Can Eating Crab Shells Activate the Immune System and Improve Metabolic Health?

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Can Eating Crab Shells Activate the Immune System and Improve Metabolic Health?

Can Eating Crab Shells Activate the Immune System and Improve Metabolic Health?

Food is considered paramount in people’s lives, directly influencing human health. The food we consume plays a crucial role in our physiological functions and metabolic processes. Adopting good and sensible dietary habits is an important aspect of healthcare, enabling the body to grow and develop healthily.

Chitin, also known as chitosan, is a natural polysaccharide abundantly present in arthropods and fungi. It can trigger type 2 immune responses and is widely found in the exoskeletons of marine organisms, mushrooms, and the shells of crustaceans. Previously, the mechanism of action of dietary chitin in mammalian bodies was not clear.

Recently, researchers from the University of Washington School of Medicine in the United States published a study titled “A type 2 immune circuit in the stomach controls mammalian adaptation to dietary chitin” in the journal “Science.”

The study indicates that ingesting chitin activates innate immune responses in the stomach, promoting the production of more chitinase by cells. Dietary intake of chitin can improve the metabolic health of high-fat obese mice, including reducing weight gain, decreasing body fat, and enhancing resistance to obesity.

Can Eating Crab Shells Activate the Immune System and Improve Metabolic Health?

The immune system is a defense mechanism in our bodies that helps us resist various threats, including bacteria, viruses, allergens, and cancer.

In this study, researchers analyzed the response of the mouse gastrointestinal tract to dietary chitin. They fed different groups of mice with feed containing 5-20% chitin or feed containing cellulose as a control, with the same food intake.

Researchers found that compared to the control group fed cellulose, mice in the chitin group showed significant gastric dilation and more gastric contents. Gastric epithelial cells responded quickly to chitin, activating innate immune responses in the stomach, and promoting cells to produce more chitinase to break down chitin. In addition, mice in the chitin group also showed increased levels of gastrin and glucagon-like peptide-1.

Since the intestinal microbiota is the main source of chitinase, researchers also conducted experiments using germ-free mice lacking intestinal bacteria.

The study found that ingesting chitin induced gastric dilation, increased eosinophils, expanded ILC2, and promoted cluster cell proliferation in germ-free mice. This suggests that dietary chitin can also activate immune responses in the absence of microbiota.

Finally, because obesity is influenced by interactions between neurons and ILC2 and type 2 immune responses, researchers also tested the effect of dietary chitin on obesity.

Researchers found that when dietary chitin activated the immune system but was not digested, it had the greatest impact on mouse obesity.

In obese mice fed a high-fat diet lacking chitinase, ingesting dietary chitin resulted in significant weight loss, reduced fat mass, increased resistance to obesity, and significantly improved insulin sensitivity in mice, indicating that dietary chitin can regulate metabolism and contribute to metabolic homeostasis.

In conclusion, the results indicate that dietary chitin activates innate immune responses and improves the metabolic health of high-fat obese mice, resulting in significant weight loss, reduced fat mass, and increased resistance to obesity. This provides new insights for treating metabolic diseases such as obesity.

Next, researchers will test whether chitin can control obesity in humans and combine methods to inhibit gastric chitinase for further testing.

DOI: 10.1126/science.add5649