Gastrointestinal Autonomic Neuropathy Exacerbates Gut Microbiota Dysbiosis in Adult Patients With Type 2 Diabetes Mellitus.

Fan Yang,Xiangyang Kong,Yongbo Kang,Shuai Zhou,Fubing Yu,Xinwei Huang,Minghui Chen,Liqiong Guo,Qiongli Neng,Jingan Hong,Yu Li,Jianhua Zhao,Yuhui Du,Heng Su

doi:10.3389/fcimb.2021.804733

Abstract

ObjectiveThe diabetic autonomic neuropathy is one of the most common complications in type 2 diabetes mellitus (T2DM), especially gastrointestinal autonomic neuropathy (GAN), which occurs in up to 75% of patients. The study aimed to investigate the gut microbiota composition, structure, and function in T2DM patients with GAN (T2DM_GAN) and set up a link between gut microbiota and clinical characteristics of patients.MethodsDNA was extracted from fecal samples of three groups using the kit method: healthy volunteers (n = 19), the patients with T2DM (n = 76), and T2DM_GAN (n = 27). Sequencing of 16S ribosomal DNA was performed using the MiSeq platform.ResultsAccording to the clinical data, higher age, lower triglyceride, and lower body mass index were the main features of patients with T2DM_GAN. The gut microbiota analysis showed that Bacteroidetes, Firmicutes, and Proteobacteria constituted the three dominant phyla in healthy individuals. In addition, the gut microbiota structure and function of T2DM_GAN patients were clearly different from that of T2DM patients. T2DM patients were characterized by Fusobacteria, Fusobacteriia, Fusobacteriales, Fusobacteriaceae, Fusobacterium, Lachnoclostridium, and Fusobacterium_mortiferum. Those gut microbiota may be involved in carotenoid and flavonoid biosyntheses. Relatively, the Gammaproteobacteria, Enterobacteriales, Enterobacteriaceae, Escherichia-Shigella, Megasphaera, Escherichia_coli, and Megasphaera_elsdenii were characteristic in the T2DM_GAN patients. Those may be involved in bacterial invasion of epithelial cells and pathogenic Escherichia coli infection.ConclusionsGAN exacerbated gut microbiota dysbiosis in adult patients with T2DM. The findings indicated that phyla Fusobacteria and class Gammaproteobacteria were closely related to the occurrence of T2DM. Especially the latter may promote T2DM_GAN.

Highlights

With the increasing incidence of diabetes, diabetes complications have increasingly become one of the most critical health problems in the world today (Cho et al, 2018; Meldgaard et al, 2018)
We demonstrated that gastrointestinal autonomic neuropathy (GAN) exacerbates gut microbiota dysbiosis in adult patients with type 2 diabetes mellitus (T2DM) and suggested that the development of diabetes can be affected by the gut microbiota
It is interesting to note that the correlation of this study found that the dominant bacteria in T2DM_GAN patients, Proteobacteria phylum and its members, were likely to be involved in bacterial invasion of epithelial cells and pathogenic E. coli infection

Summary

Introduction

With the increasing incidence of diabetes, diabetes complications have increasingly become one of the most critical health problems in the world today (Cho et al, 2018; Meldgaard et al, 2018). Once diabetes occurs, it can cause various complications and a negative impact on the whole organism (Leustean et al, 2018). A typical example is gastrointestinal autonomic neuropathy (GAN), which occurred in 75% of diabetic patients (Bytzer et al, 2001; Asgharnezhad et al, 2019). Those patients may experience a range of adverse gastrointestinal symptoms, such as postprandial fullness, nausea, vomiting, bloating, abdominal pain, diarrhea, and constipation (Bytzer et al, 2001; Asgharnezhad et al, 2019). GAN remains underrecognized and poorly treated in type 2 diabetes mellitus (T2DM) patients

Results

Discussion

Conclusion