United States securities and exchange commission logo

                            February 18, 2021

       Duncan Peyton
       Chief Executive Officer
       4D Pharma PLC
       5th Floor, 9 Bond Court
       LS1 2JZ
       United Kingdom

                                                        Re: 4D Pharma PLC
                                                            Amendment No. 3 to
Registration Statement on Form F-4
                                                            Filed on February
16, 2021
                                                            File No. 333-250986

       Dear Mr. Peyton:

             We have reviewed your amended registration statement and have the
       comments. In some of our comments, we may ask you to provide us with
information so we
       may better understand your disclosure.

              Please respond to this letter by amending your registration
statement and providing the
       requested information. If you do not believe our comments apply to your
facts and
       circumstances or do not believe an amendment is appropriate, please tell
us why in your

              After reviewing any amendment to your registration statement and
the information you
       provide in response to these comments, we may have additional comments.
Unless we note
       otherwise, our references to prior comments are to comments in our
February 9, 2021 letter.

       Amendment No. 3 to Registration Statement on Form F-4, Filed February
16, 2021

       Collaborations, page 195

   1.                                                   We note your disclosure
added to page 196 regarding the Clinical Trial Collaboration and
                                                        Supply Agreement with
Merck KGaA, Darmstadt, Germany and Pfizer. Please revise to
                                                        state the obligations
of the parties under the agreement, including any financial terms.
 Duncan Peyton
4D PharmaLastNameDuncan Peyton
February  Name4D
            2021 Pharma PLC
Page 2 18, 2021 Page 2
FirstName LastName

2.       We note the revised the legal opinion filed as Exhibit 5.1. Please
reconcile the number
         of ordinary shares now included in the introduction paragraph of the
opinion with the
         number of ordinary shares listed in the fee table to the registration
3.       Please have counsel revise its opinion, filed as Exhibit 5.2, to
revise the limitation on
         reliance in the last two sentences of the opinion. Refer to Staff
Legal Bulletin No. 19,
         Section II.B.3.d.

4.       We note that you have now included the warrants in the registration
statement in response
         to our prior comment 3. However, because the warrants are exercisable
within one year it
         appears the shares underlying the warrants must be registered at this
time as well. Please
         revise the registration statement to include these shares. See
Securities Act Sections C&DI
         Question 139.01.
        You may contact Kristin Lochhead at 202-551-3664 or Terence O'Brien at
if you have questions regarding comments on the financial statements and
matters. Please contact Margaret Schwartz at 202-551-7153 or Laura Crotty at
with any other questions.


                                                                Division of
Corporation Finance
                                                                Office of Life
cc:      Bradley Finkelstein, Esq.