Assessment of Modulatory Effect of Some Synthetic Food Dyes (Carmoisine and Tartrazine) on Gut Microbiota of Albino Rats
Onugha, Nneka Concilia
Department of Medical Microbiology, Faculty of Medical Laboratory Science, Rivers State University, Port Harcourt, Nigeria.
Monsi, Tombari Pius
Department of Medical Microbiology, Faculty of Medical Laboratory Science, Rivers State University, Port Harcourt, Nigeria.
Ollor, Amba Ollor *
Department of Medical Microbiology, Faculty of Medical Laboratory Science, Rivers State University, Port Harcourt, Nigeria.
*Author to whom correspondence should be addressed.
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.
Keywords: Food dyes, gut microbiota, microbial dysbiosis, bacteria load