Enzymatically modified rice bran (EMRB) is rice bran — the nutrient-dense outer layer of the rice grain — that has been treated with enzymes derived from shiitake mushrooms (Lentinus edodes). This enzymatic process breaks apart complex carbohydrate chains called hemicelluloses, unlocking arabinoxylan compounds that would otherwise pass through the body unused. The result is a highly bioavailable supplement with well-documented effects on immune function and metabolic health.

The key active compounds — particularly arabinoxylan — act as biological response modifiers, meaning they interact with immune cells and signal them to become more active. Natural killer (NK) cells, which patrol the body and destroy abnormal or infected cells, show especially strong responses. EMRB also slows glucose absorption in the gut and helps regulate cholesterol metabolism through its fiber and phytosterol content.

Powder sachets (often 1 g per sachet) are the most studied form and can be mixed into water or juice. Capsules and tablets offer convenience for daily use. Powder dissolved in liquid is generally considered optimal for absorption. Quality varies significantly between brands — look for products standardized to arabinoxylan content and ideally tested by third parties.

• Weakened immune system
• Cancer treatment support
• High blood sugar and type 2 diabetes
• High cholesterol
• Chronic fatigue
• Hepatitis B and C
• HIV immune support
• Inflammation and oxidative stress
• Allergy and asthma
• Digestive health

• Cardiovascular disease risk reduction through LDL cholesterol lowering
• Blood sugar dysregulation and progression to type 2 diabetes in at-risk individuals
• Infection recurrence in immunocompromised patients (supported by NK cell activation data)

• Brown rice (unprocessed) — Retains the bran layer where arabinoxylan and other active compounds are naturally found — though not enzymatically modified, it provides the precursor nutrients.
• Rice bran oil — Contains gamma-oryzanol, tocotrienols, and phytosterols that are among EMRB's key active components.
• Shiitake mushrooms — Provide the enzymes used in EMRB's modification process and independently contain beta-glucans that support NK cell activity similarly.
• Whole wheat and rye (bran-containing) — Contain arabinoxylan in their bran fractions — the same class of immune-active fiber found in EMRB, though in lower concentrations.
• Oats — Rich in beta-glucans and soluble fiber that support immune modulation and cholesterol reduction through overlapping mechanisms.