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Updated: May 27, 2026

Microbiota Analysis Using Two-step PCR and Next-generation 16S rRNA Gene Sequencing

Microbiota Analysis Using Two-step PCR and Next-generation 16S rRNA Gene Sequencing

Published on: October 15, 2019

The intestinal microbiota and obesity.

Samuel J Kallus¹, Lawrence J Brandt

¹Department of Medicine, Georgetown University Hospital, Washington, DC, USA.

Journal of Clinical Gastroenterology

|November 9, 2011

Summary

The human gut microbiome, particularly the balance of Firmicutes and Bacteroidetes bacteria, is linked to obesity. Altering the gut microbiome composition can influence body fat, suggesting a role in weight gain and obesity development.

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Microbiota Analysis Using Two-step PCR and Next-generation 16S rRNA Gene Sequencing

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Published on: October 15, 2019

An In Vitro Batch-culture Model to Estimate the Effects of Interventional Regimens on Human Fecal Microbiota

An In Vitro Batch-culture Model to Estimate the Effects of Interventional Regimens on Human Fecal Microbiota

Published on: July 31, 2019

Area of Science:

Microbiology
Human Physiology
Obesity Research

Background:

Obesity is a widespread epidemic in the United States, with rates increasing despite various health initiatives.
Current obesity treatments, including diets and surgery, have not been optimal.
The gut microbiome composition, specifically the ratio of Firmicutes to Bacteroidetes, differs between lean and obese individuals.

Purpose of the Study:

To review the relationship between the gut microbiome and obesity.
To discuss proposed mechanisms by which the intestinal microbiota influences weight gain.

Main Methods:

Comparison of gut microbiome composition (Bacteroidetes and Firmicutes phyla) in lean and obese mice and humans.
Experimental colonization of germ-free mice with gut microbiota from obese mice.
Review of existing literature on microbiome-host interactions related to obesity.

Main Results:

Obese individuals and mice exhibit a higher proportion of Firmicutes to Bacteroidetes compared to lean counterparts.
Colonizing germ-free mice with microbiota from obese mice resulted in increased body fat in recipients.
Potential mechanisms include enhanced calorie absorption by Firmicutes, lipopolysaccharide-induced inflammation, and regulation of host genes.

Conclusions:

The gut microbiome plays a significant role in host obesity.
The balance of bacterial phyla like Firmicutes and Bacteroidetes is a key factor in energy metabolism and weight regulation.
Further research into microbiome-host interactions may reveal novel therapeutic targets for obesity.