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Quorum sensing peptides (QSPs) are bacterial peptides produced by Gram-positive bacteria to communicate with their peers in a cell-density dependent manner. These peptides do not only act as interbacterial communication signals, but can also have effects on the host. Compelling evidence demonstrates the presence of a gut-brain axis and more specifically, the role of the gut microbiota in microglial functioning. The aim of this study is to investigate microglial activating properties of a selected QSP (PapRIV) which is produced by Bacillus cereus species. PapRIV showed in vitro activating properties of BV-2 microglia cells and was able to cross the in vitro Caco-2 cell model and reach the brain. In vivo peptide presence was also demonstrated in mouse plasma. The peptide caused induction of IL-6, TNFα and ROS expression and increased the fraction of ameboid BV-2 microglia cells in an NF-κB dependent manner. Different metabolites were identified in serum, of which the main metabolite still remained active. PapRIV is thus able to cross the gastro-intestinal tract and the blood–brain barrier and shows in vitro activating properties in BV-2 microglia cells, hereby indicating a potential role of this quorum sensing peptide in gut-brain interaction. [ABSTRACT FROM AUTHOR]

Background: Sarcopenia, defined as the pathological decline in muscle mass, muscle strength and physical performance with aging, has become one of the geriatric giants because of its increasing prevalence and devastating health effects. The Belgian Society of Gerontology and Geriatrics (BSGG) is currently developing evidence-based guidelines for the prevention and therapy of sarcopenia for use in broad clinical practice. This systematic review summarizes the results of the Working Group on Pharmacology.Objective: Our objective was to provide an evidence-based overview of the possible pharmacological interventions for sarcopenia with a focus on interventions that have already been studied in systematic reviews or meta-analyses.Methods: We conducted a systematic umbrella review. Using the electronic databases PubMed and Web of Science, we identified systematic reviews and meta-analyses that assessed the effect of pharmacological interventions on criteria for sarcopenia in subjects aged ≥ 65 years. Study selection, quality assessment and data extraction were performed by two independent reviewers.Results: We identified seven systematic reviews or meta-analyses, encompassing ten pharmacological interventions: vitamin D, combined estrogen-progesterone, dehydroepiandrosterone, growth hormone, growth hormone-releasing hormone, combined testosterone-growth hormone, insulin-like growth factor-1, pioglitazone, testosterone and angiotensin-converting enzyme inhibitors. Importantly, very few systematic reviews or meta-analyses clearly mentioned baseline sarcopenia status. Therefore, our recommendations are generalised to older people, without specifying whether the muscle effect is more effective in healthy, pre-sarcopenic or sarcopenic older people. Vitamin D had a significant effect on muscle strength and physical performance, especially in women with low baseline values (< 25 nmol/l). Adverse events were rare. Testosterone had a strong effect on muscle mass and a modest to minimal effect on muscle strength and physical performance, respectively, when supplementing men with low serum levels (< 200-300 ng/dl). The adverse events were rare and mild. Insufficient evidence was available to recommend other pharmacological interventions.Conclusion: Only vitamin D, especially in older women, and testosterone in older men with clinical muscle weakness and low testosterone serum levels can be justified in daily clinical practice to improve muscle mass, muscle strength and/or physical performance. [ABSTRACT FROM AUTHOR]