<SEC-DOCUMENT>0000899243-23-010716.txt : 20230405
<SEC-HEADER>0000899243-23-010716.hdr.sgml : 20230405
<ACCEPTANCE-DATETIME>20230405161511
ACCESSION NUMBER:		0000899243-23-010716
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20230403
FILED AS OF DATE:		20230405
DATE AS OF CHANGE:		20230405

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Awad Antoine
		CENTRAL INDEX KEY:			0001820122

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37566
		FILM NUMBER:		23802712

	MAIL ADDRESS:	
		STREET 1:		C/O SYNLOGIC, INC.
		STREET 2:		301 BINNEY STREET, SUITE 402
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02142

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>X0407</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-04-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001820122</rptOwnerCik>
            <rptOwnerName>Awad Antoine</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>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2023-04-03</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6438</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.5758</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>74732</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents the number of shares sold by the reporting person on April 3, 2023 to cover the tax liability in connection with the vesting of three restricted stock awards, vesting on April 1, 2023, that were granted in 2020, 2021, and 2022.</footnote>
        <footnote id="F2">The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.5750 to $0.5798, inclusive. The reporting person will provide to the staff of the Securities and Exchange Commission, the issuer, or any security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Antoine Awad</signatureName>
        <signatureDate>2023-04-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
