Christopher Reyes, PhD, Bloom Science’s founder and CEO
A First Patient — and a New Idea
Bloom Science, a San Diego-based biotech company, has dosed its first patient in a Phase 1b clinical trial of BL-001, an investigational oral therapy for obesity. The milestone is clinically routine — but what Bloom is testing is anything but.
BL-001 is a Live Biotherapeutic Product, or LBP: a precisely formulated capsule containing two defined strains of beneficial bacteria. The therapy is designed to engage the same metabolic pathways activated by the ketogenic diet — a low-carbohydrate regimen known to produce significant weight loss — without requiring patients to change what they eat. No injections. No restrictive meal plans. Just a pill.
“The basis of our therapy is to utilize specific microbes or gut bacteria to reproduce some of the metabolic effects of the ketogenic diet,” said Christopher Reyes, PhD, Bloom Science’s founder and CEO. BL-001, he explains, “It is designed to influence metabolic pathways and gut-brain signaling that are associated with fat metabolism and appetite regulation.”
The Science: Ketogenic Biology Without the Ketogenic Diet
The ketogenic diet was developed over 100 years ago. By sharply limiting carbohydrates, it prompts the body to burn fat rather than glucose, producing ketone bodies that serve as an alternative fuel source — particularly for the brain. In clinical settings, the diet has shown meaningful effects on weight, insulin sensitivity, and even seizure frequency in treatment-resistant epilepsy.
The challenge is adherence. The ketogenic diet is difficult to maintain long-term, and few patients sustain it beyond several months. Bloom’s hypothesis is that specific bacterial strains can activate the same gut-brain axis signaling that the ketogenic diet triggers — bypassing the diet entirely.
Rather than attempting to broadly reshape the microbiome — an approach that has produced mixed results across the field — Bloom has focused narrowly on two defined bacterial strains chosen for their ability to reproduce specific ketogenic metabolic effects. This targeted strategy also simplifies manufacturing and makes the clinical development path more predictable.
“BL-001 is designed to reproduce some of the metabolic effects associated with the ketogenic diet in a daily oral capsule, without injections or dietary restriction,” Reyes said.
The Market Gap Bloom Is Targeting
According to a 2024 study covered by Forbes, 85% of patients discontinue GLP-1s within two years. That’s not a supply problem — it’s a product problem. And for Bloom, it may represent the biggest untapped opportunity in drug development.
Bloom believes BL-001 will be directly competitive with oral GLP-1s and other incretin pathway drugs — but the company’s ambitions don’t stop there. Its data also points to strong interest from patients who are currently untreated entirely: people who have not started any obesity therapy, have discontinued existing options, or are actively seeking a non-injection alternative.
“This is about bringing a real treatment option to patients who are currently on the sidelines,” said Louis Licamele, PhD, Chief Development Officer. “Advancing into a dedicated obesity program is a milestone not just for Bloom, but for patients who have been waiting for something different.”
Learning From the Microbiome Field’s Struggles
Bloom is not the first company to bet on the therapeutic potential of the gut microbiome. But the field has had a difficult decade. Seres Therapeutics and Vedanta Biosciences, two well-funded microbiome companies, have each faced clinical setbacks — in part because of the inherent complexity of trying to broadly correct microbiome dysbiosis, a poorly defined target with significant individual variability.
Bloom’s leadership believes their narrower hypothesis — reproduce a specific metabolic effect with specific strains — reduces that variability and creates a cleaner clinical signal to measure. The Phase 1b trial is designed in part to validate that assumption, with pharmacodynamic biomarkers built into the protocol.
Whether the approach succeeds will depend on the data. But the strategic logic is sound: by targeting a defined mechanism rather than a diffuse one, Bloom has a more tractable path to demonstrating efficacy.
Built in San Diego — By Design
Founded in 2018, Bloom is headquartered in the Sorrento Valley area of San Diego, one of the most active biotech clusters in the United States. The company currently has around 10 full-time employees, with its core leadership and scientific team based locally. Reyes began his career at Biogen Idec when it had a significant presence in the city, and previously founded Eclipse Therapeutics, spun out of Biogen Idec’s oncology group here. Bloom was built to take advantage of the region’s strong biotechnology ecosystem and experienced talent pool.
Bloom participates actively in San Diego’s biotech community and draws on the regional ecosystem for scientific and operational expertise, though it does not hold formal institutional partnerships with UC San Diego or Scripps Research.
Beyond Obesity: A Platform With Broader Ambitions
Bloom’s clinical focus is not limited to obesity. The company is also developing BL-001 for developmental and epileptic encephalopathies (DEEs) — a group of severe, treatment-resistant seizure disorders in which the ketogenic diet has long been used as a frontline therapy. The fact that the same diet already has clinical credibility in epilepsy gives Bloom’s platform a meaningful head start in that indication.
The parallel development programs reflect a broader thesis: that ketogenic biology is a versatile therapeutic platform, not a single-disease solution. Obesity and DEEs share common metabolic roots — abnormal energy utilization, dysregulated neurological signaling — that the same bacterial mechanism may be able to address.
It is an ambitious bet. But if BL-001 shows meaningful activity in either indication, the platform’s value expands considerably — and Bloom would find itself with a differentiated position in a field that is otherwise crowded with GLP-1 follow-ons.
The Road Ahead
Phase 1b trials are primarily designed to evaluate safety and tolerability, with early signals on biomarker activity. They are not the final word on whether a therapy works. If BL-001 clears this stage, Bloom aims to begin Phase 2 in 2027, with a potential commercial launch by the end of the decade — timelines that are optimistic but not unreasonable for a company with a clearly defined mechanism and focused development plan.
Bloom’s goal is to build toward independent commercialization, while remaining open to strategic partnerships that could accelerate development — particularly around obesity and developmental epilepsies like Dravet syndrome. The company confirms it is already in active discussions with potential partners across the pharmaceutical and biotechnology industries.
For now, the first patient has been dosed, the trial is underway, and Bloom is doing what every early-stage biotech must eventually do: generating data. Everything else follows from that.