<SEC-DOCUMENT>0000899243-18-007529.txt : 20180315
<SEC-HEADER>0000899243-18-007529.hdr.sgml : 20180315
<ACCEPTANCE-DATETIME>20180315160527
ACCESSION NUMBER:		0000899243-18-007529
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180314
FILED AS OF DATE:		20180315
DATE AS OF CHANGE:		20180315

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Gengos Andrew
		CENTRAL INDEX KEY:			0001563623

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37566
		FILM NUMBER:		18692400

	MAIL ADDRESS:	
		STREET 1:		21900 BURBANK BOULEVARD
		STREET 2:		3RD FLOOR
		CITY:			WOODLAND HILLS
		STATE:			CA
		ZIP:			91367

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SYNLOGIC, INC.
		CENTRAL INDEX KEY:			0001527599
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				261824804
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		301 BINNEY STREET
		STREET 2:		SUITE 402
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02142
		BUSINESS PHONE:		617-401-9975

	MAIL ADDRESS:	
		STREET 1:		301 BINNEY STREET
		STREET 2:		SUITE 402
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02142

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Mirna Therapeutics, Inc.
		DATE OF NAME CHANGE:	20110809
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-03-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001527599</issuerCik>
        <issuerName>SYNLOGIC, INC.</issuerName>
        <issuerTradingSymbol>SYBX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001563623</rptOwnerCik>
            <rptOwnerName>Gengos Andrew</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SYNLOGIC, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>301 BINNEY STREET, SUITE 402</rptOwnerStreet2>
            <rptOwnerCity>CAMBRIDGE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02142</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Operating Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>9.95</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-03-14</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2028-03-14</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The options vest and become exercisable in substantially equal monthly installments beginning on April 14, 2018 and continuing until March 14, 2022, subject to the Reporting Person continuing to provide services to the Issuer through each such vesting date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ William J. Bussiere, Jr., Attorney-in-fact</signatureName>
        <signatureDate>2018-03-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
