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   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>As filed with the Securities and Exchange Commission on March&nbsp;13, 2025 </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="right"><B>Registration <FONT STYLE="white-space:nowrap">No.&nbsp;333-&#8195;&#8195;&#8195;</FONT> </B></P>
  <P STYLE="font-size:4pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P>
  <P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="margin-top:4pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>UNITED STATES </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>SECURITIES AND EXCHANGE COMMISSION </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Washington, D.C. 20549 </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
  <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>FORM <FONT
  STYLE="white-space:nowrap">S-8</FONT></B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>REGISTRATION STATEMENT </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B><I>UNDER </I></B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B><I>THE
  SECURITIES ACT OF 1933 </I></B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:24pt; font-family:Times New Roman" ALIGN="center"><B>SERES THERAPEUTICS, INC. </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(Exact Name of Registrant as Specified in Its Charter) </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
  <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:8pt" ALIGN="center">
  
  
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  <TD VALIGN="top" ALIGN="center"><B>Delaware</B></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"><B><FONT STYLE="white-space:nowrap">27-4326290</FONT></B></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(State or other jurisdiction of</B></P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>incorporation or organization)</B></P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(I.R.S. Employer</B></P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Identification No.)</B></P></TD></TR>
  </TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>101 Cambridgepark Drive </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Cambridge, MA 02140 </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Address of Principal Executive Offices) (Zip Code) </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Seres Therapeutics, Inc. 2015 Incentive Award Plan </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Seres Therapeutics, Inc. 2015 Employee Stock Purchase Plan </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Full Title of the Plan) </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Eric D. Shaff. </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>President and Chief Executive Officer </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Seres Therapeutics, Inc. </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>101 Cambridgepark Drive </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Cambridge, MA 02140 </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Name
  and Address of Agent for Service) </B></P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(617) <FONT STYLE="white-space:nowrap">945-9626</FONT></B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Telephone Number, including Area Code, of Agent for Service) </B></P>
  <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>Copies to: </I></B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Peter
  N. Handrinos, Esq. </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Latham&nbsp;&amp; Watkins LLP </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>200 Clarendon Street </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Boston, MA 02116 </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(617) <FONT
  STYLE="white-space:nowrap">948-6060</FONT></B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
  <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Indicate by check mark whether
  the registrant is a large accelerated filer, an accelerated filer, a <FONT STYLE="white-space:nowrap">non-accelerated</FONT> filer, a smaller reporting company or an emerging growth company. See the definitions of &#147;large accelerated
  filer,&#148; &#147;accelerated filer,&#148; &#147;smaller reporting company,&#148; and &#147;emerging growth company&#148; in Rule <FONT STYLE="white-space:nowrap">12b-2</FONT> of the Exchange Act. </P>
  <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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  <TD VALIGN="bottom"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">Large&nbsp;accelerated&nbsp;filer</P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">&#9744;</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">Accelerated&nbsp;filer</P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">&#9746;</P></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman"><FONT STYLE="white-space:nowrap">Non-accelerated&nbsp;filer</FONT></P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">&#9744;</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">Smaller&nbsp;reporting&nbsp;company</P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">&#9746;</P></TD></TR>
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  <TD VALIGN="bottom"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">Emerging growth company</P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">&#9744;</P></TD></TR>
  </TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period
  for complying with new or revised financial accounting standards provided pursuant to Section&nbsp;7(a)(2)(B) of the Securities Act.&#8194;&#9744; </P> <P STYLE="font-size:10pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>
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   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>EXPLANATORY NOTE </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">This Registration Statement on Form <FONT STYLE="white-space:nowrap">S-8</FONT> is being filed for the purpose of registering an additional 400,000 shares of
  the common stock of Seres Therapeutics, Inc. (the &#147;<B><I>Registrant</I></B>&#148;) to be issued pursuant to the Seres Therapeutics, Inc. 2015 Employee Stock Purchase Plan (the &#147;<B><I>ESPP</I></B>&#148;) and an additional 6,920,327 shares
  of the Registrant&#146;s common stock to be issued pursuant to the Seres Therapeutics, Inc. 2015 Incentive Award Plan (the &#147;<B><I>Incentive Plan</I></B>,&#148; and together with the ESPP, the &#147;<B><I>Plans</I></B>&#148;). A Registration
  Statement of the Registrant on Form <FONT STYLE="white-space:nowrap">S-8</FONT> relating to the Plans is effective. </P> <P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>INCORPORATION BY
  REFERENCE OF CONTENTS OF </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>REGISTRATION STATEMENTS ON FORM <FONT STYLE="white-space:nowrap">S-8</FONT></B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The contents of the Registration Statements on Form <FONT STYLE="white-space:nowrap">S-8</FONT> (File Nos. <A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312515236648/d948161ds8.htm">
  <FONT STYLE="white-space:nowrap">333-205253</FONT></A>, <A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312516503517/d288825ds8.htm"><FONT STYLE="white-space:nowrap">333-210171</FONT></A>, <A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312518074569/d526660ds8.htm">
  <FONT STYLE="white-space:nowrap">333-223514</FONT></A>, <A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312519065218/d698213ds8.htm"><FONT STYLE="white-space:nowrap">333-230092</FONT></A>, <A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312520058927/d865737ds8.htm">
  <FONT STYLE="white-space:nowrap">333-236824</FONT></A>, <A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312521064827/d24654ds8.htm"><FONT STYLE="white-space:nowrap">333-253776</FONT></A>, <A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312522060244/d683320ds8.htm">
  <FONT STYLE="white-space:nowrap">333-263134</FONT></A>, <A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312523062117/d465067ds8.htm"><FONT STYLE="white-space:nowrap">333-270319</FONT></A> and <A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312524058891/d801055ds8.htm">
  <FONT STYLE="white-space:nowrap">333-277658</FONT></A>), including any amendments thereto, filed with the Securities and Exchange Commission, relating to the Plans, are incorporated by reference herein. </P>
  <P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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  <TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>Item&#8201;8.</B></TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>Exhibits. </B></P></TD></TR></TABLE> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">
  
  
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  <TD VALIGN="bottom" ALIGN="center"><B>Number</B></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center"><B>Description</B></TD></TR>
  
  
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  <TD VALIGN="top" NOWRAP>&#8199;4.1</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312515242845/d48188dex31.htm">Restated Certificate of Incorporation of the Registrant (incorporated by reference to Exhibit 3.1 to the Registrant&#146;s Current Report on Form
  <FONT STYLE="white-space:nowrap">8-K</FONT> (File No.&nbsp;001-37465) filed on July&nbsp;1, 2015) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;4.2</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312523176795/d506361dex31.htm">Certificate of Amendment to Restated Certificate of Incorporation of the Registrant, dated June&nbsp;
  27, 2023 (incorporated by reference to Exhibit 3.1 to the Registrant&#146;s Current Report on Form <FONT STYLE="white-space:nowrap">8-K</FONT> (File No.&nbsp;001-37465) filed on June&nbsp;28, 2023)</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;4.3</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312524089654/d798362dex31.htm">Certificate of Amendment to Restated Certificate of Incorporation of the Registrant, dated April&nbsp;
  5, 2024 (incorporated by reference to Exhibit 3.1 to the Registrant&#146;s Current Report on Form <FONT STYLE="white-space:nowrap">8-K</FONT> (File No.&nbsp;001-37465) filed on April&nbsp;8, 2024)</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;4.4</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312524000683/d582286dex31.htm">Amended and Restated <FONT STYLE="white-space:nowrap">By-Laws</FONT> of the Registrant (incorporated by reference to Exhibit 3.1 to the Registrant&#146;s
   Current Report on Form <FONT STYLE="white-space:nowrap">8-K</FONT> (File No.&nbsp;001-37465) filed on January&nbsp;2, 2024) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;5.1+</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d914755dex51.htm">Opinion of Latham&nbsp;&amp; Watkins LLP, counsel to the Registrant </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>23.1+</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d914755dex231.htm">Consent of PricewaterhouseCoopers LLP, Independent Registered Public Accounting Firm </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>23.2+</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d914755dex51.htm">Consent of Latham&nbsp;&amp; Watkins LLP (included in Exhibit 5.1) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>24.1+</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d914755ds8.htm#sig">Power of attorney (included on signature pages below) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>99.1</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000095017023006374/mcrb-ex10_1.htm">Seres Therapeutics, Inc. 2015 Incentive Award Plan (incorporated by reference to Exhibit 10.1 to the Registrant&#146;s Annual Report on Form
  <FONT STYLE="white-space:nowrap">10-K</FONT> (File No.&nbsp;001-37465) filed on March&nbsp;7, 2023) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>99.2</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1609809/000119312515202059/d816354dex103.htm">Seres Therapeutics, Inc. 2015 Employee Stock Purchase Plan (incorporated by reference to Exhibit 10.3 to the Registrant&#146;s Registration Statement
   on Form <FONT STYLE="white-space:nowrap">S-1</FONT> (Reg. <FONT STYLE="white-space:nowrap">No.&nbsp;333-204484)</FONT> filed on May&nbsp;27, 2015) </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>107+</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d914755dexfilingfees.htm">Filing Fee Table </A></TD></TR>
  </TABLE> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="2%" VALIGN="top" ALIGN="left">+</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Filed herewith </P></TD></TR></TABLE>
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  
  <Center><DIV STYLE="width:8.5in" align="left">
   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><A NAME="sig"></A>SIGNATURES </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the
  requirements for filing on Form <FONT STYLE="white-space:nowrap">S-8</FONT> and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Cambridge, Commonwealth of
  Massachusetts, on this 13th day of March, 2025. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><DIV ALIGN="right">
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt">
  
  
  <TR>
  
  <TD WIDTH="7%"></TD>
  
  <TD VALIGN="bottom" WIDTH="1%"></TD>
  <TD WIDTH="92%"></TD></TR>
  
  
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" COLSPAN="3"><B>SERES THERAPEUTICS, INC.</B></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom">By:</TD>
  <TD VALIGN="bottom" STYLE=" BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
  <TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000">/s/ Eric D. Shaff</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom"></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">Eric D. Shaff</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom"></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">President and Chief Executive Officer</TD></TR>
  </TABLE></DIV> <P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>POWER OF ATTORNEY </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Eric D. Shaff and Marella Thorell, or either of them,
  as his or her true and lawful <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">attorneys-in-fact</FONT></FONT> and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead,
  in any and all capacities, to file and sign any and all amendments, including post-effective amendments, to this registration statement, with the Securities and Exchange Commission, granting unto said <FONT STYLE="white-space:nowrap"><FONT
  STYLE="white-space:nowrap">attorneys-in-fact</FONT></FONT> and agents, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith as fully to all intents and purposes as he or
  she might or could do in person, hereby ratifying and confirming all that said <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">attorneys-in-fact</FONT></FONT> and agents, or their substitute or substitutes may lawfully do or cause
  to be done by virtue hereof. This power of attorney shall be governed by and construed with the laws of the State of Delaware and applicable federal securities laws. </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the
  dates indicated. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt">
  
  
  <TR>
  
  <TD WIDTH="38%"></TD>
  
  <TD VALIGN="bottom"></TD>
  <TD WIDTH="44%"></TD>
  
  <TD VALIGN="bottom" WIDTH="1%"></TD>
  <TD WIDTH="16%"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
  <TD VALIGN="bottom" ALIGN="center"><B>SIGNATURE</B></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center"><B>TITLE</B></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center"><B>DATE</B></TD></TR>
  
  
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Eric D. Shaff</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Eric D. Shaff</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">President, Chief Executive Officer, Director</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">(<I>principal executive officer</I>)</P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP>March&nbsp;13, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Marella Thorell</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Marella Thorell</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Executive Vice President and Chief Financial Officer</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">(<I>principal accounting officer and principal</I> <I>financial officer</I>)</P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP>March&nbsp;13, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Stephen Berenson</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Stephen Berenson</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top">Chairman of the Board</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP>March&nbsp;13, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Dennis Ausiello</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Dennis Ausiello, M.D.</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top">Director</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP>March&nbsp;13, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Paul R. Biondi</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Paul R. Biondi</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top">Director</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP>March&nbsp;13, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Willard H. Dere</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Willard H. Dere, M.D.</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top">Director</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP>March&nbsp;13, 2025</TD></TR></TABLE>
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  
  <Center><DIV STYLE="width:8.5in" align="left">
  
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt">
  
  
  <TR>
  
  <TD WIDTH="38%"></TD>
  
  <TD VALIGN="bottom"></TD>
  <TD WIDTH="44%"></TD>
  
  <TD VALIGN="bottom" WIDTH="1%"></TD>
  <TD WIDTH="16%"></TD></TR>
  
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Claire M. Fraser</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Claire M. Fraser, Ph.D.</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top">Director</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP>March&nbsp;13, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Kurt C. Graves</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Kurt C. Graves</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top">Director</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP>March&nbsp;13, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Richard N. Kender</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Richard N. Kender</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top">Director</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP>March&nbsp;13, 2025</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Hans-Juergen Woerle</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Hans-Juergen Woerle</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top">Director</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP>March&nbsp;13, 2025</TD></TR>
  </TABLE>
  </DIV></Center>
  
  </BODY></HTML>
metadata_documents: [{"type": "S-8", "sequence": "1", "filename": "d914755ds8.htm", "description": "S-8", "secsgml_size_bytes": 34502}]
metadata_filer: {"company-data": {"conformed-name": "Seres Therapeutics, Inc.", "cik": "0001609809", "assigned-sic": "2834", "organization-name": "03 Life Sciences", "irs-number": "274326290", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-285769", "film-number": "25734504"}, "business-address": {"street1": "200 SIDNEY STREET", "city": "CAMBRIDGE", "state": "MA", "zip": "02139", "phone": "617 945 9626"}, "mail-address": {"street1": "200 SIDNEY STREET", "city": "CAMBRIDGE", "state": "MA", "zip": "02139"}, "former-company": {"former-conformed-name": "Seres Health, Inc.", "date-changed": "20140603"}}
text: S-8
  As filed with the Securities and Exchange Commission on March 13, 2025
  Registration
  No. 333-
  UNITED STATES
  SECURITIES AND EXCHANGE COMMISSION
  Washington, D.C. 20549
  FORM
  S-8
  REGISTRATION STATEMENT
  UNDER
  THE
  SECURITIES ACT OF 1933
  SERES THERAPEUTICS, INC.
  (Exact Name of Registrant as Specified in Its Charter)
  Delaware
  27-4326290
  (State or other jurisdiction of
  incorporation or organization)
  (I.R.S. Employer
  Identification No.)
  101 Cambridgepark Drive
  Cambridge, MA 02140
  (Address of Principal Executive Offices) (Zip Code)
  Seres Therapeutics, Inc. 2015 Incentive Award Plan
  Seres Therapeutics, Inc. 2015 Employee Stock Purchase Plan
  (Full Title of the Plan)
  Eric D. Shaff.
  President and Chief Executive Officer
  Seres Therapeutics, Inc.
  101 Cambridgepark Drive
  Cambridge, MA 02140
  (Name
  and Address of Agent for Service)
  (617)
  945-9626
  (Telephone Number, including Area Code, of Agent for Service)
  Copies to:
  Peter
  N. Handrinos, Esq.
  Latham & Watkins LLP
  200 Clarendon Street
  Boston, MA 02116
  (617)
  948-6060
  Indicate by check mark whether
  the registrant is a large accelerated filer, an accelerated filer, a
  non-accelerated
  filer, a smaller reporting company or an emerging growth company. See the definitions of "large accelerated
  filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule
  12b-2
  of the Exchange Act.
  Large accelerated filer
  ☐
  Accelerated filer
  ☒
  Non-accelerated filer
  ☐
  Smaller reporting company
  ☒
  Emerging growth company
  ☐
  If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period
  for complying with new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐
  EXPLANATORY NOTE
  This Registration Statement on Form
  S-8
  is being filed for the purpose of registering an additional 400,000 shares of
  the common stock of Seres Therapeutics, Inc. (the "
  Registrant
  ") to be issued pursuant to the Seres Therapeutics, Inc. 2015 Employee Stock Purchase Plan (the "
  ESPP
  ") and an additional 6,920,327 shares
  of the Registrant's common stock to be issued pursuant to the Seres Therapeutics, Inc. 2015 Incentive Award Plan (the "
  Incentive Plan
  ," and together with the ESPP, the "
  Plans
  "). A Registration
  Statement of the Registrant on Form
  S-8
  relating to the Plans is effective.
  INCORPORATION BY
  REFERENCE OF CONTENTS OF
  REGISTRATION STATEMENTS ON FORM
  S-8
  The contents of the Registration Statements on Form
  S-8
  (File Nos.
  333-205253
  ,
  333-210171
  ,
  333-223514
  ,
  333-230092
  ,
  333-236824
  ,
  333-253776
  ,
  333-263134
  ,
  333-270319
  and
  333-277658
  ), including any amendments thereto, filed with the Securities and Exchange Commission, relating to the Plans, are incorporated by reference herein.
  Item 8.
  Exhibits.
  Number
  Description
  4.1
  Restated Certificate of Incorporation of the Registrant (incorporated by reference to Exhibit 3.1 to the Registrant's Current Report on Form
  8-K
  (File No. 001-37465) filed on July 1, 2015)
  4.2
  Certificate of Amendment to Restated Certificate of Incorporation of the Registrant, dated June 
  27, 2023 (incorporated by reference to Exhibit 3.1 to the Registrant's Current Report on Form
  8-K
  (File No. 001-37465) filed on June 28, 2023)
  4.3
  Certificate of Amendment to Restated Certificate of Incorporation of the Registrant, dated April 
  5, 2024 (incorporated by reference to Exhibit 3.1 to the Registrant's Current Report on Form
  8-K
  (File No. 001-37465) filed on April 8, 2024)
  4.4
  Amended and Restated
  By-Laws
  of the Registrant (incorporated by reference to Exhibit 3.1 to the Registrant's
   Current Report on Form
  8-K
  (File No. 001-37465) filed on January 2, 2024)
  5.1+
  Opinion of Latham & Watkins LLP, counsel to the Registrant
  23.1+
  Consent of PricewaterhouseCoopers LLP, Independent Registered Public Accounting Firm
  23.2+
  Consent of Latham & Watkins LLP (included in Exhibit 5.1)
  24.1+
  Power of attorney (included on signature pages below)
  99.1
  Seres Therapeutics, Inc. 2015 Incentive Award Plan (incorporated by reference to Exhibit 10.1 to the Registrant's Annual Report on Form
  10-K
  (File No. 001-37465) filed on March 7, 2023)
  99.2
  Seres Therapeutics, Inc. 2015 Employee Stock Purchase Plan (incorporated by reference to Exhibit 10.3 to the Registrant's Registration Statement
   on Form
  S-1
  (Reg.
  No. 333-204484)
  filed on May 27, 2015)
  107+
  Filing Fee Table
  +
  Filed herewith
  SIGNATURES
  Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the
  requirements for filing on Form
  S-8
  and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Cambridge, Commonwealth of
  Massachusetts, on this 13th day of March, 2025.
  SERES THERAPEUTICS, INC.
  By:
  /s/ Eric D. Shaff
  Eric D. Shaff
  President and Chief Executive Officer
  POWER OF ATTORNEY
  KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Eric D. Shaff and Marella Thorell, or either of them,
  as his or her true and lawful
  attorneys-in-fact
  and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead,
  in any and all capacities, to file and sign any and all amendments, including post-effective amendments, to this registration statement, with the Securities and Exchange Commission, granting unto said
  attorneys-in-fact
  and agents, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith as fully to all intents and purposes as he or
  she might or could do in person, hereby ratifying and confirming all that said
  attorneys-in-fact
  and agents, or their substitute or substitutes may lawfully do or cause
  to be done by virtue hereof. This power of attorney shall be governed by and construed with the laws of the State of Delaware and applicable federal securities laws.
  Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the
  dates indicated.
  SIGNATURE
  TITLE
  DATE
  /s/ Eric D. Shaff
  Eric D. Shaff
  President, Chief Executive Officer, Director
  (
  principal executive officer
  )
  March 13, 2025
  /s/ Marella Thorell
  Marella Thorell
  Executive Vice President and Chief Financial Officer
  (
  principal accounting officer and principal
  financial officer
  )
  March 13, 2025
  /s/ Stephen Berenson
  Stephen Berenson
  Chairman of the Board
  March 13, 2025
  /s/ Dennis Ausiello
  Dennis Ausiello, M.D.
  Director
  March 13, 2025
  /s/ Paul R. Biondi
  Paul R. Biondi
  Director
  March 13, 2025
  /s/ Willard H. Dere
  Willard H. Dere, M.D.
  Director
  March 13, 2025
  /s/ Claire M. Fraser
  Claire M. Fraser, Ph.D.
  Director
  March 13, 2025
  /s/ Kurt C. Graves
  Kurt C. Graves
  Director
  March 13, 2025
  /s/ Richard N. Kender
  Richard N. Kender
  Director
  March 13, 2025
  /s/ Hans-Juergen Woerle
  Hans-Juergen Woerle
  Director
  March 13, 2025