ClostraBio’s next-gen probiotic gains GRAS approval for gut health
Biotech firm ClostraBio, specializing in microbiome solutions for gastrointestinal health, unveils a next-generation probiotic strain, Anaerostipes caccae CLB101. The offering was granted self-affirmed GRAS (generally recognized as safe) status by a panel of scientific experts.
The milestone clears CLB101 for US market entry as the first and only commercially available strain of Anaerostipes caccae.
CLB101 is an anaerobe isolated from a healthy human and was identified as a strain “critical to gut health” through its direct production of butyrate in targeted areas of the lower intestine.
Butyrate is commonly recognized as a key molecule to support gut health, with mechanisms of action including “strengthening intestinal barrier integrity, providing immune support, and promoting a diverse microbiome,” highlights ClostraBio.
“Receiving GRAS status marks a critical milestone for ClostraBio and validates the safety of CLB101 as we move toward commercial launch,” says Ritu Shah, CEO of ClostraBio. “This recognition reinforces our commitment to advancing safe, science-driven solutions that can help support gut health for the many people who are struggling today.”
CLB101, a human-isolated anaerobe, is "critical to gut health" due to its butyrate production in the lower intestine.Upcoming commercial launch
The GRAS designation is based on a rigorous review of safety data, including genomic characterization, multiple toxicology studies, and a demonstrated manufacturing process with stringent quality control.

ClostraBio is preparing to launch CLB101 as a probiotic supplement in fall 2025, through direct and partner distribution channels. This includes a strategic collaboration with an undisclosed healthcare practitioner-focused supplement brand.
Next to this probiotic innovation, ClostraBio is developing a novel polymeric prodrug platform designed to deliver small molecules to the lower gut. The company was spun out of the University of Chicago, US, and incubated at Portal Innovations.
Latest in gut science
In other scientific advances this month, food scientists revealed that ancient microbes in traditional Ethiopian fermented foods could unlock a series of next-generation probiotics. Darwin Bioprospecting Excellence pinpointed strains in heritage foods rich in lactic acid species and environmental microorganisms with purported benefits.
As personalized nutrition continues to progress, other research has developed a method to predict the nutritional adaptations of Bifidobacterium strains by analyzing the distribution of metabolic genes across thousands of genomes. Sanford Burnham Prebys, US, scientists say their findings offer a “critical resource” for developing personalized probiotics.