The present study investigated the effect of RBAC on natural killer cell activity (NKCA) and the production of cytokines and growth factors over 4 weeks among healthy adults.

The purpose of this study is to investigate the outcomes of a 60-day trial of Rice Bran Arabinoxylan Compound (RBAC) among adults. Specifically, subjects will participate in a two-group, randomized intervention that is based on a nutritional supplement made from a water soluble extract of rice bran that has been partially hydrolyzed by the action of a natural enzyme complex extracted from Shitake mushroom. One group will take 1 gram/day and the other group will take 3 gram/day to compare differences in outcomes between the two groups. We hypothesize that the 3 gram/day condition will demonstrate faster increases in outcomes compared to the 1 gram/day condition. The primary outcomes for this study will be Natural Killer (NK) cell activity, cytokines, total bilirubin, creatinine, and liver function tests. These outcomes will be compared between those subjects enrolled in the two treatment groups before and after 60 days.

No substantial psychological, medical, or social risks exist to the participants, other than minor discomfort associated with the venipuncture. Although all measures to protect confidentiality will be put in place, the possibility exists that electronic data could be jeopardized. In the remote case that such event occurs, it will be immediately reported to the IRB.

The components of RBAC should be harmless without significant food allergies. No serious, untoward side effects have been reported to the company by consumers nor observed during previous human studies. If any side effect does occur, the remedy is to discontinue until asymptomatic, and then reintroduce at 1/4 dosage, increasing by the same amount every 2 days, if uneventful, until full dosage is achieved. Dr. Ali will provide additional follow-up and consultation with any subject who experiences an untoward side effect.

A toxicology search for each component reveals no unique toxicity characteristic of the materials. As reported by Daiwa Health Development, the manufacturer of the product, thousands of people currently use RBAC (under the trade names BRM4 and PeakImmune 4), and Daiwa is unaware of significant toxicities. Daiwa applies the latest scientific methods to ensure the value and safety of their raw materials. Daiwa products are manufactured in state-of-the-art facilities, under strict quality control and environmental protection standards.

Participants will incur no additional appreciable psychological or social risks by participating in this study, although they may undergo psychological and physical discomfort sometimes. The process of interviewing during the assessment may cause discomfort. Discomfort or fatigue may also be experienced in completing the assessment battery.

Alternatives to this study for enhancing immune system functioning include prescription medications, exercise, dietary modification, and other nutritional supplements. The risks of medications can be very significant, including life-threatening, but the risk of taking nutritional supplements is not totally understood, since they are not regulated by the US Food and Drug Administration. Medications and nutritional supplements, as part of a change in lifestyle behaviors, may also prove to be beneficial for immune system functioning, but their long-term use has unknown consequences.

The information obtained in this study will help in determining the efficacy of using a rice bran extract nutritional supplement for enhancing immune system outcomes. By participating in the study, subjects may experience improved NK cell activity and cytokine functioning. The risk of participating in this study is reasonable because of the potential enhancements in immune system functioning with improved nutritional status.

Inclusion Criteria:

1. Women and men ages 18 years and over.
2. Interest in participating in a novel nutritional supplement program.
3. Willingness to follow recommendations.

Exclusion Criteria:

1. Currently enrolled in another research trial for investigative nutritional or other therapies thought to have an impact on immune system functioning.
2. Unable to consent to the study.
3. Women who are pregnant or are attempting conception, especially in the presence of a history of recurrent spontaneous abortion.
4. Other medical complications that might preclude one from participating in the study, i.e., recent heart attack or stroke or chronic kidney disease.
5. Currently taking immunomodulatory medication, i.e. interferon.
6. Currently taking other medications thought to have an impact on immune system functioning, i.e., chemotherapeutic agents.
7. Known allergy to rice, rice bran, or related food products.
8. Known allergy to mushrooms or related food products.
9. History of malignancies related to the NK cell line, including: NK cell leukemias and T-cell large granular lymphocyte leukemias, NK-cell lymphoproliferative disease of granular lymphocytes, and NK cell lymphomas, e.g., nasal and nasal-like NK/T-cell lymphomas.
10. Current smoker.