The role of trehalase in trehalose digestion
Trehalose is a disaccharide, or a double sugar, made up of two glucose molecules joined together by an α,α-1,1-glycosidic bond. To digest this sugar, your body needs a specific enzyme called trehalase. In healthy individuals, trehalase is produced in the intestinal mucosa and is found on the surface of the small intestine's brush border. When trehalose is ingested, the trehalase enzyme cleaves the bond connecting the two glucose molecules, releasing them for absorption and use as energy. The rate of digestion is slower compared to sugars like sucrose, leading to a more gradual rise in blood sugar levels. This process is efficient for most people, allowing them to consume trehalose from natural food sources without issue.
The mechanism of digestion
- Ingestion: Trehalose is consumed, typically from natural sources like mushrooms or as a food additive.
- Transport to the small intestine: The trehalose travels through the digestive tract to the small intestine.
- Enzymatic cleavage: In the small intestine, the trehalase enzyme, located in the brush border, breaks the trehalose down into two glucose molecules.
- Glucose absorption: The resulting glucose molecules are then absorbed by the intestinal mucosal cells via the sodium-glucose cotransporter 1 (SGLT 1).
- Metabolism: The absorbed glucose enters the bloodstream and is utilized by the body for energy.
What is trehalase deficiency?
While most people can efficiently digest trehalose, a small percentage of the population has a condition called trehalase deficiency, or isolated trehalose intolerance. This is a rare, genetic metabolic disorder where the body has either low levels of the trehalase enzyme or lacks it entirely. Without sufficient trehalase, ingested trehalose cannot be properly broken down in the small intestine. Instead, it travels to the large intestine, where it is fermented by gut bacteria. This fermentation process can lead to uncomfortable gastrointestinal symptoms, similar to those experienced by individuals with lactose intolerance.
Symptoms and diagnosis of trehalase deficiency
For those with a trehalase deficiency, consuming trehalose-containing foods can trigger a range of digestive issues. The severity of symptoms can vary depending on the amount of trehalose consumed and the individual's level of enzyme activity.
Symptoms may include:
- Bloating
- Abdominal pain
- Diarrhea
- Increased flatulence
Diagnosing trehalase deficiency typically involves a trehalose tolerance test, which can be done through a blood sample or by analyzing breath for hydrogen, a byproduct of bacterial fermentation. A definitive diagnosis may also involve a small intestinal biopsy to measure trehalase activity directly.
Trehalose in food sources
Trehalose is naturally found in certain foods, but the quantities are often small. Mushrooms are one of the most common natural sources, which is why some individuals with trehalase deficiency may notice symptoms after consuming them. The widespread use of trehalose has increased in recent decades, particularly in the food manufacturing industry, where it is used as a low-sweetness sugar, stabilizer, and texturizer in items like frozen foods, baked goods, and confectionary. This makes it more prevalent in many processed foods than ever before, which is an important consideration for those with trehalase intolerance.
| Feature | Trehalose Digestion (Normal) | Trehalose Digestion (Deficient) |
|---|---|---|
| Enzyme | Present (Trehalase) | Absent or low levels (Trehalase) |
| Location | Small intestine | Large intestine |
| Mechanism | Trehalase breaks trehalose into two glucose molecules. | Gut bacteria ferment undigested trehalose. |
| Symptoms | No gastrointestinal discomfort. | Abdominal pain, bloating, and diarrhea. |
| Outcome | Glucose absorbed for energy. | Glucose fermented, leading to symptoms. |
Potential links to health conditions
Recent research has explored potential links between trehalose and certain health issues, though the evidence is not conclusive. One notable study suggested a link between trehalose consumption and the increased virulence of Clostridium difficile (C. diff) bacteria, though this finding has been disputed and contradicted by later research. The media widely reported the initial study, causing some unnecessary fear around the sugar. However, subsequent epidemiological studies have largely failed to find a valid correlation between trehalose usage and the emergence of hypervirulent C. diff strains. Furthermore, trehalose has also been explored for its therapeutic potential in neurodegenerative diseases due to its ability to induce autophagy, though this research is still in preliminary stages.
Conclusion: Can we digest trehalose?
Yes, most people can and do digest trehalose without any problems, thanks to the enzyme trehalase in the small intestine. The key difference in digestion lies in the presence or absence of this enzyme. For individuals with trehalase deficiency, an inability to break down the sugar leads to malabsorption and uncomfortable gastrointestinal symptoms. This condition, while rare, highlights the importance of reading food labels, especially for those sensitive to mushrooms or other trehalose-containing products. Ongoing research continues to shed light on trehalose's full impact on human health, but for the general population, it remains a safe and digestible sugar.
Key takeaways
- Trehalose is typically digested normally: The majority of people can efficiently digest trehalose using the enzyme trehalase in their small intestine.
- Trehalase breaks down trehalose: The enzyme cleaves the double sugar into two glucose molecules, which are then absorbed by the body for energy.
- Trehalase deficiency is a rare condition: This genetic disorder results in insufficient trehalase, leading to malabsorption and digestive issues.
- Mushrooms are a common source: Natural sources of trehalose include mushrooms, which can cause symptoms in intolerant individuals.
- Trehalose is a common food additive: It is used in processed foods for its stabilizing properties, increasing dietary exposure.
- Studies on C. diff were inconclusive: Initial studies suggesting a link to more virulent C. diff have been widely disputed by later research.
FAQs
Q: What is trehalose? A: Trehalose is a natural disaccharide (double sugar) composed of two glucose molecules bonded together. It is found in some plants, insects, and fungi, and is also used commercially as a food additive.
Q: What is the main enzyme involved in trehalose digestion? A: The main enzyme is trehalase, which is produced in the small intestine. It breaks the bond in the trehalose molecule, releasing two glucose molecules for absorption.
Q: What causes trehalase deficiency? A: Trehalase deficiency is a rare, genetic metabolic condition. It occurs when an individual inherits genes that result in low or nonexistent levels of the trehalase enzyme.
Q: What are the symptoms of trehalase intolerance? A: Symptoms can include abdominal pain, bloating, diarrhea, and increased flatulence after eating foods containing trehalose.
Q: Is trehalose deficiency more common in certain populations? A: Yes, research has shown a higher prevalence of trehalase deficiency in specific populations, such as the Greenlandic Inuit, but it is considered rare globally.
Q: What happens to undigested trehalose in the body? A: In individuals with trehalase deficiency, undigested trehalose passes to the large intestine, where it is fermented by gut bacteria, causing gas and other digestive discomfort.
Q: Are there treatments for trehalase deficiency? A: There is currently no treatment for trehalase deficiency. Management involves avoiding foods and products that contain trehalose to prevent symptoms.
Q: Is trehalose a safe food additive? A: Yes, trehalose is considered safe for human consumption and is approved for use in many countries. Concerns raised by early studies linking it to virulent C. diff have been refuted by further research.
Q: What foods contain trehalose? A: Natural sources include mushrooms, yeast, and some seafood. It is also added to many processed foods, such as baked goods, frozen foods, and confectionary.
