SEC FORM 3 SEC Form 3
FORM 3 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
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1. Name and Address of Reporting Person*
DesRosier Thomas

(Last) (First) (Middle)
C/O SERES THERAPEUTICS, INC.
200 SIDNEY ST.

(Street)
CAMBRIDGE MA 02139

(City) (State) (Zip)
2. Date of Event Requiring Statement (Month/Day/Year)
05/16/2016
3. Issuer Name and Ticker or Trading Symbol
Seres Therapeutics, Inc. [ MCRB ]
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director 10% Owner
X Officer (give title below) Other (specify below)
See Remarks
5. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
X Form filed by One Reporting Person
Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5)
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4) 2. Date Exercisable and Expiration Date (Month/Day/Year) 3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 6. Nature of Indirect Beneficial Ownership (Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Explanation of Responses:
Remarks:
Chief Legal Officer and Executive Vice President
No securities are beneficially owned.
/s/ Eric Shaff, Attorney-in-fact 05/17/2016
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
                               POWER OF ATTORNEY

     KNOW ALL BY THESE PRESENTS, as of this 17th day of May, 2016, that the
undersigned hereby constitutes and appoints the Chief Executive Officer of Seres
Health, Inc. (the "Company"), who is currently Roger J. Pomerantz, and the Chief
Financial Officer of the Company who is currently Eric D. Shaff, or either of
them signing singly, and with full power of substitution, the undersigned's true
and lawful attorney-in-fact to:

 (1) prepare, execute in the undersigned's name and on the undersigned's
     behalf, and submit to the U.S. Securities and Exchange Commission (the
     "SEC") a Form ID, including amendments thereto, and any other documents
     necessary or appropriate to obtain codes and passwords enabling the
     undersigned to make electronic filings with the SEC of reports required by
     Section 16(a) of the Securities Exchange Act of 1934 or any rule or
     regulation of the SEC;

 (2) execute for and on behalf of the undersigned, in the undersigned's
     capacity as an officer and/or director of Seres Health, Inc. (the
     "Company"), Forms 3, 4, and 5 in accordance with Section 16(a) of the
     Securities Exchange Act of 1934 and the rules thereunder;

 (3) do and perform any and all acts for and on behalf of the undersigned
     which may be necessary or desirable to
 complete and execute any such Form
     3, 4, or 5, complete and execute any amendment or amendments thereto, and
     timely file such form with the SEC and any stock exchange or similar
     authority; and

 (4) take any other action of any type whatsoever in connection with the
     foregoing which, in the opinion of such attorney-in-fact, may be of
     benefit to, in the best interest of, or legally required by, the
     undersigned, it being understood that the documents executed by such
     attorney-in-fact on behalf of the undersigned pursuant to this Power of
     Attorney shall be in such form and shall contain such terms and conditions
     as such attorney-in-fact may approve in such attorney-in-fact's discretion.

    The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to for me to fix your for all intents and purposes as
the undersigned might or could do if personally present, with full power of
substitution or revocation, hereby ratifying and confirming all that such
attorney-in-fact, or such attorney-in-fact's substitute or substitutes, shall
lawfully do or cause to be done by virtue of this power of attorney and the
rights and powers herein granted. The undersigned acknowledges that the
foregoing attorneys-in-fact, in serving in such capacity at the request of the
undersigned, are not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with Section 16 of the Securities
Exchange Act of 1934.

    This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, and 5 with respect to the
undersigned's holdings of and transactions in securities issued by the Company,
unless earlier revoked by the undersigned in a signed writing delivered to the
foregoing attorneys-in-fact.

    IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of the date first written above.

                                           /s/ Thomas DesRosier
                                           ----------------------
                                           Signature

                                           Thomas DesRosier
                                           ----------------------
                                           Printed Name