Changes in Composition and Function of Human Intestinal Microbiota Exposed to Chlorpyrifos in Oil as Assessed by the SHIME® Model

Abstract

The presence of pesticide residues in food is a public health problem. Exposure to these substances in daily life could have serious effects on the intestine—the first organ to come into contact with food contaminants. The present study investigated the impact of a low dose (1 mg/day in oil) of the pesticide chlorpyrifos (CPF) on the community structure, diversity and metabolic response of the human gut microbiota using the SHIME® model (six reactors, representing the different parts of the gastrointestinal tract). The last three reactors (representing the colon) were inoculated with a mixture of feces from human adults. Three time points were studied: immediately before the first dose of CPF, and then after 15 and 30 days of CPF-oil administration. By using conventional bacterial culture and molecular biology methods, we showed that CPF in oil can affect the gut microbiota. It had the greatest effects on counts of culturable bacteria (with an increase in Enterobacteria, Bacteroides spp. and clostridia counts, and a decrease in bifidobacterial counts) and fermentative activity, which were colon-segment-dependent. Our results suggest that: (i) CPF in oil treatment affects the gut microbiota (although there was some discordance between the culture-dependent and culture-independent analyses); (ii) the changes are “SHIME®-compartment” specific; and (iii) the changes are associated with minor alterations in the production of short-chain fatty acids and lactate.

Amoxicillin Increased Functional Pathway Genes and Beta-Lactam Resistance Genes by Pathogens Bloomed in Intestinal Microbiota Using a Simulator of the Human Intestinal Microbial Ecosystem

“…In this study, Klebsiella and Bacteroides uniformis were found to be more significantly enriched in the ascending colon than other two colonic-regions, which was in keeping with the previous reports of the alteration in intestinal microbiota by exposure of antibiotics mixture and other toxic compounds like chlorpyrifos and arsenic (Reygner et al, 2016;Yu et al, 2016;Marzorati et al, 2017). These studies revealed the "SHIME-compartment" specific effects that could be due to the inconsistent biodegradation of multiple compounds, gut microbiome community, and pH in different colon regions (Reygner et al, 2016;Yu et al, 2016;Marzorati et al, 2017). Moreover, a large number of functional pathways related genes was also shown to be increased in the ascending colon after AMX exposure, which further clarified that the primary effect observed at the level of the microbiota could also be identified at the genomic and metabolic levels (Garcia-Villalba et al, 2017;Wang et al, 2018).…”

“…Moreover, in vitro experiment using simulator of the human intestinal microbial ecosystem (SHIME) can elucidate the direct effects of medicines on different regions of the human intestinal microbiota, which allows the complex human microbiota to be stably maintained in the absence of host cells (Van de . The SHIME model is known to be a useful tool for the in vitro study, which has already been used to identify the influence of bacteria and compounds on the colon microbiota, including probiotics such as Clostridium cluster XIVa and Bifidobacterium longum (Van den Abbeele et al, 2013;Truchado et al, 2015), prebiotics and prebiotics like compounds such as inulin, polyphenols and orange juice (Kemperman et al, 2013;Duque et al, 2016;Selak et al, 2016), and other toxic compounds such as Chlorpyrifos and Arsenic (Reygner et al, 2016;Yu et al, 2016). However, to the best of our knowledge, there are very few research that applied antibiotics into the SHIME model (Van den Abbeele et al, 2012;Bussche et al, 2015;Marzorati et al, 2017;Ichim et al, 2018;El Hage et al, 2019;Liu et al, 2020).…”

Amoxicillin exposure significantly increases the population and virulence of antibiotic-resistant Klebsiella pathogen in the simulated human intestinal microbiota

“…In this study, Klebsiella was found to be more significantly enriched in ascending colon than the other two colon-regions ( Fig. 1), which was in keeping with previous reports for the changes of intestinal microbiota in exposure to the antibiotic mixtures and other toxic compounds like chlorpyrifos and arsenic [17,28,48]. These "SHIME-compartment" specific effects could be due to the inconsistent compounds biodegradation, gut microbiome community, and pH in different colon regions [17,28,48].…”

Following the community development of SIHUMIx – a new intestinal in vitro model for bioreactor use

“…8,9 Most often fecal bacteria are cultivated in these bioreactor systems. [8][9][10][11] However, true experimental replication is hard to achieve due to the intra-individual and longitudinal heterogeneity of fecal samples. 12 Additionally, a variety of methods, like denaturing gradient gel electrophoresis (DGGE), 13 short chain fatty acid 14 and next-generation 16S rRNA sequencing analysis, 10 have been used to define constant in vitro community states, when the community remains unchanged (often referred to as stable state).…”

“…of dietary compounds, the impact of pathogenic microorganisms on the intestinal microbiota or the response to chemicals has already been investigated in in vitro bioreactor systems. 8 , 9 Most often fecal bacteria are cultivated in these bioreactor systems. 8 – 11 However, true experimental replication is hard to achieve due to the intra-individual and longitudinal heterogeneity of fecal samples.…”