--- title: "Microbiotica Closes £36M First Tranche of Series C for MB310" description: "British Business Bank led Microbiotica's £36M/$48M Series C first close to advance MB310 into Phase 2. Valuation and a final round target remain undisclosed." date: 2026-10-16T23:10:32.890Z source: https://venturecapitaltracker.com/microbiotica-36m-series-c-first-close-mb310 --- # Microbiotica Closes £36M First Tranche of Series C for MB310 > British Business Bank led Microbiotica's £36M/$48M Series C first close to advance MB310 into Phase 2. Valuation and a final round target remain undisclosed. [Microbiotica has completed a £36 million ($48 million) first close of its Series C](https://www.globenewswire.com/news-release/2026/10/16/3382257/0/en/microbiotica-raises-36-million-48-million-in-series-c-financing-to-advance-pipeline-into-phase-2-clinical-development.html), giving the Cambridge-area biopharma company capital to take its lead microbiome medicine into Phase 2 testing. British Business Bank led the financing announced on October 16. Tencent, IP Group, Cambridge Innovation Capital, Flerie Invest and Seventure Partners participated, with every existing Series B investor returning. The company did not disclose its valuation, individual check sizes or a final target for the Series C. ## What the first close actually funds The principal use of proceeds is a larger trial of MB310 for ulcerative colitis. It is an oral live-biotherapeutic product: a capsule containing eight selected bacterial strains, designed to influence the gut environment and its protective barrier. In the [company announcement republished by investor IP Group](https://www.ipgroupplc.com/news-and-events/ip-group-news/2026/2026-10-16), Microbiotica says its earlier COMPOSER-1 Phase 1b study met its primary and secondary endpoints. The next trial is intended to test whether the preliminary findings hold in a randomized, blinded, placebo-comparison setting. These are company-reported research findings, not evidence of an approved treatment. A small early-stage trial can identify a promising signal while leaving important questions about the magnitude, durability and reproducibility of benefit unanswered. For investors, the financing therefore buys a more informative experiment. Its value depends on what that experiment establishes, not simply on whether the company can enroll a larger study. ## Why the microbiome platform matters Microbiotica uses genomic analysis to identify bacteria associated with better outcomes in defined patient groups. It then develops selected strains as potential medicines. The platform offers a route from observed biological patterns to a testable product. But the transition is not automatic: association with favorable outcomes does not on its own establish that administering a bacterial consortium causes a clinically meaningful benefit. That is why the trial design matters more than broad platform language. Patient selection, dosing, endpoints, background therapies and follow-up length will shape the eventual interpretation of the Phase 2 results. The company also has an immuno-oncology program, MB097, under evaluation with pembrolizumab in advanced melanoma. That provides a second clinical application of its approach, although it remains investigational and should not be treated as a validated commercial pipeline. ## The financing signal is investor continuity Returning Series B investors are supporting the move into a more expensive development phase, while British Business Bank leads the new financing. That continuity can reduce fundraising friction and preserve institutional knowledge of the program. It does not eliminate clinical risk. Nor does participation by well-known investors prove that a drug will work. The more useful interpretation is that the syndicate is willing to finance a defined next step with clearer evidence requirements. A first close also has a precise meaning. The company has announced an initial completed portion of the round; it has not announced that the Series C fundraising process is finished. Without a disclosed final target, there is no basis for estimating how much more it intends to raise. ## Manufacturing is part of the investment thesis Unlike a conventional software product, a live bacterial medicine must be manufactured consistently and remain suitable through storage and delivery. The commercial question extends beyond whether MB310 produces a positive trial result. The company must also demonstrate reliable production, controlled product characteristics and a practical cost base as development expands. Microbiotica says it has developed a scalable manufacturing process. Investors will need evidence that performance persists at the volumes and consistency required for later trials and any eventual commercialization. This is an execution milestone, not a settled outcome. ## What to watch after the financing The next useful disclosures are the Phase 2 protocol, trial registration, enrollment progress and the expected readout schedule. The funding announcement does not provide a detailed cash runway, so a specific number of funded years should not be inferred from the £36 million headline. Any later Series C closing should be reported as an incremental addition, with the already closed £36 million preserved as the initial tranche. That avoids double-counting the same capital when the round is expanded. ## Bottom line Microbiotica’s Series C first close finances the transition from early clinical signals toward a larger test of MB310. The £36 million is confirmed equity capital, not a grant or a final-close target. The decisive milestone will be reproducible patient benefit supported by a manufacturable product—not the financing announcement itself. For related context, see VCT’s [Microbiotica profile](/startup/microbiotica), [British Business Bank profile](/fund/british-business-bank) and coverage of [OMass’s $310 million Series C](/omass-310m-series-c-clinical-development). **By:** [Venture Capital Tracker](https://venturecapitaltracker.com/editorial-policy) **Last updated:** October 16, 2026 **Editorial note:** AI tools assisted with research, structure, or drafting. Venture Capital Tracker retains human editorial responsibility for factual accuracy, relevance, and source quality before publication.