The humble shahtoot, the purple-stained mulberry many of us picked off trees as children, is drawing fresh attention from scientists. The question they are asking is a simple one: can this small fruit, and the leaves it grows among, change the bacteria living in your gut?
- A 2026 review from Wroclaw Medical University found that mulberry leaves and fruit changed gut bacteria in favourable ways in animal studies.
- Mice on high-fat diets given mulberry extracts made more short-chain fatty acids, which help protect the gut lining.
- Blood sugar and blood fat measures also improved in these animals.
- Fibre-like polysaccharides and polyphenols from white mulberry fruit worked better together than alone.
- There are no human trials on mulberry and gut bacteria yet, so it is a promising food, not a proven treatment.
So, can mulberries reshape your gut bacteria? In animals, the answer appears to be yes. A 2026 review published in the journal Biomolecules by researchers at Wroclaw Medical University in Poland looked at the existing studies on white mulberry (Morus alba) and black mulberry (Morus nigra). It found that compounds from both the leaves and the fruit shifted the gut bacteria of mice towards a healthier mix, and that this shift came with better blood sugar and fat metabolism. What we do not know yet is whether the same thing happens in people.
What the researchers looked at
The review pulled together experiments that used different parts of the mulberry plant, prepared in different ways: dried, fermented, or extracted with water. Most of the studies were done on mice fed a high-fat diet, a common way to mimic the effects of an unhealthy modern diet in the lab.
Mulberry is rich in a few important compounds. The leaves contain 1-deoxynojirimycin, often shortened to DNJ, a natural substance known to slow the breakdown of sugars in the gut. The fruit is packed with anthocyanins, the pigments that give dark mulberries their deep purple colour, along with other polyphenols and polysaccharides, which are complex carbohydrates that act much like fibre.
How mulberry seems to help the gut
Your gut microbiota is the large community of bacteria living in your intestines. These bacteria feed on the parts of food your body cannot digest on its own, such as fibre and many plant compounds.
In the studies reviewed, mice that received mulberry extracts produced more short-chain fatty acids, namely acetate, propionate and butyrate. These are made when gut bacteria ferment fibre. Butyrate in particular is a main source of energy for the cells lining the colon, and it helps keep that lining strong.
One finding stood out. When the researchers compared separate parts of white mulberry fruit, the polyphenols and polysaccharides gave better results together than either did alone. This fits a pattern seen across nutrition science: whole foods often work better than single isolated compounds.
The link to blood sugar and metabolism
The changes did not stay in the gut. Mice given mulberry also showed improvements in markers of glucose and fat metabolism. In some experiments, scientists transferred gut bacteria from mulberry-fed mice into other animals, and those animals showed metabolic improvements too. This suggests the bacteria themselves may be doing part of the work.
"The gut microbiota not only contributes to the functioning of the gastrointestinal tract but may also influence metabolism throughout the body," said Professor Anna Prescha, one of the review's authors.
Why you should not rush to buy supplements
This is where honesty matters. Every study in the review was done in animals or in the lab. The researchers point out that results changed a great deal depending on the type of mulberry, the part of the plant used and how it was processed. Many studies also did not measure exactly which compounds were in their extracts, which makes them hard to compare.
Professor Prescha put it plainly: the findings are promising, but they do not yet show whether the same effects happen in humans. Proper human trials with standardised mulberry products are still needed. Mulberry leaf supplements may also affect how the body handles sugar, so anyone taking diabetes medication should speak to their doctor before trying them.
A simple, food-first way to enjoy mulberries
You do not need an extract to benefit from mulberries as a food. Fresh shahtoot is in season in many parts of India in spring and early summer, and dried mulberries are available all year. Enjoy a handful on their own, stir them into curd, or add them to a breakfast bowl alongside other fruits, nuts and seeds. Eating a wide range of fibre-rich plant foods is still the best-supported way to feed your gut bacteria.
If you enjoy fruit-based sweetness without refined sugar, our iHTF Dry Fruit Ladoo, made with dates, figs and raisins, is a gentle way to bring more whole fruit and fibre into your day.
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Frequently Asked Questions
1. Are mulberries good for gut health?
Mulberries contain fibre-like polysaccharides and polyphenols that gut bacteria can ferment. A 2026 review from Wroclaw Medical University found mulberry leaf and fruit extracts shifted gut bacteria in a healthier direction and raised short-chain fatty acids in mice. Human studies are still needed, but whole mulberries are a healthy, fibre-rich fruit.
2. Does mulberry leaf lower blood sugar?
Mulberry leaves contain 1-deoxynojirimycin (DNJ), a natural compound that slows the breakdown of sugars in the gut. Animal studies show improved glucose and fat metabolism with mulberry extracts. Because mulberry leaf may affect blood sugar, people taking diabetes medicines should consult their doctor before using mulberry leaf supplements or teas regularly.
3. What is the difference between white and black mulberries?
White mulberry (Morus alba) and black mulberry (Morus nigra) are two different species. Black mulberries are darker and richer in anthocyanin pigments, while white mulberry leaves are the main source of DNJ. Research shows the effects of mulberry vary depending on the species, the plant part used and how it is processed.
4. How can I add mulberries to my diet?
Fresh mulberries, called shahtoot in India, can be eaten as a snack when in season, usually in spring and early summer. Dried mulberries are available all year and can be added to curd, oats, salads or trail mixes. Pairing them with other fruits, nuts and seeds gives your gut bacteria a wider range of fibre.
