Impact of food additives on the composition and function of gut microbiota: A review

Background: Dietary factors substantially influence the community structure and function of human gut microbiota. Although many dietary components, such as carbohydrates, fats, proteins and phytochemicals, have been extensively explored for their impact on gut microbiota, little attention has been paid to the influences of various food additives on gut microbiota. Scope and approach: This review summarizes the current findings on the impact of common food additives on gut microbiota structure and function. The food additives discussed include artificial sweeteners, emulsifiers, preservatives, colorants and acidity regulators. We begin with introduction of gut microbiota and its association with health and disease, and the factors affecting its composition. Then we discuss existing studies on the effects of different types of food additives on the composition and function of gut microbiota. Finally, we present issues that require consideration when interpreting the current findings and highlight the future perspective. Key findings and conclusion: In vitro studies (such as M-Shime model), animal models (such as mice, rats, pigs and monkeys), and human clinical trials all indicate that different types of food additives could modify gut microbiota and health status. Various models have their own advantages and limitations, therefore cautions need to be taken when the data are interpreted. Considering the ubiquitous use of food additive in processed food, the long-term impact of food additives on gut microbiota needs to be examined in future research. Moreover, whether the changes of specific microbial species caused by food additives could lead to corresponding changes in metabolic and immune functions needs to be further elucidated.