Assessment of Modulatory Effect of Some Synthetic Food Dyes (Carmoisine and Tartrazine) on Gut Microbiota of Albino Rats

Abstract

Background: Food additives are commonly used to improve the color, taste, aroma, texture, and nutritional quality of processed foods. Aim: The aim of this study was to determine the effects of the artificial food colors carmoisine and tartrazine on the intestinal microbiota of rats. Study Design: An experimental design approach was chosen. Using a randomized control method, twenty (20) albino rats were divided into five groups of four (4) rats each. Methods: 0.1 g of each dye was weighed and dissolved in 0.9 ml of water, giving a total of 1 ml administered orally. After two (2) weeks of acute exposure, stool samples were collected aseptically. The plates were incubated at 37°C for 24 hours and examined for bacterial growth. Bacterial burden and prevalence were determined using conventional and molecular techniques. Results: The food dyes showed a significant (p=0.0043) reduction in the bacterial load of carmoisine-treated rats compared to the control. Although the other treatment groups had a greatly reduced bacterial load, there were no significant measurements in their means (p<0.05) compared to the control. The frequency and percentage occurrence of bacterial isolates from the sample revealed that E. coli was 74 (29%), Staphylococcus aureus was 68 (26%), Micrococcus species was 65 (25%) and Proteus species by 53 (20%). The result showed that E. coli had the highest number of bacteria. The before-exposure group of rats were observed to have the highest bacterial abundances ranging from 28 (41.2%) to 21 (39.6%). While the lowest occurrences were noted in carmoisine + tartrazine group, which ranges from 6 (8.1%) to 3 (5.7%). The result from the use of the molecular method identified the bacteria as E. coli, Klebsiella pneumoniae, Pseudomonas xianmensis, and P. aeruginosa. Conclusion: This work has shown that artificial food dyes interact with the gut microbiota of rats by reducing them and may result in microbial dysbiosis.