to determine the diversity and relative abundance of mucosal bacterial and fungal communities from endoscopically active vs quiescent mucosa in patients with UC, and aimed to predict contributions of mucosal microbial communities to butyrate synthesis. Systematic, segmental right- and left-sided biopsies were obtained from endoscopically active (n = 13) or quiescent (n = 17) colonic mucosa, among 15 patients with pan-colonic ulcerative colitis. Dietary fiber intake of patients was performed using the validated five-item FiberScreen questionnaire. Amplicon sequencing of mucosal bacteria and fungi was performed. The diversity and relative abundance of mucosal bacterial and fungal taxa were quantified, and predicted contributions to butyrate synthesis were ascertained. Bacterial alpha and beta diversity were similar between active vs quiescent mucosa. Butyrogenic taxa were significantly increased in quiescence, including Butyricimonas, Subdoligranulum, and Alistipes. Predicted butyrate kinase activity was significantly and concomitantly increased in quiescent mucosa. Fiber intake was positively correlated with butyrogenic microbes. Compared to mucosal bacterial prevalence, mucosal fungi were detected in low prevalence. Butyrogenic microbes are relatively increased in quiescent mucosa in ulcerative colitis, and may be related to increased fiber intake during quiescence. Manipulation of the mucosal microbiome towards butyrate-producing bacteria may be associated with endoscopic quiescence.

Inflammatory bowel disease (IBD) is an immune mediated chronic inflammatory disorder of gastrointestinal tract, which has underlying multifactorial pathogenic determinants such as environmental factors, susceptibility genes, gut microbial dysbiosis and a dysregulated immune response. Human gut is a frequent inhabitant of complex microbial ecosystem encompassing bacteria, viruses, parasites, fungi and other microorganisms that have an undisputable role in maintaining balanced homeostasis. All of these microbes interact with immune system and affect human gut physiology either directly or indirectly with interaction of each other. Intestinal fungi represent a smaller but crucial component of the human gut microbiome. Besides interaction with bacteriome and virome, it helps in balancing homoeostasis between pathophysiological and physiological processes, which is often dysregulated in patients with IBD. Understanding of gut mycobiome and its clinical implications are still in in its infancy as opposed to bacterial component of gut microbiome, which is more often focused. Modulation of gut mycobiome represents a novel and promising strategy in the management of patients with IBD. Emerging mycobiome-based therapies such as diet interventions, fecal microbiota transplantation (FMT), probiotics (both fungal and bacterial strains) and antifungals exhibit substantial effects in calibrating the gut mycobiome and restoring dysbalanced immune homeostasis by restoring the core gut mycobiome. In this review, we summarized compositional and functional diversity of the gut mycobiome in healthy individuals and patients with IBD, gut mycobiome dysbiosis in patients with IBD, host immune-fungal interactions and therapeutic role of modulation of intestinal fungi in patients with IBD.

The gut microbiome is a diverse microbial community composed of bacteria, viruses, and fungi that plays a major role in human health and disease. Dysregulation of these gut organisms in a genetically susceptible host is fundamental to the pathogenesis of inflammatory bowel disease (IBD). While bacterial dysbiosis has been a predominant focus of research for many years, there is growing recognition that fungal interactions with the host immune system are an important driver of gut inflammation. Candida albicans is likely the most studied fungus in the context of IBD, being a near universal gut commensal in humans and also a major barrier-invasive pathogen. There is emerging evidence that intra-strain variation in C. albicans virulence factors exerts a critical influence on IBD pathophysiology. In this review, we describe the immunological impacts of variations in C. lbicans colonisation, morphology, genetics, and proteomics in IBD, as well as the clinical and therapeutic implications.