Related Experiment Video
Updated: Dec 28, 2025

Functional Assessment of Intestinal Permeability and Neutrophil Transepithelial Migration in Mice using a Standardized Intestinal Loop Model
Published on: February 11, 2021
Protective effects of lactic acid bacteria on gut epithelial barrier dysfunction are Toll like receptor 2 and protein
Chengcheng Ren1, Qiuxiang Zhang2, Bart J de Haan3
1Immunoendocrinology, Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen and University Medical Center Groningen, Hanzeplein 1, 9700 RB Groningen, The Netherlands. ccren1989@hotmail.com and School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
Abstract:
Lactic acid bacteria (LAB) are recognized for support of host gut homeostasis but the precise mechanisms remain to be identified. LABs interact with Toll-like receptors (TLRs) which might stimulate barrier function of gut epithelial cells. We previously identified six TLR2-signalling LAB strains. As TLR2 is involved in barrier-function enhancement in gut-epithelium, the epithelial barrier-protective effect of these TLR2-signalling strains was studied by using T84 human colorectal cancer cell monolayer as an in vitro gut epithelial barrier model. The protein kinase C (PKC) dependent barrier disruptor A23187 and mitogen-activated protein kinase dependent barrier stressor deoxynivalenol were tested to determine which pathways LAB influenced. We found that exclusively the PKC dependent disruption was prevented by the selected TLR2-signalling LAB strains. This study suggests that TLR2 is a pivotal epithelial barrier modulator, and provides novel insight in the molecular mechanisms by which LAB contribute to intestinal health.
Related Concept Videos
Mucosal Barrier of the Stomach
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 Health
Pathophysiology of Peptic Ulcer Disease: Mucosal Defense Factors
Defense Mechanism Against Infection
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...
Peptic Ulcer Disease II: Pathophysiology
Damaging agents such as Helicobacter pylori, gastric acid, pepsin, and nonsteroidal anti-inflammatory drugs (NSAIDs) can weaken the mucosal defense, allowing hydrogen ions to infiltrate back and harm epithelial cells.
Defense Against Bacterial Pathogens
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...

