Related Experiment Video
Updated: Jun 8, 2026
10:24
Assessing the Viability of a Synthetic Bacterial Consortium on the In Vitro Gut Host-microbe Interface
Published on: July 4, 2018
Gut commensal flora: tolerance and homeostasis
1Department of Experimental Oncology, European Institute of Oncology Via Ripamonti 435, 20141 Milan Italy. maria.rescigno@ifom-ieo-campus.it
F1000 Biology Reports
|October 16, 2010
Summary
The intestinal immune system actively engages with commensal microorganisms. These microbes help maintain gut immune homeostasis by signaling through intestinal epithelial cells to immune cells.
Area of Science:
- Immunology
- Microbiology
- Gastroenterology
Background:
- The intestinal immune system constantly interacts with a vast community of commensal microorganisms.
- Traditionally, commensals were viewed as passive inhabitants, but emerging evidence highlights their active role.
Purpose of the Study:
- To elucidate the mechanisms by which commensal microorganisms influence intestinal immune homeostasis.
- To understand the communication pathways between commensals, intestinal epithelial cells, and the immune system.
Main Methods:
- The study reviews recent evidence and experimental findings.
- Analysis of molecular and cellular interactions at the host-microbe interface.
- Investigation of signaling pathways involved in immune tolerance.
Main Results:
- Commensal microorganisms are recognized and processed by the intestinal immune system.
- Commensals actively contribute to maintaining intestinal immune homeostasis.
- Interaction with intestinal epithelial cells is crucial for transmitting tolerogenic signals.
Conclusions:
- Commensal microbes play a vital role in educating and regulating the intestinal immune system.
- The intestinal immune system utilizes signals from commensals to maintain a balanced state of tolerance.
- Understanding these interactions is key to developing strategies for immune-mediated gut disorders.
Related Concept Videos
01:18Functions 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...
01:22Introduction 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...
01:18Dysbiosis of the Gut Microbiota
The human gut microbiome includes a diverse array of microbial species, including beneficial commensals and opportunistic pathogens, which interact to support host health. These microbes contribute to essential functions such as nutrient metabolism, immune system modulation, and maintenance of intestinal barrier integrity. However, disruptions to this equilibrium—referred to as dysbiosis—can have widespread physiological consequences.Dysbiosis is often characterized by reduced microbial...
01:27Microbiota 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,...
01:27Microbiota 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...
01:29Bacterial Flora of the Large Intestine
The gut microbiome is formed by a vast and diverse community of bacteria that colonizes our large intestine. These bacteria start residing in the gut from birth and continue diversifying throughout life, influenced by factors such as diet, lifestyle, and stress. The gut bacterial community also includes bacteria from food and those that enter the colon through the anus.
The normal gut flora of the colon plays a critical role in generating essential vitamins such as vitamins K, B5, and B7.
The normal gut flora of the colon plays a critical role in generating essential vitamins such as vitamins K, B5, and B7.