Objective

2

To explore the structural characteristics and functional differences of intestinal flora in patients with type 2 diabetes mellitus （T2DM） of dampness heat trapping spleen（DHTS） syndrome and Qi-Yin deficiency（QYD） syndrome.

Method

2

From June 2018 to January 2020，62 T2DM patients with DHTS syndrome and 60 with QYD syndrome were selected from Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese Medicine. Serum and fecal samples were collected to compare body mass index（BMI），glucose and lipid metabolism，fasting insulin （FINS） and fasting C-peptide （FCP） levels，and homeostasis model assessment of insulin resistance（HOMA-IR） of the two syndrome types. Fecal samples were extracted for DNA database construction，and 16S rDNA high-throughput sequencing was used to analyze and compare the intestinal flora and metabolic pathways.

Result

2

① The BMI，fasting plasma glucose（FPG），2-hour postprandial blood glucose （2 h PBG），total cholesterol（TC），triglyceride（TG），low density lipoprotein（LDL），FINS，FCP，and HOMA-IR were higher in patients with DHTS syndrome than in patients with QYD syndrome，and the high density lipoprotein（HDL） of the former was lower than that of the latter，（

P

<

0.05，

P

<

0.01）. ② In terms of species composition and differences，Bacteroidetes， Clostridia and Gammaproteobacteria were dominant at the class level，and the relative abundance of Clostridia，Mollicutes and Verrucomicrobiae in QYD syndrome group was higher than that in DHTS syndrome group. At the order level，Bacteroidales，Clostridiales and Enterobacteriales were mainly found. The relative abundance of Clostridiales，Erysipelotrichales and Verrucomicrobiales in QYD syndrome group was obviously higher than that in DHTS syndrome group，while Aeromonadales in the former was lower than that in the latter （

P

<

0.05）. At the family level，Bacteroidaceae，Prevotellaceae and Ruminococcaceae were predominant. The relative abundance of Ruminococcaceae，Porphyromonadaceae and Erysipelotrichaceae in QYD syndrome group was higher than that in DHTS syndrome group（

P

<

0.05）. At the genus level，

Bacteroides

，

Prevotella

and

Parabacteroide

s were mainly found. The relative abundance of

Parabacteroides

，

Butyrivibrio

and

Ruminiclostridium

in QYD syndrome group was higher than that in DHTS syndrome group，while that of

Klebsiella

and

Megasphaera

in DHTS syndrome group was higher than that in QYD syndrome group（

P

<

0.05）. ③ Through Venn analysis of operational taxonomic units（OTU），it was found that there were 49 OTUs in patients with DHTS syndrome patients and 47 OTUs in QYD syndrome patients. ④ The results of OTU

β

diversity and

α

analysis showed that Shannon and Simpson indexes had statistical differences，while Ace and Chao indexes had no statistical differences. The intestinal microbial diversity of patients with QYD syndrome was higher than that of patients with DHTS syndrome（

P

<

0.05）. The analysis of similarities （ANOSIM） showed that the difference of

β

diversity between the two groups was significant（

P

<

0.05）. ⑤ Linear discriminant analysis Effect Size（LEfSe） results demonstrated that

Klebsiella

，

Megasphaera

and Aeromonadales could be selected as the key biomarkers for DHTS syndrome； 14 bacteria such as

Ruminiclostridium

，Burkholderiaceae，

Lautropia

，

Butyrivibrio

，Erysipelotrichales can be selected as the key biomarkers for QYD syndrome. ⑥Functional annotation and analysis showed that the DHTS syndrome involved 9 metabolic pathways，including arginine and proline metabolism，lipopolysaccharide biosynthesis，nicotinic acid and nicotinamide metabolism，while the QYD syndrome involved 10 metabolic pathways，including acarbose and valinomycin biosynthesis，glucagon signaling pathway and NOD-like receptor signaling pathway.

Conclusion

2

There are obvious differences in intestinal flora and functions in T2DM patients of DHTS syndrome and QYD syndrome，which can be used as reference for traditional Chinese medicine （TCM） syndrome differentiation and the target of TCM treatment.