Browsing by Person "Brzozowska, Ewa"

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Intestinal dysbiosis associated with non-nutritive sweeteners intake: an effect without a cause?
(2025) Marongiu, Luigi; Brzozowska, Ewa; Hetjens, Svetlana; Hoelzle, Ludwig E.; Venturelli, Sascha; Brzozowska, Ewa; Laboratory of Medical Microbiology, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland; Hetjens, Svetlana; Department of Medical Statistics, Biomathematics and Information Processing, University Clinic Mannheim, Mannheim, Germany; Hoelzle, Ludwig E.; Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, University of Hohenheim, Stuttgart, Germany; Venturelli, Sascha; Department of Nutritional Biochemistry, University of Hohenheim, Stuttgart, Germany
Non-nutritive sweeteners (NNS) are present in various commercial articles, from foodstuffs to oral hygiene products. Despite their alleged safety, mounting evidence indicates that NNS intake is associated with an alteration of intestinal bacterial populations (dysbiosis) in animals and humans. Since NNS are commercialized based on the assumption that they are not metabolized by human cells and negligible effect on bacterial, the insurgence of dysbiosis associated with NNS intake remains unexplained. The current review aims to assess the effect of selected NNS (acesulfame potassium, advantame, aspartame, neotame, saccharin, stevia, and sucralose) on the human intestinal microbiota. Findings from this review suggests that NNS intake is linked not only to alterations in human physiology but also to modifications of bacterial biochemistry, including the hindrance of quorum sensing pathways, in a species-specific manner. Moreover, there were suggestions that NNS could also affect the biology of phages, namely by binding to the active sites of proteins involved in the infection process and altering the induction rate of prophages. The studies gathered in the present review provide a framework for understanding how NNS might be connected to dysbiosis, both directly through alterations in bacterial biochemistry and indirectly through impaired phage activity.
The non-nutritive sweetener rebaudioside a enhances phage infectivity
(2025) Marongiu, Luigi; Brzozowska, Ewa; Brykała, Jan; Burkard, Markus; Schmidt, Herbert; Szermer-Olearnik, Bożena; Venturelli, Sascha
Non-nutritive sweeteners (NNS) are widely employed in foodstuffs. However, it has become increasingly evident that their consumption is associated with bacterial dysbiosis, which, in turn, is linked to several health conditions, including a higher risk of type 2 diabetes and cancer. Among the NNS, stevia, whose main component is rebaudioside A (rebA), is gaining popularity in the organic food market segment. While the effect of NNS on bacteria has been established, the impact of these sweeteners on bacterial viruses (phages) has been neglected, even though phages are crucial elements in maintaining microbial eubiosis. The present study sought to provide a proof-of-concept of the impact of NNS on phage infectivity by assessing the binding of rebA to phage proteins involved in the infection process of enteropathogenic bacteria, namely the fiber protein gp17 of Yersinia enterocolitica phage φYeO3-12 and the tubular baseplate protein gp31 of Klebsiella pneumoniae phage 32. We employed docking analysis and a panel of in vitro confirmatory tests (microscale thermophoresis, RedStarch ™ depolymerization, adsorption, and lysis rates). Docking analysis indicated that NNS can bind to both fiber and baseplate proteins. Confirmatory assays demonstrated that rebA can bind gp31 and that such binding increased the protein’s enzymatic activity. Moreover, the binding of rebA to gp17 resulted in a decrease in the adsorption rate of the recombinant protein to its host but increased the Yersinia bacteriolysis caused by the whole phage compared to unexposed controls. These results support the hypothesis that NNS can impair phage infectivity, albeit the resulting effect on the microbiome remains to be elucidated.