Vossen J., Pálková L., Keijser B., Montijn R., Schuren F.
TNO, The Netherlands

The relation between ingested products and health has been acknowledged widely. Ingested food and medicine exert their influence on the microbiota of the gastrointestinal tract. Possibilities to study these effects in human subjects are limited. We developed the i-screen platform that allows for studying effects of compounds on the gut microbiome. This contribution describes the features of the system as well as its application for screening ingredients and studying effects of medication on the gut microbiome.

In the i-screen platform the ex-vivo gut microbiota can be simultaneously maintained in multiple wells and individually exposed to up to hundreds of different conditions covering different ingredients and compounds. The effect of different food ingredients, probiotics, prebiotics and antibiotics, on the microbiota composition and - activity can be analyzed and described by applying a polyphasic analysis. This analysis consists of next generation 16S rDNA sequencing for microbiota composition, metagenomics sequencing, RNA-sequencing for the meta transcriptome and short chain fatty acid (SCFA) analysis as part of the metabolome.

Effects of food fibers and prebiotics including inulin, xylobiose are presented. Xylobiose showed a strong concentration dependent effect on the proliferation of Bifidobacterium spp. in the gut microbiome. By using metatranscriptome analysis the specific upregulation of genes involved in the xylose metabolic pathway in Bifidobacterium was detected. In the presence of xylobiose, the microbiota produces SCFA including butyrate. Butyrate was produced at a higher level than in the absence of xylobiose. Apart from beneficial bacteria, the fate of potential pathogenic bacteria in the i-screen is also shown. When challenging the microbiota with antibiotics, significant changes in the microbiota composition are noticed. Introducing ESBL Enterobacteriaceae in the microbiota in presence and absence of beta lactam antibiotics resulted in typical effects of bacterial overgrowth. The type of beta lactam antibiotic is rather dictating the effect. Amoxicillin has a general Enterobacteriaceae stimulating effect on the expense of other microbiota members while cefotaxime only stimulate the relative abundance of ESBL bacteria. Mitigating effects of prebiotics in case of antibiotic use are observed and will be shared.

From these results we conclude that prebiotic effects in the presence of food fibers can be identified and dysbiosis in case of a gastrointestinal infection with ESBL while using beta lactam antibiotics can be simulated. Although the i-screen platform is a model representing the large intestine in this study, it clearly simulates effects on the gut microbiota as observed in vivo. This result implies that the i-screen platform has predictive value and can be used to screen and study initial effects of different compounds on a complex ecosystem in the absence of the mammalian immune system.

Keywords: Microbiota, Prebiotics, Screening model, Polyphasic analysis, Antibiotics, Metagenomics, Metatranscriptomics

Vossen J., et al. (2016). Intestinal microbiota screening platform (I-SCREEN) provides insights into the effects of food ingredients and medication on gut microbiota composition and – activity. Conference Proceedings of IPC2016. Paper presented at the International Scientific Conference on Probiotics and Prebiotics, Budapest (p. 79.). IPC2016

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