Candida albicans in celiac disease: A wolf in sheep's clothing

Coincidence of antibodies against Hwp1 and ASCA, two distinct molecular targets of Candida albicans, reinforces the link between this fungal species and coeliac disease

Candida albicans is an immunogen for anti-Saccharomyces cerevisiae antibodies (ASCA), a serological marker of Crohn's disease. ASCA has also been reported in other autoimmune diseases, including coeliac disease (CeD). A strong antibody response against Hwp1, a protein associated with invasive hyphal form of C. albicans which presents peptide sequence homologies with gliadin, has also been described in CeD. This observation supports the hypothesis that C. albicans hyphal transition in C. albicans may trigger CeD onset through a mechanism of molecular/antigenic mimicry. In this study, we assessed whether the anti-C. albicans oligomannose and anti-Hwp1 protein responses may be linked despite their different pathophysiological significance. The measurement of ASCA levels in a cohort of patients involved in our previous Hwp1 study showed a significant correlation between the two biomarkers. This new observation further reinforces the link between C. albicans and CeD.

From ASCA breakthrough in Crohn's disease and Candida albicans research to thirty years of investigations about their meaning in human health

Anti-Saccharomyces cerevisiae antibodies (ASCA) are human antibodies that can be detected using an enzyme-linked immunosorbent assay involving a mannose polymer (mannan) extracted from the cell wall of the yeast S. cerevisiae. The ASCA test was developed in 1993 with the aim of differentiating the serological response in two forms of inflammatory bowel disease (IBD), Crohn's disease and ulcerative colitis. The test, which is based on the detection of anti-oligomannosidic antibodies, has been extensively performed worldwide and there have been hundreds of publications on ASCA. The earlier studies concerned the initial diagnostic indications of ASCA and investigations then extended to many human diseases, generally in association with studies on intestinal microorganisms and the interaction of the micro-mycobiome with the immune system. The more information accumulates, the more the mystery of the meaning of ASCA deepens. Many fundamental questions remain unanswered. These questions concern the heterogeneity of ASCA, the mechanisms of their generation and persistence, the existence of self-antigens, and the relationship between ASCA and inflammation and autoimmunity. This review aims to discuss the gray areas concerning the origin of ASCA from an analysis of the literature. Structured around glycobiology and the mannosylated antigens of S. cerevisiae and Candida albicans, this review will address these questions and will try to clarify some lines of thought. The importance of the questions relating to the pathophysiological significance of ASCA goes far beyond IBD, even though these diseases remain the preferred models for their understanding.

Correlation of Celiac Diseases with Candida Spp. Based on Anti-gliadin Antibodies

A variety of Candida spp. can be found as a natural commensal fungus in various parts of the human body. This fungus may be associated with various diseases such as celiac disease (CD). Gliadin, a component of the gluten protein complex that is mostly found in wheat, is the main inducer of CD. A number of studies have demonstrated that patients infected with Candida can develop CD, and vice versa. C. albicansis presumed to induce CD because it has a protein homologous to gliadin in its cell wall called Hwp1. Despite the non-specificity of the anti-gliadin test, the detection of antibodies against anti-gliadin (AGA) and anti-tissue transglutaminase (anti-tTG) are important in the diagnosis of CD. Some evidence is now available to support the hypothetical correlation between Candida spp. and CD, as high levels of AGA have been found in patients infected with candidiasis without CD. Further study is needed to confirm this relationship.

The Gut Microbiome and Its Implication in the Mucosal Digestive Disorders

The gastrointestinal (GI) tract is one of the most studied compartments of the human body as it hosts the largest microbial community including trillions of germs. The relationship between the human and its associated flora is complex, as the microbiome plays an important role in nutrition, metabolism and immune function. With a dynamic composition, influenced by many intrinsic and extrinsic factors, there is an equilibrium maintained in the composition of GI microbiota, translated as "eubiosis". Any disruption of the microbiota leads to the development of different local and systemic diseases. This article reviews the human GI microbiome's composition and function in healthy individuals as well as its involvement in the pathogenesis of different digestive disorders. It also highlights the possibility to consider flora manipulation a therapeutic option when treating GI diseases.

What Is Candida Doing in My Food? A Review and Safety Alert on Its Use as Starter Cultures in Fermented Foods

The use of yeasts as starter cultures was boosted with the emergence of large-scale fermentations in the 20th century. Since then, Saccharomyces cerevisiae has been the most common and widely used microorganism in the food industry. However, Candida species have also been used as an adjuvant in cheese production or as starters for coffee, cocoa, vegetable, meat, beer, and wine fermentations. A thorough screening of candidate Candida is sometimes performed to obtain the best performing strains to enhance specific features. Some commonly selected species include C. pulcherrima (teleomorph Metschnikowia pulcherrima) (wine), C. parapsilosis (teleomorph Monilia parapsilosis) (coffee), C. famata (teleomorph Debaryomyces hansenii) (cheese), and C. zeylanoides (teleomorph Kurtzmaniella zeylanoides) and C. norvegensis (teleomorph Pichia norvegensis) (cocoa). These species are associated with the production of key metabolites (food aroma formation) and different enzymes. However, safety-associated selection criteria are often neglected. It is widely known that some Candida species are opportunistic human pathogens, with important clinical relevance. Here, the physiology and metabolism of Candida species are addressed, initially emphasizing their clinical aspects and potential pathogenicity. Then, Candida species used in food fermentations and their functional roles are reported. We recommended that Candida not be used as food cultures if safety assessments are not performed. Some safety features are highlighted to help researchers choose methods and selection criteria.

Use of soil actinomycetes for pharmaceutical, food, agricultural, and environmental purposes

In this article, we reviewed the international scientific production of the last years on actinomycetes isolated from soil aiming to report recent advances in using these microorganisms for different applications. The most promising genera, isolation conditions and procedures, pH, temperature, and NaCl tolerance of these bacteria were reported. Based on the content analysis of the articles, most studies have focused on the isolation and taxonomic description of new species of actinomycetes. Regarding the applications, the antimicrobial potential (antibacterial and antifungal) prevailed among the articles, followed by the production of enzymes (cellulases and chitinases, etc.), agricultural uses (plant growth promotion and phytopathogen control), bioremediation (organic and inorganic contaminants), among others. Furthermore, a wide range of growth capacity was verified, including temperatures from 4 to 60 °C (optimum: 28 °C), pH from 3 to 13 (optimum: 7), and NaCl tolerance up to 32% (optimum: 0-1%), which evidence a great tolerance for actinomycetes cultivation. Streptomyces was the genus with the highest incidence among the soil actinomycetes and the most exploited for different uses. Besides, the interest in isolating actinomycetes from soils in extreme environments (Antarctica and deserts, for example) is growing to explore the adaptive capacities of new strains and the secondary metabolites produced by these microorganisms for different industrial interests, especially for pharmaceutical, food, agricultural, and environmental purposes.

Checkpoint Inhibitors and Induction of Celiac Disease-like Condition

Immune checkpoint inhibitors herald a new era in oncological therapy-resistant cancer, thus bringing hope for better outcomes and quality of life for patients. However, as with other medications, they are not without serious side effects over time. Despite this, their advantages outweigh their disadvantages. Understanding the adverse effects will help therapists locate, apprehend, treat, and perhaps diminish them. The major ones are termed immune-related adverse events (irAEs), representing their auto-immunogenic capacity. This narrative review concentrates on the immune checkpoint inhibitors induced celiac disease (CD), highlighting the importance of the costimulatory inhibitors in CD evolvement and suggesting several mechanisms for CD induction. Unraveling those cross-talks and pathways might reveal some new therapeutic strategies.

Inhibition of Candida albicans in vivo and in vitro by antimicrobial peptides chromogranin A-N12 through microRNA-155/suppressor of cytokine signaling 1 axis

Antimicrobial peptides (AMPs) have proven to inhibit a variety of pathogens. Chromogranin A-N12 (CGA-N12) is a kind of AMP, and it is characterized by stable structure, high anti-Candida activity, and good safety. However, it remains unclear whether CGA-N12 could effectively inhibit the growth of Candida albicans (C. albicans). Colony forming assays were used to measure minimal inhibitory concentration (MIC), minimal fungicidal concentration (MFC), and time-kill curve. Disseminated C. albicans rabbit model was established to investigate the influence of CGA-N12 on histological damage. The protein and mRNA levels of suppressor of cytokine signaling 1 (SOCS1) after treatment were investigated. The MIC and MFC of CGA-N12 against C. albicans was 6 mg/mL. CGA-N12 considerably inhibited germ tube formation of C. albicans. The fungal load in the tissues and inflammatory factors in the serum were suppressed by CGA-N12. CGA-N12 significantly reduced the histological changes caused by C. albicans, and the protein and mRNA levels of SOCS1 were markedly inhibited. The inhibition effect of CGA-N12 on C. albicans and significant improvement of histological damage by CGA-N12 through microRNA-155/SOCS1 axis were proved in this study. This study proposes a novel therapeutic strategy for the treatment and prevention of C. albicans.

Abbreviations: AMPs: Antimicrobial peptides; MIC: Minimal inhibitory concentration; MFC: Minimal fungicidal concentration; AIDS: Acquired immune deficiency syndrome; PBS: Phosphate buffer saline; FBS: Fetal bovine serum; ROS: Reactive oxygen species; CFU: Colony formation unit; CGA: Chromogranin A; SOCS1: Suppressor of cytokine signaling 1; SDA: Sabouraud Dextrose Agar; GRAVY: Grand average of hydropathicity; C. parapsilosis: Candida parapsilosis; C. albicans: Candida albicans

Fungal Dysbiosis in Children with Celiac Disease

BACKGROUND

Although intestinal fungi are known to interact with the immune system, the relationship between intestinal fungi and childhood celiac disease (CeD), an immune-mediated condition, has rarely been reported.

AIMS

The aim of this study was to describe gut fungal profiles in a cohort of children with new-onset CeD.

METHODS

Mucosal and fecal samples were collected from children with CeD and controls and subjected to metagenomics analysis of fungal microbiota communities. DNA libraries were sequenced using Illumina HiSeq platform 2 × 150 bp. Bioinformatic analysis was performed to quantify the relative abundance of fungi. Shannon alpha diversity metrics and beta diversity principal coordinate (PCo) analyses were calculated, and DESeq tests were performed between celiac and non-celiac groups.

RESULTS

Overall more abundant taxa in samples of children with CeD included Tricholomataceae, Saccharomycetaceae, Saccharomycetes Saccharomyces cerevisiae, and Candida, whereas less abundant taxa included Pichiaceae, Pichia kudriavzevii, Pneumocystis, and Pneumocystis jirovecii. Alpha diversity between CeD and control individuals did not differ significantly, and beta diversity PCo analysis showed overlap of samples from CeD and controls for both fecal or mucosal samples; however, there was a clear separation between mucosal and fecal overall samples CONCLUSIONS: We report fungal dysbiosis in children with CeD, suggesting a possible role in the pathogenesis of CeD. Further larger, controlled, prospective and longitudinal studies are needed to verify the results of this study and clarify the functional role of fungi in CeD.

Microbial Transglutaminase Is a Very Frequently Used Food Additive and Is a Potential Inducer of Autoimmune/Neurodegenerative Diseases

Microbial transglutaminase (mTG) is a heavily used food additive and its industrial transamidated complexes usage is rising rapidly. It was classified as a processing aid and was granted the GRAS (generally recognized as safe) definition, thus escaping full and thorough toxic and safety evaluations. Despite the manufacturers claims, mTG or its cross-linked compounds are immunogenic, pathogenic, proinflammatory, allergenic and toxic, and pose a risk to public health. The enzyme is a member of the transglutaminase family and imitates the posttranslational modification of gluten, by the tissue transglutaminase, which is the autoantigen of celiac disease. The deamidated and transamidated gliadin peptides lose their tolerance and induce the gluten enteropathy. Microbial transglutaminase and its complexes increase intestinal permeability, suppresses enteric protective pathways, enhances microbial growth and gliadin peptide’s epithelial uptake and can transcytose intra-enterocytically to face the sub-epithelial immune cells. The present review updates on the potentially detrimental side effects of mTG, aiming to interest the scientific community, induce food regulatory authorities’ debates on its safety, and protect the public from the mTG unwanted effects.

Gluten-free diet can ameliorate the symptoms of non-celiac autoimmune diseases

CONTEXT

A gluten-free diet (GFD) is the recommended treatment for gluten-dependent disease. In addition, gluten withdrawal is popular and occasionally is suggested as a treatment for other autoimmune diseases (ADs).

OBJECTIVE

The current systematic review summarizes those entities and discusses the logic behind using a GFD in classical non-gluten-dependentADs.

DATA SOURCES

A search for medical articles in PubMed/MEDLINE, Web of Sciences, LILACS, and Scielo published between 1960 and 2020 was conducted, using the key words for various ADs and GFDs.

DATA EXXTRACTION

Eight-three articles were included in the systematic review (using PRISMA guidelines).

DATA ANALYSIS

Reduction in symptoms of ADs after observance of a GFD was observed in 911 out of 1408 patients (64.7%) and in 66 out of the 83 selected studies (79.5%). The age of the patients ranged from 9 months to 69 years. The duration of the GFD varied from 1 month to 9 years. A GFD can suppress several harmful intraluminal intestinal events. Potential mechanisms and pathways for the action of GFD in the gut - remote organs' axis have been suggested.

CONCLUSION

A GFD might represent a novel nutritional therapeutic strategy for classical non-gluten-dependent autoimmune conditions.

Alpha-enolase involvement in intestinal and extraintestinal manifestations of celiac disease

Celiac disease is a life-long intestinal autoimmune disease, characterized by the gluten intolerance and chronic enteric inflammation. Traditionally presented by intestinal manifestations, however, a shift toward extra intestinal presentation is taking place. One of the affected organs is the nervous systems presented by neuropsychiatric manifestations, hence the mechanism and pathways are not clear. The presence of neuronal and alpha-enolases and their corresponding antibodies were noticed in the mucosa and serum of celiac disease patients, as well as in other various autoimmune diseases with psycho-neurological manifestations. The aims of the present review are to screen the literature on different isoforms of enolase, mainly alpha enolase, and their specific antibodies and to suggest their potential pathophysiological mechanisms relaying the enolases to intestinal or extraintestinal celiac disease manifestations. The shared aspects between the enolases and celiac disease and the cross-talks between alpha-enolase and tissue transglutaminase suggest new potential pathophysiological mechanisms that might drive celiac disease evolvement.

Intestinal mycobiota in health and diseases: from a disrupted equilibrium to clinical opportunities

Bacteria, viruses, protozoa, and fungi establish a complex ecosystem in the gut. Like other microbiota, gut mycobiota plays an indispensable role in modulating intestinal physiology. Notably, the most striking characteristics of intestinal fungi are their extraintestinal functions. Here, we provide a comprehensive review of the importance of gut fungi in the regulation of intestinal, pulmonary, hepatic, renal, pancreatic, and brain functions, and we present possible opportunities for the application of gut mycobiota to alleviate/treat human diseases. Video Abstract.