Sulfated Chinese Yam Polysaccharides Alleviate LPS-Induced Acute Inflammation in Mice through Modulating Intestinal Microbiota

Abstract

This study aimed to test the preventive anti-inflammatory properties of Chinese yam polysaccharides (CYP) and sulfated Chinese yam polysaccharides (SCYP) on LPS-induced systemic acute inflammation in mice and investigate their mechanisms of action. The results showed that SCYP can efficiently reduce plasma TNF-α and IL-6 levels, exhibiting an obvious anti-inflammation ability. Moreover, SCYP reduced hepatic TNF-α, IL-6, and IL-1β secretion more effectively than CYP, and significantly altered intestinal oxidative stress levels. In addition, a 16S rRNA gene sequencing analysis showed that CYP regulated the gut microbiota by decreasing Desulfovibrio and Sutterella and increasing Prevotella. SCYP changed the gut microbiota by decreasing Desulfovibrio and increasing Coprococcus, which reversed the microbiota dysbiosis caused by LPS. Linear discriminant analysis (LDA) effect size (LEfSe) revealed that treatment with CYP and SCYP can produce more biomarkers of the gut microbiome that can promote the proliferation of polysaccharide-degrading bacteria and facilitate the intestinal de-utilization of polysaccharides. These results suggest that SCYP can differentially regulate intestinal flora, and that they exhibit anti-inflammatory effects, thus providing a new reference to rationalize the exploitation of sulfated yam polysaccharides.

Keywords: LPS; anti-inflammation; gut microbiota; sulfation; yam polysaccharide.

Figure 1

Percentage change in body weight compared with day 1 for each group (A). Body weight ratio of day 14/15 for each group (B). Levels of pro-inflammatory cytokines TNF-α (C) and IL-6 (D) in the plasma. Values are expressed as means ± SD. (n = 6 for A,B and n = 5 for C,D). Different letters represent significant differences between different groups (p < 0.05).

Figure 2

Influence of CYP and SCYP on pro-inflammatory cytokines TNF-α (A), IL-6 (B) and IL-1β (C) in the livers of LPS-induced mice. Values are expressed as means ± SD. (n = 6). Different letters represent significant differences between different groups (p < 0.05).

Figure 3

Oxidative stress in jejunal tissue evaluated in terms of SOD (A), CAT (B), and MDA (C). Levels of pro-inflammatory cytokines IL-1β (D) in jejunal tissue. Values are expressed as means ± SD. (n = 6 for A and n = 5 for B,C). Different letters represent significant differences between different groups (p < 0.05).

Figure 4

α-diversity evaluated using Shannon, Simpson, Chao1, and observed_species indices (A). β-diversity evaluated according to the PCA (B). (n = 5). Different letters represent significant differences between different groups (p < 0.05).

Figure 5

Species composition of colon microbiota at the phylum level (A). Relative abundance of colon microbiota at the phylum level (B–E). Values are expressed as means ± SD. (n = 5). Different letters represent significant differences between different groups (p < 0.05).

Figure 6

Species composition of colon microbiota at the genus level (A). Relative abundance of colon microbiota at the genus level (B–G). Values are expressed as means ± SD. (n = 5). Different letters represent significant differences between different groups (p < 0.05).

Figure 7

Taxonomic cladogram of the LEfSe analysis (A). Distribution histogram of the LEfSe analysis (B). The LDA threshold is 4. (n = 5).