Recently, an increased interest in nanotechnology applications can be observed in various fields (medicine, materials science, pharmacy, environmental protection, agriculture etc.). Due to an increasing scope of applications, the exposure of humans to nanoparticles (NPs) is inevitable. A number of studies revealed that after inhalation or oral exposure, NPs accumulate in, among other places, the lungs, alimentary tract, liver, heart, spleen, kidneys and cardiac muscle. In addition, they disturb glucose and lipid homeostasis in mice and rats. In a wide group of nanoparticles currently used on an industrial scale, titanium dioxide nanoparticles—TiO2 NPs—are particularly popular. Due to their white colour, TiO2 NPs are commonly used as a food additive (E 171). The possible risk to health after consuming food containing nanoparticles has been poorly explored but it is supposed that the toxicity of nanoparticles depends on their size, morphology, rate of migration and amount consumed. Scientific databases inform that TiO2 NPs can induce inflammation due to oxidative stress. They can also have a genotoxic effect leading to, among others, apoptosis or chromosomal instability. This paper gives a review of previous studies concerning the effects of exposure to TiO2 NPs on a living organism (human, animal). This information is necessary in order to demonstrate potential toxicity of inorganic nanoparticles on human health.

Exposure to Cd and Pb reduces the activity of antioxidant enzymes, which points to a decrease in the antioxidant potential of the body as a result of supplying factors which enhance cellular oxidation processes. Man is exposed to the effects of toxic metals because they are present in the environment, including in food. Since no effective ways to reduce the concentrations of Cd an Pb in food exist, studies are undertaken to develop methods of reducing their toxic effect on the body through chelating these metals using nutrients (which reduces their absorption by tissues) or increasing the oxidative capacity of the body (which decreases the possibility of inducing oxidative damage to internal organs). Studies performed on laboratory animals have shown that the use of tea infusions fulfil both functions.

Mother's milk is the fundamental food for infants. It contains proteins, fat, carbohydrates and essential metals which are necessary to ensure correct functioning of the organism. Unfortunately, breast milk is a potential source of toxic metals, which are dangerous for a baby. In Poland, previous research concerning the content of metals in breast milk was very scarce or its results were unavailable. The present study aimed at assessing the content of Cd, Pb, Cu and Zn in human breast milk, as well as estimating the mean weekly intake of these metals by breast-fed infants from Poland. The average concentrations of Cd, Pb, Cu and Zn were 2.114 μg/l, 6.331 μg/l, 0.137 mg/l and 1.623 mg/l, respectively. The admissible levels of supply of these toxic metals has not been exceeded, but their contents were high, particularly in 6-month-old infants (nearly 85 % TWI for Cd and nearly 70 % BMDL01 for Pb). The daily intake of Cu and Zn did not fully satisfy the infant's requirements determined by Polish standards and WHO recommendations. Since the lifestyle of lactating women has a direct influence on the content of these elements in breast milk, women should be educated in this respect with particular focus on eliminating tobacco smoking, both by breastfeeding mothers and by their direct environment.

Probiotics, prebiotics, and phytobiotics could be a possible solution as immunostimulants in monogastric animal nutrition. Beneficial effects of application thereof in animals are determined by many factors, e.g. the type of the probiotic strain, probiotic compounds, or plant species used as a supplement. A significant role is also played by the animal species, dosage, and the time and method of administration. The activity of these compounds is primarily focused on prevention of pathogen infections and, consequently, improvement of animal welfare. Probiotics compete with pathogenic bacteria by covering the intestinal epithelium mucosa, thereby interrupting pathogen colonization in the gastrointestinal tract. Supplementation with probiotics, prebiotics, and phytobiotics can also induce positive changes in the intestinal morphology, e.g. elongation of villi or deepening of intestinal crypts. In a majority of cases, they also modulate the immune response of the host. They mobilise the cellular components of the innate immune system (macrophages and heterophils), which defend the animal organism against gastrointestinal infection. Another possibility is the synthesis and release of pro-inflammatory cytokines that modulate adaptive immunity or stabilization of the intestinal microbiome. The main target of immunomodulatory feed additives is reduction of local inflammation, enhancement of the function of the immune system, a substantial impact on the health status of livestock animals, and improvement of their health status and production performance.

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