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Science Review: Lactobacillus salivarius UCC118

The development of probiotics targeted for their specific actions on
host cells (including metabolism and intracellular signaling pathways)
to confer targeted health benefits and outcomes represents a relatively
recent advance in our understanding and use of beneficial bacteria for
health. Lactobacillus salivarius UCC118 is a thoroughly researched probiotic
selected for its effects on gut barrier function.


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Research Highlights 

  • L. salivarius UCC118 helps to maintain tight junctions via
    a cell adhesion-dependent mechanism in an intestinal
    epithelial cell line.1
  • L. salivarius UCC118 can be detected at the mucosal
    surface in humans and adheres to human intestinal epithelial
    cell lines.2
  • L. salivarius UCC118 produces a bacteriocin upon adherence
    to intestinal epithelial cells that is effective against
    pathogenic bacteria in animal models.3
  • In a pilot, open-label study, oral intake of L. salivarius UCC118
    in patients with mildly active Crohn’s disease resulted in a
    decrease in CDAI scores and a decrease in TNFa production.4

Intestinal Permeability and Leaky Gut
Nutrients and other beneficial molecules (e.g., short-chain fatty acids
produced by the microbiome) pass in a regulated fashion across the
intestinal epithelial cell barrier. A breakdown in this regulation, also
known as “leaky gut,” may lead to the unregulated passage of harmful
molecules including toxins, antigens, and bacteria across the intestinal
barrier. Leaky gut may be a key factor in the development of intestinal
inflammation and underlie the pathogenesis of various inflammatory

  • Researchers at University College Cork tested 33 strains on the hydrogen
    peroxide (H2O2)-induced tight junction dysfunction in human epithelial
    cells. Of the strains that demonstrated positive results, L. salivarius
    UCC118 had an immediate ability to restore transepithelial electrical
    resistance (TEER), a measure of barrier function.1,7
  • In addition, tight junction proteins (such as zona occludins-1 ZO-1)
    remained associated with the cellular membrane in cells pretreated
    with UCC118 and then exposed to H2O2 (Figure 1).
  • Taken together, these data suggest that L. salivarius UCC118 may help
    to maintain the integrity of the intestinal epithelial barrier and help to
    maintain a healthy gut lining.

Open-Label Study in Patients with Mildly Active Crohn’s

  • In an open-label pilot study, L. salivarius UCC118 was administered in
    yogurt to 21 patients with mildly active Crohn’s disease for 6 weeks.4
  • In the study population, the Crohn’s Disease Activity Index (CDAI)
    decreased from 208 ± 10 (mean ± SE) at baseline to 147 ± 17.5 at the
    end of the 6 weeks.4
  • In addition, 11 of 21 patients were able to avoid corticosteroid
    treatment for 2 months or more after they stopped consuming
    the probiotic.4

Summary of Properties—L. salivarius UCC118
Emerging Research
In a quality improvement trial conducted at the Cleveland Clinic Center
for Gut Rehabilitation and Transplantation Outpatient Clinic, 29 patients
presenting with symptoms of small intestinal bacterial overgrowth (SIBO)
received L. salivarius UCC118 at a dose of 100 million CFU per day in
addition to standard of care.12

  • Patients reported a reduction in diarrhea (p<0.05) associated with SIBO
    after 90 days.12
  • Authors further reported inclusion of the probiotics in the protocol
    negated or delayed the need for antibiotics in this patient population.12
  • This study highlights the need for further investigation into the
    applicability of L. salivarius UCC118 for patients with SIBO.

Bacteriocin Production and Effects in vivo

Many probiotic bacteria harbor genes that encode for bacteriocins,
peptides that can limit the growth of other bacteria, including some
that are potentially harmful. However, very few bacteriocins expressed
by probiotics have been demonstrated to be effective in vivo.8

  • L. salivarius UCC118 has a bacteriocin gene known as ABP-118, shown to
    inhibit a number of pathogenic species in vitro including Bacillus, Listeria, Enterococcus, and Staphylococcus.9
  • In a mouse model, the gene encoding for ABP-118 has been shown to
    be crucial for limiting the spread of Listeria monocytogenes.

Effects on Gut Microbiota and Immune Function

  • In a randomized, placebo-controlled trial, L. salivarius UCC118 delivered
    in fermented milk resulted in increased levels of Enterococci and
    Lactobacilli—bacteria that are generally “friendly” to humans.10
  • Exposure of human mesenteric lymph node (MLN) cells to L. salivarius
    UCC118 in vitro resulted in the production of the immune regulatory
    cytokines IL-10 and TGF-b.11
  • Furthermore, human MLN cells from inflamed tissue were more
    responsive to L. salivarius UCC118 than cells from non-inflamed
    tissue—suggesting that L. salivarius UCC118 may be able to limit
    ongoing inflammation.11

L. salivarius UCC118 represents a new trend in probiotic selection—
utilizing a targeted approach with optimal strain-specific characteristics.
Although further research is needed, L. salivarius UCC118 shows promising
effects for supporting healthy intestinal barrier function.

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