Ingmar Claes

Ingmar Claes
University of Antwerp | UA · Department of Bioengineering

PhD

About

50
Publications
14,097
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Introduction
Currently, I am the head of science at YUN NV, a Belgian biotech company with a new vision on health and hygiene. At YUN we are building a new era of personal care based on everyone’s natural strength. YUN is doing this based on good bacteria which protect, strenghten and repair the skin’s natural protective layer. To do so, YUN has developed effective solutions for common skin conditions and personal care. This is how YUN helps its users to feel better in their own skin. The further develop new products, I am a closely working together with the Department of Bioscience Engineering of the University of Antwerp, the lab of Applied Microbiology and Biotechnology of prof. Sarah Lebeer, the lab of Pharmaceutical Technology and Biopharmacy of prof. Filip Kiekens and prof. dr. Julien Lambert
Skills and Expertise

Publications

Publications (50)
Article
Viral respiratory tract infections result in significant health and economic burdens, as highlighted by the COVID-19 pandemic. Primary care patients represent 90% of those infected with SARS-CoV-2, yet their treatment options are limited to analgesics and antiphlogistics, and few broadly acting antiviral strategies are available.
Preprint
Objectives Primary care urgently needs treatments for COVID-19 patients because current options are limited, while these patients account for more than 90% of the people infected with SARS-CoV-2. Methods We evaluated a throat spray containing three Lactobacillaceae strains with broad antiviral properties in a randomized double-blind placebo-contro...
Article
Full-text available
Tailored skin microbiome modulation approaches with probiotics are highly challenging. Here, we show that lactobacilli are underestimated members of the skin microbiota. We select specific strains of nomadic lactobacilli for their functional applicability on the skin and capacity to inhibit growth and inflammation by skin pathobionts. The strains a...
Preprint
Respiratory viruses such as influenza viruses, respiratory syncytial virus (RSV), and coronaviruses initiate infection at the mucosal surfaces of the upper respiratory tract (URT), where the resident respiratory microbiome has an important gatekeeper function. In contrast to gut-targeting administration of beneficial bacteria against respiratory vi...
Article
Full-text available
During the current COVID-19 pandemic, the use of face masks has become increasingly recommended and even mandatory in community settings. To evaluate the risk of bacterial cross-contamination, this study analyzed the bacterial bioburden of disposable surgical masks and homemade cotton masks, and surveyed the habits and face mask preferences of the...
Article
The human skin microbiota forms a key barrier against skin pathogens and is important in modulating immune responses. Recent studies identify lactobacilli as endogenous inhabitants of healthy skin, while inflammatory skin conditions are often associated with a disturbed skin microbiome. Consequently, lactobacilli-based probiotics are explored as a...
Article
Full-text available
In vitro studies suggest that certain probiotic bacterial strains have potential activity against opportunistic infections such as Candida. There are few in vivo trials using probiotics as a single treatment for acute Candida vulvovaginitis (CV). In this open-label, proof-of-concept study, selected Lactobacillus strains were tested in women with ac...
Article
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Vulvovaginal candidosis (VVC) is a common condition with severe symptoms and high recurrence rates. Probiotic lactobacilli are explored as alternatives to azole treatments. Although the vaginal microbiota is generally not depleted in lactobacilli during VVC, studies indicate that the functionality and antimicrobial activity of the lactobacilli is i...
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The preservation of the viability of microorganisms in probiotic formulations is the most important parameter ensuring the adequate concentration of live microorganisms at the time of administration. The formulation and processing techniques used to produce these probiotic formulations can influence the preservation of the microbial viability. Howe...
Preprint
Full-text available
The skin is home to an important part of our commensal microbiota, despite it being a cool, acidic and desiccated environment. Tailored microbiome modulation approaches with, for example probiotics, are highly challenging for this body site. Here we show by next-generating sequencing that Lactobacillus taxa -especially those known to be dominant in...
Article
Spontaneous vegetable fermentations, with their rich flavors and postulated health benefits, are regaining popularity. However, their microbiology is still poorly understood, therefore raising concerns about food safety. In addition, such spontaneous fermentations form interesting cases of man-made microbial ecosystems. Here, samples from 38 carrot...
Article
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Probiotics, mainly lactic acid bacteria (LAB), are widely focused on gastrointestinal applications. However, recent microbiome studies indicate that LAB can be endogenous members of other human body sites such as the upper respiratory tract (URT). Interestingly, DNA-based microbiome research suggests an inverse correlation between the presence of L...
Article
New sequencing technologies have dramatically increased our knowledge on the composition of the human intestinal microbiota in health and disease. In parallel, various omics as well as focused molecular studies have revealed novel insights in host–microbiome interactions at the cellular and molecular level. Although these studies are mainly descrip...
Article
Full-text available
Probiotics are the live microorganisms which when ingested in adequate amounts confer health benefits. The strains most frequently used as probiotics include Lactic acid bacteria, bifidobacteria and yeast Saccharomyces boulardii. However, several other bacterial strains are being investigated for potential probiotic value viz. Enterococcus, Strepto...
Article
Full-text available
Recently, spaCBA-encoded pili were identified on the cell surface of L. rhamnosus GG as key molecules for binding to human intestinal mucus and Caco-2 intestinal epithelial cells. Here, we investigated the role of the SpaCBA pilus of L. rhamnosus GG in the interaction with macrophages in vitro by comparing the wild-type with surface mutants. Our re...
Article
The health promoting effects of probiotics have been well established. World Health Organization (WHO) advocates utilization of prophylactic and therapeutic potential of probiotics. Probiotics are live microorganisms (single/ mixed cultures) which impart multiple health benefits to the consumer animals or humans. Probiotics include different lactic...
Article
Full-text available
Bacterial cell wall hydrolases are essential for peptidoglycan remodeling as required for bacterial cell growth and division. In this study, peptidoglycan hydrolases (PGHs) of different Lactobacillus buchneri strains were investigated. First, the genome sequence of L. buchneri CD034 and L. buchneri NRRL B-30929 was analysed in silico for the presen...
Article
Full-text available
Lactobacilli are important for the maintenance of a healthy ecosystem in the human vagina. Various mechanisms are postulated but so far are poorly substantiated by molecular studies, such as mutant analysis. Bacterial autoaggregation is an interesting phenomenon that can promote adhesion to host cells and displacement of pathogens. In this study, w...
Article
Knowledge of the mechanisms by which bacterial pili adhere to host cells and withstand external forces is critical to our understanding of their functional roles and offers exciting avenues in biomedicine for controlling the adhesion of bacterial pathogens and probiotics. While much progress has been made in the nanoscale characterization of pili f...
Article
Full-text available
Background Probiotic bacteria are increasingly used as immunomodulatory agents. Yet detailed molecular knowledge on the immunomodulatory molecules of these bacteria is lagging behind. Lipoteichoic acid (LTA) is considered a major microbe-associated molecular pattern (MAMP) of Gram-positive bacteria. However, many details and quantitative data on it...
Article
Full-text available
Peptidoglycan (PG) is the major component of Gram positive bacteria cell wall and is essential for bacterial integrity and shape. Bacteria synthesize PG hydrolases (PGHs) which are able to cleave bonds in their own PG and play major roles in PG remodelling required for bacterial growth and division. Our aim was to identify the main PGHs in Lactobac...
Data
Full-text available
RP-HPLC profile of muropeptides obtained from L. casei BL23 PG digested by mutanolysin (A) or by mutanolysin and recombinant Lc-p75 (B). (PDF)
Data
Detection of Strep-tagged Lc-p75 in a culture supernatant of the lcabl_02770-negative mutant (PAR006). (A) SDS-PAGE gel, (B) Western Blot with monoclonal antibody directed against Strep-tag and (C) zymogram. (TIF)
Data
Full-text available
Primers used for RT-PCR experiments. (PDF)
Data
Full-text available
Protein identification by MS-MS analysis with X!tandem software. (PDF)
Data
SDS-PAGE of proteins from cytoplasmic (A) cell envelope (B) and lithium chloride (C) fractions prepared from L. casei BL23. The gel was stained with colloidal Coomasie blue. Labeled gel sections from 1 to 26 were cut lane by lane, then digested with trypsin and analyzed separately by LC-MS/MS. (TIF)
Data
Full-text available
Structures, molecular masses and proportions of muropeptides obtained from L. casei BL23 PG digested by mutanolysin or by mutanolysin and recombinant Lc-p75. (PDF)
Article
Full-text available
Lactobacillus rhamnosus GG (LGG) produces two major secreted proteins, designated here Msp1 (LGG_00324 or p75) and Msp2 (LGG_00031 or p40), which have been reported to promote the survival and growth of intestinal epithelial cells. Intriguingly, although each of these proteins shares homology with cell wall hydrolases, a physiological function that...
Data
Primers sequences used in this study. (DOC)
Data
Structures, molecular masses and proportions of muropeptides obtained from LGG PG digested by mutanolysin and by mutanolysin and recombinant Msp1 protein. (DOC)
Data
RP-HPLC separation profile of muropeptides obtained from LGG PG digested by mutanolysin (A) and by mutanolysin and recombinant Msp1 (B). (TIF)
Article
Full-text available
Although the occurrence, biosynthesis and possible functions of glycoproteins are increasingly documented for pathogens, glycoproteins are not yet widely described in probiotic bacteria. Nevertheless, knowledge of protein glycosylation holds important potential for better understanding specific glycan-mediated interactions of probiotics and for gly...
Article
Lipoteichoic acid (LTA) mutants of lactobacilli suppress inflammation in animal models of experimental colitis. The fact that a single mutation of an administered Lactobacillus strain can result in enhanced probiotic efficacy is surprising given the genetic diversity and complexity of the intestinal niche, but at the same time exciting from a micro...
Article
Full-text available
Lactobacillus rhamnosus GG, a probiotic with good survival capacity in the human gut, has well-documented adhesion properties and health effects. Recently, spaCBA-encoded pili that bind to human intestinal mucus were identified on its cell surface. Here, we report on the phenotypic analysis of a spaCBA pilus knockout mutant in comparison with the w...
Article
In living cells, sophisticated functional interfaces are generated through the self-assembly of bioactive building blocks. Prominent examples of such biofunctional surfaces are bacterial nanostructures referred to as pili. Although these proteinaceous filaments exhibit remarkable structure and functions, their potential to design bioinspired self-a...
Article
In inflammatory bowel diseases (IBD), it is known that besides genetic and environmental factors (e.g. diet, drugs, stress), the microbiota play an important role in the pathogenesis. Patients with IBD have an altered microbiota (dysbiosis) and therefore, probiotics, defined as 'live micro-organisms that when administered in adequate amounts can co...
Article
Aims: To investigate the spatial organization of endogenous and exogenously applied Lactobacillus communities at specific locations in the adult gastrointestinal tract of different hosts. Methods and results: Samples of the human, murine and avian gastrointestinal tract of subjects that received or not received a Lactobacillus probiotic were ana...
Article
While some probiotic strains might have adjuvant effects in the therapy for inflammatory bowel diseases (IBD), these effects remain controversial and cannot be generalized. In this study, a dltD mutant of the model probiotic Lactobacillus rhamnosus GG (LGG), having a drastic modification in its lipoteichoic acid (LTA) molecules, was analysed for it...
Article
Abstract The probiotic Lactobacillus rhamnosus GG, first isolated from healthy human gut microbiota, has been reported to adhere very well to components of the intestinal mucosa, thereby enabling transient colonization of the gastrointestinal tract (GIT). In a search for the genes responsible for the good adherence capacity of this strain, a genomi...
Article
Probiotic bacteria are administered as live microorganisms to provide a health benefit to the host. Insight into the adaptation factors that promote the survival and persistence of probiotics in the gastrointestinal tract (GIT) is important to understand their performance. In this study, the role of the long galactose-rich exopolysaccharides (EPS)...
Article
Full-text available
It is generally believed that probiotic bacteria need to survive gastrointestinal transit to exert a health-promoting effect. In this study, a genuine luxS mutant and a luxS mutant containing unknown suppressor mutations of the probiotic strain Lactobacillus rhamnosus GG were compared to the wild type for survival and persistence in the murine gast...

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Projects (2)
Project
At YUN, in close collaboration with the University of Antwerp, we are building a new era of personal care based on everyone’s natural strength. YUN is doing this based on good bacteria which protect, strenghten and repair the skin’s natural protective layer. To do so, YUN has developed effective solutions for common skin conditions and personal care