Selenium: From Redox Signaling to Interactions with the Gut Microbiome

Selenium is an element that plays a crucial role in the proper functioning of the body. It is a component of selenoproteins, which exhibit strong antioxidant properties. This allows it to neutralize reactive oxygen species and protect cells from oxidative stress. It also plays a crucial role in supporting the proper functioning of the immune system. In this context, particular importance is attributed to its influence on the Th1/Th2 immune response and the activity of T lymphocytes and NK cells. There is a mutual relationship between selenium and the intestinal microbiota. Microorganisms in the gastrointestinal tract participate in the accumulation, transformation, and differentiation of selenium's chemical forms. These processes influence selenium's bioavailability and its activity in the host organism. The development of metagenomic methods has enabled the identification of specific selenium-dependent metabolic pathways within the microbiome. This represents an important research direction in the development of this field of biotechnology. In turn, appropriate selenium levels and selenoprotein activity influence the composition of the intestinal microbiota and the metabolite profile it produces. It is worth emphasizing that in the context of the development of microbiome engineering, there are also emerging concepts of designing probiotics capable of controlled selenium biotransformation. The beneficial properties of selenium for organisms depend on its appropriate chemical form and dose. It is worth noting that selenium deficiency can impair the antioxidant system, leading to a redox imbalance. Such processes can weaken the integrity of the intestinal barrier, leading to the development of various gastrointestinal diseases. Therefore, the interaction with intestinal microflora is such a crucial element of selenium's action. Microorganisms inhabiting the digestive tract participate in the processes of accumulation and transformation of various chemical forms of this element. These biochemical properties of microorganisms are crucial for the bioavailability of selenium in the human body. Therefore, the appropriate form of selenium is crucial for the proper functioning of the intestinal barrier. This article discusses the importance of selenium in redox processes and in the function of the gut microbiota. It highlights the potential role of this element in the prevention and treatment of gastrointestinal diseases. Future research should focus on further understanding these interactions and developing targeted approaches that utilize selenium-dependent pathways to restore intestinal homeostasis.