Most biotech stories begin with a breakthrough in a lab. AOBiome’s story begins with a question: What if modern hygiene — our soaps, sanitizers, and shower routines — has wiped away a microbe we actually needed? From that question grew a company determined to challenge how we think about skin, immunity, and the biological partnerships humans once shared with the natural world.
Founded in 2013 and headquartered in Cambridge, Massachusetts, AOBiome is the work of a curious and ambitious founding team: Jamie Heywood, the social-health innovator behind PatientsLikeMe; chemical engineer and citizen scientist David Whitlock; along with co-founders Lenny Barshack and Hilly Thompson. Together, they built a company around an old idea made new again — that the human body evolved in harmony with “good bacteria,” and that losing them may contribute to many of today’s inflammatory diseases.
At the heart of AOBiome is a single microbe: Ammonia Oxidizing Bacteria, specifically Nitrosomonas eutropha. This isn’t a fancy probiotic or a trendy cosmetic ingredient. It’s a naturally occurring environmental bacterium that humans frequently encountered before urban living, heavy cleansing habits, and chemical hygiene routines became the norm.
AOBiome believes that this microbe once played a crucial role in maintaining the skin’s immune balance. Through millions of years of evolution, AOB helped convert ammonia in human sweat into beneficial molecules like nitric oxide and nitrite — compounds known to calm inflammation, support vascular function, and keep harmful microbes in check. As modern living reduced our exposure to these bacteria, we may have lost an invisible ally.
This is the philosophical and scientific compass guiding AOBiome’s work: restore what was lost, and allow the skin to regulate itself again.
A Live Biotherapeutic Approach to Skin Health
AOBiome isn’t just theorizing about the microbiome — it has taken its lead product, B244, deep into clinical trials. B244 is a topical formulation of its proprietary AOB strain, designed to rebalance inflammatory pathways in conditions like eczema, acne, rosacea, and chronic itch.
Where most dermatology drugs attack one molecular target, B244 works more like a system modulator. The bacterium interacts with sweat, produces nitric oxide, and signals the immune system to dial down inflammatory cytokines such as IL-4, IL-5, IL-13 and IL-31 — the very messengers linked to eczema and uncontrolled itch. Rather than suppressing the immune system, B244 nudges it toward equilibrium.
It’s a living medicine — one of the earliest of its kind in dermatology.
AOBiome has already made history by running the largest-ever trial of a live topical biotherapeutic in atopic dermatitis, enrolling more than 500 patients. Earlier studies have shown meaningful reductions in itch severity and strong safety results. Today, B244 is advancing toward Phase 3, the final major step before regulatory filings.
For a company built around a single microbe, this is a remarkable climb.
A Manufacturing Engine Built for Growth
One advantage AOBiome holds is focus. It works with one strain, deeply characterized and protected by patents. This gives the company tighter control over quality, consistency, and scalability — all critical for live biotherapeutics.
AOBiome reports producing over 200,000 bottles of AOB-based formulations using processes aligned with its clinical production standards. Their manufacturing team has successfully scaled to 300-liter batches early in the process — a strong sign that commercial manufacturing won’t be a bottleneck once approvals come into view.
The company’s intellectual property portfolio is equally robust, with composition-of-matter patents securing exclusivity around its bacterial strain and delivery method — a valuable moat in the fast-growing microbiome therapeutics sector.
The Philosophy: Rethinking Cleanliness and Immunity
Beyond the science, AOBiome represents a shift in thinking. It challenges the “more hygiene is better” mindset and argues for a more nuanced understanding of how humans interact with the microbial world.
AOBiome’s perspective is simple but radical:
Modern skin problems may come, in part, from removing beneficial bacteria your biology wasn’t designed to live without.
By reframing bacteria as partners instead of pathogens, the company is helping usher in a new era in dermatology and immune health — one that treats disease by restoring biology rather than suppressing it.
This mindset also led to the creation of Mother Dirt, the company’s consumer-facing skincare brand built on the same principles. While the therapeutics division focuses on clinical medicine, Mother Dirt raised consumer awareness about microbiome-friendly routines and the idea that not all bacteria are bad.
A Small Company with a Big Vision
AOBiome may not be a household name yet, but inside the biotech community, it is watched closely. Live biotherapeutics are gaining traction, and regulatory agencies are increasingly familiar with how to evaluate them. If B244 succeeds in Phase 3 trials, AOBiome could become one of the first companies to commercialize a live topical microbiome therapy — a milestone that could reshape the future of dermatology.
The company’s vision extends even further. Early research explored conditions ranging from migraines to hypertension and allergy-related inflammation. While the current focus is skin disease — a smart and strategic starting point — the broader potential remains open.
For a world dealing with rising allergy rates, chronic inflammation, and environmental stressors that disrupt the skin barrier, AOBiome’s approach feels both timely and necessary.
A Company Built on Curiosity, Courage, and Biology
At its core, AOBiome is a company built on curiosity:
What happens when you restore a microbe humans evolved with but lost in modern times?
That question has powered more than a decade of research, millions of dollars in investment, and a pipeline that is inching closer to transforming patient care.
It’s a rare story in biotechnology — one that blends ancient biology, cutting-edge science, and surprising simplicity. A microbe from the soil may one day become a modern therapeutic, not because we invented it, but because we rediscovered it.
If AOBiome succeeds, it won’t just launch a new drug. It will introduce a new way of thinking about our relationship with the microbial world — a world we may need more than we ever realized.
