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Amino acids are organic compounds that serve as the fundamental building blocks of proteins. In addition to their role in tissue synthesis, they are involved in the production of enzymes, hormones, neurotransmitters, and numerous other biologically active molecules. Twenty standard amino acids have been identified in the human body, which together enable the synthesis of all bodily proteins.
Antioxidants include enzymes and other compounds that limit or prevent oxidative damage by neutralizing free radicals and other reactive molecules. The body possesses its own antioxidant defense systems, while additional amounts are obtained through a diet rich in fruits, vegetables, and other plant-based foods. Their function is based on maintaining the redox balance necessary for normal cellular function.
The capacity of the immune system to react against the body’s own antigens. Under physiological conditions, such reactions are controlled by mechanisms of immune tolerance, whereas their dysregulation may lead to the development of autoimmune diseases. The onset of these conditions results from a complex interaction of genetic predisposition, environmental factors, and alterations in immune regulation.
Bioavailability refers to the extent and rate at which an active substance reaches the systemic circulation following administration and becomes available at its site of action. This parameter is influenced by the chemical properties of the compound, the pharmaceutical formulation, the route of administration, processes of absorption, metabolism, and elimination, as well as individual physiological characteristics. It is considered one of the key indicators of the effectiveness of medicines and dietary supplements.
A biofilm is an organized community of microorganisms attached to a biological or inert surface and enclosed within a protective extracellular matrix that they produce themselves. This organization facilitates intercellular communication, nutrient exchange, and increased resistance to external influences, including certain antimicrobial agents and the host immune system.
The force exerted by circulating blood against the walls of the arteries during cardiac activity and circulation. It is expressed as systolic and diastolic pressure, which reflect the pressure during contraction and relaxation of the heart muscle, respectively. Blood pressure values depend on cardiac output, vascular elasticity, and peripheral vascular resistance, while persistently elevated blood pressure is considered one of the leading risk factors for cardiovascular disease.
Carbohydrates are the primary source of energy for most cells in the body. Following digestion, they are broken down into simple sugars, primarily glucose, which serves as the principal metabolic fuel for the brain, muscles, and other tissues. Their physiological effects depend on their chemical structure, fiber content, and the overall composition of the meal.
Cellular stress encompasses the adaptive responses by which cells react to adverse conditions such as oxidative stress, infections, oxygen deprivation, nutritional deficiencies, or exposure to toxins. By activating protective signaling pathways, cells strive to preserve their function and prevent permanent damage. When the intensity or duration of these stimuli exceeds the cell’s adaptive capacity, cellular dysfunction or cell death may occur.
A lipid molecule essential for the formation of cell membranes and the synthesis of steroid hormones, vitamin D, and bile acids. The majority of cholesterol is produced by the liver, while smaller amounts are obtained through foods of animal origin. Because it is not water-soluble, it is transported through the bloodstream bound to lipoproteins of varying densities, whose composition and function determine its metabolic significance.
An internal biological cycle that lasts approximately 24 hours and synchronizes physiological processes with the day–night cycle. It regulates hormone secretion, the sleep–wake cycle, body temperature, metabolism, and numerous other bodily functions. The central regulator of this rhythm is located in the hypothalamus, while light serves as the most important external cue involved in its synchronization.
The most abundant structural protein in the human body and a fundamental component of connective tissue. It contributes to the formation of the skin, bones, cartilage, tendons, ligaments, blood vessels, and other tissues by providing mechanical strength and elasticity. The synthesis of collagen naturally declines with age and may also be influenced by diet, hormonal status, smoking, and exposure to ultraviolet radiation.
A diverse group of signaling proteins produced by immune cells, as well as by numerous other cell types within the body. Their primary role is to facilitate communication between cells and coordinate immune responses, inflammation, tissue repair, and hematopoiesis. Depending on their type and concentration, cytokines may exert pro-inflammatory or anti-inflammatory effects, thereby maintaining the balance between the activation and resolution of immune processes.
Detoxification comprises the physiological processes through which the body chemically modifies and eliminates potentially harmful substances produced during metabolism or introduced from the external environment. The liver, kidneys, digestive system, lungs, and skin play key roles in these processes, with most biochemical reactions being mediated by specific enzymes. These mechanisms function continuously and represent an integral part of the body’s normal physiology.
Dietary fiber consists of indigestible components of plant-based foods that pass through the small intestine without being digested and serve as substrates for fermentation by the intestinal microbiota in the large intestine. They contribute to normal digestive function, influence stool consistency, promote satiety, and help regulate postprandial glycemia. Certain types of dietary fiber also play a significant role in maintaining the health of the gut microbiome.
A qualitative or quantitative disturbance in the composition, diversity, or metabolic activity of the microbiota. It may arise as a consequence of antibiotic use, inadequate nutrition, infections, chronic stress, or other factors that disrupt microbial balance. Dysbiosis has been associated with impaired intestinal barrier function, altered immune responses, and an increased risk of various gastrointestinal, metabolic, and inflammatory conditions.
Minerals that carry an electrical charge in body fluids and are essential for numerous physiological processes. Sodium, potassium, calcium, magnesium, chloride, and phosphate are involved in maintaining fluid balance, transmitting nerve impulses, facilitating muscle contraction, regulating acid-base balance, and supporting normal cardiac function. Their concentrations are maintained within narrow physiological ranges through complex mechanisms of hormonal and renal regulation.
Biological catalysts that accelerate biochemical reactions without being consumed during the process. Nearly all metabolic pathways in the body depend on their activity, including food digestion, energy production, protein synthesis, DNA repair, and the regulation of cellular signaling pathways. Their function depends on precise environmental conditions, such as temperature, pH, and the presence of appropriate cofactors.
Essential amino acids are those that cannot be synthesized by the body in sufficient quantities and must therefore be obtained through the diet. They are indispensable for protein synthesis, tissue growth and repair, the preservation of muscle mass, and the normal functioning of the immune system. Their quality and quantity are important indicators of the nutritional value of protein-containing foods.
Fats are a group of lipids with multiple physiological functions, including energy storage, the formation of cell membranes, hormone synthesis, and the absorption of fat-soluble vitamins. The quality of dietary fats is considered more important than their total quantity, which is why contemporary nutritional recommendations place particular emphasis on the types of fatty acids consumed.
Fatty acids are the fundamental structural components of fats and phospholipids that contribute to the formation of cell membranes, energy storage, and the synthesis of numerous signaling molecules. Depending on their chemical structure, they are classified as saturated, monounsaturated, or polyunsaturated fatty acids, each possessing distinct physiological characteristics and metabolic functions.
A biochemical process in which microorganisms or their enzymatic activities break down organic substances in the absence of oxygen or under conditions of limited oxygen availability. During this process, various metabolites are produced, including organic acids, vitamins, and other bioactive compounds that may alter the nutritional and functional properties of foods or raw materials. In the pharmaceutical and food industries, fermentation is used in the production of numerous active ingredients, while contemporary research continues to investigate its role in enhancing the bioavailability of certain compounds.
Ferritin is the principal intracellular iron-storage protein and the most important laboratory marker of the body’s iron reserves. Its concentration in the blood may indicate depleted or increased iron stores, although its values must be interpreted in conjunction with other laboratory parameters, as ferritin is also an acute-phase protein whose concentration increases during inflammation and certain chronic diseases.
Molecules or atoms containing one or more unpaired electrons, which makes them highly chemically reactive. They are produced as part of normal cellular metabolism, particularly during energy production in the mitochondria, but may also arise as a result of external factors such as ultraviolet radiation, tobacco smoke, or environmental pollution. At physiological concentrations, they play important roles in cellular signaling and defense against microorganisms, whereas their excessive accumulation may contribute to oxidative tissue damage.
Glucose is the most important monosaccharide and the primary source of energy for most cells of the human body. Its concentration in the bloodstream is maintained within narrow physiological ranges through complex regulatory mechanisms involving hormones, particularly insulin and glucagon. Long-term disturbances of this regulation have been associated with the development of metabolic disorders, including diabetes mellitus.
A measure of the rate at which carbohydrate-containing foods increase blood glucose concentrations compared with a reference food. Its value depends on the type of carbohydrates, fiber content, food preparation methods, and the presence of fats or proteins within a meal. It is used as one of the indicators of the effects of specific foods on postprandial glycemia.
A parameter that takes into account both the glycemic index and the amount of carbohydrates contained in a single serving of food. As such, it provides a more accurate estimate of a meal’s actual impact on blood glucose concentrations than the glycemic index alone. Its application is particularly important in dietary planning for individuals with disorders of glucose metabolism.
High-density lipoprotein (HDL) is involved in the transport of excess cholesterol from peripheral tissues back to the liver, where it is further metabolized or excreted. This process, known as reverse cholesterol transport, is considered one of the mechanisms that contribute to maintaining vascular health. Higher HDL cholesterol concentrations are generally associated with lower cardiovascular risk, although their significance is evaluated within the context of an individual’s overall lipid profile.
Hemoglobin is a protein found in red blood cells that enables the transport of oxygen from the lungs to tissues and the return transport of a portion of carbon dioxide back to the lungs. Its structure consists of four protein chains and four iron-containing heme groups that are essential for oxygen binding. Blood hemoglobin concentration is one of the primary indicators of the body’s capacity to supply tissues with oxygen.
The ability of the body to maintain a stable internal environment despite continuous changes in both external and internal conditions. This dynamic process includes the regulation of body temperature, blood pressure, glucose concentration, pH levels, electrolyte balance, and other physiological parameters. Its maintenance depends on the coordinated activity of the nervous, endocrine, and immune systems.
Biologically active signaling molecules secreted by endocrine glands or specific tissues that exert their effects on target cells through specialized receptors. Their primary role is to coordinate numerous physiological processes, including growth and development, metabolism, reproductive functions, the stress response, and the maintenance of homeostasis. Even minor changes in their concentrations can significantly influence the functioning of the body.
A complex system of innate and adaptive defense mechanisms that enables the recognition and elimination of potentially harmful microorganisms while also monitoring altered or damaged cells within the body. Its function relies on the coordinated activity of numerous cells, signaling molecules, and lymphoid organs. The effectiveness of the immune system is influenced by genetic factors, age, nutritional status, and overall health.
A coordinated biological response of the body to infection, injury, or other forms of tissue damage, aimed at eliminating the cause of harm and initiating tissue repair processes. During this process, numerous immune cells are activated and mediators are released to regulate the intensity and duration of the response. While acute inflammation is a physiological protective mechanism, chronic low-grade inflammation is considered one of the factors involved in the development of many chronic non-communicable diseases.
Insulin is a peptide hormone produced by the pancreatic β-cells in response to elevated blood glucose concentrations. Its primary functions include facilitating the uptake of glucose into cells, regulating carbohydrate, fat, and protein metabolism, and promoting the storage of energy in the form of glycogen and triglycerides. Disturbances in insulin secretion or action underlie the development of diabetes mellitus and other metabolic disorders.
A condition in which the body’s cells exhibit a reduced response to insulin, prompting the pancreas to secrete increasing amounts of this hormone in an effort to maintain normal blood glucose concentrations. Over time, this compensatory mechanism may become insufficient, increasing the risk of developing prediabetes and type 2 diabetes mellitus. Insulin resistance is frequently associated with abdominal obesity, metabolic syndrome, and chronic low-grade inflammation.
A multilayered protective system composed of epithelial cells, intercellular junctions, a protective mucus layer, immune cells, and the intestinal microbiota. Its primary function is the selective absorption of nutrients while simultaneously preventing the passage of pathogenic microorganisms, toxins, and other potentially harmful substances into the body’s internal environment. Preserving its integrity is considered essential for the normal functioning of both the digestive and immune systems.
Low-density lipoprotein (LDL) is responsible for transporting cholesterol from the liver to peripheral tissues. When its concentration is elevated, cholesterol may accumulate within arterial walls and contribute to the formation of atherosclerotic plaques. Persistently elevated LDL cholesterol levels are considered one of the most significant risk factors for cardiovascular disease.
Macronutrients are nutrients that provide the body with energy and the building blocks necessary for growth, development, and the maintenance of vital functions. This group includes proteins, carbohydrates, and fats, whose relative proportions significantly influence metabolic health, body weight, and body composition.
The sum of all biochemical reactions that enable energy production, the synthesis of new molecules, and the breakdown of existing compounds necessary for sustaining life. It consists of catabolic processes, during which complex substances are broken down with the release of energy, and anabolic processes, in which that energy is utilized to build cellular components. Its regulation is controlled by hormones, enzymes, and various signaling pathways.
A complex ecosystem of microorganisms that naturally inhabit the human body, with the greatest diversity found in the digestive system. It is involved in the breakdown of certain dietary components, vitamin synthesis, the production of short-chain fatty acids, the maturation of the immune system, and the maintenance of intestinal barrier function. Changes in its composition and metabolic activity have been associated with various gastrointestinal, metabolic, and immune-related disorders, although the precise clinical significance of many underlying mechanisms remains under investigation.
Micronutrients are vitamins and minerals required by the body in relatively small amounts but are essential for numerous biochemical processes. They contribute to energy production, immune and nervous system function, hormone synthesis, protection against oxidative stress, and the maintenance of healthy bones, skin, and other tissues. Inadequate intake or increased physiological requirements may lead to various disorders and nutritional deficiencies.
Mitochondria are cellular organelles responsible for producing the majority of adenosine triphosphate (ATP), the primary source of energy for nearly all cellular processes. In addition to their role in energy production, they are involved in regulating metabolism, calcium homeostasis, the generation of reactive oxygen species, and programmed cell death. Their proper function is considered one of the key factors in maintaining cellular and metabolic health.
Omega-3 fatty acids belong to the group of polyunsaturated essential fatty acids and play an important role in maintaining cell membrane structure and the synthesis of regulatory molecules involved in inflammatory processes. The most significant among them are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), which contribute to the normal function of the heart, brain, and vision in accordance with scientifically substantiated effects and approved health claims.
Oxidative stress arises from an imbalance between the production of reactive oxygen and nitrogen species and the ability of antioxidant defense systems to neutralize them. It may result in damage to lipids, proteins, nucleic acids, and other cellular structures, thereby affecting tissue and organ function. This process has been associated with aging, as well as the development of cardiovascular, neurodegenerative, metabolic, and other chronic diseases.
Peristalsis refers to the coordinated rhythmic contractions of the smooth muscles of the digestive tract that propel its contents through the esophagus, stomach, small intestine, and large intestine. This process is regulated by the enteric nervous system in conjunction with hormones and other regulatory mechanisms. Its proper functioning is essential for efficient digestion, nutrient absorption, and the elimination of undigested food residues.
A measure of the concentration of hydrogen ions in a solution and an indicator of its acidity or alkalinity. In the human body, different tissues and body fluids have characteristic pH values that are essential for the proper functioning of biochemical processes. Even minor deviations from physiological ranges, particularly in the blood, may impair enzyme activity, cellular function, and the function of vital organs.
Bioactive compounds produced through the metabolic activity of beneficial microorganisms, as well as their structural components that may exert biological effects within the body. This group includes short-chain fatty acids, peptides, polysaccharides, enzymes, and other metabolites whose contributions to maintaining intestinal mucosal function, regulating immune responses, and supporting metabolic health continue to be investigated.
Substrates that are selectively utilized by beneficial microorganisms in the digestive system to support their growth and metabolic activity, thereby contributing to the maintenance of a balanced intestinal microbiota. They are most commonly represented by dietary fibers and other non-digestible carbohydrates that reach the large intestine, where they undergo fermentation and promote the production of beneficial metabolites.
Live microorganisms that, when administered in adequate amounts, may confer health benefits on the host. Their effects depend on the specific strain, dosage, and duration of use, which is why findings obtained for one microorganism cannot automatically be attributed to other probiotic cultures. Their clinical application is based on evidence supporting individual strains and specific health indications.
Proteins are macromolecules composed of amino acids that participate in nearly all biological processes. In addition to serving as the primary structural components of muscles, skin, and other tissues, they are essential for the synthesis of enzymes, hormones, transport proteins, and antibodies. Their functions depend on their three-dimensional structure and the specific sequence of amino acids from which they are composed.
A combination of probiotics and prebiotics designed so that both components act synergistically. The aim of such formulations is to enhance the survival and activity of beneficial microorganisms within the digestive system while creating favorable conditions for establishing and maintaining a balanced microbiota.
The interaction of two or more factors whose combined effect is greater than the sum of their individual effects. In other words, synergy occurs when collaborating elements achieve better outcomes together than they would independently. This concept is applied across various fields—from biology and medicine to psychology, economics, management, and interpersonal relationships—and symbolizes successful cooperation, harmony, and the creation of added value.
The most abundant form of fat in the body and the primary means of energy storage within adipose tissue. Their concentration in the blood is influenced by diet, body weight, physical activity, hormonal status, and genetic factors. Elevated triglyceride levels are frequently associated with metabolic syndrome, insulin resistance, and an increased risk of cardiovascular disease.