Felix Sommer

Felix Sommer
Christian-Albrechts-Universität zu Kiel | CAU · Institute of Clinical Molecular Biology

PhD

About

171
Publications
26,300
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Introduction
My main scientific interest is to understand the intricate and complex interactions between the host, its associated microbiota and environmental factors that determine a healthy homeostasis of the metaorganism. A particular focus lies on selection mechanisms shaping the intestinal ecosystem and how the microbiota contributes to host metabolism and immune responses. My current research investigates the functional effects of nutritional variations, i.e. malnutrition or excessive caloric regimes, on host-microbe interactions and host health. Together my research projects aim to develop novel therapeutic strategies for treating common metabolic and inflammatory disorders by targeting the microbiota.
Additional affiliations
October 2015 - present
Christian-Albrechts-Universität zu Kiel
Position
  • PostDoc Position
September 2010 - September 2015
University of Gothenburg
Position
  • PostDoc Position

Publications

Publications (171)
Article
Full-text available
Energy and anabolic metabolism are essential for normal cellular homeostasis but also play an important role in regulating immune responses and cancer development as active immune and cancer cells show an altered metabolic profile. Mitochondria take a prominent position in these metabolic reactions. First, most key energetic reactions take place wi...
Article
Full-text available
Colon cancer is one of the leading causes of death within the western world, incidence of which increases with age. The colonic epithelium is a rapidly renewing tissue, tasked with water and nutrient absorption, as well as hosting intestinal microbes. The colon sub-mucosa is populated with immune cells interacting with and regulating the epithelial...
Article
The microbiota of hibernating squirrels salvages urea to replenish amino acids
Article
Background & Aims Crohn’s disease (CD) globally emerges with Westernization of lifestyle and nutritional habits. However, a specific dietary constituent that comprehensively evokes gut inflammation in human IBD remains elusive. Here, we aimed at delineating how increased intake of polyunsaturated fatty acids (PUFAs) in a Western diet, known to impa...
Article
Hexokinases (HK) catalyze the first step of glycolysis limiting its pace. HK2 is highly expressed in gut epithelium, contributes to immune responses, and is upregulated during inflammation. We examined the microbial regulation of HK2 and its impact on inflammation using mice lacking HK2 in intestinal epithelial cells (Hk2ΔIEC). Hk2ΔIEC mice were le...
Article
Full-text available
The gut microbiota affects remote organ functions but its impact on organotypic endothelial cell (EC) transcriptomes remains unexplored. The liver endothelium encounters microbiota-derived signals and metabolites via the portal circulation. To pinpoint how gut commensals affect the hepatic sinusoidal endothelium, a magnetic cell sorting protocol, c...
Article
Full-text available
Background Human well-being has been linked to the composition and functional capacity of the intestinal microbiota. As regular exercise is known to improve human health, it is not surprising that exercise was previously described to positively modulate the gut microbiota, too. However, most previous studies mainly focused on either elite athletes...
Preprint
Full-text available
Hexokinases (HK) catalyze the first step of glycolysis and thereby limit its pace. HK2 is highly expressed in the gut epithelium, plays a role in immune responses and is upregulated in inflammation and ulcerative colitis. Here, we examined the microbial regulation of HK2 and its impact on intestinal inflammation by generating mice lacking HK2 speci...
Article
Full-text available
The molecular foundation of chronic inflammatory diseases (CIDs) can differ markedly between individuals. As our understanding of the biochemical mechanisms underlying individual disease manifestations and progressions expands, new strategies to adjust treatments to the patient's characteristics will continue to profoundly transform clinical practi...
Article
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Homeostatic interactions with the microbiome are central for a healthy human physiology and nutrition is the main driving force shaping the microbiome. In the past decade, a wealth of preclinical studies mainly using gnotobiotic animal models demonstrated that malnutrition and chronic inflammation stress these homeostatic interactions and various m...
Preprint
Full-text available
Background: Human well-being has been linked to the composition and functional capacity of the intestinal microbiota. As regular exercise is known to improve human health, it is not surprising that exercise was previously described to positively modulate the gut microbiota, too. However, most previous studies mainly focused on either elite athletes...
Article
Full-text available
Over-consumption of high-fat diets (HFDs) is associated with several pathologies. Although the intestine is the organ that comes into direct contact with all diet components, the impact of HFD has mostly been studied in organs that are linked to obesity and obesity related disorders. We used Drosophila as a simple model to disentangle the effects o...
Article
Full-text available
The increased incidence of inflammatory bowel disease (IBD) has become a global phenomenon that could be related to adoption of a Western life-style. Westernization of dietary habits is partly characterized by enrichment with the ω-6 polyunsaturated fatty acid (PUFA) arachidonic acid (AA), which entails risk for developing IBD. Glutathione peroxida...
Article
Full-text available
Background & Aims Loss-of-function variants in nucleotide-binding oligomerization domain-containing protein 2 (NOD2) impair the recognition of the bacterial cell wall component muramyl-dipeptide and are associated with an increased risk for developing Crohn’s disease (CD). Likewise, exposure to antibiotics increases the individual risk for developi...
Article
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α-Linolenic acid (ALA) is well-known for its anti-inflammatory activity. In contrast, the influence of an ALA-rich diet on intestinal microbiota composition and its impact on small intestine morphology are not fully understood. In the current study, we kept adult C57BL/6J mice for 4 weeks on an ALA-rich or control diet. Characterization of the micr...
Article
Full-text available
Multicellular life evolved in the presence of microorganisms and formed complex associations with their microbiota, the sum of all associated archaea, bacteria, fungi and viruses. These associations greatly affect the health and life history of the host, which led to a new understanding of “self” and establishment of the “metaorganism” concept. How...
Article
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Atherosclerotic plaque development depends on chronic inflammation of the arterial wall. A dysbiotic gut microbiota can cause low-grade inflammation, and microbiota composition was linked to cardiovascular disease risk. However, the role of this environmental factor in atherothrombosis remains undefined. To analyze the impact of gut microbiota on a...
Article
Full-text available
Background:The interplay between hosts and their associated microbiome is now recognized as a fundamental basis of the ecology, evolution, and development of both players. These interdependencies inspired a new view of multicellular organisms as “metaorganisms.” The goal of the Collaborative Research Center “Origin and Function of Metaorganisms” is...
Article
Background Human diseases are often associated with changes in the microbiome.Objectives The goal of the work was to investigate the contribution of the microbiome to diseases associated with aging and their treatment.ResultsThere are considerable changes in the microbiome and its environment in the context of aging. In the treatment of diseases as...
Preprint
Over-consumption of high-fat diets (HFDs) is associated with several pathologies. Although the intestine is the organ that comes into direct contact with all diet components, the impact of HFD has mostly been studied in organs that are linked to obesity and obesity related disorders. We used Drosophila as a simple model to disentangle the effects o...
Preprint
Full-text available
Background The interplay between hosts and their associated microbiome is now recognized as a fundamental basis of the ecology, evolution and development of both players. These interdependencies inspired a new view of multicellular organisms as “metaorganisms”. The goal of the Collaborative Research Center “Origin and Function of Metaorganisms” is...
Article
Full-text available
Animals are usually regarded as independent entities within their respective environments. However, within an organism, eukaryotes and prokaryotes interact dynamically to form the so-called metaorganism or holobiont, where each partner fulfils its versatile and crucial role. This review focuses on the interplay between microorganisms and multicellu...
Article
Full-text available
In Fig. 1d of this Letter, the third group along should have been labelled 'WT' rather than 'Tlr5'. This has been corrected online.
Data
Summary of effects of specific microorganisms on cancer. This table provides an overview of the known functions of specific microorganisms for cancer development or treatment of the respective hosts–human, mouse, and Drosophila.
Article
Full-text available
The eukaryotic host is in close contact to myriads of resident and transient microbes, which influence the crucial physiological pathways. Emerging evidence points to their role of host–microbe interactions for controlling tissue homeostasis, cell fate decisions, and regenerative capacity in epithelial barrier organs including the skin, lung, and g...
Article
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Alterations in enteric microbiota are associated with several highly prevalent immune-mediated and metabolic diseases1,2,3, and experiments involving faecal transplants have indicated that such alterations have a causal role in at least some such conditions4,5,6. The postnatal period is particularly critical for the development of microbiota compos...
Article
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Background: The interplay of epigenetic processes and the intestinal microbiota may play an important role in intestinal development and homeostasis. Previous studies have established that the microbiota regulates a large proportion of the intestinal epithelial transcriptome in the adult host, but microbial effects on DNA methylation and gene expr...
Article
The composition of the intestinal microbiota varies among individuals and throughout development, and is dependent on host and environmental factors. However, although the microbiota is constantly exposed to environmental challenges, its composition and function in an individual are stable against perturbations, as microbial communities are resilie...
Article
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Human gut microbiota is an important determinant for health and disease, and recent studies emphasize the numerous factors shaping its diversity. Here we performed a genome-wide association study (GWAS) of the gut microbiota using two cohorts from northern Germany totaling 1,812 individuals. Comprehensively controlling for diet and non-genetic para...
Article
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Enteropathogenic Escherichia coli (EPEC) represents a major causative agent of infant diarrhea associated with significant morbidity and mortality in developing countries. Although studied extensively in vitro, the investigation of the host-pathogen interaction in vivo has been hampered by the lack of a suitable small animal model. Using RT-PCR and...
Data
Characterization of the different EPEC strains used in this study. (A) Immunostaining of colonic tissue sections collected 8 days p.i. from mice orally infected at birth with WT EPEC (EPEC, red; E-cadherin, white; wheat germ agglutinin (mucus), green; DAPI, blue; bar = 10μm). (B) mICcl2 cells grown for 6 days on 8 chamber slides were left untreated...
Data
Microbiota-independent generation of EPEC microcolonies in neonates. (A) Immunostaining of small intestinal tissue sections collected 8 days p.i. from GF mice orally infected on the day of birth with WT EPEC (EPEC, red; E-cadherin, white; wheat germ agglutinin (mucus), green; DAPI, blue, bar = 5μm). (B) Number of microcolonies per small intestinal...
Data
OTUs significantly altered between infected and non-infected animals. Bacterial DNA was extracted from the small intestine and the colon of newborn mice infected with WT EPEC or left untreated at 8 and 20 days p.i. and analyzed by 16S rDNA sequencing. The table lists all OTUs that were significantly altered upon infection. (XLSX)
Data
Clinical consequences of EPEC infection. (A) 1-day-old mice were orally infected with WT EPEC. The small intestine was collected at 8 days p.i. and divided into 3 equal parts. Each part was homogenized and plated on LB agar plates supplemented with the appropriate antibiotic (n = 10 from 2 different litters; mean ± SD). (B-C) 1-day-old mice were or...
Article
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Interactions between the host and its associated microbiota differ spatially and the local cross talk determines organ function and physiology. Animals and their organs are not uniform but contain several functional and cellular compartments and gradients. In the intestinal tract, different parts of the gut carry out different functions, tissue str...
Article
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Hibernation is an adaptation that helps many animals to conserve energy during food shortage in winter. Brown bears double their fat depots during summer and use these stored lipids during hibernation. Although bears seasonally become obese, they remain metabolically healthy. We analyzed the microbiota of free-ranging brown bears during their activ...
Article
Full-text available
Objective: The gut microbiota has been implicated as an environmental factor that modulates obesity, and recent evidence suggests that microbiota-mediated changes in bile acid profiles and signalling through the bile acid nuclear receptor farnesoid X receptor (FXR) contribute to impaired host metabolism. Here we investigated if the gut microbiota...
Article
Full-text available
The two gut hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) are well known to be co-expressed, co-stored and released together to co-act in the control of key metabolic target organs. However, recently it became clear that several other gut hormones can be co-expressed in the intestinal specific lineage of enteroendocrine cells. Here...
Article
Full-text available
The intestinal epithelium separates us from the microbiota but also interacts with it and thus affects host immune status and physiology. Previous studies investigated microbiota-induced responses in the gut using intact tissues or unfractionated epithelial cells, thereby limiting conclusions about regional differences in the epithelium. Here, we s...