October 23, 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
           Filed March 29, 2019
           File No. 000-51353

Dear Mr. Arrow:

       We have limited our review of your filing to the financial statements
and related
disclosures and have the following 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 these comments 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
comments apply to your facts and circumstances, please tell us why in your
response.

       After reviewing your response to these comments, we may have additional
comments.

Form 10-K filed March 3, 2019

Signatures, page 60

1.     The annual report should also be signed by Alexander K Arrow in his
capacity as the
       Chief Accounting Officer or Controller. Please revise. Refer to General
Instruction D2(a)
       to Form 10-K .
Note 6 Stockholders' Equity (Deficit), page F-14

2.     Please tell us your consideration of disclosing the weighted-average
grant-date fair value
       of equity options granted during the years presented. Refer to ASC
718-10-50-2d.1.
Note 5 Derivative Liabilities, page F14

3.     We note your disclosure that the cashless exercise feature requires you
to classify warrants
       as a derivative liability. Please explain to us in detail how this
cashless exercise feature
       results in liability classification under existing accounting
literature.
 Alexander Arrow
Protagenic Therapeutics, Inc.\new
October 23, 2019
Page 2

       In closing, we remind you that the company and its management are
responsible for the
accuracy and adequacy of their disclosures, notwithstanding any review,
comments, action or
absence of action by the staff.

      You may contact Tony Watson at (202) 551-3318 or Bill Thompson at (202)
551-
3344 with any questions.



FirstName LastNameAlexander Arrow                         Sincerely,
Comapany NameProtagenic Therapeutics, Inc.\new
                                                          Division of
Corporation Finance
October 23, 2019 Page 2                                   Office of Trade &
Services
FirstName LastName