Protocol for extraction of gut interstitial fluid in mice with two-front nutrient supply.

The intestine features a two-front nutrient supply environment, comprising an enteral side enriched with microbial and dietary metabolites and a serosal side supplied by systemic nutrients, collectively supporting intestinal and systemic homeostasis, but there is currently no optimal approach for extracting and assessing the local intestinal microenvironment. Here, we present a protocol for constructing a nutrient supply model in mice and extracting gut interstitial fluid (GIF) via centrifugation. This model and the extracted GIF are suitable for downstream analyses. For complete details on the use and execution of this protocol, please refer to Zhang et al.¹.