What’s the Latest in Prebiotic Research?

October 2025

A randomised controlled trial of the effects of galacto-oligosaccharides on the gut brain-axis of young females

An abundance of research over the past 15 years has highlighted the gut–brain axis as a promising and novel approach for improving youth mental health. Specifically, the gut microbiota is known to influence brain function and mental health by producing and regulating neurotransmitters such as gamma-aminobutyric acid (GABA). This two-arm, randomized, double-blind, placebo-controlled trial aimed to assess the effects of galacto-oligosaccharide (GOS) supplementation on the gut-brain axis. This study included 83 women age 17-25 years and participants were randomized to either consume GOS (7.5 g/day containing 5.5g/day active Biotis® GOS) or a placebo (7.5g/day maltodextrin) for 28 days. The primary outcome of this study was anxiety, measured using the State-Trait anxiety inventory. Secondary outcomes included neurochemical GABA levels, assessed using proton magnetic resonance spectroscopy (H-MRS), and gut microbiome composition, assessed using metagenomic shotgun sequencing. Additionally, social anxiety, depression, emotion behaviour, reaction time, nutritional intake, and the longevity of effects were evaluated. All assessments were conducted at baseline, at the end of supplementation, and 28 days post-supplementation. Results suggest that supplementation with GOS did not lead to significant reductions in trait anxiety. However, supplementation with GOS was associated with reduced GABA at trend significance in regions of the brain among participants with high anxiety, and these effects persisted at follow-up. Additionally, supplementation with GOS significantly increases abundance of Bifidobacterium, however, there were no significant changes observed in microbial diversity after intervention. Overall, this study demonstrates that GOS supplementation modulates specific gut bacteria and neurochemicals, indicating potential effects on the gut–brain axis. Future studies are warranted to evaluate gut–brain axis effects in other populations such as males and older participants, as well as investigating the use of other prebiotic ingredients.

Key takeaways:

  • The gut-brain axis represents a promising and novel avenue to target youth mental health for its ability to regulate and produce neurochemicals.
  • Supplementation with GOS did not lead to improvements in anxiety among young females, but increased Bifidobacterium abundance, suggesting microbiota modulation.
  • Further research is warranted in male participants, older populations, and using other prebiotic ingredients.

 

Access the study: https://www.sciencedirect.com/science/article/pii/S0889159125002375?via%3Dihub

 

Reference: Johnstone, N., & Cohen Kadosh, K. (2025). A randomised controlled trial of the effects of Galacto-Oligosaccharides on the gut brain-axis of young females. Brain, behavior, and immunity, 129, 573–584. https://doi.org/10.1016/j.bbi.2025.06.020

Impact of prebiotics and postbiotics in their management of constipation: analysis of their differentiated modulation of intestinal microbiota

Chronic constipation is marked by hard stools, bloating, abdominal distention, and flatulence, and is linked to changes in the gut microbiota, particularly an increase in methanogenic organisms. Conventional drug treatments are commonly used to treat chronic constipation but often cause side effects and may fail to fully relieve symptoms. Current nutraceuticals have targeted the intestinal microbiota as a therapeutic strategy for chronic constipation and may provide additional benefits such as promoting the immune system, preventing pathogenic bacteria, stimulating the production of short-chain fatty acids (SCFAs), gut-derived neurochemicals, and anti-inflammatory effects. Specifically, research has demonstrated that prebiotics and probiotics may improve constipation by modulating the gut microbiome. Accordingly, this randomized, double-blind, parallel-arm clinical study aimed to evaluate the effects of prebiotics and postbiotics on stool consistency and gut microbiota composition. A total of 24 patients (age 18 years and older) were included in this study and were randomly divided into two groups to consume either; 1) prebiotic (5g NextDext™) or 2) prebiotic and postbiotic combination (ABB C24; 5g NextDext™ and 200 mg ABB C22®) 3 times daily, for 14 days. Stool form, consistency, and characteristics, as well as microbiological species were assessed at baseline and after 14 days. Results suggest that the prebiotic group showed significantly greater improvement in stool consistency, and prebiotic and postbiotic group showed a trend towards improvement. Among participants who were treated with the prebiotic, those with improved stool consistency exhibited greater microbiome modulation than those without improvements. These modulations include increases in beneficial bacteria (such as Bifidobacterium longum) and decreases in constipation-related bacteria. Similarly, among participants who were treated with prebiotic and postbiotic, those with clinical improvements in constipation exhibited greater modulation to microbiome including increased beneficial bacteria (such as Clostridium leptum) and decreases in methanogenic bacteria. Overall, supplementation with both prebiotics and the combination of prebiotics and postbiotics for 14 days altered microbiota composition and may be beneficial in patients with constipation.

Key takeaways:

  • Chronic constipation is associated with changes in the gut microbiota, such as increased presence of methanogenic organisms.
  • Supplementation with a prebiotic alone, or in combination with postbiotics improves stool consistency and gut microbiota in constipated patients, with greatest stool improvement observed among the prebiotic-only group.
  • Participants who observed greater stool improvement also showed microbiota modulation (i.e. increased Bifidobacterium longum and decreased constipation-related bacteria), compared to those without stool improvement.

Access the study: https://www.clinicalnutritionespen.com/article/S2405-4577(25)02889-X/fulltext

Reference: Culqui Lévano, D. R., Rodríguez Sanz, P., Palacios Sanchez, R., Saldaña Miranda, M. Y., Santa Cruz López, C. Y., & Mateus Rodríguez, J. A. (2025). Impact of prebiotics and postbiotics in the management of constipation: Analysis of their differentiated modulation of intestinal microbiota. Clinical nutrition ESPEN, 69, 625–633. https://doi.org/10.1016/j.clnesp.2025.08.003

Multi-omics analysis of a prebiotic intervention with pectin in lipid transfer proteins (LTPs) allergic patients

Gut microbiota dysbiosis contributes to inflammatory and immune diseases, such as food allergies. This randomized, double-blind, placebo-controlled intervention study aimed to assess the effects of two esterified pectins on the immune response, gut microbiota, SCFAs, and bile acids (BAs) in patients with a food allergy to peach. A total of 61 adults aged 18-65 years with a confirmed allergy to the lipid transfer protein (LTP) in peach, Pru p 3, were included in the study. Participants were divided into three groups to receive oral administration of; 1) low methoxyl citrus-derived pectin (LMP; CP-DElow), 2) high methoxyl apple-derived pectin (HMP; AP-DWhigh), or 3) placebo, twice daily for 2 months, for a total quantity of 20g/day pectin. Serum and stool samples were collected before and after the intervention. Results suggest that both groups exhibited decreased inflammatory cytokines that were associated with an allergic inflammatory response, such as interleukin (IL) 13. Regarding gut microbiota modulation, alpha diversity decreased in both groups treated with pectin after the intervention, compared to their values at baseline. Additionally, within the CP-DWlow group, there was an increase in the genus Bacteroides_H and species Roseburia intestinalis, known as pectin-fermenting taxa. However, AP-DWhigh was associated with an increase in the genera Bifidobacterium and Succinivibrio, and species Faecalibacterium prausnitzii, which may have anti-inflammatory properties and a role in carbohydrate fermentation. Additionally, both treatment groups showed significant changes in fecal levels of secondary bile acids and in the concentrations of branched-chain SCFAs. Overall, results suggest that treatment with prebiotics led to a significant improvement in allergen tolerance and was proven to be safe. Further research is needed to explore the effects of prebiotics on other food allergies and to identify additional treatment options for patients with LTP allergy.

Key takeaways:

  • Dysbiosis of the gut microbiota contributes to inflammatory diseases and immune diseases, such as food allergies.
  • Treatment with both pectins led to significant improvements in allergen tolerance, as indicated by decreased cytokines associated with an allergic inflammatory response, such as IL-13.
  • Further research is warranted to investigate and identify additional treatment options for patients with LTP allergy.

 

Access the study: https://www.sciencedirect.com/science/article/pii/S0144861725010215?via%3Dihub

Reference: Gómez, F., Pérez-Sánchez, N., Macías-Camero, A., Núñez, R., Contreras, N., Cañas, J. A., Jiménez-Sánchez, I. M., Díez-Echave, P., Barbas, C., Guéant, J. L., Barber, D., Vieths, S., Scheurer, S., Villaseñor, A., Rodríguez-Nogales, A., Mayorga, C., & Torres, M. J. (2025). Multi-omics analysis of a prebiotic intervention with pectin in lipid transfer proteins (LTPs) allergic patients. Carbohydrate polymers, 369, 124236. https://doi.org/10.1016/j.carbpol.2025.124236

Multi-species synbiotic supplementation enhances gut microbial diversity, increases urolithin A and butyrate production, and reduces inflammation in healthy adults: a randomized, placebo-controlled trial

Synbiotics are a combination of probiotics and prebiotics that have demonstrated the potential to promote the growth and activity of beneficial microbes in the gut. Urolithin A (UroA) is a metabolite that plays key roles in maintaining intestinal barrier integrity. This randomized, placebo-controlled trial aimed to assess the effects of a synbiotic containing multiple probiotic strains and a polyphenol-based prebiotic on gastrointestinal related biological functions. A total of 32 healthy adults were randomized to either consume a synbiotic (containing 53.6 billion AFU multi-species probiotic and 400 mg Indian pomegranate extract) or a placebo for a total of 91 days. Changes in fecal microbiome composition, urinary UroA, fecal butyrate, serum C-reactive protein (CRP), and safety were assessed. Outcomes were measured at baseline, Day 7, Day 14, Day 49, and Day 91 of the study. Results suggest that supplementation with the synbiotic led to significant increases in Bifidobacterium and Lactobacillus spp alpha-diversity at all time points. There were also increases observed in beneficial microbes, UroA, fecal butyrate levels, butyrate producing species. Additionally, participants supplementing with the synbiotic demonstrated increased abundance of Lactobacillus spp. and Gordonibacter spp, involved in metabolism of UroA precursors and production of UroA, respectively. Overall, supplementation with a synbiotic containing a variety of probiotic strains in combination with a polyphenol-based prebiotic from Indian pomegranate extract led to improvements in diversity and abundance of beneficial gut bacteria, UroA production, and butyrate production. Further research is needed to investigate other potential polyphenol-based prebiotics and their efficacy compared to dietary fiber-based prebiotics.

Key takeaways

  • UroA is a metabolite involved in maintaining the integrity of the intestinal barrier.
  • Supplementation with a synbiotic led to increased production of UroA, which was linked to increased abundance of Lactobacillus spp. and UroA-producing Gordonibacter spp and butyrate production.
  • Synbiotic supplementation beneficially modulated the gut microbiome. Future research should compare the efficacy of polyphenol-based prebiotics with dietary fiber-based prebiotics.

 

Access the study: https://www.mdpi.com/2072-6643/17/17/2734

Reference: Napier, B. A., Allegretti, J. R., Feuerstadt, P., Kelly, C. R., Van Hise, N. W., Jäger, R., Kassam, Z., & Reid, G. (2025). Multi-Species Synbiotic Supplementation Enhances Gut Microbial Diversity, Increases Urolithin A and Butyrate Production, and Reduces Inflammation in Healthy Adults: A Randomized, Placebo-Controlled Trial. Nutrients, 17(17), 2734. https://doi.org/10.3390/nu17172734