Obesogens, as environmental endocrine-disrupting chemicals, are supposed to have had an impact on the prevalence of rising obesity around the world over the last forty years. These chemicals are probably able to contribute not only to the development of obesity and metabolic disturbances in individuals, but also in their progeny, having the capability to epigenetically reprogram genetically inherited set-up points for body weight and body composition control during critical periods of development, such as fetal, early life, and puberty. In individuals, they may act on myriads of neuro-endocrine–immune metabolic regulatory pathways, leading to pathophysiological consequences in adipogenesis, lipogenesis, lipolysis, immunity, the influencing of central appetite and energy expenditure regulations, changes in gut microbiota–intestine functioning, and many other processes. Evidence-based medical data have recently brought much more convincing data about associations of particular chemicals and the probability of the raised risk of developing obesity. Foods are the main source of obesogens. Some obesogens occur naturally in food, but most are environmental chemicals, entering food as a foreign substance, whether in the form of contaminants or additives, and they are used in a large amount in highly processed food. This review article contributes to a better overview of obesogens, their occurrence in foods, and their impact on the human organism.

Burden of obesity is increasing in the contemporary world. Although multifactorial in origin, appropriate mitochondrial function of adipocytes emerges as a factor essential for healthy adipocyte differentiation and adipose tissue function. Our study aimed to evaluate mitochondrial functions of human adipose-derived mesenchymal stem cells committed to adipogenesis. On days 0, 4, 10, and 21 of adipogenesis, we have characterized adipocyte proliferation and viability, quantified lipid accumulation in maturing cells, performed qualitative and quantitative analysis of mitochondria, determined mitochondrial respiration of cells using high-resolution respirometry, and evaluated mitochondrial membrane potential. In the course of adipogenesis, mitochondrial oxygen consumption progressively increased in states ROUTINE and E (capacity of the electron transfer system). State LEAK remained constant during first days of adipogenesis and then increased probably reflecting uncoupling ability of maturing adipocytes. Citrate synthase activity and volume of mitochondrial networks increased during differentiation, particularly between days 10 and 21. In addition, lipid accumulation remained low until day 10 and then significantly increased. In conclusion, during first days of adipogenesis, increased mitochondrial respiration is needed for transition of differentiating cells from glycolytic to oxidative metabolism and clonal expansion of preadipocytes and then more energy is needed to acquire typical metabolic phenotype of mature adipocyte.

The contribution of environmental pollutants to the obesity pandemic is still not yet fully recognized. Elucidating possible cellular and molecular mechanisms of their effects is of high importance. Our study aimed to evaluate the effect of chronic, 21-day-long, 2,2-bis (4-chlorophenyl)-1,1-dichlorethylenedichlorodiphenyldichloroethylene (p,p′-DDE) exposure of human adipose-derived mesenchymal stem cells committed to adipogenesis on mitochondrial oxygen consumption on days 4, 10, and 21. In addition, the mitochondrial membrane potential (MMP), the quality of the mitochondrial network, and lipid accumulation in maturing cells were evaluated. Compared to control differentiating adipocytes, exposure to p,p′-DDE at 1 μM concentration significantly increased basal (routine) mitochondrial respiration, ATP-linked oxygen consumption and MMP of intact cells on day 21 of adipogenesis. In contrast, higher pollutant concentration seemed to slow down the gradual increase in ATP-linked oxygen consumption typical for normal adipogenesis. Organochlorine p,p′-DDE did not alter citrate synthase activity. In conclusion, in vitro 1 μM p,p′-DDE corresponding to human exposure is able to increase the mitochondrial respiration per individual mitochondrion at the end of adipocyte maturation. Our data reveal that long-lasting exposure to p,p′-DDE could interfere with the metabolic programming of mature adipocytes.

Enterococcus spp. is the most controversial group of lactic acid bacteria that have been for years ascribed with beneficial or detrimental role in food and feed. The aim of our study was to monitor the occurrence of Enterococcus spp. as the indicator of the contamination from collected samples of raw cow's milk, goat's colostrum and whey (n = 186). Cultures of enterococci were cultivated and purified and identified by the genus-specific and species-specific PCR method (n = 230). Among suspected isolates in total 222 isolates (96.5%) were identified as Enterococcus spp. The results were the same in all samples separately, more than 90% each of them were positive to Enterococcus spp. The results of counting the number of cultivated colonies showed that the largest number of enterococci is found in the samples of whey taken after the process of electrodialysis and the smallest in the native whey sample. From collected whey samples, 64 samples (90%) were PCR positive for enterococci species. Afterwards within the identification of several selected isolates that were identified, as Enterococcus spp. by the species-specific PCR method the most frequently presented in all of isolates was Enterococccus faecalis. Apparently the presence of enterococci was detected in all samples, but in amounts that aren't hazardous for human health. Although enterococci are oportunistic pathogens, it seems that they occur frequently in foods (especially fermented) in large numbers.