Relationship between faecal microbiota and plasma metabolome in rats fed NK603 and MON810 GM maize from the GMO90+ study

Abstract

Safety concerns arising from the consumption of foods derived from genetically modified (GM) crops remains a highly debated and controversial subject. We report here a faecal microbiota compositional analysis in Wistar rats from the GMO90+ study, which fed glyphosate-tolerant NK603 (+/-Roundup application during cultivation) and Bt toxin MON810 GM maize for 6 months (at 11 and 33% composition of the feed) in comparison to their closest non-GM isogenic lines. We first integrated the faecal microbiota compositional data with results from plasma metabolomics to establish a baseline allowing us to understand which bacterial species can influence host metabolism. Coriobacteriaceae and Acetatifactor significantly predicted plasma metabolic profile in males, while Bifidobacterium and Ruminococcus were able to predict female plasma metabolites. We then investigated the differences in fecal microbiota composition between group of rats fed MON810 or NK603 GM maize varieties in comparison to their respective isogenic lines. Bacterial community richness was not altered by the test diets. There were no statistically significant differences in taxa abundance in the rat faecal microbiota that we could attribute to the consumption of either MON810 or NK603 GM maize varieties. In conclusion, we show that the consumption of the widely cultivated GM maize varieties NK603 and MON810 even up to 33% of the total diet had no effect on the status of the faecal microbiota compared to non-GM near isogenic lines.

Effects of glyphosate exposure on intestinal microbiota, metabolism and microstructure: a systematic review

“…In this context the studies reported diverse findings, with an increase of bacteria from Bacteroidetes, 18,[48][49][50][51] Proteobacteria, 16,48,52 Tenericutes, 18,49 Actinobacteria, 49,53 Desulfobacteria, 16 Spirochaetes, 49 Fusobacteria, 12 Deferribacteres 51 and Firmicutes phyla. 49,54 In contrast, some results highlighted a decrease of bacterial numbers from Bacteroidetes, Proteobacteria 12,51,55 and Firmicutes phyla. 18,51,53,55 In addition, it was described that the phyla Gemmatimonadetes, Acidobacteria, Cyanobacteria, Chlorobi, and Nitrospirae were generally altered in the gut after GLY exposure, but the study did not report whether there was an increase or decrease in microorganisms.…”

“…12 Furthermore, it is worth noting that in some studies, differences in gut microbiota composition were identified in each age group and between sexes after herbicide ingestion. Two papers reported a greater impact of GLY and GBH exposure in young animals; 51,53 two papers reported a greater impact in female animals 53,54 and one paper reported a greater impact in male animals. 56 Taking into account the bacterial species, Snodgrassella alvi stands out as one of the most affected species, 44,57,58 in addition to an increase in environmental bacteria in the bee gut, such as Lactobacillus kunkeei and Fructobacillus spp.…”

“…18 In another rat study, there was an increase in carnitine, methylhistamine, butyrylcarnitine, L-threonic acid, carnosine, and acetylcholine in males, and an increase in lysine, 5-methyldeoxycytidine, glycylcorticosterone-L-leucine, N6-acetyl-L-lysine, tryptophan, perillic acid, and indolacrylic acid in females. 54…”

“…In our research, some differences in gut microbiota composition by age group and between sexes after herbicide ingestion were also identified, with two articles reporting a greater impact on GLY and GBH exposure in young animals 51,53 and two other articles reporting a greater impact in female animals. 53,54 Only one article reported a greater impact on male animals. 56 Such a result does not fully corroborate what is found in the literature, since in a study conducted with mice, an increase in the concentration of Bacteroidetes was observed directly proportional to the increase in age of the animals, followed by a considerable decrease in the number of microorganisms of the Cyanobacteria, Firmicutes and Proteobacteria phyla.…”

“…Such results, however, do not demonstrate a directly relevant effect of GLY ingestion on animal metabolism. 54 The effect of ingestion of the herbicide and its formulations on intestinal microstructure and animal metabolism has also been analyzed in other animals, such as fish, bees, and the Chinese crab (Eriocheir sinensis). In the study with fish, changes were found in lipid metabolism, the circulatory system, energy metabolism, cofactor and vitamin metabolism, replication and repair, translation and metabolic pathways; 12 in the study with bees, the activity of glucose-6-phosphate dehydrogenase (G6PDH) in the head and lactate dehydrogenase (LDH) in the abdomen of the animal was higher in the group exposed to the herbicide; 62 and in the study with Eriocheir sinensis, GLY altered the activity of some digestive enzymes, such as lipase, amylase and trypsin.…”