Indigestible dextrin, also sold as resistant maltodextrin, is the single most-used material in Japan’s Foods with Function Claims and Specified Health Use Foods systems, and it turns up in everything from bottled tea to powder sticks. Brands abroad ask for a Japan-made fibre product because that regulatory track record is hard to miss.
This guide sets out what the trial evidence actually shows for bowel movements, who funded that evidence, and how Japan’s regulatory notifications for this ingredient are worded — without turning any of it into a blood-sugar or cholesterol claim for your product.
Health supplements are foods, not medicines, and are not a substitute for medical treatment. Nothing here is a claim that any product prevents, treats or cures a disease.
💬 Planning a dietary fibre product made in Japan? We check the full formula against Japanese food law first. See Japan-made supplement OEM.
What the research shows
Randomised trials and a pooled meta-analysis both found that resistant maltodextrin increases stool frequency and stool volume compared with placebo, and the funding for this evidence comes overwhelmingly from one Japanese ingredient manufacturer.
| Study | Design/What was analysed | Reported result |
|---|---|---|
| Systematic review and meta-analysis, Clinical and Experimental Gastroenterology 2018 (PMID 29535547, doi 10.2147/CEG.S153924) | 29 randomised controlled trials (28 articles) of resistant maltodextrin in healthy adults and people with a tendency to constipation | Resistant maltodextrin significantly increased stool frequency (mean difference 0.71, 95% CI 0.48–0.94) and stool volume (mean difference 1.65, 95% CI 1.10–2.20) versus placebo |
| Randomised, placebo-controlled, double-blind trial, European Journal of Nutrition 2016;55(8):2389–2397 (PMID 26437831, doi 10.1007/s00394-015-1045-4) | 66 healthy adults aged 18–30 without a daily defecation habit enrolled, given 15 g/day of digestion-resistant maltodextrin or placebo for 21 days; 57 were assessed for colonic transit time | Colonic transit time fell by about 25% (roughly 13.3 hours) in the resistant-maltodextrin group; stool volume rose by about 56%; placebo group showed no change |
Both trials were funded by the manufacturer of the resistant maltodextrin material used, and in the meta-analysis one author was an employee of that company. That funding pattern does not make the results wrong, but it means the evidence base for this specific material is not independent, and a brand should say so honestly rather than present it as neutral academic research. Both study populations were either healthy adults or adults with a self-reported tendency toward infrequent bowel movements, not a diagnosed digestive disease, and neither result should be read as a claim about any digestive disorder.
Checked against the published abstracts on 13 October 2026.
What Japanese products say
Indigestible dextrin is Japan’s most widely used Specified Health Use Foods material, individually approved across several functions including intestinal regularity, and post-meal glucose and triglyceride moderation.
Japanese regulators have reviewed and approved individual products containing indigestible dextrin for a range of notified functions, commonly including helping to regularise bowel movements, moderating the rise in blood glucose or triglycerides after a meal, and helping to reduce visceral fat — each backed by the specific evidence the notifying business submitted for that product. This is a description of Japan’s regulatory framework, not a claim for any Sunsho-made product: this guide’s rules do not permit attaching blood-sugar or cholesterol claims to a product, in Japan or elsewhere, regardless of what any individual Japanese product has been approved to say.
Two points matter for a brand abroad:
- A Japanese notification belongs to one product’s submitted evidence, not to “dietary fibre” as a category, and not to your formulation.
- The blood-glucose and triglyceride wording used in Japan is a Japanese regulatory mechanism for products sold in Japan. Your label abroad follows your own market’s rules on such claims, and this guide does not recommend using them.
💬 Need an evidence summary for your regulatory adviser that separates Japanese notifications from independent reviews? We prepare it with the manufacturing documents. Tell us your market.
Wording that stays on safe ground
Describe the fibre by what it is and what bowel-movement evidence supports it; leave out blood-sugar or cholesterol language entirely.
| Safer wording | Wording to avoid |
|---|---|
| ”Contains [x] g of dietary fibre (resistant maltodextrin) per serving” | Any blood-sugar, blood-glucose or cholesterol claim |
| ”Studied for stool frequency and volume” | Names of digestive diseases, or “treats constipation" |
| "A soluble fibre used in Japanese food formulations" | "Clinically proven” without naming the study, its funding and its limits |
How dietary fibre is formulated
Resistant maltodextrin is water-soluble, low in sweetness and stable through heat processing, which is why Japan uses it in drinks, powder sticks and capsules alike.
| Dosage form | Why brands choose it | What to weigh up |
|---|---|---|
| Powder stick or sachet | Dissolves into any drink, familiar Japanese format | Some products carry a mild off-taste at higher doses |
| Capsule | Convenient, flavourless | Lower fibre amount per serving than a powder |
| Drink or beverage | Matches the Japanese Tokuho beverage category | Lower fibre concentration relative to a powder dose |
Decisions that shape the specification:
- Source and grade. Ask the supplier for the resistant maltodextrin or indigestible dextrin grade, its dietary-fibre content (commonly stated as a percentage), and its solubility data.
- Amount per serving. Match the amount to a study you intend to cite, and note that gastrointestinal tolerance (bloating, loose stool) rises with dose, so most products stay in the single-digit-to-mid-teens gram range per serving.
- Companion ingredients. Fibre is often combined with other gut-themed ingredients; each companion needs its own check against Japanese food law.
- Your market’s status and claim rules for fibre. Fibre itself is broadly permitted as a food ingredient in most markets, but the wording allowed around it — especially anything implying a blood-sugar or cholesterol effect — differs sharply between countries. Confirm your market’s rules before you draft the pack.
The check that comes first
Every ingredient must be permitted in foods in Japan, or a Japanese factory cannot make the product.
Indigestible dextrin and resistant maltodextrin used in foods are common and well established in Japan. The risk in a “gut” formula usually sits in companion probiotics, botanicals or added actives, not in the fibre itself. See the Japan-made supplement OEM page, and our lactic acid bacteria guide for a companion ingredient commonly paired with fibre in gut formulas.
Before you ask for a quotation
A factory can quote accurately once the fibre grade, the amount, the form and the packaging are fixed.
- Fibre material and grade, and its dietary-fibre content
- Amount per serving and servings per pack
- Dosage form and packaging
- Companion ingredients and their amounts
- Countries you will sell in, and each market’s rules on fibre-related wording
- First order and annual volume
💬 Ready to design a Japan-made dietary fibre product? Send us the concept — fibre amount, form, companion ingredients and the countries you will sell in.
Frequently asked questions
1. Does resistant maltodextrin actually improve bowel movements?
A 2018 meta-analysis of 29 randomised trials found significant increases in stool frequency and stool volume compared with placebo. Most of the underlying trials, including that meta-analysis, were funded by the material’s manufacturer, which is worth disclosing rather than hiding.
2. Can I claim my fibre product lowers blood sugar or cholesterol?
No. Some individual Japanese products have been approved with that wording for their specific formulation, but this guide’s rules avoid blood-sugar and cholesterol claims for any product, in any market, because they cross into medical-claim territory.
3. Why is indigestible dextrin so common in Japanese products?
It is water-soluble, nearly tasteless, stable under heat processing, and backed by more Japanese regulatory notifications than any other fibre material, which is why it appears across drinks, powders and capsules.
4. How much fibre per serving is realistic?
Trial doses commonly range from about 5 g to 15 g per day. Higher doses raise the chance of bloating or loose stool, so the amount should be set with gastrointestinal tolerance in mind, not only the study you are citing.
5. What can stop a Japanese factory making my fibre product?
Usually a companion ingredient — a probiotic strain, a botanical or an added active — rather than the fibre itself. Every ingredient must be permitted in foods in Japan, so we check the full formula first.
Sources: “Effects of resistant maltodextrin on bowel movements: a systematic review and meta-analysis”, Clinical and Experimental Gastroenterology 2018, PMID 29535547, doi 10.2147/CEG.S153924; “Digestion-resistant maltodextrin effects on colonic transit time and stool weight: a randomized controlled clinical study”, European Journal of Nutrition 2016;55(8):2389–2397, PMID 26437831, doi 10.1007/s00394-015-1045-4; Japan Consumer Affairs Agency, Specified Health Use Foods and Foods with Function Claims notifications for indigestible dextrin. Checked on 13 October 2026.