Bioaccessibility and health risk of neonicotinoids in apple and pear samples as affected by in vitro digestion

Previous studies have only focused on the bioaccessibility of single pesticide/metal without considering the potential impact of post-uptake interactions on bioaccessibility of pesticides/metals in the human digestive system. Hence, the influences of chromium (Cr) speciation on neonicotinoids bioaccessibility were investigated and the potential health risk based on the oral bioaccessibility was evaluated. Bioaccessibility of four neonicotinoids in apple and pear was measured using three common in vitro methods (SBRC, PBET, and IVG). Bioaccessibility of neonicotinoids in apple and pear varied between in vitro methods, which may reflect the difference of determination parameters (i.e., pH values, incubation time, and constituents). The neonicotinoids bioaccessibility was remarkably reduced by 17.21–81.21% and 11.61–73.70% with the addition of Cr(III) and Cr(VI), respectively. Risk assessment based on the hazard quotient (HQ) with bioaccessibility revealed that exposure to pesticide residues in the tested fruits were all below levels that might pose a health risk. These findings are of theoretical value for the safety evaluation of pesticide residues on food.

Seaweed Components as Potential Modulators of the Gut Microbiota

Macroalgae, or seaweeds, are a rich source of components which may exert beneficial effects on the mammalian gut microbiota through the enhancement of bacterial diversity and abundance. An imbalance of gut bacteria has been linked to the development of disorders such as inflammatory bowel disease, immunodeficiency, hypertension, type-2-diabetes, obesity, and cancer. This review outlines current knowledge from in vitro and in vivo studies concerning the potential therapeutic application of seaweed-derived polysaccharides, polyphenols and peptides to modulate the gut microbiota through diet. Polysaccharides such as fucoidan, laminarin, alginate, ulvan and porphyran are unique to seaweeds. Several studies have shown their potential to act as prebiotics and to positively modulate the gut microbiota. Prebiotics enhance bacterial populations and often their production of short chain fatty acids, which are the energy source for gastrointestinal epithelial cells, provide protection against pathogens, influence immunomodulation, and induce apoptosis of colon cancer cells. The oral bioaccessibility and bioavailability of seaweed components is also discussed, including the advantages and limitations of static and dynamic in vitro gastrointestinal models versus ex vivo and in vivo methods. Seaweed bioactives show potential for use in prevention and, in some instances, treatment of human disease. However, it is also necessary to confirm these potential, therapeutic effects in large-scale clinical trials. Where possible, we have cited information concerning these trials.

Effects of carbonaceous materials and particle size on oral and inhalation bioaccessibility of PAHs and OPEs in airborne particles

Bioavailability of environmental contaminants is attracting considerable scientific attention due to growing awareness of its importance for risk assessment. In this study, potential factors governing bioaccessibility of airborne particles-bound polycyclic aromatic hydrocarbons (PAHs) and organophosphorus esters (OPEs) in stimulated gastrointestinal and respiratory tracts were elucidated. Particle concentrations of PAHs and OPEs at the eight sites were 2.4−32.3 ng/m3 and 1.6−19.9 ng/m3, respectively. In fine particles (with aerodynamic diameter less than 2.5 µm), 4- to 6-ring PAHs were more strongly correlated with organic carbon (OC) than elemental carbon (EC); while 3- and 4-ring PAHs in coarse particles (2.5−10 µm) tended to associate with EC. OPEs mostly showed significant correlations with EC in both fine and coarse particles. OC and EC exerted a significantly restraining effect on the oral and inhalation bioaccessibility of most HOCs in fine particles due to sorption of HOC molecules to these components. Furthermore, the effects varied, which could depend either on the emission sources (for oral bioaccessibility of PAHs) or the physicochemical properties of HOCs (for bioaccessibility of OPEs and inhalation bioaccessibility of PAHs). Linear regression indicated that EC should play a more important role in the inhalation bioaccessibility than the oral bioaccessibility. Particle size of airborne particles is a relatively less significant factor determining the bioaccessibility.