What’s the Latest in Prebiotic Research?

May 2026

Prospective, randomized, double-blind, placebo-controlled study of an oral antioxidant-rich synbiotic supplement on skin health and photoaging.

Photoaged skin results from prolonged exposure to ultraviolet radiation, leading to increased pigmentation, reduced elasticity, and wrinkle formation. Prevention has historically relied on topical therapies; however, there is growing recognition of the influence of nutrition on skin health, with dietary elements emerging as an alternative approach to preventing photoaging. This study evaluates the effects of an antioxidant-rich synbiotic supplement on facial elasticity, hydration, and photoaging markers including erythema and pigmentation. A total of thirty-six women aged 35-55 years with facial fine lines and wrinkles were randomized to receive either one capsule of an antioxidant-rich synbiotic supplement, containing 112 mg fructo-oligosacahrides (FOS), 6 mg medium-chain triglyceride powder, 5 mg astaxanthin, 25 mg B. coagulans, 25 mg B. subtilis, and 15 mg B. clausii, or a placebo for 8-weeks. Participants underwent non-invasive facial measurements including hydration, elasticity, erythema, and pigmentation at baseline, week 4 and week 8. Facial photography and tolerability were also assessed. At week 8, the treatment group showed a significant reduction in wrinkle severity compared to the placebo group. Cheek elasticity was increased significantly at week 4 and week 8, along with firmness at week 8, compared to placebo. Additionally, the viscoelasticity of the cheek increased at week 4 in the treatment group compared to the placebo group. Overall, the antioxidant-rich synbiotic supplement improved wrinkle severity, skin facial elasticity, and skin firmness, enhancing several parameters of skin health. This study demonstrated that an antioxidant-rich synbiotic (including FOS) may support skin health by increasing skin facial elasticity and firmness and reducing wrinkle severity. Future studies should explore these effects in a larger sample size. 

Key Takeaways: 

  • Recent evidence has suggested the influence of nutrition on skin health, with dietary elements emerging as potential approach to prevent skin photoaging. 
  • A synbiotic supplement, including FOS and B. subtilis, B. coagulans, and B. clausii was administered to participants for 8 weeks and compared to a placebo. 
  • The antioxidant-rich synbiotic supplement improved wrinkle severity, skin facial elasticity, and skin firmness, enhancing several parameters of photoaging.  
  •  Future studies are needed to confirm results in a larger sample size. 

Access the study: https://pubmed.ncbi.nlm.nih.gov/41947475/ 

Reference: Afzal, L., Nguyen, N., Afzal, N., Adnan, S., Khan, Z., Dulai, A., Nayak, S., Trivedi, R., Min, A., & Sivamani, R. (2026). Prospective, randomized, double-blind, placebo-controlled study of an oral antioxidant-rich synbiotic supplement on skin health and photoaging. Journal of Cosmetic Dermatology, 25(4):e70836. doi: 10.1111/jocd.70836. 

Green tea catechin plus inulin improves insulin resistance without reducing visceral fat and shows exploratory gut microbiota signals in adults with visceral obesity: a double-blind randomized controlled trial

Visceral fat accumulation is strongly implicated in the development and progression of insulin resistance, type 2 diabetes, hypertension, dyslipidemia, and other obesity-related complications. Green tea catechins are polyphenols abundantly found in green tea and have been reported to exhibit anti-obesity and metabolic effects through multiple mechanisms. Inulin functions as a prebiotic and has been reported to selectively increase beneficial bacteria and enhance the production of short chain fatty acids. This randomized, double-blind, controlled trial assessed the effects of green tea catechin with inulin on visceral fat accumulation, insulin resistance, and gut microbiota. A total of ninety-six adults with visceral obesity were randomized to either consume a catechin + inulin beverage (400 mg/day catechins and 2.3 g/day inulin) or a placebo for 12 weeks. The primary outcome was the change in visceral fat accumulation as assessed by bioelectrical impedance, and secondary outcomes included homeostatic model assessment for insulin resistance (HOMA-IR), metabolic markers, liver fat, and genus-level gut microbiota. The 12-week change in visceral fat accumulation did not differ between groups. HOMA-IR decreased significantly in the catechin + inulin group and increased in the placebo group. In exploratory microbiota analysis, no genus remained statistically significant; however, Coproccus and Bifidobacterium showed nominal between-group differences. Changes in Coproccus were inversely correlated with changes in HOMA-IR. Overall, catechin + inulin did not reduce visceral fat accumulation, but were associated with improvements in insulin resistance. Adequately powered trials to confirm the metabolic effects and clarify microbiota-related mechanisms are warranted.  

Key Takeaways: 

  • Visceral adipose tissue is recognized as an independent risk factor for cardiovascular events and all-cause mortality.  
  • A drink containing catechin and inulin was administered to adults with visceral obesity for 12-weeks. 
  • Catechin and inulin consumption for 12-weeks did not reduce visceral fat but was associated with improved insulin resistance.  
  • Exploratory analysis suggests a potential association between increased Coproccus and improved insulin resistance, warranting further research.  

Access the study: Green Tea Catechin Plus Inulin Improves Insulin Resistance Without Reducing Visceral Fat and Shows Exploratory Gut Microbiota Signals in Adults with Visceral Obesity: A Double-Blind Randomized Controlled Trial – PubMed 

 

Reference: Iino C, Mikami K, Furusawa K, Sato S, Yoshida K, Yamaguchi T, Bushita H, Kinoshita K, Matsui Y, Imoto S, Iwane T, Tamada Y, Murashita K, Nakaji S, Mikami T, & Sakuraba H. (2026). Green tea catechin plus inulin improves insulin resistance without reducing visceral fat and shows exploratory gut microbiota signals in adults with visceral obesity: a double-blind randomized controlled trial. Nutrients, 18(5):851. doi: 10.3390/nu18050851. 

Synbiotic supplementation reduces intestinal permeability and inflammation in overweight or obese kidney transplant recipients: a randomized controlled trial

Kidney transplants are the most effective treatment for patients with end-stage renal disease, meanwhile cardiovascular disease (CVD) is a major cause of mortality among kidney transplant recipients, accounting for approximately 25% of deaths in this population. This randomized controlled trial investigated the effects of synbiotics on intestinal permeability, systemic and vascular inflammation markers, oxidative stress, and fibrosis in kidney transplant recipients. A total of forty-six kidney transplant recipients were randomly assigned to consume either two synbiotic capsules containing 21 mg of FOS and 1.0×109 CFU of probiotics, or a placebo daily for 12 weeks. Serum lipopolysaccharide binding protein (LBP), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), soluble intracellular adhesion molecule type 1 (slCAM-1), malondialdehyde (MDA), galectin-3, urea, and creatinine were measured at baseline and week 12. Serum LBP, hs-CRP, ICAM-1, and IL-6 showed significant reductions in the synbiotic group compared to the placebo group. Serum MDA, galectin-3, urea, and creatinine did not show significant changes within each group. Overall, synbiotics reduce LBP, a marker of intestinal permeability, as well as hs-CRP, IL-6, and slCAM-1, which are risk factors for CVD and graft failure in kidney transplant recipients. Future studies should confirm the mechanism of the effects of synbiotics on intestinal permeability and inflammation by analyzing the intestinal microbiome. 

Key Takeaways: 

  • Cardiovascular disease is a major cause of mortality among kidney transplant recipients.  
  • Kidney transplant recipients were randomized to receive a synbiotic containing 1.0×109 CFU/day probiotics and 21 mg of FOS, or a placebo, daily for 12-weeks. 
  • Serum lipopolysaccharide binding protein, high-sensitivity C-reactive protein, soluble intercellular adhesion molecule type 1, and interleukin-6 showed significant reductions in the synbiotic group compared to the placebo group. 
  • This study indicates that synbiotics reduce markers of intestinal permeability, and risk factors for cardiovascular disease and graft failure in kidney transplant patients.  

Access the study: https://pubmed.ncbi.nlm.nih.gov/41883170/ 

Reference: Karimni, Z., Tabibi, H., Nafar, M., Samavat, S., Firouzan, A., Hedayati, M., & Yari, Z. (2026). Synbiotic supplementation reduces intestinal permeability and inflammation in overweight or obese kidney transplant recipients: a randomized controlled trial. Renal Failure, 48(1):2644711. doi: 10.1080/0886022X.2026.2644711. 

Synbiotic Bactecal® reduces airway obstruction, sputum eosinophils and IL-4 but increases sputum IL-8 in patients with uncontrolled asthma

sthma is a common chronic inflammatory airway disease, often featuring a type 2 immune profile and further associated with intestinal dysbiosis due to a lack of bacterial species diversity in the gut microbiome. Synbiotics can modulate the intestinal microbiota homeostasis and are shown to have anti-inflammatory properties and immunomodulatory activities. This randomized, placebo-controlled trial assessed the impact of a synbiotic, Bectecal®, on asthma control, quality of life, lung function, blood and airway inflammation in patients with uncontrolled asthma. A total of fifty patients with uncontrolled asthma were randomized to consume either 3 pills/day of Bactecal® synbiotic containing 18 billion CFU/dose of probiotics, and 20 mg of prebiotic FOS), or a placebo for 3 months. Patients were evaluated at baseline, and at 1 and 3 months after treatment initiation, with a follow-up visit at 6 months. At each visit, lung function, fractional exhaled nitric oxide value (FeNO), inflammatory blood and sputum inflammatory profiles, and quality of life and asthma control were assessed using questionnaires including the Asthma Control Test (ACT), Asthma Control Questionnaire (ACQ), Asthma Quality of Life Questionnaire (AQLQ). Compared to the placebo, the synbiotic significantly improved lung function parameters including forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) and significantly reduced eosinophilic airway inflammation. Sputum interleukin-4 levels were additionally significantly reduced in the synbiotic group, while sputum interleukin-8 levels were increased. Overall, the synbiotic had a positive impact on patients with uncontrolled asthma, and improved airway obstruction while decreasing airway type-2 inflammation. Future studies should confirm these results in larger, adequately powered trials that may assess clinical outcomes such as exacerbation rate.  

Key Takeaways: 

  • Asthma is associated with intestinal dysbiosis, characterized by reduced gut microbiome diversity, which may contribute to altered  immune system responses. 
  • Patients with uncontrolled asthma were randomized to consume a synbiotic containing 18 billion CFU/dose of probiotics and 20 mg of FOS, or a placebo for 3 months.  
  • The synbiotic had a positive impact on patients with uncontrolled asthma, improving airway obstruction while decreasing airway type-2 inflammation. 
  • Larger multicentric trials are warranted to confirm these findings.  

Access the study: https://pubmed.ncbi.nlm.nih.gov/41936275/ 

Reference: Moermans, C., Graff, S., Medard, L., Nekoee, H., Donneau, A.F., Njock, M.S., Kempeneers, C., Bricmont, N., Bonhiver, R., Gerday, S., Nasir, N., Poulet, C., Paulus, V., Fuissard, F., Sanchez, C., Schleich, F., & Louis, R. (2026). Synbiotic Bactecal® reduces airway obstruction, sputum eosinophils and IL-4 but increases sputum IL-8 in patients with uncontrolled asthma. Cytokine, 202:157145. doi: 10.1016/j.cyto.2026.157145.