## 3 Results
At the genus level, compared to the CD and CD + NR groups, both HFD and HFD + NR groups resulted in a higher relative abundance of the _Faccalibaccum_ and _[Eubacterium]_coprostanoligenes_group_, and a lower relative abundance of the _Murbucalaceae_, _Alistipes_, _Alioprecrotella_ and _Lachnospirace_NK4A136_group_ (all _P-diet_ \(<\) 0.05) (Table 2). However, the relative abundance of these genera did not change with NR supplementation. The relative abundance of _Coriobacteriaceae_UCG-002_ was lower in the HFD + NR than in the HFD and CD + NR groups (_P-diet_\({}^{\ast}\)NR = 0.0007) (Table 2). The relative abundance of _Bacteroidees_ in the HFD + NR and CD + NR groups were lower than those in the CD and  
\begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline
**Gut Microbiota** & **CD** & **CD + NR** & **HFD** & **HFD + NR** & _P-diet_ & **P-NR** & _P-diet\({}^{\ast}\)NR_ \\ \hline Phylum & & & & & & & \\ _Firmicutes_ & 56.65 \(\pm\) 1.48 b  & 54.33 \(\pm\) 3.04 b  & 67.34 \(\pm\) 4.49 a  & 60.27 \(\pm\) 5.84 a  & 0.0451 & 0.25 & 0.56 \\ _Bacteroidees_ & 23.10 \(\pm\) 1.91 a  & 20.41 \(\pm\) 1.78 a  & 12.61 \(\pm\) 2.94 b  & 14.22 \(\pm\) 2.35 b  & 0.0008 & 0.81 & 0.35 \\ _Desulfobacteria_ & 5.46 \(\pm\) 0.81 & 9.95 \(\pm\) 1.70 & 9.42 \(\pm\) 1.79 & 9.82 \(\pm\) 2.30 & 0.28 & 0.17 & 0.25 \\ _Actinobacteria_ & 4.13 \(\pm\) 1.02 ab  & 5.87 \(\pm\) 0.55 a  & 5.40 \(\pm\) 0.86 a  & 2.08 \(\pm\) 0.31 b  & 0.10 & 0.29 & 0.0016 \\ _Verrucontemicobia_ & 4.75 \(\pm\) 1.42 & 2.07 \(\pm\) 0.57 & 1.05 \(\pm\) 0.44 & 7.60 \(\pm\) 3.92 & 0.36 & 0.86 & 0.82 \\ _Deferibulcetres_ & 0.98 \(\pm\) 0.57 & 1.20 \(\pm\) 0.37 & 2.16 \(\pm\) 0.63 & 2.10 \(\pm\) 0.60 & 0.05 & 0.33 & 0.22 \\ _Proteobacteria_ & 0.21 \(\pm\) 0.05 a  & 0.41 \(\pm\) 0.10 a  & 0.25 \(\pm\) 0.11 b  & 0.36 \(\pm\) 0.29 b  & 0.0476 & 0.66 & 0.30 \\ _Firmicutes: Bacteroidetes_ & 2.43 \(\pm\) 0.18 b  & 2.91 \(\pm\) 0.31 b  & 9.78 \(\pm\) 2.67 a  & 5.47 \(\pm\) 1.66 a  & 0.0018 & 0.29 & 0.13 \\ Genus & & & & & & & \\ _Faccalibaculum_ & 33.58 \(\pm\) 4.40 b  & 26.11 \(\pm\) 4.31 b  & 42.22 \(\pm\) 4.63 a  & 38.32 \(\pm\) 5.49 a  & 0.0332 & 0.24 & 0.71 \\ _Murbucalaceae_ & 15.68 \(\pm\) 1.59 a  & 14.96 \(\pm\) 1.01 a  & 7.68 \(\pm\) 1.24 b  & 10.88 \(\pm\) 1.63 b  & 0.0001 & 0.38 & 0.17 \\ _Lactobacillus_ & 4.01 \(\pm\) 1.31 & 4.62 \(\pm\) 1.22 & 4.80 \(\pm\) 1.82 & 2.72 \(\pm\) 0.72 & 0.83 & 0.89 & 0.25 \\ _Duboisella_ & 1.87 \(\pm\) 0.43 & 4.76 \(\pm\) 2.05 & 4.62 \(\pm\) 1.35 & 2.28 \(\pm\) 0.48 & 0.23 & 0.66 & 0.42 \\ _Coriobacteriaceae_UCG-002_ & 3.46 \(\pm\) 0.90 b  & 5.41 \(\pm\) 0.55 a  & 5.18 \(\pm\) 0.85 a  & 1.96 \(\pm\) 0.28 b  & 0.22 & 0.37 & 0.0007 \\ _Akkermansia_ & 4.75 \(\pm\) 1.42 & 2.07 \(\pm\) 0.57 & 1.05 \(\pm\) 0.44 & 7.60 \(\pm\) 3.92 & 0.36 & 0.93 & 0.76 \\ _Coslrida_ _UCG-014_ & 4.91 \(\pm\) 1.58 & 4.37 \(\pm\) 1.27 & 0.14 \(\pm\) 0.01 & 0.28 \(\pm\) 0.06 & 0.35 & 0.32 & 0.87 \\ _Mucispirillum_ & 0.98 \(\pm\) 0.57 & 1.20 \(\pm\) 0.37 & 2.16 \(\pm\) 0.63 & 2.10 \(\pm\) 0.60 & 0.05 & 0.33 & 0.22 \\ _Alistipes_ & 2.78 \(\pm\) 0.44 a  a: footnotemark: [ENDFOOTNOTE] a: footnotemark: [OTNOTE] a: footnotemark: [OTNOTE] a: footnotemark: [OTNOTE] a: footnotemark: [OTNOTE] b: footnotemark: [ENDFOOTNOTE] & 2.83 \(\pm\) 0.40 a  a: footnotemark: [ENDFOOTNOTE] a: footnotemark: [OTNOTE] a: footnotemark: [ENDFOOTNOTE] a: footnotemark: [ENDFOOTNOTE] a: footnotemark: [ENDFOOTNOTE] a: footnotemark: [ENDFOOTNOTE] a: footnotemark: [ENDFOOTNOTE] b: footnotemark: [ENDFOOTNOTE] a: footnotemark: [ENDFOOTNOTE] b: footnotemark: [ENDFOOTNOTE] a: footnotemark: [ENDFOOTNOTE] b: footnotemark: [ENDFOOTNOTE] a: footnotemark: [ENDFOOTNOTE] b: footnotemark: [ENDFOOTNOTE] a: footnotemark: [ENDFOOTNOTE] a: footnotemark: [ENDFOOTNOTE] b: footnotemark: [ENDFOOTHFD groups, respectively (_P-NR_ = 0.0001, _P-diet_ = 0.0006) (Table 2). Similarly, the relative abundance of _Lactococcus_ was also lower in the CD + NR and HFD + NR groups compared to the CD and HFD groups (_P-NR_ = 0.0013) (Table 2).