In vitro study of soil arsenic release by human gut microbiota and its intestinal absorption by Caco-2 cells.
Arsenic (As) speciation is essential in assessing health risks from As-contaminated soil. Release of soil-bound arsenic, As transformation by human gut microbiota, and the subsequent intestinal absorption of soil As metabolites were evaluated. A colon microbial community in a dynamic human gut model and the intestinal epithelial cell line Caco-2 were cultured. Arsenic speciation analysis and absorption of different As species were undertaken. In this study, soil As release (3.7-581.2 mg kg-1) was observed in the colon. Arsenic in the colon digests was transformed more quickly than that in the soil solid phase. X-ray absorption near-edge spectroscopy (XANES) analysis showed that 44.2-97.6% of arsenite [As(III)] generated due to arsenate [As(V)] reduction was in the soil solid phase after the colon phase. We observed a high degree of cellular absorption of soil As metabolites, exhibiting that the intestinal absorption of monomethylarsonic acid and As(III) (33.6% and 30.2% resp.) was slightly higher than that of dimethylarsinic acid and As(V) (25.1% and 21.7% resp.). Our findings demonstrate that human gut microbiota can directly release soil-bound arsenic, particularly As-bearing amorphous Fe/Al-oxides. Determining As transformation and intestinal absorption simultaneously will result in an accurate risk assessment of human health with soil As exposures.
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China.
Naiyi
N
Yin
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China.
Xiaolin
X
Cai
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China.
Huili
H
Du
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China.
Zhennan
Z
Zhang
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China.
Zejiao
Z
Li
College of Environment and Resources, Fuzhou University, Fujian, 350108, People's Republic of China.
Xiaochen
X
Chen
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China.
Guoxin
G
Sun
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China. Electronic address: cuiyanshan@ucas.ac.cn.
Yanshan
Y
Cui
D001149:Arsenates / Q000032:analysis; D001151:Arsenic / Q000032:analysis*; D001152:Arsenicals / Q000032:analysis; D018053:Arsenites / Q000032:analysis; D018938:Caco-2 Cells; D002101:Cacodylic Acid / Q000032:analysis; D003106:Colon / Q000187:drug effects / Q000378:metabolism; D000069196:Gastrointestinal Microbiome / Q000187:drug effects*; D006801:Humans; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000187:drug effects*; D012989:Soil Pollutants / Q000032:analysis*; D056928:X-Ray Absorption Spectroscopy
D001149:Arsenates; D001152:Arsenicals; D018053:Arsenites; D012989:Soil Pollutants; D002101:Cacodylic Acid; C020300:monomethylarsonic acid; C015001:arsenite; D001151:Arsenic; C025657:arsenic acid
Arsenic; Caco-2 cell; Gut microbiota; Soil; Speciation