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Study published in the journal Cell Host & Microbe offers proof of concept that a human milk-based synbiotic could allow therapeutic manipulation of the gut microbiome

First Time a Change to the Gut Microbiome Was Introduced, Maintained, and Then Reversed Without the Use of Antibiotics; Nature’s Microbiome Starter KitTM Could Hold Promise for Patients

DUARTE, Calif., May 3, 2022 – Demonstrating its commitment to Advancing the Science of Human Milk®, Prolacta Bioscience® announced today that Cell Host & Microbe has published a proof-of-concept study evaluating the unique relationship between human milk oligosaccharides (HMOs) and the infant gut microbe Bifidobacterium longum subspecies infantis (B. infantis) to control B. infantis engraftment into the adult gut microbiome. In the publication “Dosing a Synbiotic of Human Milk Oligosaccharides and B. infantis Leads to Reversible Engraftment in Healthy Adult Microbiomes Without Antibiotics,” scientists report that in healthy adult subjects, simultaneous ingestion of a combination of human milk-derived HMOs and B. infantis results in high-level, controllable, HMO-dependent engraftment of B. infantis.1 This is the first time that a change to the microbiome was introduced, maintained at a high level independent from the bacterial inoculum, and then reversed in healthy adult subjects, without the use of antibiotics.

HMOs are a family of approximately 200 structurally diverse sugars2 present in human breast milk that serve as a prebiotic to help establish an infant’s immune system and guide the development of appropriate bacteria in the gut.3 One species of “good” bacteria in the infant gut microbiome is B. infantis, which is unique in its ability to utilize the HMOs in breast milk. B. infantis has been shown to help the infant immune system and intestinal tract mature. HMOs also suppress inflammation and improve intestinal barrier function.4 After infants are weaned from human milk, B. infantis levels decline, to be overtaken by different species of bacteria through childhood and into adulthood.5

The publication presents findings from a clinical study that enrolled 62 healthy adult subjects in an unblinded, multi-dose study. Six groups of about 10 healthy adult volunteers received either multiple doses of HMOs derived from pooled donor human milk, a commercially available B. infantis supplement, or both. Engraftment of B. infantis and impact of treatment on the gut microbiome were assessed at multiple points during the study. No serious adverse events were observed in the study. The authors concluded that giving human milk-derived HMOs and B. infantis to healthy adult subjects simultaneously resulted in high-level colonization with B. infantis that was maintained with HMO treatment alone and reversible upon stopping the HMO treatment.1

This study supports the hypothesis that the combination of HMOs and B. infantis may be Nature’s Microbiome Starter KitTM and can act as a key to selectively unlock the adult gut microbiome’s resistance to new bacterial species. The findings may open the door to the development of live biotherapeutic products (LBPs) that reconstitute the gut microbiome when it has been damaged or is out of balance as seen in numerous diseases, including diabetes and Crohn’s disease.

A synbiotic combines a prebiotic (HMOs) with a probiotic (B. infantis), as used in this study. “We’re using the same building blocks that nature uses to shape the development of the microbiome in human milk-fed infants. Rebuilding damaged microbiomes could treat a variety of conditions, including infectious, autoimmune, and metabolic diseases,” said Julie Button, Ph.D., lead researcher. “As the first study of its kind, our work opens the door to the development of new therapies for diseases linked to gut microbe imbalances.”

“Expanding the science of human milk to aid in the development of therapeutics for other vulnerable patient populations is core to our mission,” said Scott Elster, CEO of Prolacta. “We are encouraged by the results of this study and are committed to extending the healing properties of human milk for those who need it most.”

About Prolacta Bioscience
Prolacta Bioscience® Inc. is a privately held, global life sciences company dedicated to Advancing the Science of Human Milk® to improve the health of critically ill, premature infants. Prolacta's 100% human milk-based nutritional products have been evaluated in more than 20 clinical studies published in peer-reviewed journals. More than 80,000 premature infants have benefited from Prolacta’s nutritional products worldwide to date.* Established in 1999, Prolacta is the world’s leading provider of human milk-based nutritional products for hospital use and is also exploring the therapeutic potential of human milk across a wide spectrum of diseases. Prolacta maintains the industry’s strictest quality and safety standards for screening, testing, and processing human donor milk. Operating the world’s first pharmaceutical-grade human milk processing facilities, Prolacta uses vat pasteurization and a patented, U.S. Food and Drug Administration-reviewed manufacturing process to ensure pathogen inactivation while protecting the nutritional composition and bioactivity of its human milk-based products. Prolacta is headquartered in Duarte, California, and can be found on Twitter, Instagram, Facebook, and LinkedIn.

*Estimated number of premature infants fed Prolacta’s products from January 2007 to December 2021; data on file.

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Media Contact:
Loren Kosmont


  1. Button et al, Dosing a synbiotic of human milk oligosaccharide and B. infantis leads to reversible engraftment in healthy adult microbiomes without antibiotics. Cell Host & Microbe (2022)
  2. Moukarzel S, Bode L. Human milk oligosaccharides and the preterm infant: a journey in sickness and in health. Clin Perinatol. 2017;44(1):193-207. doi:10.1016/j.clp.2016.11.014
  3. Wicinski M, Sawicka E, Gebalski J, et al. Human milk oligosaccharides: health benefits, potential applications in infant formulas and pharmacology. Nutrients. 2020 Jan;12(1):266. doi: 10.3390/nu12010266
  4. Chichlowski M, Shah N, Wampler JL, et al. Bifidobacterium longum subspecies infantis (B. infantis) in pediatric nutrition: current state of knowledge. Nutrients. 2020 Jun;12(6):1581. Published online 2020 May 28. doi: 10.3390/nu12061581
  5. Arboleya S, Watkins C, Stanton C, et al. Gut bifidobacteria populations in human health and aging. Front Microbiol. 2016;7:1204. Published online 2016 Aug 19. doi: 10.3389/fmicb.2016.01204