Seres Therapeutics Inc

Limitations on Effectiveness of Controls and Procedures

In designing and evaluating our disclosure controls and procedures, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives. In addition, the design of disclosure controls and procedures must reflect the fact that there are resource constraints and that management is required to apply judgment in evaluating the benefits of possible controls and procedures relative to their costs.

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our principal executive officer and our principal financial officer, has evaluated the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended), as of the end of the period covered by this Quarterly Report. Based on such evaluation, our principal executive officer and principal financial officer concluded that as of September 30, 2024, our disclosure controls and procedures were effective at the reasonable assurance level.

Changes in Internal Control Over Financial Reporting

On September 30, 2024, we completed the sale of the VOWST Business to SPN under the Purchase Agreement entered into as of August 5, 2024. As a result, during the three months ended September 30, 2024, we made the following modifications to our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act), including changes to accounting policies and procedures, operational processes, and documentation practices that materially affected, or are reasonably likely to materially affect, our internal control over financial reporting:

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added internal controls over the identification of accounts and transactions related to the sale of the VOWST Business;

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added controls and documentation processes related to the accounting for the discontinued operation; and

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added controls to address related disclosures for the discontinued operation.

Other than the items described above, there were no changes in our internal control over financial reporting that occurred during the three months ended September 30, 2024 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.