New research findings | Eosinophils may be crucial to the body's intestinal health!

The intestine contains a large number of resident eosinophils, but the function of intestinal eosinophils is currently unknown.

Recently, in a research report titled "Small intestinal resident eosinophils maintain gut homeostasis following microbial colonization" published in the international journal Immunity, scientists from Monash University and other institutions in Australia found through research that eosinophils (a type of white blood cell associated with the onset of asthma and allergies) may play an important role in maintaining a healthy intestine.

New discovery! Eosinophils may be essential for intestinal health.

Image source: Immunity (2022). DOI: 10.1016/j.immuni.2022.05.014

Researcher Professor Harris said that the results of this study revealed that eosinophils play a key role in promoting the interaction between the host and the microbial community, which may overturn our view of the function of eosinophils and will undoubtedly promote scientists to conduct more in-depth research on these cells in the future. Eosinophils account for about 1%-2% of the circulating white blood cells in healthy people in developed countries, and their number increases in patients with severe allergies, playing a pathological role in tissue destruction during these allergic reactions.

About 10-15 years ago, scientists realized that eosinophils accounted for 10%-30% of the white blood cells in the gastrointestinal tract, and they wanted to know why. The answer has always been a mystery, so the researchers set out to answer why these so-called tissue-destroying cells are located in the intestine. In this study, they used a germ-free animal model and advanced 3D microscopy technology to analyze the possible role of eosinophils in the main functions of the small intestine. The results showed that eosinophils may be able to coordinate the intestinal response to bacteria.

Researchers are currently working to limit excessive inflammation in patients, and by doing so they are limiting tissue damage. The most important factor in this damage is the length of the villi, which are finger-like projections on the intestinal wall that help absorb nutrients. Researchers have found that eosinophils maintain the integrity of these villi, and without these cells, the villi become shorter and lipid absorption is reduced. Therefore, eosinophils help maintain this absorption area so that the nutrients obtained from the diet are at the appropriate level. Researchers have also found that in the absence of eosinophils, the movement of the intestine becomes dysregulated, which may affect the structure of the tissue.

Image source: https://www.cell.com/immunity/fulltext/S1074-7613(22)00234-5?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS1074761322002345%3Fshowall%3Dtrue

"These cells may be much more complex than previously thought, so researchers may need to think about them in a completely different way, and they are currently doing a lot of things that are completely fruitless," said the researchers. "Together, our results reveal a key role for eosinophils in facilitating interactions between the host and microbiota, and provide a theoretical basis for their functional significance in early life recruitment to the small intestine."

Original source:

Aline Ignacio,Kathleen Shah,Jeremiah Bernier-Latmani,et al. Small intestinal resident eosinophils maintain gut homeostasis following microbial colonization, Immunity (2022). DOI: 10.1016/j.immuni.2022.05.014