Investigation of bioaccessibility of Cu, Fe, Mn, and Zn in market vegetables in the colon using PBET combined with SHIME

Naiyi Yin,Xiaolin Cai,Xiaochen Chen,Huili Du,Guoxin Sun,Lihong Wang,Jiayan Xu,Yanshan Cui

doi:10.1038/s41598-017-17901-1

Abstract

The in vitro bioaccessibility of trace metals associated with oral ingestion of market vegetables (lettuce, pak choi, cole, and leaf lettuce) of Beijing, China was studied. The physiologically based extraction test (PBET) combined with the Simulator of Human Intestinal Microbial Ecosystem (SHIME) was applied to simulate stomach, small intestine, and colon of human. In the gastro-intestinal phases, the bioaccessibility of Cu, Fe, Mn, and Zn varied within 5.7–75.5%, 17.3–50.4%, 13.3–49.1%, and 19.9–63.7%, respectively. There was no significant difference in the metal bioaccessibility between the gastric and small intestinal phases, except for higher Cu bioaccessibility in the small intestine. Besides, the bioaccessibility of the four trace metals in the colon phase was first ever reported. A significant decline in Cu bioaccessibility (1.8–63.7%) and slight increases in the bioaccessibility of Fe (16.7–56.4%), Mn (21.2–71.6%), and Zn (15.7–69.7%) were revealed, which could mainly be attributed to the effect of colon microbiota. In addition, the estimated daily intakes (EDIs) of Cu, Fe, Mn, and Zn were worked out to be 0.7, 8.8, 2.7, and 4.5 μg kg−1 body weight d−1, based on which the potential influences of these trace metals in vegetables on the health of the local consumers was demonstrated.

Highlights

Food nutrition has always been receiving broad attention
In an oral ingestion scenario, the in vitro gastrointestinal methods were applied to estimate the bioaccessibility of heavy metals in various food sources, such as rice, vegetables, and seafood[8,9,10]
Due to the dramatic increase of pH and the introduction of more enzymes in the small intestine, a series of reactions such as complexation, adsorption and precipitation could happen to the metal ions

Summary

Introduction

Food nutrition has always been receiving broad attention. The daily oral ingestion of food is the major way, through which more than 90% of nutrients/contaminants enters human body[1]. In an oral ingestion scenario, the in vitro gastrointestinal methods were applied to estimate the bioaccessibility of heavy metals in various food sources, such as rice, vegetables, and seafood[8,9,10]. Some factors affecting the bioaccessible metals in the gastric and small intestinal phases were studied, including vegetable species, cooking, and the difference in fresh and dry samples[11,12,13]. Considering the significance of presystemic metabolism in the human body, it was deemed indispensable to investigate the effects of gut microbiota on metal bioaccessibility associated with oral food ingestion. The previous in vitro bioaccessibility studies mainly focused on simulating the gastric and small intestinal phases. Regarding market vegetables there have been no data about the bioaccessibility of Cu, Fe, Mn, and Zn in the colon phase

Methods

Results

Conclusion