Fermented Deer Blood Ameliorates Intense Exercise-Induced Fatigue via Modulating Small Intestine Microbiota and Metabolites in Mice

Abstract

Intense and excessive exercise-induced fatigue has become an important health issue and can damage intestinal health. Deer blood, as a food byproduct with nutritional value, has been found to restore physical strength. However, little is known about the antifatigue effect of fermented deer blood (FDB) on intense exercise mice. The purpose of the present study is to investigate the antifatigue effect of FDB, and whether this effect is correlated with the altered small intestinal microbiota and metabolites in exercise mice. In this study, 5-week-old male C57BL/6J mice are given treadmill exercise with or without FDB supplementation (30 and 150 mg/kg/d) for 3 weeks. FDB significantly reduces metabolic byproduct accumulation, liver and intestinal damage, and enhances glycogen storage and antioxidant capacity in intense exercise mice. Moreover, FDB restructures the small intestinal microbiota by increasing the abundance of probiotics and butyric acid producing bacteria and decreasing the abundance of pathogenic bacteria. FDB also regulates the levels of metabolites involved in TCA cycle and amino acid metabolism in urine and small intestine content. Correlation analysis shows that FDB-modulated microbiota is highly associated with its antifatigue effect. FDB may ameliorate fatigue and intestinal injury through targeting small intestinal microbiota.

Keywords: antioxidant; exercise-induced fatigue; fermented deer blood; intestinal health; metabolomics; small intestinal microbiota.

Figure 1

Effects of FDB on ameliorating fatigue and oxidative stress in intense exercise mice. (A) Serum biochemical parameters and HG. (B) SOD, GSH-Px, T-AOC, and MDA levels in the serum and liver. (C) The mRNA expression of oxidative stress-related signaling genes in the ileum and liver. ^# p < 0.05, ^{# #} p < 0.01, and ^{# # #} p < 0.001 vs. NC (normal control) group; * p < 0.05, ** p < 0.01, and *** p < 0.001 vs. EC (exercise control) group. FDB30: 30 mg/kg FDB group; FDB150: 150 mg/kg FDB group. BUN: urea nitrogen; LA: lactic acid; HG: hepatic glycogen; LDH: lactate dehydrogenase; LPS: lipopolysaccharide; ALT: alanine aminotransferase; AST: aspartate aminotransferase; SOD: superoxide dismutase; GSH-Px: glutathione peroxidase; T-AOC: total antioxidative capacity; MDA: malondialdehyde.

Figure 2

Effects of FDB on the mRNA expression of intestinal barrier protein, inflammatory cytokines, and antimicrobial peptide in the ileum. (A) Muc-2, ZO-1, Occludin, and Claudin 1; (B) IL-4, IL-10, IL-1β, IFN-γ, and TNF-α; (C) Reg3γ and DEFA. ^# p < 0.05, ^{# #} p < 0.01, and ^{# # #} p < 0.001 vs. normal control (NC) group; * p < 0.05, ** p < 0.01, and *** p < 0.001 vs. exercise control (EC) group. FDB30: 30 mg/kg FDB group; FDB150: 150 mg/kg FDB group.

Figure 3

FDB supplementation altered the composition of small intestinal microbiota in fatigued mice. (A) Taxonomic distributions of bacteria from small intestine content 16S rDNA sequencing data at the phylum level. Relative abundance of significantly altered bacterial taxa at (B) phylum and (C,E) genus levels between NC and EC mice. (D,F) Relative abundance of significantly altered bacterial taxa at genus level between EC and FDB mice. ^# p < 0.05, ^{# #} p < 0.01, and ^{# # #} p < 0.001 vs. normal control (NC) group; * p < 0.05, ** p < 0.01, and *** p < 0.001 vs. exercise control (EC) group. FDB30: 30 mg/kg FDB group; FDB150: 150 mg/kg FDB group.

Figure 4

Effects of FDB on urinary and small intestine metabolites in fatigued mice. Significant changes in (A) urinary and (B) small intestine metabolites in NC and EC groups are shown in the histogram. Significant changes in (C) urinary and (D) small intestine metabolites in EC and FDB-treated groups are shown in the histogram. ^# p < 0.05, ^{# #} p < 0.01, and ^{# # #} p < 0.001 vs. normal control (NC) group; * p < 0.05, ** p < 0.01, and *** p < 0.001 vs. exercise control (EC) group. FDB30: 30 mg/kg FDB group; FDB150: 150 mg/kg FDB group. TMA: trimethylamine; PAG: phenylacetyl glycine.

Figure 5

Correlation analysis between small intestine microbiota (genus level) reversed by FDB intervention with fatigue related parameters and metabolites. Correlation of 13 genera with (A) fatigue related parameters and (B) urinary and small intestine metabolites. The heat map represents the correlation coefficient value. The parameters and metabolites for the serum, liver, ileum and urine were labeled as S, L, I, and U, respectively. Significant correlations are marked by * p < 0.05, ** p < 0.01.

Figure 6

Overview of the effects of FDB on the fatigue related parameters, small intestine microbiota and metabolites in intense exercise mice. BUN: urea nitrogen; LA: lactic acid; LPS: lipopolysaccharide; ALT: alanine aminotransferase; AST: aspartate aminotransferase; HG: hepatic glycogen; SOD: superoxide dismutase; GSH-Px: glutathione peroxidase; T-AOC: total antioxidative capacity; MDA: malondialdehyde; PAG: phenylacetyl glycine.