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Zhang L, Zhan H, Xu W, Yan S, Ng SC. The role of gut mycobiome in health and diseases. Therap Adv Gastroenterol 2021; 14:17562848211047130. [PMID: 34589139 PMCID: PMC8474302 DOI: 10.1177/17562848211047130] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 08/31/2021] [Indexed: 02/04/2023] Open
Abstract
The gut microbiome comprised of microbes from multiple kingdoms, including bacteria, fungi, and viruses. Emerging evidence suggests that the intestinal fungi (the gut "mycobiome") play an important role in host immunity and inflammation. Advances in next generation sequencing methods to study the fungi in fecal samples and mucosa tissues have expanded our understanding of gut fungi in intestinal homeostasis and systemic immunity in health and their contribution to different human diseases. In this review, the current status of gut mycobiome in health, early life, and different diseases including inflammatory bowel disease, colorectal cancer, and metabolic diseases were summarized.
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Affiliation(s)
| | | | - Wenye Xu
- Center for Gut Microbiota Research, Faculty of
Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong,
China,Li Ka Shing Institute of Health Science, The
Chinese University of Hong Kong, Shatin, Hong Kong, China,State Key Laboratory for Digestive disease,
Institute of Digestive Disease, The Chinese University of Hong Kong, Shatin,
Hong Kong, China,Department of Medicine and Therapeutics,
Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong,
China
| | - Shuai Yan
- Center for Gut Microbiota Research, Faculty of
Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong,
China,Li Ka Shing Institute of Health Science, The
Chinese University of Hong Kong, Shatin, Hong Kong, China,State Key Laboratory for Digestive disease,
Institute of Digestive Disease, The Chinese University of Hong Kong, Shatin,
Hong Kong, China,Department of Anaesthesia and Intensive Care
and Peter Hung Pain Research Institute, The Chinese University of Hong Kong,
Shatin, Hong Kong, China
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Lok B, Adam MAA, Kamal LZM, Chukwudi NA, Sandai R, Sandai D. The assimilation of different carbon sources in Candida albicans: Fitness and pathogenicity. Med Mycol 2021; 59:115-125. [PMID: 32944760 DOI: 10.1093/mmy/myaa080] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 08/07/2020] [Accepted: 08/14/2020] [Indexed: 01/31/2023] Open
Abstract
Candida albicans is a commensal yeast commonly found on the skin and in the body. However, in immunocompromised individuals, the fungi could cause local and systemic infections. The carbon source available plays an important role in the establishment of C. albicans infections. The fungi's ability to assimilate a variety of carbon sources plays a vital role in its colonization, and by extension, its fitness and pathogenicity, as it often inhabits niches that are glucose-limited but rich in alternative carbon sources. A difference in carbon sources affect the growth and mating of C. albicans, which contributes to its pathogenicity as proliferation helps the fungi colonize its environment. The carbon source also affects its metabolism and signaling pathways, which are integral parts of the fungi's fitness and pathogenicity. As a big percentage of the carbon assimilated by C. albicans goes to cell wall biogenesis, the availability of different carbon sources will result in cell walls with variations in rigidity, adhesion, and surface hydrophobicity. In addition to the biofilm formation of the fungi, the carbon source also influences whether the fungi grow in yeast- or mycelial-form. Both forms play different roles in C. albicans's infection process. A better understanding of the role of the carbon sources in C. albicans's pathogenicity would contribute to more effective treatment solutions for fungal infections.
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Affiliation(s)
- Bronwyn Lok
- Infectomics Cluster, Advance Medical and Dental Institute, Universiti Sains Malaysia, Penang, Malaysia
| | - Mowaffaq Adam Ahmad Adam
- Infectomics Cluster, Advance Medical and Dental Institute, Universiti Sains Malaysia, Penang, Malaysia
| | - Laina Zarisa Mohd Kamal
- Infectomics Cluster, Advance Medical and Dental Institute, Universiti Sains Malaysia, Penang, Malaysia
| | - Nwakpa Anthony Chukwudi
- Infectomics Cluster, Advance Medical and Dental Institute, Universiti Sains Malaysia, Penang, Malaysia
| | - Rosline Sandai
- Faculty of Languages and Communication, Universiti Pendidikan Sultan Idris, Perak Darul Ridzuan, Malaysia
| | - Doblin Sandai
- Infectomics Cluster, Advance Medical and Dental Institute, Universiti Sains Malaysia, Penang, Malaysia
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3
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Liboro K, Yu SR, Lim J, So YS, Bahn YS, Eoh H, Park H. Transcriptomic and Metabolomic Analysis Revealed Roles of Yck2 in Carbon Metabolism and Morphogenesis of Candida albicans. Front Cell Infect Microbiol 2021; 11:636834. [PMID: 33796481 PMCID: PMC8008151 DOI: 10.3389/fcimb.2021.636834] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 02/08/2021] [Indexed: 12/05/2022] Open
Abstract
Candida albicans is a part of the normal microbiome of human mucosa and is able to thrive in a wide range of host environments. As an opportunistic pathogen, the virulence of C. albicans is tied to its ability to switch between yeast and hyphal morphologies in response to various environmental cues, one of which includes nutrient availability. Thus, metabolic flexibility plays an important role in the virulence of the pathogen. Our previous study has shown that C. albicans Yeast Casein Kinase 2 (CaYck2) regulates the yeast-to-hyphal switch, but its regulatory mechanisms remain unknown. This study further elucidated the role of Yck2 in governing morphology and carbon metabolism by analyzing the transcriptome and metabolome of the C. albicans YCK2 deletion mutant strain (yck2Δ strain) in comparison to the wild type strain. Our study revealed that loss of CaYck2 perturbs carbon metabolism, leading to a transcriptional response that resembles a transcriptional response to glucose starvation with coinciding intracellular accumulation of glucose and depletion of TCA cycle metabolites. This shift in the metabolome is likely mediated by derepression of glucose-repressed genes in the Mig1/2-mediated glucose sensing pathway and by downregulation of glycolytic genes, possibly through the Rgt1-mediated SRR pathway. In addition, genes involved in beta-oxidation, glyoxylate cycle, oxidative stress response, and arginine biosynthesis were upregulated in the yck2Δ strain, which is highly reminiscent of C. albicans engulfment by macrophages. This coincides with an increase in arginine degradation intermediates in the yck2Δ strain, suggesting arginine catabolism as a potential mechanism of CaYck2-mediated filamentation as seen during C. albicans escape from macrophages. Transcriptome analysis also shows differential expression of hyphal transcriptional regulators Nrg1 and Ume6. This suggests dysregulation of hyphal initiation and elongation in the yck2Δ strain which may lead to the constitutive pseudohyphal phenotype of this strain. Metabolome analysis also detected a high abundance of methyl citrate cycle intermediates in the yck2Δ strain, suggesting the importance of CaYck2 in this pathway. Taken together, we discovered that CaYck2 is an integral piece of carbon metabolism and morphogenesis of C. albicans.
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Affiliation(s)
- Karl Liboro
- Department of Biological Sciences, California State University, Los Angeles, CA, United States
| | - Seong-Ryong Yu
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Juhyeon Lim
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Yee-Seul So
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Yong-Sun Bahn
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Hyungjin Eoh
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Hyunsook Park
- Department of Biological Sciences, California State University, Los Angeles, CA, United States
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4
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Li XV, Leonardi I, Iliev ID. Gut Mycobiota in Immunity and Inflammatory Disease. Immunity 2019; 50:1365-1379. [PMID: 31216461 DOI: 10.1016/j.immuni.2019.05.023] [Citation(s) in RCA: 136] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/01/2019] [Accepted: 05/29/2019] [Indexed: 02/08/2023]
Abstract
The mammalian intestine is colonized by a wealth of microorganisms-including bacteria, viruses, protozoa, and fungi-that are all integrated into a functional trans-kingdom community. Characterization of the composition of the fungal community-the mycobiota-has advanced further than the much-needed mechanistic studies. Recent findings have revealed roles for the gut mycobiota in the regulation of host immunity and in the development and progression of human diseases of inflammatory origin. We review these findings here while placing them in the context of the current understanding of the pathways and cellular networks that induce local and systemic immune responses to fungi in the gastrointestinal tract. We discuss gaps in knowledge and argue for the importance of considering bacteria-fungal interactions as we aim to define the roles of mycobiota in immune homeostasis and immune-associated pathologies.
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Affiliation(s)
- Xin V Li
- Gastroenterology and Hepatology Division, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY 10021, USA; Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, Cornell University, New York, NY 10021, USA
| | - Irina Leonardi
- Gastroenterology and Hepatology Division, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY 10021, USA; Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, Cornell University, New York, NY 10021, USA
| | - Iliyan D Iliev
- Gastroenterology and Hepatology Division, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY 10021, USA; Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, Cornell University, New York, NY 10021, USA; Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, NY 10065, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, Cornell University, New York, NY 10065, USA.
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5
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Salli K, Lehtinen MJ, Tiihonen K, Ouwehand AC. Xylitol's Health Benefits beyond Dental Health: A Comprehensive Review. Nutrients 2019; 11:nu11081813. [PMID: 31390800 PMCID: PMC6723878 DOI: 10.3390/nu11081813] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/28/2019] [Accepted: 07/31/2019] [Indexed: 12/16/2022] Open
Abstract
Xylitol has been widely documented to have dental health benefits, such as reducing the risk for dental caries. Here we report on other health benefits that have been investigated for xylitol. In skin, xylitol has been reported to improve barrier function and suppress the growth of potential skin pathogens. As a non-digestible carbohydrate, xylitol enters the colon where it is fermented by members of the colonic microbiota; species of the genus Anaerostipes have been reported to ferment xylitol and produce butyrate. The most common Lactobacillus and Bifidobacterium species do not appear to be able to grow on xylitol. The non-digestible but fermentable nature of xylitol also contributes to a constipation relieving effect and improved bone mineral density. Xylitol also modulates the immune system, which, together with its antimicrobial activity contribute to a reduced respiratory tract infection, sinusitis, and otitis media risk. As a low caloric sweetener, xylitol may contribute to weight management. It has been suggested that xylitol also increases satiety, but these results are not convincing yet. The benefit of xylitol on metabolic health, in addition to the benefit of the mere replacement of sucrose, remains to be determined in humans. Additional health benefits of xylitol have thus been reported and indicate further opportunities but need to be confirmed in human studies.
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Affiliation(s)
- Krista Salli
- Global Health & Nutrition Sciences, DuPont Nutrition & Biosciences, 02460 Kantvik, Finland
| | - Markus J Lehtinen
- Global Health & Nutrition Sciences, DuPont Nutrition & Biosciences, 02460 Kantvik, Finland
| | - Kirsti Tiihonen
- Global Health & Nutrition Sciences, DuPont Nutrition & Biosciences, 02460 Kantvik, Finland
| | - Arthur C Ouwehand
- Global Health & Nutrition Sciences, DuPont Nutrition & Biosciences, 02460 Kantvik, Finland.
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Van Ende M, Wijnants S, Van Dijck P. Sugar Sensing and Signaling in Candida albicans and Candida glabrata. Front Microbiol 2019; 10:99. [PMID: 30761119 PMCID: PMC6363656 DOI: 10.3389/fmicb.2019.00099] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/16/2019] [Indexed: 12/30/2022] Open
Abstract
Candida species, such as Candida albicans and Candida glabrata, cause infections at different host sites because they adapt their metabolism depending on the available nutrients. They are able to proliferate under both nutrient-rich and nutrient-poor conditions. This adaptation is what makes these fungi successful pathogens. For both species, sugars are very important nutrients and as the sugar level differs depending on the host niche, different sugar sensing systems must be present. Saccharomyces cerevisiae has been used as a model for the identification of these sugar sensing systems. One of the main carbon sources for yeast is glucose, for which three different pathways have been described. First, two transporter-like proteins, ScSnf3 and ScRgt2, sense glucose levels resulting in the induction of different hexose transporter genes. This situation is comparable in C. albicans and C. glabrata, where sensing of glucose by CaHgt4 and CgSnf3, respectively, also results in hexose transporter gene induction. The second glucose sensing mechanism in S. cerevisiae is via the G-protein coupled receptor ScGpr1, which causes the activation of the cAMP/PKA pathway, resulting in rapid adaptation to the presence of glucose. The main components of this glucose sensing system are also conserved in C. albicans and C. glabrata. However, it seems that the ligand(s) for CaGpr1 are not sugars but lactate and methionine. In C. glabrata, this pathway has not yet been investigated. Finally, the glucose repression pathway ensures repression of respiration and repression of the use of alternative carbon sources. This pathway is not well characterized in Candida species. It is important to note that, apart from glucose, other sugars and sugar-analogs, such as N-acetylglucosamine in the case of C. albicans, are also important carbon sources. In these fungal pathogens, sensing sugars is important for a number of virulence attributes, including adhesion, oxidative stress resistance, biofilm formation, morphogenesis, invasion, and antifungal drug tolerance. In this review, the sugar sensing and signaling mechanisms in these Candida species are compared to S. cerevisiae.
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Affiliation(s)
- Mieke Van Ende
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Stefanie Wijnants
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Patrick Van Dijck
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
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Ting SY, Ishola OA, Ahmed MA, Tabana YM, Dahham S, Agha MT, Musa SF, Muhammed R, Than LTL, Sandai D. Metabolic adaptation via regulated enzyme degradation in the pathogenic yeast Candida albicans. J Mycol Med 2016; 27:98-108. [PMID: 28041812 DOI: 10.1016/j.mycmed.2016.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Revised: 11/01/2016] [Accepted: 12/05/2016] [Indexed: 11/29/2022]
Abstract
The virulence of Candida albicans is dependent upon fitness attributes as well as virulence factors. These attributes include robust stress responses and metabolic flexibility. The assimilation of carbon sources is important for growth and essential for the establishment of infections by C. albicans. Previous studies showed that the C. albicans ICL1 genes, which encode the glyoxylate cycle enzymes isocitratelyase are required for growth on non-fermentable carbon sources such as lactate and oleic acid and were repressed by 2% glucose. In contrast to S. cerevsiae, the enzyme CaIcl1 was not destabilised by glucose, resulting with its metabolite remaining at high levels. Further glucose addition has caused CaIcl1 to lose its signal and mechanisms that trigger destabilization in response to glucose. Another purpose of this study was to test the stability of the Icl1 enzyme in response to the dietary sugars, fructose, and galactose. In the present study, the ICL1 mRNAs expression was quantified using Quantitative Real Time PCR, whereby the stability of protein was measured and quantified using Western blot and phosphoimager, and the replacing and cloning of ICL1 ORF by gene recombination and ubiquitin binding was conducted via co-immuno-precipitation. Following an analogous experimental approach, the analysis was repeated using S. cerevisiaeas a control. Both galactose and fructose were found to trigger the degradation of the ICL1 transcript in C. albicans. The Icl1 enzyme was stable following galactose addition but was degraded in response to fructose. C. albicans Icl1 (CaIcl1) was also subjected to fructose-accelerated degradation when expressed in S. cerevisiae, indicating that, although it lacks a ubiquitination site, CaIcl1 is sensitive to fructose-accelerated protein degradation. The addition of an ubiquitination site to CaIcl1 resulted in this enzyme becoming sensitive to galactose-accelerated degradation and increases its rate of degradation in the presence of fructose. It can be concluded that ubiquitin-independent pathways of fructose-accelerated enzyme degradation exist in C. albicans.
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Affiliation(s)
- S Y Ting
- Infectomics Cluster, advanced medical and dental institute, universiti Sains Malaysia, Jln Tun Hamdan Sheikh Tahir, 13200 Bertam Penang, Malaysia
| | - O A Ishola
- Infectomics Cluster, advanced medical and dental institute, universiti Sains Malaysia, Jln Tun Hamdan Sheikh Tahir, 13200 Bertam Penang, Malaysia
| | - M A Ahmed
- Infectomics Cluster, advanced medical and dental institute, universiti Sains Malaysia, Jln Tun Hamdan Sheikh Tahir, 13200 Bertam Penang, Malaysia
| | - Y M Tabana
- Infectomics Cluster, advanced medical and dental institute, universiti Sains Malaysia, Jln Tun Hamdan Sheikh Tahir, 13200 Bertam Penang, Malaysia
| | - S Dahham
- Infectomics Cluster, advanced medical and dental institute, universiti Sains Malaysia, Jln Tun Hamdan Sheikh Tahir, 13200 Bertam Penang, Malaysia
| | - M T Agha
- Infectomics Cluster, advanced medical and dental institute, universiti Sains Malaysia, Jln Tun Hamdan Sheikh Tahir, 13200 Bertam Penang, Malaysia
| | - S F Musa
- Infectomics Cluster, advanced medical and dental institute, universiti Sains Malaysia, Jln Tun Hamdan Sheikh Tahir, 13200 Bertam Penang, Malaysia
| | - R Muhammed
- Regenerative medicine cluster, advanced medical and dental institute, UniversitiSains Malaysia, 13200 Bertam Penang, Malaysia
| | - L T L Than
- Department of medical microbiology and parasitology, faculty of medicine and health sciences, universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - D Sandai
- Infectomics Cluster, advanced medical and dental institute, universiti Sains Malaysia, Jln Tun Hamdan Sheikh Tahir, 13200 Bertam Penang, Malaysia.
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DiNicolantonio JJ, Berger A. Added sugars drive nutrient and energy deficit in obesity: a new paradigm. Open Heart 2016; 3:e000469. [PMID: 27547437 PMCID: PMC4975866 DOI: 10.1136/openhrt-2016-000469] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 07/07/2016] [Indexed: 12/14/2022] Open
Abstract
Obesity has traditionally been thought of as a state of caloric imbalance, where the intake of calories exceeds the expenditure or ‘burning’ of calories. However, a more nuanced appreciation for the complex biochemistry and physiology of cellular energy generation suggests that obesity is a state of hormonal imbalance causing increased shunting of food energy into adipose tissue for storage, resulting in decreased satiety and ultimately leading to increased caloric intake. Adding to this hypothesis, we propose that obesity is also a state of nutrient and energy deficit, leading to decreased fatty acid mobilisation and oxidation, the result of which may be a natural disinclination towards physical activity. Added sugars (sucrose, a.k.a. table sugar and high-fructose corn syrup) may provide energy (4 kcal/g) but at current intakes they do not facilitate—and may even hinder—the production of energy. Not only do added sugars displace nutritionally superior foods in the diet, but they may also deplete nutrients from other foods that have been consumed, as well as from body stores, in order to enable their proper oxidation and liberate their calories as energy. Additionally, the consumption of added sugars damages the mitochondria and hence impairs energy generation. Moreover, overconsuming added sugars may result in a kind of ‘internal starvation’ (via leptin and insulin resistance) leading to further hunger signals in the body. Added sugars promote nutrient and energy deficit and through this novel pathway promote obesity.
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Ur-Rehman S, Mushtaq Z, Zahoor T, Jamil A, Murtaza MA. Xylitol: a review on bioproduction, application, health benefits, and related safety issues. Crit Rev Food Sci Nutr 2016; 55:1514-28. [PMID: 24915309 DOI: 10.1080/10408398.2012.702288] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Xylitol is a pentahydroxy sugar-alcohol which exists in a very low quantity in fruits and vegetables (plums, strawberries, cauliflower, and pumpkin). On commercial scale, xylitol can be produced by chemical and biotechnological processes. Chemical production is costly and extensive in purification steps. However, biotechnological method utilizes agricultural and forestry wastes which offer the possibilities of economic production of xylitol by reducing required energy. The precursor xylose is produced from agricultural biomass by chemical and enzymatic hydrolysis and can be converted to xylitol primarily by yeast strain. Hydrolysis under acidic condition is the more commonly used practice influenced by various process parameters. Various fermentation process inhibitors are produced during chemical hydrolysis that reduce xylitol production, a detoxification step is, therefore, necessary. Biotechnological xylitol production is an integral process of microbial species belonging to Candida genus which is influenced by various process parameters such as pH, temperature, time, nitrogen source, and yeast extract level. Xylitol has application and potential for food and pharmaceutical industries. It is a functional sweetener as it has prebiotic effects which can reduce blood glucose, triglyceride, and cholesterol level. This review describes recent research developments related to bioproduction of xylitol from agricultural wastes, application, health, and safety issues.
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Affiliation(s)
- Salim Ur-Rehman
- a National Institute of Food Science & Technology, University of Agriculture , Faisalabad , 38040 , Pakistan
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Ohshima T, Kojima Y, Seneviratne CJ, Maeda N. Therapeutic Application of Synbiotics, a Fusion of Probiotics and Prebiotics, and Biogenics as a New Concept for Oral Candida Infections: A Mini Review. Front Microbiol 2016; 7:10. [PMID: 26834728 PMCID: PMC4724717 DOI: 10.3389/fmicb.2016.00010] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 01/08/2016] [Indexed: 01/07/2023] Open
Abstract
Candida is a major human fungal pathogen causing infectious conditions predominantly in the elderly and immunocompromised hosts. Although Candida resides as a member of the oral indigenous microbiota in symbiosis, some circumstances may cause microbial imbalance leading to dysbiosis and resultant oral candidiasis. Therefore, oral microbial symbiosis that suppresses the overgrowth of Candida is important for a healthy oral ecosystem. In this regard, probiotics, prebiotics, and synbiotics can be considered a potential therapeutic and preventive strategy against oral candidiasis. Prebiotics have a direct effect on microbial growth as they stimulate the growth of beneficial bacteria and suppress the growth of pathogens. Probiotics render a local protective effect against pathogens and a systemic indirect effect on immunological amelioration. Synbiotics are fusion products of prebiotics and probiotics. This mini review discusses the potential use and associated limitations of probiotics, prebiotics, and synbiotics for the prevention and treatment of oral candidiasis. We will also introduce biogenics, a recent concept derived from the work on probiotics. Biogenics advocates the use of beneficial bioactive substances produced by probiotic bacteria, whose activities are independent from the viability of probiotic bacteria in human bodies.
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Affiliation(s)
- Tomoko Ohshima
- Department of Oral Microbiology, School of Dental Medicine, Tsurumi UniversityKanagawa, Japan
| | - Yukako Kojima
- Department of Oral Microbiology, School of Dental Medicine, Tsurumi UniversityKanagawa, Japan
| | - Chaminda J. Seneviratne
- Department of Oral Sciences, Faculty of Dentistry, National University of SingaporeSingapore, Singapore
| | - Nobuko Maeda
- Department of Oral Microbiology, School of Dental Medicine, Tsurumi UniversityKanagawa, Japan
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Manipulation of Host Diet To Reduce Gastrointestinal Colonization by the Opportunistic Pathogen Candida albicans. mSphere 2015; 1:mSphere00020-15. [PMID: 27303684 PMCID: PMC4863630 DOI: 10.1128/msphere.00020-15] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 10/17/2015] [Indexed: 11/30/2022] Open
Abstract
Candida albicans, the most common human fungal pathogen, can cause infections with a mortality rate of ~40%. C. albicans is part of the normal gut flora, but when a patient’s immune system is compromised, it can leave the gut and cause infections. By reducing the amount of C. albicans in the gut of susceptible patients, infections (and the resulting fatalities) can be prevented. Currently, this is done using antimicrobial drugs; to “preserve” drugs for treating infections, we looked for a dietary change to reduce the amount of C. albicans in the gut. Using a mouse model, we showed that adding coconut oil to the diet could become the first drug-free way to reduce C. albicans in the gut. More broadly, this model lets us study the interactions between our diet and the microbes in our body and the reasons why some of those microbes, under certain conditions, cause disease. Candida albicans, the most common human fungal pathogen, can cause systemic infections with a mortality rate of ~40%. Infections arise from colonization of the gastrointestinal (GI) tract, where C. albicans is part of the normal microflora. Reducing colonization in at-risk patients using antifungal drugs prevents C. albicans-associated mortalities. C. albicans provides a clinically relevant system for studying the relationship between diet and the microbiota as it relates to commensalism and pathogenicity. As a first step toward a dietary intervention to reduce C. albicans GI colonization, we investigated the impact of dietary lipids on murine colonization by C. albicans. Coconut oil and its constituent fatty acids have antifungal activity in vitro; we hypothesized that dietary coconut oil would reduce GI colonization by C. albicans. Colonization was lower in mice fed a coconut oil-rich diet than in mice fed diets rich in beef tallow or soybean oil. Switching beef tallow-fed mice to a coconut oil diet reduced preexisting colonization. Coconut oil reduced colonization even when the diet also contained beef tallow. Dietary coconut oil also altered the metabolic program of colonizing C. albicans cells. Long-chain fatty acids were less abundant in the cecal contents of coconut oil-fed mice than in the cecal contents of beef tallow-fed mice; the expression of genes involved in fatty acid utilization was lower in C. albicans from coconut oil-fed mice than in C. albicans from beef tallow-fed mice. Extrapolating to humans, these findings suggest that coconut oil could become the first dietary intervention to reduce C. albicans GI colonization. IMPORTANCECandida albicans, the most common human fungal pathogen, can cause infections with a mortality rate of ~40%. C. albicans is part of the normal gut flora, but when a patient’s immune system is compromised, it can leave the gut and cause infections. By reducing the amount of C. albicans in the gut of susceptible patients, infections (and the resulting fatalities) can be prevented. Currently, this is done using antimicrobial drugs; to “preserve” drugs for treating infections, we looked for a dietary change to reduce the amount of C. albicans in the gut. Using a mouse model, we showed that adding coconut oil to the diet could become the first drug-free way to reduce C. albicans in the gut. More broadly, this model lets us study the interactions between our diet and the microbes in our body and the reasons why some of those microbes, under certain conditions, cause disease. Podcast: A podcast concerning this article is available.
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Kim YG, Udayanga KGS, Totsuka N, Weinberg JB, Núñez G, Shibuya A. Gut dysbiosis promotes M2 macrophage polarization and allergic airway inflammation via fungi-induced PGE₂. Cell Host Microbe 2014; 15:95-102. [PMID: 24439901 DOI: 10.1016/j.chom.2013.12.010] [Citation(s) in RCA: 262] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 10/02/2013] [Accepted: 12/24/2013] [Indexed: 11/16/2022]
Abstract
Although imbalances in gut microbiota composition, or "dysbiosis," are associated with many diseases, the effects of gut dysbiosis on host systemic physiology are less well characterized. We report that gut dysbiosis induced by antibiotic (Abx) treatment promotes allergic airway inflammation by shifting macrophage polarization in the lung toward the alternatively activated M2 phenotype. Adoptive transfer of alveolar macrophages derived from Abx-treated mice was sufficient to increase allergic airway inflammation. Abx treatment resulted in the overgrowth of a commensal fungal Candida species in the gut and increased plasma concentrations of prostaglandin E₂ (PGE₂), which induced M2 macrophage polarization in the lung. Suppression of PGE₂ synthesis by the cyclooxygenase inhibitors aspirin and celecoxib suppressed M2 macrophage polarization and decreased allergic airway inflammatory cell infiltration in Abx-treated mice. Thus, Abx treatment can cause overgrowth of particular fungal species in the gut and promote M2 macrophage activation at distant sites to influence systemic responses including allergic inflammation.
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Affiliation(s)
- Yun-Gi Kim
- Department of Immunology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology (CREST), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan; Pathology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Kankanam Gamage Sanath Udayanga
- Department of Immunology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology (CREST), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Naoya Totsuka
- Department of Immunology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology (CREST), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Jason B Weinberg
- Department of Pediatrics and Communicable Diseases, Microbiology, and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Gabriel Núñez
- Pathology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Akira Shibuya
- Department of Immunology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology (CREST), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan; Life Science Center of Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan.
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13
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Pal S, Choudhary V, Kumar A, Biswas D, Mondal AK, Sahoo DK. Studies on xylitol production by metabolic pathway engineered Debaryomyces hansenii. BIORESOURCE TECHNOLOGY 2013; 147:449-455. [PMID: 24012734 DOI: 10.1016/j.biortech.2013.08.065] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 08/07/2013] [Accepted: 08/09/2013] [Indexed: 05/24/2023]
Abstract
Debaryomyces hansenii is one of the most promising natural xylitol producers. As the conversion of xylitol to xylulose mediated by NAD(+) cofactor dependent xylitol dehydrogenase (XDH) reduces its xylitol yield, xylitol dehydrogenase gene (DhXDH)-disrupted mutant of D. hansenii having potential for xylose assimilating pathway stopping at xylitol, was used to study the effects of co-substrates, xylose and oxygen availability on xylitol production. Compared to low cell growth and xylitol production in cultivation medium containing xylose as the only substrate, XDH disrupted mutants grown on glycerol as co-substrate accumulated 2.5-fold increased xylitol concentration over those cells grown on glucose as co-substrate. The oxygen availability, in terms of volumetric oxygen transfer coefficient, kLa (23.86-87.96 h(-1)), affected both xylitol productivity and yield, though the effect is more pronounced on the former. The addition of extra xylose at different phases of xylitol fermentation did not enhance xylitol productivity under experimental conditions.
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Affiliation(s)
- Suksham Pal
- CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh 160036, India
| | - Vikas Choudhary
- CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh 160036, India
| | - Anil Kumar
- CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh 160036, India
| | - Dipanwita Biswas
- CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh 160036, India
| | - Alok K Mondal
- CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh 160036, India
| | - Debendra K Sahoo
- CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh 160036, India.
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14
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Ligaarden SC, Lydersen S, Farup PG. IgG and IgG4 antibodies in subjects with irritable bowel syndrome: a case control study in the general population. BMC Gastroenterol 2012; 12:166. [PMID: 23170971 PMCID: PMC3526446 DOI: 10.1186/1471-230x-12-166] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 11/14/2012] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Patients with Irritable Bowel Syndrome (IBS) often relate their symptoms to the intake of food and modify their diet. IgE-mediated food allergy is uncommon in IBS, but the role of IgG-mediated food hypersensitivity remains inconclusive. The primary aim of this study was to compare food- and yeast-specific IgG and IgG4 antibodies in subjects with and without IBS. METHODS This was a case control study in the general population for which subjects completed questionnaires about abdominal complaints and their intake of common food items. Blood samples were collected, and food- and yeast-specific IgG and IgG4 antibodies were measured. Antibodies were measured in mg/L. RESULTS We included 269 subjects with IBS and 277 control subjects. After correction for subject characteristics and diet, there were no significant differences with regard to food- and yeast-specific IgG and IgG4 antibodies between subjects with IBS and controls. Lower values of IgG antibodies against egg (OR 0.99 (0.98 to 1.00), p = 0.002) and beef (OR 0.75 (0.60 to 0.94), p = 0.012) and higher values of IgG antibodies against chicken (OR 1.14 (1.03 to 1.27), p = 0.009) were associated with more severe symptoms. CONCLUSIONS Our findings suggest that IgG-and IgG4-mediated food and yeast hypersensitivity in IBS is unlikely. IgG antibodies against food and yeast may reflect the diet.
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Affiliation(s)
- Solveig C Ligaarden
- Department of Medicine, Innlandet Hospital Trust, Kyrre Grepps gt 19, 2819, Gjøvik, Norway
- Unit for Applied Clinical Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Stian Lydersen
- Regional Centre for Child and Adolescent Mental Health (RBUP), Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway
| | - Per G Farup
- Unit for Applied Clinical Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Research, Innlandet Hospital Trust, Gjøvik, Norway
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15
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Cutler JE, Corti M, Lambert P, Ferris M, Xin H. Horizontal transmission of Candida albicans and evidence of a vaccine response in mice colonized with the fungus. PLoS One 2011; 6:e22030. [PMID: 21818288 PMCID: PMC3139608 DOI: 10.1371/journal.pone.0022030] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 06/13/2011] [Indexed: 11/27/2022] Open
Abstract
Disseminated candidiasis is the third leading nosocomial blood stream infection in the United States and is often fatal. We previously showed that disseminated candidiasis was preventable in normal mice by immunization with either a glycopeptide or a peptide synthetic vaccine, both of which were Candida albicans cell wall derived. A weakness of these studies is that, unlike humans, mice do not have a C. albicans GI flora and they lack Candida serum antibodies. We examined the influence of C. albicans GI tract colonization and serum antibodies on mouse vaccination responses to the peptide, Fba, derived from fructose bisphosphate aldolase which has cytosolic and cell wall distributions in the fungus. We evaluated the effect of live C. albicans in drinking water and antimicrobial agents on establishment of Candida colonization of the mouse GI tract. Body mass, C. albicans in feces, and fungal-specific serum antibodies were monitored longitudinally. Unexpectedly, C. albicans colonization occurred in mice that received only antibiotics in their drinking water, provided that the mice were housed in the same room as intentionally colonized mice. The fungal strain in unintentionally colonized mice appeared identical to the strain used for intentional GI-tract colonization. This is the first report of horizontal transmission and spontaneous C. albicans colonization in mice. Importantly, many Candida-colonized mice developed serum fungal-specific antibodies. Despite the GI-tract colonization and presence of serum antibodies, the animals made antibodies in response to the Fba immunogen. This mouse model has potential for elucidating C. albicans horizontal transmission and for exploring factors that induce host defense against disseminated candidiasis. Furthermore, a combined protracted GI-tract colonization with Candida and the possibility of serum antibody responses to the presence of the fungus makes this an attractive mouse model for testing the efficacy of vaccines designed to prevent human disseminated candidiasis.
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Affiliation(s)
- Jim E Cutler
- Department of Pediatrics, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America.
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Rodaki A, Bohovych IM, Enjalbert B, Young T, Odds FC, Gow NAR, Brown AJP. Glucose promotes stress resistance in the fungal pathogen Candida albicans. Mol Biol Cell 2009; 20:4845-55. [PMID: 19759180 DOI: 10.1091/mbc.e09-01-0002] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Metabolic adaptation, and in particular the modulation of carbon assimilatory pathways during disease progression, is thought to contribute to the pathogenicity of Candida albicans. Therefore, we have examined the global impact of glucose upon the C. albicans transcriptome, testing the sensitivity of this pathogen to wide-ranging glucose levels (0.01, 0.1, and 1.0%). We show that, like Saccharomyces cerevisiae, C. albicans is exquisitely sensitive to glucose, regulating central metabolic genes even in response to 0.01% glucose. This indicates that glucose concentrations in the bloodstream (approximate range 0.05-0.1%) have a significant impact upon C. albicans gene regulation. However, in contrast to S. cerevisiae where glucose down-regulates stress responses, some stress genes were induced by glucose in C. albicans. This was reflected in elevated resistance to oxidative and cationic stresses and resistance to an azole antifungal agent. Cap1 and Hog1 probably mediate glucose-enhanced resistance to oxidative stress, but neither is essential for this effect. However, Hog1 is phosphorylated in response to glucose and is essential for glucose-enhanced resistance to cationic stress. The data suggest that, upon entering the bloodstream, C. albicans cells respond to glucose increasing their resistance to the oxidative and cationic stresses central to the armory of immunoprotective phagocytic cells.
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Affiliation(s)
- Alexandra Rodaki
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
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Abu-Elteen KH. The influence of dietary carbohydrates onin vitroadherence of fourCandidaspecies to human buccal epithelial cells. MICROBIAL ECOLOGY IN HEALTH AND DISEASE 2009. [DOI: 10.1080/08910600500442917] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Khaled H. Abu-Elteen
- Department of Biological Sciences, Faculty of Science, Hashemite University, Zarqa, Jordan
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18
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Haidaris CG. Patents on antifungal compounds effective against Candida species: 1999 – 2002. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.13.12.1849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
A previous review of alternative treatments (Tx) of ADHD--those other than psychoactive medication and behavioral/psychosocial Tx--was supplemented with an additional literature search focused on adults with ADHD. Twenty-four alternative Tx were identified, ranging in scientific documentation from discrediting controlled studies through mere hypotheses to positive controlled double-blind clinical trials. Many of them are applicable only to a specific subgroup. Although oligoantigenic (few-foods) diets have convincing double-blind evidence of efficacy for a properly selected subgroup of children, they do not appear promising for adults. Enzyme-potentiated desensitization, relaxation/EMG biofeedback, and deleading also have controlled evidence of efficacy. Iron supplementation, magnesium supplementation, Chinese herbals, EEG biofeedback, massage, meditation, mirror feedback, channel-specific perceptual training, and vestibular stimulation all have promising prospective pilot data, many of these tests reasonably controlled. Single-vitamin megadosage has some intriguing pilot trial data. Zinc supplementation is hypothetically supported by systematic case-control data, but no systematic clinical trial. Laser acupuncture has promising unpublished pilot data and may be more applicable to adults than children. Essential fatty acid supplementation has promising systematic case-control data, but clinical trials are equivocal. RDA vitamin supplementation, non-Chinese herbals, homeopathic remedies, and antifungal therapy have no systematic data in ADHD. Megadose multivitamin combinations are probably ineffective for most patients and are possibly dangerous. Simple sugar restriction seems ineffective. Amino acid supplementation is mildly effective in the short term, but not beyond 2-3 months. Thyroid treatment is effective in the presence of documented thyroid abnormality. Some alternative Tx of ADHD are effective or probably effective, but mainly for certain patients. In some cases, they are the Tx of choice, and initial evaluation should consider the relevant etiologies. A few have failed to prove effective in controlled trials. Most need research to determine whether they are effective and/or to define the applicable subgroup. Some of them, although not safer than standard Tx, may be preferable for an etiologic subgroup.
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Affiliation(s)
- L E Arnold
- Department of Psychiatry, Ohio State University, Columbus, Ohio 43210, USA.
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20
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Mellado E, Cuenca-Estrella M, Regadera J, González M, Díaz-Guerra TM, Rodríguez-Tudela JL. Sustained gastrointestinal colonization and systemic dissemination by Candida albicans, Candida tropicalis and Candida parapsilosis in adult mice. Diagn Microbiol Infect Dis 2000; 38:21-8. [PMID: 11025180 DOI: 10.1016/s0732-8893(00)00165-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ability of nine clinical isolates of Candida species (three C. albicans, three C. tropicalis and three C. parapsilosis) to colonize and invade the gastrointestinal (GI) tract of adult male CD-1 (ICR) mice was determined. The effect of dietary tetracycline plus glucose supplementation on colonization was evaluated. Strains were intragastrically inoculated. Tetracycline and glucose altered substantially aerobic flora, especially streptococci (average fall 1.1 +/-0.3 log(10) CFU/g, p<0.01 by the Student's t test). At two weeks after oral challenge, sustained and high colonization of GI tract by Candida (mean 5,28 +/- 0.18 log(10) CFU/g, p<0.01) was achieved in all mice receiving glucose-tetracycline supplementation, excepting in animals inoculated with one of C. tropicalis isolates. Histologic sections of the stomachs revealed multiple intraepithelial micro-abscesses associated with hyphae in the region of the cardial-atrium fold. Under immunosuppression, systemic spread of C. albicans and C. tropicalis was observed in 62% and 24% of animals receiving dietary supplementation respectively. Dissemination was not noted for C. parapsilosis isolates. We have developed a simple and inexpensive murine model of sustained colonization of GI tract. This model could be useful for analyzing prophylaxis, treatment and diagnosis of systemic Candida infections and for evaluating virulence of strains.
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Affiliation(s)
- E Mellado
- Servicio de Micología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
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Weig M, Werner E, Frosch M, Kasper H. Limited effect of refined carbohydrate dietary supplementation on colonization of the gastrointestinal tract of healthy subjects by Candida albicans. Am J Clin Nutr 1999; 69:1170-3. [PMID: 10357735 DOI: 10.1093/ajcn/69.6.1170] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Infections due to Candida albicans occur readily in situations in which ample glucose is available. In mice, dietary refined carbohydrate supplementation leads to higher rates of Candida growth in the gastrointestinal tract and favors mucosal invasion. OBJECTIVE The modulating properties of dietary carbohydrate supplementation on colonization of the human gastrointestinal tract by C. albicans were evaluated. DESIGN A 2-step study was conducted in 28 healthy volunteers. First, we determined the subjects' habitual uptake of refined carbohydrates and correlated these data with the C. albicans blastoconidia concentration in the mouth washes and feces of subjects with no intervention. Second, we compared C. albicans counts in the specimens before, during, and after a high-sugar diet. RESULTS No correlation between C. albicans counts in the specimens and the habitual uptake of refined carbohydrates was observed. A high-sugar diet did not increase the frequency of C. albicans-positive samples, the number of subjects positive for C. albicans in the mouth washes, or the concentration of candidal blastoconidia in the samples of the 28 subjects. However, in selected subjects with elevated counts of oral C. albicans, we observed an increase in fecal C. albicans counts in response to the diet. CONCLUSIONS The effect of adding a high amount of refined carbohydrates to the diet of healthy human subjects has a limited influence on Candida colonization. Follow-up studies should define whether selected patient groups might benefit from dietary restriction of refined carbohydrates.
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Affiliation(s)
- M Weig
- Institut für Hygiene und Mikrobiologie, Klinik und Poliklinik für Nuklearmedizin der Universität Würzburg, Germany.
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Postlethwait P, Sundstrom P. Genetic organization and mRNA expression of enolase genes of Candida albicans. J Bacteriol 1995; 177:1772-9. [PMID: 7896700 PMCID: PMC176805 DOI: 10.1128/jb.177.7.1772-1779.1995] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In previous work, we cloned a Candida albicans cDNA for the glycolytic enzyme enolase and found a single, abundant enolase transcript on Northern (RNA) blots and a single protein on immunoblots, using antiserum raised against a recombinant enolase fusion protein. Because C. albicans enolase is abundantly produced during infection and elicits strong host immune responses, the mechanisms regulating enolase production are important for understanding the growth of C. albicans in vivo. To obtain more information on enolase gene expression by C. albicans, we used the enolase cDNA clone to investigate the genetic organization of enolase genes and the steady-state levels of enolase mRNA under several growth conditions. Gene disruption techniques in combination with Southern blot analyses of genomic DNA showed the presence of two enolase gene loci that could be distinguished by the locations of ClaI and Mn/I sites in their 3' flanking regions. Enolase steady-state mRNA levels were greatest during the middle phase of the logarithmic growth curve and were low during stationary phase. Minimal differences in enolase mRNA levels between yeast cells and hyphae were found. Propagation of C. albicans in glucose did not cause increased enolase mRNA levels compared with growth in a nonfermentable carbon source (pyruvate). It was concluded that two gene loci exist for C. albicans enolase and that enolase mRNA is constitutively produced at high levels during active metabolism.
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Affiliation(s)
- P Postlethwait
- Department of Microbiology and Immunology, University of North Texas Health Sciences Center, Fort Worth 76107
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23
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Swoboda RK, Bertram G, Delbrück S, Ernst JF, Gow NA, Gooday GW, Brown AJ. Fluctuations in glycolytic mRNA levels during morphogenesis in Candida albicans reflect underlying changes in growth and are not a response to cellular dimorphism. Mol Microbiol 1994; 13:663-72. [PMID: 7997178 DOI: 10.1111/j.1365-2958.1994.tb00460.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The levels of pyruvate kinase (PYK1), alcohol dehydrogenase (ADH1), phosphoglycerate kinase (PGK1) and phosphoglycerate mutase (GPM1) mRNAs were measured during batch growth and during the yeast-to-hyphal transition in Candida albicans. The four mRNAs behaved in a similar fashion. PYK1, ADH1, PGK1 and GPM1 mRNA levels were shown to increase dramatically during the exponential growth phase of the yeast form, and then to decrease to relatively low levels in the stationary phase. The dimorphic transition was induced using two sets of conditions: (i) an increase in temperature (from 25 degrees C to 37 degrees C) combined with the addition of serum to the medium; and (ii) an increase in temperature (from 25 degrees C to 37 degrees C) and an increase in pH of the growth medium (from pH 4.5 to pH 6.5). Additional cultures were analysed to control for the addition of serum, and for changes in temperature or pH. Immediately following dilution of late-exponential cells into fresh media the levels of all four glycolytic mRNAs decreased rapidly in contrast to the ACT1 mRNA control, the level of which increased under most conditions. The recovery of glycolytic mRNA levels depended on the culture conditions, but there was no direct correlation with the formation of germ tubes, with the addition of serum to the medium, the increase in culture temperature, the medium pH, or the glucose concentration. This indicates that the changes in glycolytic gene expression that accompany the dimorphic transition in C. albicans reflect the underlying physiological status of the cells during morphogenesis and not alterations to cell shape.
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Affiliation(s)
- R K Swoboda
- University of Aberdeen, Marischal College, UK
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Hostetter MK. Adhesins and ligands involved in the interaction of Candida spp. with epithelial and endothelial surfaces. Clin Microbiol Rev 1994; 7:29-42. [PMID: 8118789 PMCID: PMC358304 DOI: 10.1128/cmr.7.1.29] [Citation(s) in RCA: 158] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Adhesion of candidal species to the epithelium of the gastrointestinal or genitourinary tract stands as a critical first step in the pathogenesis of candidal infection. After colonization and replication at mucosal surfaces, Candida albicans and other pathogenic species may penetrate the mucosal barrier, enter the vascular tree, and disseminate hematogenously. The consequences of this pathogenic cascade evoke considerable morbidity and mortality, especially among immunocompromised patients. Thus, interactions of C. albicans and other candidal species with epithelium and endothelium may lead to serious consequences for the human host. This review evaluates candidate candidal adhesions for epithelial and endothelial surfaces, with emphasis on the specificity of the interaction, the inhibitors that have been employed, and the ligands that have been identified on mammalian cells or matrices. Three types of interactions are described: protein-protein interactions, lectin-like interactions, and incompletely defined interactions in which the adhesive ligand is as yet unidentified. Special attention is given to the roles of integrin-like proteins. Differences in the mechanisms of candidal attachment to epithelium and endothelium are delineated. Last, on the basis of the available literature, avenues of potentially fruitful investigation are proposed.
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Affiliation(s)
- M K Hostetter
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis 55455
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