Biology subjects

Hannig, M.

Publications and source records attributed to Hannig, M..

3 recordsLinked to original sources

bioRxiv2025

Joint bacterial traces in the gut and oral cavity of Colitis patients provide evidence for saliva as rich microbial biomarker source

The human microbiome, distributed across various anatomical sites, holds promise for identifying diagnostic biomarkers and therapeutic targets in disease. In inflammatory bowel disease (IBD), including ulcerative colitis (UC), interactions between the gut and oral microbiomes are crucial for understanding disease mechanisms and guiding interventions. The IMAGINE study sequenced 1,931 specimens from saliva, plaque, stool, and other sources in patients and healthy controls. Here, we assess whether the oral (saliva/plaque) or gut microbiota provides greater diagnostic potential in IBD and examine shared dysregulation across sample types. Among 177 oral samples (102 healthy, 75 IBD) and 92 stool samples (57 healthy, 35 IBD), we identified 240 distinct strains in plaque, 229 in saliva, and 231 in stool, with 46 strains present in all three. Saliva showed a significantly higher average effect size (0.2) than stool (0.04) and plaque (0.06). Notably, Actinomyces sp., Bifidobacterium dentium, and Veillonella parvula exhibited increased effect sizes, suggesting their potential as diagnostic markers or therapeutic targets. These findings indicate that microbiome profiling in IBD may improve diagnostics and treatment strategies.

microbiology↗

bioRxiv2023

Extracellular release of a disintegrin and metalloproteinases orchestrates periodontal disease severity

Periodontal diseases are amongst the most common pathologies worldwide with a high risk for the development of systemic complications. Periodontal disease is driven by oral pathogens such as Porphyromonas gingivalis and the release of inflammatory cytokines. These cytokines (e.g. TNF) or their receptors (IL-1R) are substrates of a disintegrin and metalloproteinases (ADAMs). In a comparative approach, we observed an increase of ADAM8 protein expression and activity in the sulcus fluid of periodontal disease patients correlating with the disease stage. In contrast, the induced ADAM10 expression was decreased. In vitro mechanistic studies revealed that both Porphyromonas gingivalis infection and the resulting cytokine release orchestrated the release of soluble ADAM8 by keratinocytes and neutrophils as soluble ectodomain and on exosomes, respectively. Furthermore, ADAM8 regulated the release of ADAM10 and MMP9, thereby potentially influencing wound healing and tissue destruction. Thus, the dysregulation of the cell-associated and extracellular ADAM proteolytic activity mainly driven by ADAM8 may be an essential regulatory element in periodontal disease onset and progression. This potential as novel local treatment option should be addressed in future translational studies.

immunology↗

bioRxiv2021

Hydroxyapatite pellets as versatile model surfaces for systematic studies on enamel

Research into materials for medical application draws inspiration from naturally occurring or synthesized surfaces, just like many other research directions. For medical application of materials, particular attention has to be paid to biocompatibility, osseointegration and bacterial adhesion behavior. To understand their properties and behavior, experimental studies with natural materials such as teeth are strongly required. The results, however, may be highly case-dependent because natural surfaces have the disadvantage of being subject to wide variations, for instance in their chemical composition, structure, morphology, roughness, and porosity. A synthetic surface which mimics enamel in its performance with respect to bacterial adhesion and biocompatibility would, therefore, facilitate systematic studies much better. In this study, we discuss the possibility of using hydroxyapatite (HAp) pellets to simulate the surfaces of teeth and show the possibility and limitations of using a model surface. We performed single-cell force spectroscopy with single Staphylococcus aureus cells to measure adhesion-related parameters such as adhesion force and rupture length of adhesins binding to HAp and enamel. We also examine the influence of blood plasma and saliva on the adhesion properties of S. aureus. The results of these measurements are matched to water wettability, elemental composition of the samples and the change in the macromolecules adsorbed over time. We found that the adhesion properties of S. aureus were similar on both samples under all conditions: Significant decreases in adhesion strength were found equally in the presence of saliva or blood plasma on both surfaces. We therefore conclude that HAp pellets are a good alternative for natural dental material. This is especially true when slight variations in the physicochemical properties of the natural materials may affect the experimental series.

biophysics↗