Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Surface Membrane Barriers01:18

Surface Membrane Barriers

The skin and mucous membranes serve as the primary line of defense against pathogens by providing both physical and chemical protection. These barriers are essential in preventing the entry and establishment of microbes, thereby maintaining the integrity of the host.
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...
Mucosal Barrier of the Stomach01:25

Mucosal Barrier of the Stomach

The gastric glands contain parietal cells that secrete hydrochloric acid (HCl) for digestion. The cells secrete HCl because it is highly corrosive and essential for breaking down food. To achieve this, they secrete hydrogen and chloride ions into the lumen of the gastric glands, which combine to form HCl.
Within parietal cells, carbonic acid is first formed through the reaction of water and carbon dioxide. The dissociation of carbonic acid releases bicarbonate and hydrogen ions. The bicarbonate...
Physiology of Enteric Nervous System and Gut Health01:05

Physiology of Enteric Nervous System and Gut Health

The gastrointestinal tract, responsible for the digestion and absorption of nutrients, is safeguarded by the intestinal barrier, which consists of secretory, physical, and immune components. At the forefront is the secretory barrier, composed of essential elements such as mucus, gut microbiota, and defense proteins. They collaborate to break down food particles, facilitate nutrient absorption, and maintain optimal gut health. These secretory components ensure the smooth functioning of the...
Regulation of the Digestive System01:25

Regulation of the Digestive System

Digestive activity regulation hinges on three primary components. Activation is prompted by a multitude of mechanical and chemical indicators, primarily detected by receptors within the stomach and intestines' walls. These receptors predominantly respond to factors such as mechanical stretching of the organ walls, changes in pH and osmolarity, and the presence of digesting materials and their by-products.
The effectors in this regulation system are glands and smooth muscles. Activation of these...
Microbiota of the Respiratory Tract01:29

Microbiota of the Respiratory Tract

The human respiratory tract, comprising the upper and lower segments, serves as a critical interface with the external environment. The upper respiratory tract (URT)—including the nostrils, sinuses, pharynx, and oropharynx—is heavily colonized by microbes, while the lower respiratory tract (LRT), composed of the larynx, trachea, bronchi, and lungs, was long thought to be sterile. However, recent molecular studies have revealed that the lungs are not devoid of microbes but act more like...
Defense Mechanism Against Infection01:26

Defense Mechanism Against Infection

Natural flora, body system defenses, and inflammation are natural barriers of the body against infectious agents regardless of previous exposure. Normal floras of the human body refer to the microbial population that colonizes the skin and mucous membranes.
In addition, many body organ systems have unique defenses against infection. The skin is an intact, multilayered surface preventing invasion by microorganisms unless impaired. Mucous membranes lining the mouth, nose, and eyelids are barriers...

You might also read

Related Articles

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

Sort by
Same author

Single-cell recordings reveal subpopulations that grow and generate resistance at bactericidal concentrations of antibiotics.

Proceedings of the National Academy of Sciences of the United States of America·2023
Same author

The changing epidemiology of community-acquired pneumonia: nationwide register-based study in Sweden.

Journal of internal medicine·2019
Same author

Pathogenesis and prevention of risk of cardiovascular events in patients with pneumococcal community-acquired pneumonia.

Journal of internal medicine·2018
Same author

Statins influence epithelial expression of the anti-microbial peptide LL-37/hCAP-18 independently of the mevalonate pathway.

Clinical and experimental immunology·2018
Same author

Aetiology of lower respiratory tract infection in adults in primary care: a prospective study in 11 European countries.

Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases·2018
Same author

Coeliac disease and invasive pneumococcal disease: a population-based cohort study.

Epidemiology and infection·2017

Related Experiment Video

Updated: Jul 7, 2026

Three-dimensional Quantification of Intestinal Mucus Using Whole-mount Tissue Imaging
05:10

Three-dimensional Quantification of Intestinal Mucus Using Whole-mount Tissue Imaging

Published on: September 12, 2025

Secreted enteric antimicrobial activity localises to the mucus surface layer.

U Meyer-Hoffert1, M W Hornef, B Henriques-Normark

  • 1Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden.

Gut
|February 6, 2008
PubMed
Summary

Antimicrobial peptides are retained in the mucus layer of the small intestine, forming a crucial barrier against bacterial invasion. This localization ensures high peptide concentrations at vulnerable mucosal surfaces while maintaining gut microbiota balance.

More Related Videos

Application of a Mouse Ligated Peyer’s Patch Intestinal Loop Assay to Evaluate Bacterial Uptake by M cells
05:59

Application of a Mouse Ligated Peyer’s Patch Intestinal Loop Assay to Evaluate Bacterial Uptake by M cells

Published on: December 17, 2011

Related Experiment Videos

Last Updated: Jul 7, 2026

Three-dimensional Quantification of Intestinal Mucus Using Whole-mount Tissue Imaging
05:10

Three-dimensional Quantification of Intestinal Mucus Using Whole-mount Tissue Imaging

Published on: September 12, 2025

Application of a Mouse Ligated Peyer’s Patch Intestinal Loop Assay to Evaluate Bacterial Uptake by M cells
05:59

Application of a Mouse Ligated Peyer’s Patch Intestinal Loop Assay to Evaluate Bacterial Uptake by M cells

Published on: December 17, 2011

Area of Science:

  • Gastroenterology
  • Immunology
  • Microbiology

Background:

  • The intestinal mucosa faces constant challenges from microbial flora and pathogens.
  • Paneth cell-derived alpha-defensins are key antibacterial peptides for gut homeostasis.
  • Understanding their distribution is crucial, especially in conditions like Crohn's ileitis.

Purpose of the Study:

  • To analyze the spatial distribution of antimicrobial peptides within small intestinal compartments.
  • To investigate the role of mucus in retaining these peptides.
  • To understand their contribution to gut barrier function.

Main Methods:

  • Extraction and separation of intestinal contents using reversed-phase high-performance liquid chromatography.
  • Assay of antibacterial activity in various intestinal fractions.
  • Confirmation of antimicrobial peptides via N-terminal sequencing, mass spectrometry, and immunodetection.

Main Results:

  • Secreted antibacterial activity was primarily found in the mucus layer, with minimal amounts in luminal content.
  • Antimicrobial peptides in mucus showed strong, contact-dependent activity against commensal and pathogenic bacteria.
  • Specific activity percentages against various bacteria (e.g., Listeria monocytogenes, Escherichia coli) were quantified across crypt, mucus, and lumen compartments.

Conclusions:

  • Secreted antimicrobial peptides are effectively retained within the mucus layer.
  • This mucus-bound peptide layer acts as a physical and antibacterial barrier, preventing bacterial attachment and invasion.
  • This localized concentration of peptides enhances mucosal defense without disrupting the enteric microbiota.