UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No.        )

Filed by the Registrant  ☒

Filed by a Party other than the Registrant  ☐

Check the appropriate box:

☐ Preliminary Proxy Statement

☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

☐ Definitive Proxy Statement

☒ Definitive Additional Materials

☐ Soliciting Material under §240.14a-12

89bio, Inc.

(Name of Registrant as Specified in Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

☒ No fee required.

☐ Fee paid previously with preliminary materials.

☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

                                                89BIO, INC.                              142 SANSOME STREET,                              SECOND FLOOR                              SAN FRANCISCO, CA 94104                               V06783-P90697  

You invested in 89BIO, INC. and it’s time to vote!

You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy materials for the stockholder meeting to be held on June 5, 2023.

Get informed before you vote

View the Notice and Proxy Statement and Annual Report online OR you can receive a free paper or email copy of the proxy materials by requesting prior to May 22, 2023. If you would like to request a paper or email copy of the proxy materials or materials for future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. There is no charge to you for requesting a copy. Unless requested, you will not otherwise receive a paper or email copy.

Smartphone users		Vote Virtually at the Meeting* June 5, 2023 9:00 AM PDT
Point your camera here and
vote without entering a
control number
	Virtually at:             www.virtualshareholdermeeting.com/ETNB2023

*The company will be hosting the meeting live via the Internet this year at the website address above. Please check the proxy materials for instructions on how to access

 the meeting.

V1.1

  Vote at www.ProxyVote.com

  THIS IS NOT A VOTABLE BALLOT

This is an overview of the more complete proxy materials that

are available to you on the Internet. You may view the proxy

materials at www.proxyvote.com or easily request a paper copy.

We encourage you to access and review all of the important

information contained in the proxy materials before voting.

Please follow the instructions on the reverse side to vote on

these important matters.

Voting Items		Board Recommends
1.	Election of Directors: To be elected for terms expiring in 2026.		For
	Nominees:
	01)  Rohan Palekar
	02)   Edward Morrow Atkinson III, Ph.D.
	03)  Gregory Grunberg, M.D.
2.	Approval of an amendment to our Certificate of Incorporation to increase the number of authorized shares of our common stock.		For
3.	Ratification of the appointment of KPMG LLP as our independent registered public accounting firm for the year ending December 31, 2023.		For
NOTE: Such other business as may properly come before the meeting or any adjournment or postponement thereof.

Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click “Sign up for E-delivery”.

V06784-P90697