AMENDMENT NO. 1 TO NUTRACEUTIX, INC. 1995 STOCK OPTION PLAN

Exhibit 10.6

AMENDMENT NO. 1

TO

NUTRACEUTIX, INC.

1995 STOCK OPTION PLAN

The Nutraceutix, Inc. 1995 Stock Option Plan (the “Plan”) is hereby amended to reflect the increase in amount of stock subject to the plan from 2,000,000 to 3,000,000 (Section 3) as set forth on Exhibit A attached hereto.

The date of the adoption of such amendment by the Board of Directors is April 21, 1997. The date of adoption of such amendment by Shareholders is June 20, 1997.

NUTRACEUTIX, INC.

1995 Amended Stock option Plan

SECTION 1. Purpose. The purpose of the Nutraceutix, Inc. 1995 Stock Option Plan (this “Plan”) is to provide a means whereby selected employees, directors (subject to the restrictions contained in Sections 2 and 4), officers, agents, consultants and independent contractors of Nutraceutix Inc. (the “Company”) or of any parent or subsidiary (as defined in subsection 5.7 and referred to hereinafter as “related corporations”) thereof, may be granted incentive stock options and/or nonqualified stock options to purchase the Common Stock (as defined in Section 3) of the Company, in order to attract and retain the services or advice of such employees, directors, officers, agents, consultants and independent contractors and to provide added incentive to them by encouraging stock ownership in the Company.

SECTION 2. Administration. This Plan shall be administered by the Board of Directors of the Company (the “Board”) or, in the event the Board shall appoint and/or authorize a committee to administer this Plan, by such committee. The administrator of this Plan shall hereinafter be referred to as the “Plan Administrator.”

In the event a member of the Board (or the committee) may be eligible, subject to the restrictions set forth in Section 4, to participate in or receive or hold options under this Plan, no member of the Board or the committee shall vote with respect to the granting of an option hereunder to himself or herself, as the case may be, and, if state corporate law does not permit a committee to grant options to directors, then any option granted under this Plan to a director for his or her services as such shall be approved by the full board.

The foregoing notwithstanding, in the event the Company shall register any of its equity securities pursuant to Section 12(b) or 12(g) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) , and any directors are eligible to receive options under this Plan, then the following provisions shall apply to the administration of the Plan with respect to grants made to directors. The Plan Administrator shall be constituted at all times so as to meet the requirements of Section 16(b) of the Exchange Act, as amended from time to time. Currently, the Plan Administrator shall be the Board, a majority of which Board and a majority of which directors acting in the matter are disinterested, or may be a committee which consists solely of not less than three disinterested directors of the Company. In the event the Plan Administrator is a committee and state corporate law does not permit a committee to grant options to directors, then directors shall not be eligible to receive options under this Plan as compensation for their services as directors. The members of any committee serving as Plan Administrator shall be appointed by the Board for such term as the Board may determine. The Board may from time to time remove members from, or add members to, the committee. Vacancies on the committee, however caused, may be filled by the Board. If at any time an insufficient number of disinterested directors is available to serve on such committee, interested directors may serve on the committee; however, during such time, no options shall be granted under this Plan to any person if the granting of such option would not meet the requirements of Section 16(b) of the Exchange Act.

For purposes of this Section 2, a disinterested director is a member of the Board who meets the definition of “disinterested person” as set forth in the rules and regulations promulgated under Section 16(b) of the Exchange Act, as amended from time to time. Currently, a disinterested director for purposes of this Section 2 is a member of the Board who is not, during the one year prior to service as an administrator of a plan, or during such service, granted or awarded equity securities pursuant to the Plan or any other plan of the Company or any of its affiliates, other than grants or awards that, pursuant to Rule Section 240. 16b-3 (c) (2) (i) under

the Exchange Act, will not cause the director to cease to be a “disinterested person,” as defined in that rule.

2.1 Procedures. The Board shall designate one of the members of the Plan Administrator as chairman. The Plan Administrator may hold meetings at such times and places as it shall determine. The acts of a majority of the members of the Plan Administrator present at meetings at which a quorum exists, or acts reduced to or approved in writing by all Plan Administrator members, shall be valid acts of the Plan Administrator.

2.2 Responsibilities. Except for the terms and conditions explicitly set forth in this Plan, the Plan Administrator shall have the authority, in its discretion, to determine all matters relating to the options to be granted under this Plan, including selection of the individuals to be granted options, the number of shares to be subject to each option, the exercise price, and all other terms and conditions of the options. Grants under this Plan need not be identical in any respect, even when made simultaneously. The interpretation and construction by the Plan Administrator of any terms or provisions of this Plan or any option issued hereunder, or of any rule or regulation promulgated in connection herewith, shall be conclusive and binding on all interested parties, so long as such interpretation and construction with respect to incentive stock options corresponds to the requirements of Internal Revenue Code (the “Code”) Section 422, the regulations thereunder, and any amendments thereto.

2.3 Section 16(b) Compliance and Bifurcation of Plan. It is the intention of the Company that this Plan comply in all respects with Rule 16b-3 under the Exchange Act and, if any Plan provision is later found not to be in compliance with such Section, the provision shall be deemed null and void, and in all events the Plan shall be construed in favor of its meeting the requirements of Rule 16b-3. Notwithstanding anything in the Plan to the contrary, the Board, in its absolute discretion, may bifurcate the Plan so as to restrict, limit or condition the use of any provision of the Plan to participants who are officers and directors subject to Section 16(b) of the Exchange Act without so restricting, limiting or conditioning the Plan with respect to other participants.

SECTION 3. Stock Subject to This Plan. The stock subject to this Plan shall be the Company’s Common Stock (the “Common Stock”) presently authorized, but unissued or subsequently acquired by the Company. Subject to adjustment as provided in Section 7 hereof, the aggregate amount of Common Stock to be delivered upon the exercise of all options granted under this Plan shall not exceed 3,000,000 shares as of the 6/20/97 Annual Shareholders Meeting as such Common Stock was constituted on the effective date of this Plan. If any option granted under this Plan shall expire, be surrendered, exchanged for another option, cancelled or terminated for any reason without having been exercised in full, the unpurchased shares subject thereto shall thereupon again be available for purposes of this Plan, including for replacement options which may be granted in exchange for such surrendered, cancelled or terminated options.

SECTION 4. Eligibility. An incentive stock option may be granted only to any individual who, at the time the option is granted, is an employee of the Company or any related corporation. A nonqualified stock option may be granted to any employee, director, officer, agent, consultant or independent contractor of the Company or any related corporation, whether an individual or an entity. If required by Section 16(b) of the Exchange Act in order to establish a disinterested Plan Administrator, the members of the Board who are not also employees of the Company shall not be eligible to receive options under this Plan once the Company has registered any of its equity securities pursuant to Section 12(b) or 12(g) of the Exchange Act. Any party to whom an option is granted under this Plan shall be referred to hereinafter as an “Optionee.”

SECTION 5. Terms and Conditions of options. Options granted under this Plan shall be evidenced by written agreements which shall contain such terms, conditions, limitations and restrictions as the Plan Administrator shall deem advisable and which are not inconsistent with this Plan. Notwithstanding the foregoing, options shall include or incorporate by reference the following terms and conditions.

5.1 Number of Shares and Price. The maximum number of shares that may be purchased pursuant to the exercise of each option and the price per share at which such option is exercisable (the “exercise price”) shall be as established by the Plan Administrator, provided that the Plan Administrator shall act in good faith to establish the exercise price which shall be not less than the fair market value per share of the Common Stock at the time the option is granted with respect to incentive stock options and not less than 85% of the fair market value per share of the Common Stock at the time the option is granted with respect to nonqualified stock options and also provided that, with respect to incentive stock options granted to greater than 10% shareholders, the exercise price shall be as required by Section 6.

5.2 Term and Maturity. Subject to the restrictions contained in Section 6 with respect to granting incentive stock options to greater than 10% shareholders, the term of each incentive stock option shall be as established by the Plan Administrator and, if not so established, shall be 10 years from the date it is granted but in no event shall the term of any incentive stock option exceed 10 years. The term of each nonqualified stock option shall be as established by the Plan Administrator, and if not so established, shall be 10 years. To ensure that the Company or related corporation will achieve the purpose and receive the benefits contemplated in this Plan, any option granted to any Optionee hereunder shall, unless the condition of this sentence is waived or modified in the agreement evidencing the option or by resolution adopted by the Plan Administrator, be exercisable according to the following schedule:

5.3 Exercise. Subject to the vesting schedule described in subsection 5. 2 above and to any additional holding period required by applicable law, each option may be exercised in whole or in part; provided, however, that no fewer than 100 shares (or the remaining shares then purchasable under the option, if less than 100 shares) may be purchased upon any exercise of option rights hereunder and that only whole shares will be issued pursuant to the exercise of any option. During an Optionee’s lifetime, any incentive stock options granted under this Plan are personal to him or her and are exercisable solely by such Optionee. Options shall be exercised by delivery to the Company of notice of the number of shares with respect to which the option is exercised, together with payment of the exercise price.

5.4 Payment of Exercise Price. Payment of the option exercise price shall be made in full at the time the notice of exercise of the option is delivered to the Company and shall be in cash, bank certified or cashier’s check or personal check (unless at the time of exercise the Plan

Administrator in a particular case determines not to accept a personal check) for the Common Stock being purchased.

The Plan Administrator can determine at the time the option is granted for incentive stock options, or at any time before exercise for nonqualified stock options, that additional forms of payment will be permitted. To the extent permitted by the Plan Administrator and applicable laws and regulations (including, but not limited to, federal tax and securities laws and regulations and state corporate law), an option may be exercised by delivery of shares of stock of the Company held by an optionee having a fair market value equal to the exercise price, such fair market value to be determined in good faith by the Plan Administrator; provided, however, that payment in stock held by an Optionee shall not be made unless the stock shall have been owned by the optionee for a period of at least six months.

5.5 Withholding Tax Requirement. The company or any related corporation shall have the right to retain and withhold from any payment of cash or Common Stock under the Plan the amount of taxes required by any government to be withheld or otherwise deducted and paid with respect to such payment. At its discretion, the Company may require an Optionee receiving shares of common Stock to reimburse the Company for any such taxes required to be withheld by the Company and withhold any distribution in whole or in part until the company is so reimbursed. In lieu thereof, the Company shall have the right to withhold from any other cash amounts due or to become due from the Company to the Optionee an amount equal to such taxes or retain and withhold a number of shares having a market value not less than the amount of such taxes required to be withheld by the Company to reimburse the Company for any such taxes and cancel (in whole or in part) any such shares so withheld. If required by Section 16(b) of the Exchange Act, the election to pay withholding taxes by delivery of shares held by any person who at the time of exercise is subject to Section 16(b) of the Exchange Act, shall be made either six months prior to the date the option exercise becomes taxable or during the quarterly 10-day window period required under Section 16(b) of the Exchange Act for exercises of stock appreciation rights.

5.6 Nontransferability of Option. Options granted under this Plan and the rights and privileges conferred hereby may not be transferred, assigned, pledged or hypothecated in any manner (whether by operation of law or otherwise) other than by will or by the applicable laws of descent and distribution, and shall not be subject to execution, attachment or similar process. Any attempt to transfer, assign, pledge, hypothecate or otherwise dispose of any option under this Plan or of any right or privilege conferred hereby, contrary to the Code or to the provisions of this Plan, or the sale or levy or any attachment or similar process upon the rights and privileges conferred hereby shall be null and void.

5.7 Termination of Relationship. If the Optionee’s relationship with the Company or any related corporation ceases for any reason other than termination for cause, death or total disability, and unless by its terms the option sooner terminates or expires, then the Optionee may exercise, for a three-month period, that portion of the Optionee’s option which is exercisable at the time of such cessation, but the Optionee’s option shall terminate at the end of the three-month period following such cessation as to all shares for which it has not theretofore been exercised, unless such provision is waived in the agreement evidencing the option or by resolution adopted by the Plan Administrator within 90 days of such cessation. The Plan Administrator shall have sole discretion in a particular circumstance to extend the exercise period following such cessation beyond that specified above. If, however, in the case of an incentive stock option, the Optionee does not exercise the optionee’s option within three months after cessation of employment, the option will no longer qualify as an incentive stock option under the Code. If, in the case of an

incentive stock option, an Optionee’s relationship with the Company or related corporation changes (i.e., from employee to nonemployee, such as a consultant), such change shall constitute a termination of an Optionee’s employment with the Company or related corporation and the optionee’s incentive stock option shall terminate in accordance with this subsection 5.7.

If an Optionee is terminated for cause, any option granted hereunder shall automatically terminate as of the first discovery by the Company of any reason for termination for cause, and such Optionee shall thereupon have no right to purchase any shares

pursuant to such option. “Termination for cause.” shall mean dismissal for dishonesty, conviction or confession of a crime punishable by law (except minor violations), fraud, misconduct or disclosure of confidential information. If an Optionee’s relationship with the Company or any related corporation is suspended pending an investigation of whether or not the optionee shall be terminated for cause, all optionee’s rights under any option granted hereunder likewise shall be suspended during the period of investigation.

If an Optionee’s relationship with the Company or any related corporation ceases because of a total disability, the Optionee’s option shall not terminate or, in the case of an incentive stock option, cease to be treated as an incentive stock option until the end of the 12-month period following such cessation (unless by its terms it sooner terminates and expires). As used in this Plan, the term “total disability” refers to a mental or physical impairment of the Optionee which is expected to result in death or which has lasted or is expected to last for a continuous period of 12 months or more and which causes the Optionee to be unable, in the opinion of the Company and two independent physicians, to perform his or her duties for the Company and to be engaged in any substantial gainful activity. Total disability shall be deemed to have occurred on the first day after the Company and the two independent physicians have furnished their opinion of total disability to the Plan Administrator.

For purposes of this subsection 5.7, a transfer of relationship between or among the Company and/or any related corporation shall not be deemed to constitute a cessation of relationship with the Company or any of its related corporations. For purposes of this subsection 5.7, with respect to incentive stock options, employment shall be deemed to continue while the optionee is on military leave, sick leave or other bona fide leave of absence (as determined by the Plan Administrator). The foregoing notwithstanding, employment shall not be deemed to continue beyond the first 90 days of such leave, unless the Optionee’s reemployment rights are guaranteed by statute or by contract.

As used herein, the term “related corporation,” when referring to a subsidiary corporation, shall mean any corporation (other than the Company) in, at the time of the granting of the option, an unbroken chain of corporations ending with the Company, if stock possessing 50% or more of the total combined voting power of all classes of stock of each of the corporations other than the company is owned by one of the other corporations in such chain. When referring to a parent corporation, the term “related corporation” shall mean any corporation in an unbroken chain of corporations ending with the Company if, at the time of the granting of the option, each of the corporations other than the Company owns stock possessing 50% or more of the total combined voting power of all classes of stock in one of the other corporations in such chain.

5.8 Death of Optionee. If an Optionee dies while he or she has a relationship with the Company or any related corporation or within the three-month period (or 12-month period in the case of totally disabled Optionees) following cessation of such relationship, any option held by such Optionee may be exercised within one year after his or her death by the personal

representative of his or her estate or by the person or persons to whom the Optionee’s rights under the option shall pass by will or by the applicable laws of descent and distribution.

5.9 Status of Shareholder. Neither the Optionee nor any party to which the Optionee’s rights and privileges under the option may pass shall be, or have any of the rights or privileges of, a shareholder of the Company with respect to any of the shares issuable upon the exercise of any option granted under this Plan unless and until such option has been exercised.

5.10 Continuation of Employment. Nothing in this Plan or in any option granted pursuant to this Plan shall confer upon any Optionee any right to continue in the employ of the Company or of a related corporation, or to interfere in any way with the right of the Company or of any such related corporation to terminate his or her employment or other relationship with the Company at any time.

5.11 Modification and Amendment of Option. Subject to the requirements of Code Section 422 with respect to incentive stock options and to the terms and conditions and within the limitations of this Plan, the Plan Administrator may modify or amend outstanding options granted under this Plan. The modification or amendment of an outstanding option shall not, without the consent of the Optionee, impair or diminish any of his or her rights or any of the obligations of the Company under such option. Except as otherwise provided in this Plan, no outstanding option shall be terminated without the consent of the Optionee. Unless the Optionee agrees otherwise, any changes or adjustments made to outstanding incentive stock options granted under this Plan shall be made in such a manner so as not to constitute a “modification” as defined in Code Section 425(h) and so as not to cause any incentive stock option issued hereunder to fail to continue to qualify as an incentive stock option as defined in Code Section 422(b).

5.12 Limitation on Value for Incentive Stock Options. As to all incentive stock options granted under the terms of this Plan, to the extent that the aggregate fair market value (determined at the time the incentive stock option is granted) of the stock with respect to which incentive stock options are exercisable for the first time by the Optionee during any calendar year (under this Plan and all other incentive stock option plans of the Company, a related corporation or a predecessor corporation) exceeds $100,000, such options shall be treated as nonqualified stock options. The previous sentence shall not apply if the Internal Revenue Service publicly rules, issues a private ruling to the Company, any Optionee, or any legatee, personal representative or distributees of an Optionee or issues regulations changing or eliminating such annual limit.

SECTION 6. Greater Than 10% Shareholders.

6.1 Exercise Price and Term of Incentive Stock Options. If incentive stock options are granted under this Plan to employees who own more than 10% of the total combined voting power of all classes of stock of the Company or any related corporation, the term of such incentive stock options shall not exceed five years and the exercise price shall be not less than 110% of the fair market value of the Common Stock at the time the incentive stock option is granted. This provision shall control notwithstanding any contrary terms contained in an option agreement or any other document.

6.2 Attribution Rule. For purposes of subsection 6.1, in determining stock ownership, an employee shall be deemed to own the stock owned, directly or indirectly, by or for his or her brothers, sisters, spouse, ancestors and lineal descendants. Stock owned, directly or indirectly, by or for a corporation, partnership, estate or trust shall be deemed to be owned proportionately by or for its shareholders, partners or beneficiaries. If an employee or a person related to the employee

owns an unexercised option or warrant to purchase stock of the Company, the stock subject to that portion of the option or warrant which is unexercised shall not be counted in determining stock ownership. For purposes of this Section 6, stock owned by an employee shall include all stock actually issued and outstanding immediately before the grant of the incentive stock option to the employee.

SECTION 7. Adjustments Upon Changes in Capitalization. The aggregate number and class of shares for which options may be granted under this Plan, the number and class of shares covered by each outstanding option and the exercise price per share thereof (but not the total price), and each such option, shall all be proportionately adjusted for any increase or decrease in the number of issued shares of Common Stock of the Company resulting from a split-up or consolidation of shares or any like capital adjustment, or the payment of any stock dividend.

7.1 Effect of Liquidation, Reorganization or Change in Control.

7.1.1 Cash, Stock or other Property for Stock. Except as provided in subsection 7.1.2, upon a merger (other than a merger of the Company in which the holders of Common Stock immediately prior to the merger have the same proportionate ownership of Common Stock in the surviving corporation immediately after the merger), consolidation, acquisition of property or stock, separation, reorganization (other than a mere reincorporation or the creation of a holding company) or liquidation of the Company, as a result of which the shareholders of the Company receive cash, stock or other property in exchange for or in connection with their shares of Common Stock, any option granted hereunder shall terminate, but the Optionee shall have the right immediately prior to any such merger, consolidation, acquisition of property or stock, separation, reorganization or liquidation to exercise such Optionee’s option in whole or in part whether or not the vesting requirements set forth in the option agreement have been satisfied.

7.1.2 Conversion of Options on Stock for Stock Exchange. If the shareholders of the Company receive capital stock of another corporation (“Exchange Stock”) in exchange for their shares of Common Stock in any transaction involving a merger (other than a merger of the Company in which the holders of Common Stock immediately prior to the merger have the same proportionate ownership of Common Stock in the surviving corporation immediately after the merger), consolidation, acquisition of property or stock, separation or reorganization (other than a mere reincorporation or the creation of a holding company), all options granted hereunder shall be converted into options to purchase shares of Exchange Stock unless the Company and the corporation issuing the Exchange Stock, in their sole discretion, determine that any or all such options granted hereunder shall not be converted into options to purchase shares of Exchange Stock but instead shall terminate in accordance with the provisions of subsection 7.1.1. The amount and price of converted options shall be determined by adjusting the amount and price of the options granted hereunder in the same proportion as used for determining the number of shares of Exchange Stock the holders of the Common Stock receive in such merger, consolidation, acquisition of property or stock, separation or reorganization. The converted options shall be fully vested whether or not the vesting requirements set forth in the option agreement have been satisfied.

7.2 Fractional Shares. In the event of any adjustment in the number of shares covered by any option, any fractional shares resulting from such adjustment shall be disregarded and each such option shall cover only the number of full shares resulting from such adjustment.

7.3 Determination of Board to Be Final. All Section 7 adjustments shall be made by the Board, and its determination as to what adjustments shall be made, and the extent thereof, shall be

final, binding and conclusive. Unless an optionee agrees otherwise, any change or adjustment to an incentive stock option shall be made in such a manner so as not to constitute a “modification” as defined in Code Section 425(h) and so as not to cause his or her incentive stock option issued hereunder to fail to continue to qualify as an incentive stock option as defined in Code Section 422(b).

SECTION 8. Securities Regulation. Shares shall not be issued with respect to an option granted under this Plan unless the exercise of such option and the issuance and delivery of such shares pursuant thereto shall comply with all relevant provisions of law, including, without limitation, any applicable state securities laws, the Securities Act of 1933, as amended, the Exchange Act, the rules and regulations promulgated thereunder, and the requirements of any stock exchange upon which the shares may then be listed, and shall be further subject to the approval of counsel for the Company with respect to such compliance, including the availability of an exemption from registration for the issuance and sale of any shares hereunder. Inability of the Company to obtain from any regulatory body having jurisdiction, the authority deemed by the Company’s counsel to be necessary for the lawful issuance and sale of any shares hereunder or the unavailability of an exemption from registration for the issuance and sale of any shares hereunder shall relieve the Company of any liability in respect of the non-issuance or sale of such shares as to which such requisite authority shall not have been obtained.

As a condition to the exercise of an option, the Company may require the Optionee to represent and warrant at the time of any such exercise that the shares are being purchased only for investment and without any present intention to sell or distribute such shares if, in the opinion of counsel for the Company, such a representation is required by any relevant provision of the aforementioned laws. At the option of the Company, a stop-transfer order against any shares of stock may be placed on the official stock books and records of the Company, and a legend indicating that the stock may not be pledged, sold or otherwise transferred unless an opinion of counsel is provided (concurred in by counsel for the Company) stating that such transfer is not in violation of any applicable law or regulation, may be stamped on stock certificates in order to assure exemption from registration. The Plan Administrator may also require such other action or agreement by the Optionees as may from time to time be necessary to comply with the federal and state securities laws. THIS PROVISION SHALL NOT OBLIGATE THE COMPANY TO UNDERTAKE REGISTRATION OF THE OPTIONS OR STOCK HEREUNDER.

Should any at the Company’s capital stock of the same class as the stock subject to options granted hereunder be listed on a national securities exchange, all stock issued hereunder if not previously listed on such exchange shall be authorized by that exchange for listing thereon prior to the issuance thereof.

SECTION 9. Amendment and Termination.

9.1 Board Action. The Board may at any time suspend, amend or terminate this Plan, provided that except as set forth in Section 7, the approval of the Company’s shareholders is necessary within 12 months before or after the adoption by the Board of any amendment which will:

(a) increase the number of shares which are to be reserved for the issuance of options under this Plan;

(b) permit the granting of stock options to a class of persons other than those presently permitted to receive stock options under this Plan; or

(c) require shareholder approval under applicable law, including Section 16(b) of the Exchange Act.

Any amendments made to this Plan which would constitute “modifications” to incentive stock options outstanding on the date of such amendment(s), shall not be applicable to such outstanding incentive stock options but shall have prospective effect only.

9.2 Automatic Termination. Unless sooner terminated by the Board, this Plan shall terminate ten years from the earlier of (a) the date on which this Plan is adopted by the Board or (b) the date on which this Plan is approved by the shareholders of the Company. No option may be granted after such termination or during any suspension of this Plan. The amendment or termination of this Plan shall not, without the consent of the option holder, alter or impair any rights or obligations under any option theretofore granted under this Plan.

SECTION 10. Effectiveness of This Plan. This Plan shall become effective upon adoption by the Board so long as it is approved by the holders of a majority of the Company’s outstanding shares of voting capital stock at any time within 12 months before or after the adoption of this Plan.