In a recent study funded by life sciences company ABbiotek Health, researchers from Spain investigated the effects of yeast-based postbiotic blend ABB C22 on gastrointestinal health. The formulation combines Saccharomyces boulardii ABB S3, Saccharomyces cerevisiae ABB S6 and Kluyveromyces marxianus ABB S8
“This novel approach to managing diarrhea by improving the associated gastrointestinal inflammation, which current solutions do not address,” they wrote in the journal Geriatrics.
Unlike conventional treatments, the ABB C22 postbiotic was found to support the integrity and function of enterocytes through multiple complementary mechanisms. These include enhancing gut barrier function, inducing a strong anti-inflammatory response, protecting against rotavirus infection and modulating the gut microbiome.
Diarrhea impact on elderly populations
Diarrhea is a common condition in older adults that can lead to dehydration and malnutrition, impair gut barrier function and negatively impact quality of life. It is predominantly caused by infections, such as Clostridium difficile, E. coli and rotavirus.
Chronic diarrhea, which can last over four weeks, may result from underlying health conditions or as a side effect of medications—particularly antibiotics, which are commonly prescribed to older adults. Antibiotic-associated diarrhea occurs when antibiotics disrupt the gut microbiome, reducing beneficial bacteria and leading to dysbiosis.
Probiotic strains such as Saccharomyces boulardii have been found to help manage the symptoms of diarrhea, as well as irritable bowel syndrome and inflammatory bowel disease. According to the researchers, S. boulardii has a “superior capacity to modulate the gut microbiota and promote the production of short-chain fatty acids (SCFAs),” such as butyric acid that promote water reabsorption.
However, they noted that “many patients on enteral nutrition programs or suffering from acute diarrhea episodes in the hospital setting may be immunocompromised, which raises concerns for treating them with live probiotics”.
“Diarrhea-associated inflammation has a strong impact on disease outcome, becoming a risk factor for dehydration and episode recurrence,” they wrote.
“However, it is usually neglected during treatment. Current treatments like ORS target water and electrolyte loss, thus improving stool consistency, but are unable to counteract inflammation.”
Study details
The researchers conducted the randomized, double-blind, placebo-controlled, parallel-group trial at two hospital centers in Barcelona, enrolling 47 volunteers ages 65 and over who were experiencing diarrhea.
Participants were randomly assigned to receive three daily servings of a 200 ml strawberry-flavored ORS (either with ABB C22 or placebo) for up to 14 days or until diarrhea resolved.
Blood and stool samples were collected on days 1, 3 and 14 to assess fecal inflammatory biomarkers (calprotectin and lactoferrin), blood immunoglobulin A levels and changes in stool consistency using the Bristol Stool Scale.
By the final day of the study, the group using ORS + ABB C22 showed greater reductions in fecal calprotectin and lactoferrin levels compared to the placebo group. By day 3, lactoferrin-positive cases had already been halved in the intervention group. Stool consistency improved in both groups.
Elevated fecal calprotectin and lactoferrin are markers of intestinal inflammation, with lactoferrin often associated with infectious gastroenteritis.
“The addition of postbiotic ABB C22 to the standard of care with ORS leads to decreases in fecal biomarkers of gastrointestinal inflammation in older adults with diarrhea,” the researchers wrote. They also highlighted that ABB C22 provides highly bioavailable zinc, which may help improve nutritional status of people with diarrhea.
For future research, they called for microbiome analysis and longer follow-up periods to better understand the long- term effects and potential benefits of ABB C22.
Source: Geriatrics 2025, 10(2), 34. doi: 10.3390/geriatrics10020034. “Mitigating Diarrhoea-Related Inflammation in Frail Older Adults with Postbiotic-Enhanced Oral Rehydration Solution: Insights from a Randomised, Double-Blind, Placebo-Controlled Study”. Authors: Rodríguez, A. M. et al.