2.4 Animals
SD rats weighing 200-250 g (half of which were male) were purchased from
the School of Pharmacy, Jilin University (SCXK 2016-0001). All rats were
given standard food and water for seven days prior to experimentation
and were randomly divided into the blank group (control), intestinal
inflammation group (DSS) (Cosin-Roger et
al., 2017; M. Zhou et al., 2018),
low-dose group of GP treatment (DSS+GP-L, 50mg/kg), middle-dose group of
GP treatment (DSS+GP-M, 100mg/kg) and high-dose group of GP treatment
(DSS+GP-H, 200mg/kg), each group consisted of 10 rats. Experimental
procedures used for the animals and administration methods were based on
previously reported experimental protocols
(M. Wang, Gao, Xu, & Gao, 2015). The
rats fasted for 12 hours on the last day, and each rat was anesthetized
and euthanized. The blood from each rat was collected from the common
carotid artery. Ten grams of fresh feces from the rats in each group
were collected and weighed in a sterilized beaker, and 50 ml of 37 °C
sterile normal saline was added, stirred, and filtered with double-layer
sterile gauze. The filtrate was then centrifugated at 6,000 g / min for
15 min (centrifugation radius: 10 cm), and then the sediment was
suspended in 100 ml of normal saline to obtain the fecal bacteria
solution. FMT (5 ml / kg) was administered by gavage once a day for 14
days. The distal parts of the colon tissues were stored in a -80 °C
refrigerator for section or Western blot analysis. Feces were collected
for further metabolite analysis. Blood was centrifuged, and the
supernatant was stored at -20 °C for later testing. The relative serum
levels of IL-1β, IL-6 and TNF-α were determined using ELISA kits
(Beyotime Institute of Biotechnology, Shanghai, China) according to the
manufacturer’s instructions.