<SEC-DOCUMENT>0000950170-25-093273.txt : 20250702
<SEC-HEADER>0000950170-25-093273.hdr.sgml : 20250702
<ACCEPTANCE-DATETIME>20250702173414
ACCESSION NUMBER:		0000950170-25-093273
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250701
FILED AS OF DATE:		20250702
DATE AS OF CHANGE:		20250702

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Fraser Claire
		CENTRAL INDEX KEY:			0001382031
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37465
		FILM NUMBER:		251102761

	MAIL ADDRESS:	
		STREET 1:		C/O BECTON, DICKINSON AND COMPANY
		CITY:			FRANKLIN LAKES
		STATE:			NJ
		ZIP:			07417

	FORMER NAME:	
		FORMER CONFORMED NAME:	Fraser-Liggett Claire
		DATE OF NAME CHANGE:	20061122

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Seres Therapeutics, Inc.
		CENTRAL INDEX KEY:			0001609809
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				274326290
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		200 SIDNEY STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02139
		BUSINESS PHONE:		617 945 9626

	MAIL ADDRESS:	
		STREET 1:		200 SIDNEY STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02139

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Seres Health, Inc.
		DATE OF NAME CHANGE:	20140603
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>ownership.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-07-01</periodOfReport>

    <issuer>
        <issuerCik>0001609809</issuerCik>
        <issuerName>Seres Therapeutics, Inc.</issuerName>
        <issuerTradingSymbol>MCRB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001382031</rptOwnerCik>
            <rptOwnerName>Fraser Claire</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SERES THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>101 CAMBRIDGE PARK DRIVE</rptOwnerStreet2>
            <rptOwnerCity>CAMBRIDGE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02140</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>false</aff10b5One>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.71</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-07-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6452</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2035-07-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6452</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6452</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option vests and becomes exercisable in four equal quarterly installments occurring on October 1, 2025, January 1, 2026, April 1, 2026, and July 1, 2026, provided that if the issuer's 2026 annual meeting of stockholders occurs before July 1, 2026, the final quarterly vesting installment will vest on the day immediately prior to the date of such annual meeting, in each case, subject to the reporting person continuing in service on the Board as a non-employee director through the applicable vesting date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Thomas J. DesRosier, Attorney-in-Fact</signatureName>
        <signatureDate>2025-07-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
