Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

​

We hereby consent to the incorporation by reference in the Registration Statements on Form S-3 (No. 333-269365, 333-255418, 333-252412 and 333-278646), Form S-1 (No. 333-280865) and Form S-8 (No. 333-271292, 333-237535 and 333-260765) of MetaVia Inc. (the Company) of our report dated March 20, 2025, relating to the consolidated financial statements which appears in this Annual Report on Form 10-K. Our report contains an explanatory paragraph regarding the Company’s ability to continue as a going concern.

​

/s/ BDO USA, P.C.

Boston, Massachusetts

March 20, 2025