EFSA GMO Panel Working Group on Animal Feeding Trials. Safety and nutritional assessment of GM plants and derived food and feed: the role of animal feeding trials

Nutrigenomics and personalized diets: What will they mean for food?

The modern food system feeds six billion people with remarkable diversity, safety, and nutrition. Yet, the current rise in diet-related diseases is compromising health and devaluing many aspects of modern agriculture. Steps to increase the nutritional quality of individual foods will assist in personalizing health and in guiding individuals to achieve superior health. Nutrigenomics is the scientific field of the genetic basis for varying susceptibilities to disease and the diverse responses to foods. Although some of these genetic determinants will be simple and amenable to personal genotyping as the means to predict health, in practice most will not. As a result, genotyping will not be the secret to personalizing diet and health. Human assessment technologies from imaging to proteomics and metabolomics are providing tools to both understand and accurately assess the nutritional phenotype of individuals. The business models are also emerging to bring these assessment capabilities to industrial practice, in which consumers will know more about their personal health and seek personal solutions.

Molecular profiling--a tool for addressing emerging gaps in the comparative risk assessment of GMOs

Assessing the risks of genetically modified organisms (GMOs) is required by both international agreement and domestic legislation. Many view the use of the "omics" tools for profiling classes of molecules as useful in risk assessment, but no consensus has formed on the need or value of these techniques for assessing the risks of all GMOs. In this and many other cases, experts support case-by-case use of molecular profiling techniques for risk assessment. We review the latest research on the applicability and usefulness of molecular profiling techniques for GMO risk assessment. As more and more kinds of GMOs and traits are developed, broader use of molecular profiling in a risk assessment may be required to supplement the comparative approach to risk assessment. The literature-based discussions on the use of profiling appear to have settled on two findings: 1. profiling techniques are reliable and relevant, at least no less so than other techniques used in risk assessment; and 2. although not required routinely, regulators should be aware of when they are needed. The dismissal of routine molecular profiling may be confusing to regulators who then lack guidance on when molecular profiling might be worthwhile. Molecular profiling is an important way to increase confidence in risk assessments if the profiles are properly designed to address relevant risks and are applied at the correct stage of the assessment.

Analysis of caecal microbiota in rats fed with genetically modified rice by real-time quantitative PCR

The effect of genetically modified rice (GMR) on bacterial communities in caecal content was analyzed in a 90-d feeding rat model. A total of 12 groups of rats, which included male and female, were fed with the basal diets containing 30%, 50%, 70% GMR (B(1), B(2), B(3)) or 30%, 50%, 70% non-GMR (D(1), D(2), D(3)). The structure of intestinal microflora was estimated by real-time quantitative PCR (RQ-PCR) based on genus-specific 16s rDNA primers. SYBR Green was used for accurate detection and quantification of 6 kinds of major bacteria shared by humans and rats. According to RQ-PCR, the genome copies of Lactobacillus group from the cecum of male rats fed with 70% non-GMR was higher than those fed with 70% GMR and the relative abundance of Lactobacillus group also higher for group D. This result was in contrast with the E. coli subgroup, which was more numerous in proportion of group B, except D(2) and B(2) for male rats. The Clostridium perfringens subgroup was numerically more abundant in group D than group B of the same level, also except D(2) and B(2) for male rats. These results suggested that GMR had a complex effect on caecal microflora that may be related to the health of the host.

A 90-day toxicology study of high-amylose transgenic rice grain in Sprague-Dawley rats

A transgenic rice line (TRS) with high amylose level has been developed by antisense RNA inhibition of starch branching enzymes. Compositional analysis of TRS demonstrated that the content of resistant starch (RS) was significantly higher compared to conventional non-transgenic rice. High level of RS is an important raw material in food industry and has various physiological effects for human health. In order to provide the reliable theory basis for field release of TRS rice, we evaluated the potential health effects of long-term consumption of the TRS. The 90-day toxicology feeding experiment was conducted in Sprague-Dawley rats fed with diets containing 70% of either TRS rice flour, its near-isogenic rice flour or the control diet. The clinical performance variables (body weight, body weight gain and food consumption) were measured and pathological responses (hematological parameters and serum chemistry at the midterm and the completion of the experiment, urinalysis profile and serum sex hormone response at the completion of the experiment) were performed. Besides, clinical signs, relative organ weights and microscopic observations were also compared between TRS group and its near-isogenic rice group. The combined data indicates that high-amylose TRS grain is as safe as the conventional non-transgenic rice for rat consumption.

A literature review on the safety assessment of genetically modified plants

In recent years, there has been a notable concern on the safety of genetically modified (GM) foods/plants, an important and complex area of research, which demands rigorous standards. Diverse groups including consumers and environmental Non Governmental Organizations (NGO) have suggested that all GM foods/plants should be subjected to long-term animal feeding studies before approval for human consumption. In 2000 and 2006, we reviewed the information published in international scientific journals, noting that the number of references concerning human and animal toxicological/health risks studies on GM foods/plants was very limited. The main goal of the present review was to assess the current state-of-the-art regarding the potential adverse effects/safety assessment of GM plants for human consumption. The number of citations found in databases (PubMed and Scopus) has dramatically increased since 2006. However, new information on products such as potatoes, cucumber, peas or tomatoes, among others was not available. Corn/maize, rice, and soybeans were included in the present review. An equilibrium in the number research groups suggesting, on the basis of their studies, that a number of varieties of GM products (mainly maize and soybeans) are as safe and nutritious as the respective conventional non-GM plant, and those raising still serious concerns, was currently observed. Nevertheless, it should be noted that most of these studies have been conducted by biotechnology companies responsible of commercializing these GM plants. These findings suggest a notable advance in comparison with the lack of studies published in recent years in scientific journals by those companies. All this recent information is herein critically reviewed.

Performance of broiler chickens fed event DAS-40278-9 maize containing the aryloxyalkanoate dioxygenase-1 protein

Event DAS-40278-9 maize grain (containing the aryloxyalkanoate dioxygenase-1 protein), a non-transgenic near-isogenic maize grain, or one of three commercial maize grains were included in the diets of broiler chickens for six weeks. Growth, feed conversion, and carcass measurements indicated no significant difference between the groups fed the diets containing the DAS-40278-9 maize grain and those fed diets containing the matched control grain. The absence of adverse effects in this study supports the dietary safety of the AAD-1 protein expressed in event DAS-40278-9 maize.

Impact of food processing on the safety assessment for proteins introduced into biotechnology-derived soybean and corn crops

The food safety assessment of new agricultural crop varieties developed through biotechnology includes evaluation of the proteins introduced to impart desired traits. Safety assessments can include dietary risk assessments similar to those performed for chemicals intentionally, or inadvertently added to foods. For chemicals, it is assumed they are not degraded during processing of the crop into food fractions. For introduced proteins, the situation can be different. Proteins are highly dependent on physical forces in their environment to maintain appropriate three-dimensional structure that supports functional activity. Food crops such as corn and soy are not consumed raw but are extensively processed into various food fractions. During processing, proteins in corn and soy are subjected to harsh environmental conditions that drastically change the physical forces leading to denaturation and loss of protein function. These conditions include thermal processing, changes in pH, reducing agents, mechanical shearing etc. Studies have shown that processing of introduced proteins such as enzymes that impart herbicide tolerance or proteins that control insect pests leads to a complete loss of functional activity. Thus, dietary exposure to functionally active proteins in processed food products can be negligible and below levels of any safety concerns.

Short-term evaluation in growing rats of diet containing Bacillus thuringiensis Cry1Ia12 entomotoxin: nutritional responses and some safety aspects

The Cry1Ia12 entomotoxin from a Brazilian Bacillus thuringiensis strain is currently being expressed in cotton cultivars to confer resistance to insect-pests. The present study aimed to assess the effects of a diet containing Cry1Ia12 protein on growing rats. A test diet containing egg white and Cry1Ia12 (0.1% of total protein) as a protein source was offered to rats for ten days. In addition, an acute toxicity bioassay was performed in rats with a single oral dose of the entomotoxin (12 mg/animal). No adverse effects were observed in the animals receiving the test diet when compared to those receiving a control diet (egg white). The analysed parameters included relative dry weight of internal organs, duodenum histology, blood biochemistry, and nutritional parameters. The results of the acute toxicity test showed no mortality or behaviour alteration. Thus, Cry1Ia12 toxin at the tested concentration does not cause deleterious effects on growing rats when incorporated in the diet for 10 days.

A comparison of the effects of three GM corn varieties on mammalian health

We present for the first time a comparative analysis of blood and organ system data from trials with rats fed three main commercialized genetically modified (GM) maize (NK 603, MON 810, MON 863), which are present in food and feed in the world. NK 603 has been modified to be tolerant to the broad spectrum herbicide Roundup and thus contains residues of this formulation. MON 810 and MON 863 are engineered to synthesize two different Bt toxins used as insecticides. Approximately 60 different biochemical parameters were classified per organ and measured in serum and urine after 5 and 14 weeks of feeding. GM maize-fed rats were compared first to their respective isogenic or parental non-GM equivalent control groups. This was followed by comparison to six reference groups, which had consumed various other non-GM maize varieties. We applied nonparametric methods, including multiple pairwise comparisons with a False Discovery Rate approach. Principal Component Analysis allowed the investigation of scattering of different factors (sex, weeks of feeding, diet, dose and group). Our analysis clearly reveals for the 3 GMOs new side effects linked with GM maize consumption, which were sex- and often dose-dependent. Effects were mostly associated with the kidney and liver, the dietary detoxifying organs, although different between the 3 GMOs. Other effects were also noticed in the heart, adrenal glands, spleen and haematopoietic system. We conclude that these data highlight signs of hepatorenal toxicity, possibly due to the new pesticides specific to each GM corn. In addition, unintended direct or indirect metabolic consequences of the genetic modification cannot be excluded.

Modelling tissues in 3D: the next future of pharmaco-toxicology and food research?

The development and validation of reliable in vitro methods alternative to conventional in vivo studies in experimental animals is a well-recognised priority in the fields of pharmaco-toxicology and food research. Conventional studies based on two-dimensional (2-D) cell monolayers have demonstrated their significant limitations: the chemically and spatially defined three-dimensional (3-D) network of extracellular matrix components, cell-to-cell and cell-to-matrix interactions that governs differentiation, proliferation and function of cells in vivo is, in fact, lost under the simplified 2-D condition. Being able to reproduce specific tissue-like structures and to mimic functions and responses of real tissues in a way that is more physiologically relevant than what can be achieved through traditional 2-D cell monolayers, 3-D cell culture represents a potential bridge to cover the gap between animal models and human studies. This article addresses the significance and the potential of 3-D in vitro systems to improve the predictive value of cell-based assays for safety and risk assessment studies and for new drugs development and testing. The crucial role of tissue engineering and of the new microscale technologies for improving and optimising these models, as well as the necessity of developing new protocols and analytical methods for their full exploitation, will be also discussed.

A 90-day toxicology study of transgenic lysine-rich maize grain (Y642) in Sprague-Dawley rats

The gene for a lysine-rich protein (sb401) obtained from potatoes (Solanum berthaultii) was inserted into maize seed to produce Y642 transgenic maize. Compositional analysis of Y642 grain demonstrated that the concentrations of lysine and total protein were higher than those observed in maize grain from a near-isogenic non-genetically modified (non-GM) commercially available control quality protein maize (Nongda 108). The safety of Y642 maize grain was assessed by comparison of toxicology response variables in Sprague-Dawley (SD) rats consuming diets containing Y642 maize grain with those containing Nongda 108 maize grain. Maize grains from Y642 or Nongda 108 were incorporated into rodent diets at low (30%) or high concentrations (76%) and administered to SD rats (n=10/sex/group) for 90 days. An additional group of negative control group of rats (n=10/sex/group) were fed AIN93G diets. No adverse diet-related differences in body weights, feed consumption/utilization, clinical chemistry, hematology, absolute and relative organ weights were observed. Further, no differences in gross or microscopic pathology were observed between rats consuming diets with Y642 maize grain compared with rats consuming diets containing Nongda 108 maize grain. These results demonstrated that Y642 lysine-rich maize is as safe and nutritious as conventional quality protein maize.

Safety assessment considerations for food and feed derived from plants with genetic modifications that modulate endogenous gene expression and pathways

The current globally recognized comparative food and feed safety assessment paradigm for biotechnology-derived crops is a robust and comprehensive approach for evaluating the safety of both the inserted gene product and the resulting crop. Incorporating many basic concepts from food safety, toxicology, nutrition, molecular biology, and plant breeding, this approach has been used effectively by scientists and regulatory agencies for 10-15 years. Current and future challenges in agriculture include the need for improved yields, tolerance to biotic and abiotic stresses, and improved nutrition. The next generation of biotechnology-derived crops may utilize regulatory proteins, such as transcription factors that modulate gene expression and/or endogenous plant pathways. In this review, we discuss the applicability of the current safety assessment paradigm to biotechnology-derived crops developed using modifications involving regulatory proteins. The growing literature describing the molecular biology underlying plant domestication and conventional breeding demonstrates the naturally occurring genetic variation found in plants, including significant variation in the classes, expression, and activity of regulatory proteins. Specific examples of plant modifications involving insertion or altered expression of regulatory proteins are discussed as illustrative case studies supporting the conclusion that the current comparative safety assessment process is appropriate for these types of biotechnology-developed crops.