微塑料对肠道微生物群系和健康的影响：食品安全的视角-58页-WN7.pdf
FOOD SAFETY AND QUALITY SERIES 21ISSN 24151173FAOTHE IMPACT OF MICROPLASTICS ON THE GUT MICROBIOME AND HEALTHA FOOD SAFETY PERSPECTIVEFOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONSROME,2023THE IMPACT OF MICROPLASTICS ON THE GUT MICROBIOME AND HEALTHA FOOD SAFETY PERSPECTIVERequired citation:FAO.2023.The impact of microplastics on the gut microbiome and health A food safety perspective.Food Safety and Quality Series,No.21.Rome.https:/doi.org/10.4060/cc5294enThe designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations(FAO)concerning the legal or development status of any country,territory,city or area or of its authorities,or concerning the delimitation of its frontiers or boundaries.The mention of specific companies or products of manufacturers,whether or not these have been patented,does not imply that these have been endorsed or recommended by FAO in preference to others of a similar nature that are not mentioned.ISSN 2415-1173 PrintISSN 2664-5246 OnlineISBN 978-92-5-137807-6978-92-4-000629-4 electronic version(WHO)FAO,2023Some rights reserved.This work is made available under the Creative Commons Attribution-Non Commercial-ShareAlike 3.0 IGO licence(CC BY-NC-SA 3.0 IGO;https:/creativecommons.org/licenses/by-nc-sa/3.0/igo/legalcode).Under the terms of this licence,this work may be copied,redistributed and adapted for non-commercial purposes,provided that the work is appropriately cited.In any use of this work,there should be no suggestion that FAO endorses any specific organization,products or services.The use of the FAO logo is not permitted.If the work is adapted,then it must be licensed under the same or equivalent Creative Commons licence.If a translation of this work is created,it must include the following disclaimer along with the required citation:“This translation was not created by the Food and Agriculture Organization of the United Nations(FAO).FAO are not responsible for the content or accuracy of this translation.The original English edition shall be the authoritative edition.”Disputes arising under the licence that cannot be settled amicably will be resolved by mediation and arbitration as described in Article 8 of the licence except as otherwise provided herein.The applicable mediation rules will be the mediation rules of the World Intellectual Property Organization http:/www.wipo.int/amc/en/mediation/rules and any arbitration will be conducted in accordance with the Arbitration Rules of the United Nations Commission on International Trade Law(UNCITRAL).Thirdparty materials.Users wishing to reuse material from this work that is attributed to a third party,such as tables,figures or images,are responsible for determining whether permission is needed for that reuse and for obtaining permission from the copyright holder.The risk of claims resulting from infringement of any third-party-owned component in the work rests solely with the user.Sales,rights and licensing.FAO information products are available on the FAO website(www.fao.org/publications)and can be purchased through publications-salesfao.org.Requests for commercial use should be submitted via:www.fao.org/contact-us/licence-request.Queries regarding rights and licensing should be submitted to:copyrightfao.org.Cover photographs from left to right:FAO/Claudia Amico;FAO/David Hogsholt;FAO/GMB AkashDesign and layout:studio Pietro BartoleschiiiiCONTENTSAcknowledgements.vAbbreviations and acronyms.viiExecutive summary .ixCHAPTER 1INTRODUCTION.1CHAPTER 2METHODOLOGY.7Literature review.7Screening of articles and selection criteria.8CHAPTER 3FINDINGS.9Polystyrene.10Polyethylene.14Other plastics:Polyamide or nylon,polyvinyl chloride.17CHAPTER 4DISCUSSION.19Microplastics Polymer type and size.19Microplastics Concentration.21Microplastics Surface properties and adsorption of chemicals.22Models.24Exposure times.25Impacts on the host and the microbiota.25Risk assessment.26CHAPTER 5RESEARCH GAPS AND OPPORTUNITIES.29 CHAPTER 6CONCLUSIONS.31ivBIBLIOGRAPHY.32 ANNEX IFINDINGS .41FIGURES1.Gastrointestinal environment and microbiota niches.42.Examples of taxonomical composition of the gut microbiota.53.Graphic representation of the article selection process for the literature review.94.Relation of experimental PS and PE particle size/concentration used in the studies included in this review .22TABLES1.Query search terms and results from PubMed and Web of Science.7AI.1 Summary articles reporting the impact of polystyrene on the gut microbiome and its effects on the hosts health.41AI.2 Summary articles reporting the impact of polyethylene on the gut microbiome and its effects on the hosts health.43AI.3 Summary articles reporting the impact of miscellaneous plastics(nylon and PVC)on the gut microbiome and their effects on the hosts health.44vACKNOWLEDGEMENTSThe research and drafting of the publication were carried out by Carmen Diaz-Amigo(Food Systems and Food Safety Division ESF,FAO)and Sarah Najera Espinosa(ESF)under the technical leadership and guidance of Catherine Bessy,Senior Food Safety Officer(ESF).The support and guidance of Markus Lipp,Senior Food Safety Officer(ESF),and the technical inputs and insights provided by Vittorio Fattori,Food Safety Officer(ESF),Manuel Barange,Director,Fisheries and Aquaculture(FAO),Keya Mukherjee(ESF),Kang Zhou,Food Safety and Quality Officer(ESF)and Jorge Pinto-Ferreira,Food Safety and Quality Officer(ESF)during the entire process of the publications development are gratefully recognized.FAO is grateful to the experts Mark Feeley(Consultant,Canada),Sangeeta Khare(United States Food and Drug Administration)and Anil Patri(United States Food and Drug Administration)for their insightful comments and recommendations to improve the draft.Finally,special thanks go out to Karel Callens Senior Advisor to Chief Economist,Governance and Policy Support Unit(DDCG,FAO)and Fanette Fontaine,Science Policy Advisor(DDCG),for their pioneer initiative at FAO bringing attention to and starting a dialogue on the impact of microbiomes in food systems.FAO/Mustafa KayaviiABBREVIATIONS AND ACRONYMSDEHPdi-(2-ethylhexyl)phthalateEFSAEuropean Food Safety AuthorityFAOFood and Agriculture Organization of the United NationsIFNinterferonJRCJoint Research CenterKEGGKyoto Encyclopedia of Genes and GenomesMPmicroplasticsNOnitric oxideNPnanoplasticsOTUoperational taxonomic unitsPAEPhthalate estersPAHpolycyclic aromatic hydrocarbonPBDEpolybrominated diphenyl ethersPCBpolychlorinated biphenylsPEpolyethylenePETpolyethylene terephthalatePOPpersistent organic pollutantsPPpolypropylenePSpolystyrenePURpolyurethanePVCpolyvinyl chlorideROS reactive oxygen speciesTDItolerable daily intakeWHOWorld Health Organizationviiiviii FAO/Kurt Arrigo peterschreiber.media/SixEXECUTIVE SUMMARYMicroplastics(0.1 to 5000 m)and nanoplastics1(0.001 to 0.1 m)are ubiquitous contaminants of emerging interest due to their potential effects on the environment,animals and human health.Their capacity to release plastic additives or adsorb,transport and release environmental contaminants(e.g.heavy metals and organic pollutants),and therefore their capacity to modify the exposure and toxicity of these contaminants,have not been well studied.Further research is required to understand if and how microplastic exposure or co-exposure with other chemicals affects the host and the gut microbiome.Research on this topic has increased over the last two years,but only a limited number of studies have evaluated the impact of microplastics and nanoplastics on the gut microbiome.Although most of the studies have been conducted on aquatic animals,as they are considered sentinels of microplastic contamination,only a handful have been conducted on mammals(mice).Most of the studies investigated the effects of microplastics,and nanoplastics to a lesser extent,on the gastrointestinal tract,leading in some cases to an alteration of the intestinal structure and function(permeability,inflammatory and immune response),oxidative stress and gut dysbiosis.Although it is difficult to compare studies due to differences in model animals,type,size and concentration of microplastics,as well as exposure times,there is some indication that higher concentrations and non-spherical microplastic shapes increase the severity of effects.Most studies used micro-sized plastics and the limited research conducted at the nano-scale(some comparing the impacts of microplastics vs nanoplastics)suggest that the type of alterations is size-specific.The evaluation of the gut microbiota2 was mainly limited to investigating changes in its composition and diversity.3 In this sense,there is a need to study further if and how microplastics can also alter the function of the microbiome,and if alterations are a direct effect of the microplastics or a consequence of the hosts response to the particles.1 In this report,microplastics and nanoplastics refer only to primary or secondary small plastic particles/fragments.Engineered microparticles or nanoparticles(e.g.silver or gold nanoparticles)are not included in this work.2 This report includes two related terms:microbiota and microbiome.In general,microbiota refers to the collection of microbial individuals.Microbiome is a more holistic term incorporating the overall genetic composition and function of the microbiota.3 Taxonomical diversity refers to the variety and abundance of species in a defined unit of study(Magurran,2013).It has two components,richness(total number of species in the unit of study)and evenness(relative differences in the abundance of various species in the community)(Young and Schmidt,2008).xThe studies included in this review corroborate the research gaps identified by the scientific community,i.e.the need for definitions of microbiome,microplastics and nanoplastics,as well as the need for a method of harmonization and for reference materials for microplastics and nanoplastics.Experiments should be conducted with great care to avoid cross-contamination.Additional research would help provide further insights on the toxicity and kinetics of smaller microplastics and nanoplastics,and it would provide data on the occurrence in food.FAO/Luis Antonio Rojas Brent Stirton/Getty Images for FAO1CHAPTER 1INTRODUCTIONMicroplastics are ubiquitous environmental pollutants that can accumulate in organisms across the food web.Moreover,they can carry other chemical and microbiological contaminants,which may amplify the implications of plastic pollution on living organisms,including those entering the human food supply chain.This review evaluates the impact of microplastics1(0.1 m to 5 mm)and nanoplastics(100 nm)on the gut microbiome of animal models including those mimicking humans and it evaluates the potential consequences for the hosts health.Plastics are light,strong and versatile materials made through chemical processes from a wide range of organic polymers(e.g.polyethylene,polyvinyl chloride,nylon).The most commonly known types of plastic are high-and low-density polyethylene(PE),polypropylene(PP),polyvinyl chloride(PVC),polystyrene(PS),polyurethane(PUR)and polyethylene terephthalate(PET)(Geyer,Jambeck and Law,2017).When heated,plastics can be moulded into different hard or flexible shapes.Since the Second World War,plastics have become a convenient material used in nearly every industry and in our daily lives.In the last decades,the use of plastics has grown exponentially from 2million tonnes in 1950 to almost 368million tonnes in 2019 globally(Plastics Europe,2020).About 8.3billion tonnes have been produced to date.If the production trend continues,26billion tonnes of waste are estimated to be manufactured by 2050,of which 12billion tonnes are expected to end up in the environment(Geyer,Jambeck and Law,2017).When plastics are exposed to ultraviolet radiation,friction and other physical,chemical and biological processes in the environment,they break down into smaller fragments and eventually form smaller particles known as microplastics and nanoplastics2(Wayman and Niemann,2021).The size,shape and chemical composition of these particles can vary.Microplastic pollution was not recognized as a problem until the scientific community raised the issue in the early 1970s(Carpenter and Smith,1972).Plastics have become a major environmental concern because they degrade very slowly.This means that any plastics produced or used in the past still persist in the environment today,and most plastics manufactured now will also remain for hundreds or thousands of years.This is also true for microplastics and nanoplastics,either manufactured or degraded particles.1 Currently,there is no consensus definition for microplastics and nanoplastics.2 For source management purposes,microplastics and nanoplastics are divided into two categories.Primary microplastics and nanoplastics are intentionally manufactured particles found in skin care products,toothpaste,molding and cosmetics;while secondary microplastics and nanoplastics are the result of the breakdown of larger plastic fragments.2THE IMPACT OF MICROPLASTICS ON THE GUT MICROBIOME AND HEALTH A FOOD SAFETY PERSPECTIVEOver the last few decades,research has focused on plastic pollution in oceans.Large amounts of plastics have been found either floating or submerged;these can break down,increasing the number of microparticles in marine environments.However,microplastic contamination is not limited to aquatic environments(marine,freshwater).They are also found in terrestrial environments(Dissanayake etal.,2022).Although it has been reported that the microplastic load in terrestrial environments is higher than in the ocean,their impact on terrestrial ecosystems and soil microbiota remains unclear(Wei etal.,2022).Further investigations are needed to determine the effects of soil microbiota and microplastic interactions on agriculture production.Concerns have been raised about how these particles accumulate,how they become distributed throughout food webs and the health impact on living organisms,including microbiomes.Studies show that aquatic organisms(e.g.zooplankton,molluscs)ingest microplastics(Botterell etal.,2019).Microplastics and nanoplastics accumulate in the guts and gills of the marine organisms that consume them.They potentially enter the circulatory system and affect the gut microbiome of the host(Jin etal.,2018;van Raamsdonk etal.,2020).The presence of microplastics in other environments has been shown to affect microbial communities.For example,soil microbiome experts have reported that microplastic accumulation can disturb the structure and functionality of soil microorganisms(Guo etal.,2020).These effects can impact larger soil organisms and eventually affect entire food webs.Microplastics and nanoplastics can be transferred along the food chain and eventually reach our plates(Fackelmann and
