Abstract
This study aimed at probing the mitigating impacts of pectic oligosaccharide (POS) on intestinal inflammatory damages in broilers challenged by lipopolysaccharide (LPS), as it remains unclear if POS can protect animals from LPS challenge. A total of 240 one-d-old yellow-feathered male broilers with similar initial body weight (32.81 ± 0.22 g) were stochastically allocated into three groups (8 replicates per group with 10 broilers per replicate): control (CON) group, LPS group (injection of LPS every other day from 15 to 21 d of age) and LPSP group (LPS-injected broilers supplemented with 600 mg/kg POS). The trial continued for 21 d. All samples were taken at 4 h post the last injection (21 d of age). The results exhibited that LPS challenge significantly diminished (P < 0.05) growth performance (including final body weight and average daily gain) coupled with thymus index, but significantly elevated (P = 0.002) liver index; however, these changes were all counteracted by POS addition, which also alleviated LPS-caused increases (P < 0.05) in serum levels of interleukin (IL)-1β, endotoxin and diamine oxidase. Jejunal or ileal villus height, villus height to crypt depth ratio and goblet cell count together with the relative mRNA expression levels of ilealZO-1 and claudin-1 were significantly reduced (P < 0.05) by LPS challenge. Supplementation of POS restored the above indicators to levels comparable to those of the CON group, and also significantly increased (P < 0.05) the relative mRNA expression levels of jejunal ZO-1 and occludin in LPS-challenged broilers. Moreover, POS supplementation alleviated LPS-caused elevations (P < 0.05) in jejunal IL-1β and IL-6 contents along with ileal IL-6 content. It also mitigated the increases (P < 0.05) in the relative mRNA expression levels of jejunal and ileal inflammation-related genes (MyD88, NF-κB, and IL-6) and apoptosis-related gene caspase-3 in LPS-challenged broilers. Collectively, POS supplementation attenuated LPS-induced intestinal inflammatory damages probably by suppressing NF-κB pathway activation, consequently accounting for the observed alleviation of poor growth performance in LPS-challenged broilers. The findings in this study supply a foundational evidence for utilizing POS to limit the detriment of LPS challenge in chickens.