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Limited evidenceImmunity

Rice Bran Arabinoxylan

An enzymatically modified rice bran fibre (sold as MGN-3 or BioBran) that reliably raises natural killer cell activity in small trials. Whether that translates into fewer infections or better outcomes has never been shown.

Where to buy

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What the science says

  • Higher natural killer cell activity Limited evidence

    A randomized, double-blind, placebo-controlled trial in geriatric subjects reported increased NK cell activity after supplementation, and a randomized study in multiple myeloma patients found changes in innate immune cell populations. Both trials were small and measured immune markers rather than health outcomes.

  • No demonstrated clinical benefit Limited evidence

    An evidence-based review of BioBran/MGN-3 as a complementary cancer therapy concluded that the studies are small, frequently uncontrolled and heterogeneous, and that effects on survival or infection rates are not established.

Dosage & safety

Studied doseTrials have used roughly 500 mg to 3 g per day, often with a higher loading dose for the first weeks. Labels commonly suggest 1 g per day.
SafetyWell tolerated in the published trials, with mild gastrointestinal effects the main complaint. Because it is presented as an immune activator, caution is reasonable in autoimmune disease and alongside immunosuppressant therapy. No data in pregnancy. Much of the research comes from investigators connected to the manufacturer.

How to take it

TimingTiming does not matter.
With food?Either way.
Worth knowingAlmost all of the published research comes from investigators connected to the manufacturer, so treat the price premium as unearned until independent trials exist.

Interactions

With medications

  • immunosuppressants and transplant medication

    It is sold as an immune activator and could work against therapy that deliberately suppresses immunity. do not use it without your transplant or rheumatology team's agreement

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does rice bran arabinoxylan (MGN-3, BioBran) boost immunity?

Rice bran arabinoxylan raises natural killer cell activity in small trials, but it has never been shown to reduce infections or improve health outcomes, so the evidence is limited.

Does BioBran help cancer patients?

An evidence-based review of BioBran/MGN-3 as a complementary cancer therapy found the studies small, often uncontrolled and heterogeneous, with no established effect on survival or infection rates. Much of the research also comes from investigators connected to the manufacturer.

How much arabinoxylan should I take?

Trials of rice bran arabinoxylan used roughly 500 mg to 3 g per day, often with a higher loading dose in the first weeks. Labels commonly suggest 1 g per day.

Is arabinoxylan safe with immunosuppressants?

Do not use rice bran arabinoxylan with immunosuppressants or transplant medication without your transplant or rheumatology team's agreement, because it is sold as an immune activator. Otherwise it was well tolerated in trials, with mild digestive effects.

Scientific references

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