Kaleido Biosciences to Host Virtual R&D Presentation to Discuss Clinical Data and Pipeline Advancement on October 5, 2021

Kaleido Biosciences, Inc. (Nasdaq: KLDO), a clinical-stage healthcare company with a differentiated, chemistry-driven approach to targeting the microbiome to treat disease and improve human health, today announced that it will host a virtual R&D Presentation on October 5, 2021, at 8 a.m. ET. The agenda will feature an update on the Company’s corporate strategy, data from the non-IND study evaluating KB295 in mild-to-moderate UC as well as supportive preclinical data, and data supporting the advancement of KB109 into COPD. KB295 and KB109 are novel, orally administered Microbiome Metabolic Therapies (MMT™) developed using Kaleido’s proprietary synthetic chemistry technology.

The program will also feature presentations by Bruce Sands, M.D., Dr. Burrill B. Crohn Professor of Medicine at Icahn School of Medicine at Mount Sinai and Ruth Tal-Singer, Ph.D., President and Chief Scientific Officer of the COPD Foundation.

Conference Call and Webcast InformationKaleido management will host a conference call with accompanying slides at 8:00 a.m. ET on October 5, 2021. Analysts and investors are invited to participate in the conference call by dialing [phone] from the U.S. and Canada or [phone] internationally and using the conference ID 5754389. The live webcast can be accessed on the investor page of Kaleido’s website at investors.kaleido.com. A replay of the webcast will be available on Kaleido’s website approximately two hours after the completion of the event and will be archived for at least 30 days.

About Microbiome Metabolic Therapies (MMT™) Kaleido’s Microbiome Metabolic Therapies, or MMTs, are designed to drive the function and distribution of the microbiome’s existing microbes in order to decrease or increase the production of metabolites, or to advantage or disadvantage certain bacteria in the microbiome community. The Company’s initial MMT candidates are targeted, synthetic glycans that are orally administered, have limited systemic exposure, and are selectively metabolized by enzymes in the microbiome. Kaleido utilizes its discovery and development platform to study MMTs in microbiome samples to rapidly advance MMT candidates rapidly into clinical studies in healthy subjects and patients. These human clinical studies are conducted under regulations supporting research with food, evaluating safety, tolerability and impact on the microbiome or other key biomarkers. For MMT candidates that are further developed as therapeutics, the Company conducts clinical trials under an Investigational New Drug (IND) or regulatory equivalent outside the U.S., and in Phase 2 or later development.

About Kaleido BiosciencesKaleido Biosciences is a clinical-stage healthcare company with a differentiated, chemistry-driven approach to targeting the microbiome to treat disease and improve human health. The Company has built a proprietary product platform to enable the rapid and cost-efficient discovery and development of novel Microbiome Metabolic Therapies (MMT™). MMTs are designed to modulate the metabolic output and profile of the microbiome by driving the function and distribution of the gut’s existing microbes. Kaleido is advancing a broad pipeline of MMT candidates with the potential to address a variety of diseases and conditions with significant unmet patient needs. To learn more, visit https://kaleido.com/.

Forward-Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding clinical study plans and timelines, regulatory plans, and the Company’s business focus. The words “may,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “project,” “potential,” “continue,” “target” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements in this press release are based on management’s current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, those related to the breadth of our pipeline of product candidates, the strength of our proprietary product platform, the efficiency of our discovery and development approach, the clinical development and safety profile of our MMT candidates and their therapeutic potential, whether and when, if at all, regulatory agencies will approve our IND application or clinical trial applications for KB295 or KB109, whether and when, if at all, our MMT candidates will receive approval from the U.S. Food and Drug Administration or other regulatory agencies and for which, if any, indications, competition from other biotechnology companies, and other risks identified in our SEC filings, including our most recent Form 10-K, and subsequent filings with the SEC. We caution you not to place undue reliance on any forward-looking statements, which speak only as of the date they are made. We disclaim any obligation to publicly update or revise any such statements to reflect any change in expectations or in events, conditions or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements.

Contacts:

Kaleido BiosciencesWilliam Duke, Jr.Chief Financial [e-mail]

Investors and MediaKotaro YoshidaArgot [e-mail]