Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Functions of the Gut Microbiota

Functions of the Gut Microbiota

The gut microbiota includes trillions of microorganisms that colonize the human gastrointestinal tract, including bacteria, archaea, viruses, and fungi. This complex ecosystem plays a critical role in maintaining intestinal and systemic health. Most of these microbes inhabit the large intestine, establishing a relatively stable and diverse community that contributes to gut homeostasis through various metabolic, immunological, and protective mechanisms.Dominant bacterial phyla, such as...

Gut-Brain Axis

Gut-Brain Axis

The gut–brain axis is a bidirectional communication system that connects the gastrointestinal tract and the brain. This interaction is mediated through multiple pathways, including the vagus nerve, hormonal signals, immune responses, and chemical messengers produced by gut microbes.Microbial Contributions to Brain FunctionGut microbiota contributes significantly to brain function by producing neuroactive compounds. These include neuroactive compounds that influence neurotransmitters such as...

Microbiota of the Large Intestine

Microbiota of the Large Intestine

The large intestine hosts the most densely populated microbial ecosystem in the human body. This complex community primarily consists of anaerobic bacteria, with Bacillota (formerly Firmicutes) and Bacteroidota (formerly Bacteroidetes) as the predominant groups. The distribution of these microbes varies along different sections of the large intestine, influenced by local environmental factors such as oxygen availability and nutrient composition.The cecum, located at the beginning of the large...

Development of Human Microbiota

Development of Human Microbiota

The human microbiota begins developing at birth and undergoes continual change as we age. Infancy marks a critical period of microbial sensitivity, offering a “window of opportunity” during which beneficial microbes help mature the immune system. By age three, children typically develop a more stable and diverse microbial community. Newborns acquire microbes from their immediate environment; vaginal delivery favors maternal vaginal microbes, while cesarean births favor microbes from the skin...

Microbiota of the Stomach and Small Intestine

Microbiota of the Stomach and Small Intestine

The human gastrointestinal (GI) tract is characterized by distinct physicochemical conditions that shape its microbial communities. Among these, the stomach presents a particularly challenging environment for microbial colonization due to its highly acidic pH, ranging from 1 to 3. This extreme acidity effectively limits microbial density. However, certain acid-tolerant microorganisms are capable of surviving in this niche. Notably, Helicobacter pylori can colonize the gastric mucosa,...

Introduction to the Human Microbiota

Introduction to the Human Microbiota

Microorganisms colonize various regions of the human body, including the mouth, nasal passages, throat, stomach, intestines, urogenital tract, and skin. The total number of microbial cells is estimated to range from 10¹³ to 10¹⁴—comparable to, or exceeding, the number of human somatic cells. This host–microbiome relationship has led to the conceptualization of humans as supraorganisms, wherein microbial communities perform vital roles in development, immunity, and disease...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Collaborative Practice in Oral Nutritional Supplement Provision: The Critical Role of Pharmacists in the Patient Journey.

Healthcare (Basel, Switzerland)·2026

Same author

Shrinking Giants: On the Feasibility of Downsizing Hepatocellular Carcinoma with Immunotherapy Prior to Liver Transplantation.

Journal of clinical medicine·2026

Same author

Embedding nutrition into routine oncology care: about time?

Oncology reviews·2026

Same author

Bacteriophage Therapy Against <i>Shigella</i> spp.: A Precision Antimicrobial Strategy.

Antibiotics (Basel, Switzerland)·2026

Same author

Effect of vitamin D replacement on nutritional status and muscle strength in patients after allogeneic stem cell transplantation and chronic graft-versus-host disease.

Clinical nutrition ESPEN·2026

Same author

Level of health technology assessment process-related skills among doctors in Croatia: a cross-sectional survey study.

International journal of technology assessment in health care·2026

Search research articles

Related Experiment Video

Updated: May 21, 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

Gut microbiota and obesity.

Zeljko Krznarić¹, Darija Vranešić Bender, Ana Kunović

¹Department of Gastroenterology and Hepatology, School of Medicine, University of Zagreb, Croatia. zeljko.krznaric1@zg.t-com.hr

Digestive Diseases (Basel, Switzerland)

|June 23, 2012

Summary

Obesity alters gut microbiota composition, specifically decreasing the Bacteroidetes to Firmicutes ratio. Probiotics and prebiotics may offer a strategy to manage obesity-related metabolic changes.

More Related Videos

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

Related Experiment Videos

Last Updated: May 21, 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

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
Metabolic Health

Background:

The human gut microbiome comprises over 100 trillion microorganisms, with Bacteroidetes and Firmicutes as dominant phyla in adults.
Obesity is linked to significant alterations in gut microbiota composition and function, observed in animal models and human studies.
Initial research suggests a reduced ratio of Bacteroidetes to Firmicutes in obese individuals.

Purpose of the Study:

To explore the association between obesity and gut microbiota composition.
To investigate the potential role of probiotics and prebiotics in modulating host metabolism in obesity.

Main Methods:

Review of experimental data from animal studies.
Analysis of observational studies in obese human patients.
Examination of existing literature on probiotics and prebiotics in obesity.

Main Results:

Obesity is associated with substantial changes in gut microbiota.
A decreased relative proportion of Bacteroidetes to Firmicutes is a key finding in obesity.
Probiotics and prebiotics are proposed as potential modulators of obesity-host metabolism.

Conclusions:

Gut microbiota alterations are a feature of obesity.
The Bacteroidetes/Firmicutes ratio may serve as a biomarker for obesity.
Probiotics and prebiotics show promise for managing obesity and related metabolic disorders.