Gut Microbiota Signature of Obese Adults Across Different Classifications

Abstract

Purpose

Obesity is currently a major global public health issue. It has been shown by many that gut microbiota and microbial factors regulate the pathogenesis of obesity and metabolic abnormalities, but little is known about their roles in the different degrees of obesity. Here, we sought to investigate the microbial signatures of obesity of various severities.

Patients and Methods

We did this by characterizing the intestinal microbiome signature in a Chinese cohort of obese patients and healthy controls using 16S rRNA gene sequencing. To this end, obesity was sub-divided into four subgroups, including “Overweight”, Class I, Class II, and Class III obesity, based on body mass index (BMI).

Results

Microbial diversity decreased in obese subjects, and the reduction trend was correlated with the severity of obesity. We detected an expansion of Escherichia shigella in obese patients compared to healthy controls. The family Eubacterium coprostanoligenes and Tannerellaceae, the genera Eubacterium coprostanoligenes, Lachnospiraceae NK4A136, Parabacteroides, and Akkermansia, and the species Prevotella copri were microbial biomarkers of healthy people. Gammaproteobacteria and Enterobacterales were biomarkers of being “Overweight”. Erysipelatoclostridiaceae was a biomarker of Class I obesity. The class Bacilli and the order Lactobacillales were both biomarkers of Class II obesity. Negativicutes was a biomarker of Class III obesity. We further established relationships between this microbiome data and other biochemical data, including albumin, low-density lipoprotein (LDL), high-density lipoprotein (HDL), vitamin folic acid (FA) and vitamin B12 (VB12), and Interleukin-6 (IL-6) levels. Function prediction results showed a marked energy metabolism dysbiosis in obesity, especially in patients with Class III obesity.

Conclusion

These results suggested that people with different levels of obesity had distinct gut microbial signatures. Decreased microbial diversity, depletion of some specific taxa, and deviation in potential functions mirrored the severity of obesity in this cohort.

Keywords:

• body mass index
• degree of obesity
• fecal microbiota
• 16S rRNA sequencing

Data Sharing Statement

The raw sequence data reported in this study have been deposited in the Genome Sequence Archive in the National Genomics Data Center (NGDC), China National Center for Bioinformation/Beijing Institute of Genomics, Chinese Academy of Sciences (GSA: CRA007762). They are available at https://ngdc.cncb.ac.cn/gsa.

Acknowledgments

We respectfully acknowledge our participants, who selflessly helped to complete this project.

Author Contributions

All authors have contributed significantly to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation or in all these areas; they have participated in drafting, revising, or critically reviewing the article; they approved the final version to be published; they have agreed on the journal to which the article has been submitted; and they agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.

Additional information

Funding

Funds to support this work were provided by the National Natural Science Foundation of China [82170887 to LYJ]; Chengdu High-level Key Clinical Specialty Construction Project [LYJ]; and the Science and Technology Project of The Health Planning Committee of Sichuan Municipality [20PJ211 to YQ].