MIT scientists discover amino acid that helps the gut heal itself

MIT researchers have discovered that a naturally occurring amino acid found in many protein-rich foods may help the intestine repair itself after damage. In a new study, scientists found that cysteine can activate an immune response that boosts intestinal stem cells and helps regenerate tissue in the small intestine. The findings, which were observed in mice, could eventually lead to new ways to reduce intestinal damage caused by radiation therapy and chemotherapy.

Researchers say cysteine-rich diets or supplements might one day help cancer patients recover more quickly from treatment-related injuries. "The study suggests that if we give these patients a cysteine-rich diet or cysteine supplementation, perhaps we can dampen some of the chemotherapy or radiation-induced injury," says Omer Yilmaz, director of the MIT Stem Cell Initiative, an associate professor of biology at MIT, and a member of MIT's Koch Institute for Integrative Cancer Research. "The beauty here is we're not using a synthetic molecule; we're exploiting a natural dietary compound." The study, published in Nature , is the first to identify a single nutrient capable of directly enhancing intestinal stem cell regeneration. Previous research had shown that broader dietary patterns, such as fasting or calorie restriction, can influence stem cell activity, but scientists had not pinpointed one specific nutrient responsible for this type of repair response. Yilmaz and his team wanted to better understand how individual nutrients affect stem cells and tissue health. To investigate, the researchers fed mice diets enriched with one of 20 different amino acids, which are the building blocks of proteins. They then measured how each amino acid influenced regeneration in intestinal stem cells. Among all the amino acids tested, cysteine produced the strongest regenerative effect on both stem cells and progenitor cells, which eventually mature into adult intestinal cells. The researchers later uncovered the biological chain reaction behind the effect. When intestinal cells absorb cysteine from food, they convert it into a molecule called CoA. That molecule is then released into the intestinal lining, where it is absorbed by immune cells known as CD8 T cells. Once activated, these T cells begin multiplying and producing IL-22, a signaling protein called a cytokine that plays a major role in intestinal repair and stem cell regeneration.

Key points

• Researchers say cysteine-rich diets or supplements might one day help cancer patients recover more quickly from treatment-related injuries.
• "The study suggests that if we give these patients a cysteine-rich diet or cysteine supplementation, perhaps we can dampen some of the chemotherapy or radiation-induced injury," says Omer Yilmaz, d…
• "The beauty here is we're not using a synthetic molecule; we're exploiting a natural dietary compound." The study, published in Nature , is the first to identify a single nutrient capable of direct…
• Previous research had shown that broader dietary patterns, such as fasting or calorie restriction, can influence stem cell activity, but scientists had not pinpointed one specific nutrient responsi…
• Yilmaz and his team wanted to better understand how individual nutrients affect stem cells and tissue health.