Partially hydrolyzed guar gum intake alleviates lipopolysaccharide-induced systemic inflammation via gut microbial...

Interactions between dietary fiber and the gut microbiota appear to be associated with potential mechanisms to alleviate systemic inflammation. We hypothesized that partially hydrolyzed guar gum (PHGG), a soluble dietary fiber, acts on the immune system via the fermentation of gut microbiota.

In this study, we investigated the effect of PHGG intake on LPS-induced systemic inflammation and changes in gut microbiota.

Nine-wk-old male C3H/HeN mice were randomly divided into three groups: non-fiber (NF), 5% cellulose (Cellu), and 5% PHGG (PHGG) diet groups. After a 6-wk dietary intervention, all mice were injected with LPS (1 mg/kg, i.v.), after which plasma tumor necrosis factor (TNF)-α and interleukin-10 (IL-10) concentrations were measured. In addition, the relative abundance of gut microbiota in feces, short-chain fatty acids (SCFAs) in the cecum contents, and regulatory T (Treg) cell differentiation was measured.

LPS-induced TNF-α, but not IL-10, production in PHGG mice was significantly lower than that in both the NF and Cellu groups (P < 0.01). The α- and β-diversities of gut microbiota were different among the three groups. SCFAs in the cecum contents of PHGG mice were significantly higher than that in the Cellu group (P < 0.05). Furthermore, Treg cells in the colonic lamina propria were increased by PHGG intake (P < 0.05).

Taken together, the habitual intake of PHGG suppresses systemic inflammation, suggesting that this phenomenon may be related to adaptations in immune function with the induction of differentiation into Treg cells via changes in SCFA production by the gut microbiota.