Megamonas Bacteria Identified as Potential Obesity Culprit

A recent study from Cell Host & Microbe identifies Megamonas as a possible bacteria linked to obesity based on a large-scale cohort of obese Chinese people. This study demonstrates how the bacterium increases lipid absorption, breaks down intestinal myo-inositol, and causes obesity, which may lead to future approaches for managing obesity.

Ruijin Hospital, which is associated with Shanghai Jiao Tong University School of Medicine, BGI Research, and BGI Genomics Institute of Intelligent Medical Research (IIMR) are conducting the study together.

Through a large-scale study of intestinal metagenome and host genome in obese Chinese, this research reveals a strong link between gut Megamonas and obesity. The research uncovers the mechanism by which Megamonas induces obesity, providing a new target bacterium for the diagnosis and treatment of obesity.”

Dr. Yang Fangming, Study Co-First Author, BGI Genomics

Metagenomic sequencing was carried out on facal samples from 1,005 participants, of whom 631 were obese, and 374 were normal-weight. Of these, 814 underwent whole-genome sequencing (WGS). The results demonstrate a strong correlation between Megamonas and obesity, with a significant increase in the likelihood of obesity observed when Megamonas and host genetic risk factors were combined.

Megamonas was significantly more prevalent in the intestines of obese participants in the metagenomic sequencing analysis, which included both obese and normal-weight participants. Based on core genera, all samples were divided into three enterotypes: Megamonas, Prevotella, and Bacteroides. Obesity was more common and BMI was higher in those with the Megamonas-dominated enterotype.

To investigate Megamonas's impact across different genetic backgrounds associated with obesity risk, WGS was conducted on 814 individuals. The study's findings indicate that obesity is more significantly impacted by a gut microbial imbalance in people with lower genetic risk. It was determined that there is a combined effect of host genetics and Megamonas on obesity.

Animal studies provided additional support for the findings. In mice fed a high-fat diet, Megamonas rupellensis markedly increased weight and fat accumulation. The bacteria break down myo-inositol, a substance that successfully prevents fatty acid transport. Obesity results from its breakdown, which increases intestinal fat absorption.