Gut microbiota protects honey bees (Apis mellifera L.) against polystyrene microplastics exposure risks

PET Microplastics Affect Human Gut Microbiota Communities During Simulated Gastrointestinal Digestion. First Evidence of Plausible Polymer Biodegradation During Human Digestion

“…Regarding biodiversity, PET MPs promote a decrease in the alpha diversity indices in terms of Observed species and Shannon index, more evident for the TC and DC compartments. This decrease in the alpha biodiversity indices has been previously reported in animal models after a exposure to MPs, as well as the changes in the beta diversity 14,38,39,41,45 , indicating that the structure of the gut microbiota is altered after MPs exposure. Bacteroidetes levels showed an important decrease after PET MPs intervention, being this effect more powerful in the case of TC and DC compartments, reaching levels below 5% of relative abundance.…”

“…In relation to the MPs colonization, different human gut microbial species, such as Escherichia coli, Pseudomonas aeruginosa and Staphylococus epidermidis, have shown the ability to adhere and even form bio lms on diverse plastic material surfaces such as polyethylene, polypropylene and polystyrene, among others 8, 43,44 . Besides, a recent work has shown the adhesion of the gut microbiota of honey bees to the surface of polystyrene MPs 45 . Bacterial communities present on colonic microbiota adhere and colonize the gut mucosa, forming bio lms essential to their cross-feeding relationships, nutrient availability and protection against toxins (i.e.…”

Are Honey Bees at Risk from Microplastics?

“…PS-MPs exposure caused almost no survival stress in bees in a 14-day exposure study. Despite this, PS-MP administration reduced diversity of bacteria in the gut and caused major changes in gut microbiomes of bees, as well as changes in gene expression related to oxidative damage, detoxification, and immunity [ 54 ]. These sublethal effects of PS-MPs in bees were possibly caused by their aggregation and deterioration in the gut, as well as their subsequent interaction with the microbial population.…”

“…Lethality caused by MPs was significantly increased when the gut microbiota were depleted using the antibiotic tetracycline [ 54 ]. Given the reported adverse effects of this antibiotic on fitness of bees [ 61 , 62 ], the dosage used, which was equal to the median lethal dose to bees (LD 50 ) and the gut microbial communities of bees that had not been established prior to PS-MPs or/and tetracycline exposure, it is still unclear whether toxicity was caused by the elimination of the gut microbiota or by a synergistic/additive effect of each agent’s toxicity (PS-MPs and tetracycline) [ 54 ]. A study in which bees are recolonized shortly after application could provide insight into the response to that question.…”

“…Although the above-mentioned study found that exposure to PS-MPs did not result in reduced survival rates in bees [ 54 ], lethality is not the only indicator of honey bee colony health [ 64 ]. Future research is needed to investigate the potential negative effects on brood pattern, queen egg laying, drone vitality, and colony vigor.…”