Differential effects of inulin or its fermentation metabolites on gut barrier and immune function of porcine intestinal epithelial cells

Julie Uerlings,Martine Schroyen,Geert Bruggeman,Jérôme Bindelle,Nadia Everaert,Sofie Tanghe,Els Willems

doi:10.1016/j.jff.2020.103855

Abstract

Prebiotics can modulate gut fermentation and improve intestinal barrier function in mammals. First, inulin fermentation profile was tested in a three-step in vitro model of the piglet’s gastro-intestinal tract combining a hydrolysis – dialysis step to a batch fermentation. Then, the differential effects of digested inulin (after the hydrolysis – dialysis steps) or fermented inulin (after the fermentation step) on the expression of gut barrier and immune-related genes of IPEC-J2 cells were investigated by high-throughput qPCR. Inulin was associated with elevated short-chain fatty acids and butyrate levels. Upregulated expressions of tight and adherens junction genes were observed in IPEC-J2 cells supplemented with inulin fermentation supernatant compared to control IPEC-J2 cells and digested inulin. Therefore, metabolites arising from the fermentation process, including butyrate, could be responsible for the reinforcement of the barrier function.

Highlights

To date, prebiotics represent a wide-spread dietary approach to modulate intestinal fermentation and manipulate gut ecology for health purposes (Roberfroid, 2007)
The high-molecular weight polymer of fructose, mainly composed of soluble fibres, was rapidly and extensively fermented by porcine fecal microbiota which is in line with several studies highlighting the extensive gas capacities of inulin in comparison with other prebiotics using human fecal microbiota as inoculum (Carlson, Erickson, Lloyd, & Slavin, 2018; Fehlbaum et al, 2018)
We demonstrated in a previous study that the rapidity and extensity of the fermentation were directly correlated to the fructan content of the ingredient (Uerlings et al, 2019a)

Summary

Introduction

Prebiotics represent a wide-spread dietary approach to modulate intestinal fermentation and manipulate gut ecology for health purposes (Roberfroid, 2007). Prebiotics help creating and maintaining an optimal environment in the host gastro-intestinal tract by selectively stimulating the proliferation and metabolic activity of health-associated microbiota communities and lowering the pathogenic bacteria load (Gibson & Roberfroid, 1995). The fermentation of prebiotics by the endogenous microbiota yields short-chain fatty acid (SCFA) end-products, acetate, propionate, and butyrate. The latter is of special interest for its anti-inflammatory properties (Canani et al, 2011) and is used as energy source by the colonocytes (Roediger, 1982), leading to a reinforcement of the intestinal barrier integrity (Peng, Li, Green, Holzman, & Lin, 2009). The ratio between individual SCFA and the total amount of SCFAs produced vary with the source of prebiotic (Grootaert et al, 2009; Van den Abbeele, Venema, Van de Wiele, Verstraete, & Possemiers, 2013)

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