The effects of consuming probiotic‐fermented milk on the immune system: A review of scientific evidence

Fermented dairy products are commonly used as the most efficient delivery vehicle for probiotics. These foods are well known for promoting the positive health benefits of consuming probiotics. Among their beneficial effects, their immunomodulatory properties have attracted a great deal of interest in recent years. Reports, both in vitro and in vivo, on the beneficial effects of consuming fermented milks containing probiotics have demonstrated the enhancement of various parameters in animal (e.g. rats and mice) and human immune systems, such as the production of cytokines and mediators by antigen‐presenting cells and cellular markers for different cell populations. Hence, the purpose of this review was to provide an overview of the scientific literature concerning the potential of probiotic‐fermented milks to influence the host's immune system, thereby modulating the immune response in a positive fashion.     

Comparison of five in vitro digestion models to study the bioaccessibility of soil contaminants

Soil ingestion can be a major exposure route for humans to many immobile soil contaminants. Exposure to soil contaminants can be overestimated if oral bioavailability is not taken into account. Several in vitro digestion models simulating the human gastrointestinal tract have been developed to assess mobilization of contaminants from soil during digestion, i.e., bioaccessibility. Bioaccessibility is a crucial step in controlling the oral bioavailability for soil contaminants. To what extent in vitro determination of bioaccessibility is method dependent has, until now, not been studied. This paper describes a multi-laboratory comparison and evaluation of five in vitro digestion models. Their experimental design and the results of a round robin evaluation of three soils, each contaminated with arsenic, cadmium, and lead, are presented and discussed. A wide range of bioaccessibility values were found for the three soils: for As 6-95%, 1-19%, and 10-59%; for Cd 7-92%, 5-92%, and 6-99%; and for Pb 4-91%, 1-56%, and 3-90%. Bioaccessibility in many cases is less than 50%, indicating that a reduction of bioavailability can have implications for health risk assessment. Although the experimental designs of the different digestion systems are distinct, the main differences in test results of bioaccessibility can be explained on the basis of the applied gastric pH. High values are typically observed for a simple gastric method, which measures bioaccessibility in the gastric compartment at low pHs of 1.5. Other methods that also apply a low gastric pH, and include intestinal conditions, produce lower bioaccessibility values. The lowest bioaccessibility values are observed for a gastrointestinal method which employs a high gastric pH of 4.0.