December 2, 2019

Alexander Arrow
Chief Financial Officer
Protagenic Therapeutics, Inc.\new
149 Fifth Avenue
New York, New York 10010

       Re: Protagenic Therapeutics, Inc.
           Form 10-K for Fiscal Year Ended December 31, 2018
           Response dated November 25, 2019
           File No. 000-51353

Dear Mr. Arrow:

        We have reviewed your November 25, 2019 response to our comment letter
and have the
following comment. In our comment, we may ask you to provide us with
information so we may
better understand your disclosure.

       Please respond to this comment within ten business days by providing the
requested
information or advise us as soon as possible when you will respond. If you do
not believe our
comment applies to your facts and circumstances, please tell us why in your
response.

      After reviewing your response to this comment, we may have additional
comments. Unless we note otherwise, our references to prior comments are to
comments in our
October 23, 2019 letter.

Correspondence filed November 25, 2019

Note 5 Derivative Liabilities, page F-14

1.     We read your response to comment 3. It appears your warrants meet the
definition of a
       derivative; however, please provide us with your analysis of whether the
warrants should
       be classified as a liability or equity. Refer to guidance in ASC
805-40-25.
 Alexander Arrow
Protagenic Therapeutics, Inc.\new
December 2, 2019
Page 2



       You may contact Tony Watson at (202) 551-3318 or Bill Thompson at (202)
551-3344 if
you have questions regarding comments on the financial statements and related
matters.



FirstName LastNameAlexander Arrow                       Sincerely,
Comapany NameProtagenic Therapeutics, Inc.\new
                                                        Division of Corporation
Finance
December 2, 2019 Page 2                                 Office of Trade &
Services
FirstName LastName