UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d)

of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 7, 2020

KALEIDO BIOSCIENCES, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (617) 674-9000

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

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 any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

On May 7, 2020, the Board of Directors (the “Board”) of Kaleido Biosciences, Inc. (the “Company”) approved an amendment to the Company’s Second Amended and Restated By-laws (the “By-laws Amendment”). The By-laws Amendment amends Section 8 of Article VI to designate the United States District Court for the District of Massachusetts as the exclusive jurisdiction for any litigation arising under the Securities Act of 1933, as amended. Our board of directors approved this By-laws Amendment in order to reduce any potential expenses that the Company may incur in connection with any of the specified types of actions or proceedings if we were required to defend any such potential actions or proceedings in multiple jurisdictions and in parallel proceedings in federal and state courts simultaneously.

The foregoing summary and description of the provisions of the By-laws Amendment does not purport to be complete and is qualified in its entirety by reference to the full text of the By-laws Amendment, a copy of which is filed as Exhibit 3.1 with this Current Report on Form 8-K and is incorporated herein by reference.

(d) Exhibits

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has caused this Report to be signed on its behalf by the undersigned thereunto duly authorized.