Immunity improvement and gut microbiota remodeling of mice by wheat germ globulin

Abstract

The wheat germ protein (WG) and it's proteolytic peptide have a variety of biological activities. Our previous work showed that WG could improve immunity of the immunosuppressive mice established by cyclophosphamide. However, in the healthy condition and normal diet, as a supplementary food, the effects of immunity improvement and gut microbiota remodeling by the wheat germ globulin has not been studied yet. Here, we reported that WG could improve the immunity and remodel the gut microbiota of the mice, as a potentially safe functional supplementary food for the first time. The increase of interleukin-6 (IL-6) and the decrease of tumor necrosis factor α (TNF-α) and interleukin-10 (IL-10) indicated that WG could enhance the levels of activated T cells and monocytes and anti-inflammatory ability, meanwhile, the significant increase of immunoglobin G (lgG) and the notable decrease of the immunoglobin M (lgM) and immunoglobin A (lgA) illustrated that WG could improve immunity by promoting the differentiation and maturation process of B cells, compared with the NC group (normal control group). 16S rRNA sequencing showed WG could remodel the gut microbiota. At the phylum level, the Bacteroidetes were reduced and Firmicutes were increased in WG group, compared with NC group. At the genus level, the SCFA producing genera of unclassified_f_Lachnospiraceae, Blautia and especially the Roseburia (increased more than threefold) increased notably. Further, the level changes of cytokines and immunoglobulins were associated with the gut microbiota. This work showed that WG could improve immunity and has potential application value as an immune-enhancing functional food.

Keywords: Gut microbiota; Immunity improvement; Mice; Wheat germ globulin.