PDF

Clinical Evidence for Microbiome Support

The human microbiome plays a pivotal role in maintaining digestive health, supporting immune function, and regulating metabolic balance. As scientific understanding of gut microbiota continues to grow, so does the clinical validation of probiotic supplementation as a powerful tool for enhancing overall health. This review article examines the latest clinical evidence supporting the efficacy of targeted probiotic strains, highlighting their diverse benefits in gastrointestinal wellness, immune system resilience, and metabolic regulation. It also introduces the concept of postbiotics and their role in microbiome balance. With a focus on the specific clinically researched probiotics and postbiotics—including well-documented strains like Lactobacillus acidophilus DDS-1, Bifidobacterium animalis subsp. lactis HN019, and Lactobacillus rhamnosus GG—this overview provides a comprehensive look at how strategic microbiome support can help optimize health outcomes across multiple body systems.

The Power of Postbiotics

Postbiotics are active metabolites produced by commensal gut bacteria. Bacteriocins are among the many compounds produced by probiotic organisms, and they help to keep the gastrointestinal environment stable and diverse.

Pediococcus acidilactici UL5 is a robust organism capable of withstanding both the human gastric and small intestinal environments. What makes this organism unique is its ability to produce a postbiotic bacteriocin called pediocin PA-1. This postbiotic bacteriocin is an active antimicrobial against pathogenic Listeria species and does not exert detrimental effects on the ileal environment, as demonstrated in a gastrointestinal model.1

Similar to Pediococcus acidilactici UL5, Lactococcus lactis MJC18 is another probiotic organism capable of producing a potent postbiotic. The bacteriocin Nisin Z, a postbiotic of Lactococcus lactis MJC18, has antimicrobial activity against many gram positive organisms such as Listeria sp, Staphylococcus sp., Bacillus, and Clostridium.2 Nisin Z is known for both its bactericidal and bacteriostatic actions against pathogens. When used in combination with methicillin, Nisin Z was shown to improve the efficacy of the antibiotic against methicillin-resistant Staphylococcus Aureus when used topically for 3 hours on porcine skin.3 More recent studies have discovered that Nisin Z also exerts antiviral properties, especially in combination with antivirals.4

Bifidobacterium animalis subsp. lactis BLC1 is an organism used in functional foods and supplements for over a decade.5 BLC1 has demonstrated some anticancer properties in vitro when combined with pro-anthocyanidins in a simulated gastrointestinal model.6

Digestive Benefits

Lactobacillus acidophilus DDS-1 is a strain clinically shown to reduce gastrointestinal discomfort in travel and lactose intolerance. Additionally, this strain has demonstrated an ability to regulate bowel habits and stool consistency. In a double-blind, placebo controlled RCT, Bifidobacterium animalis subsp. lactis HN019 was shown to significantly increase frequency of bowel movements in patients with less than 3 per week.7

Immune System Benefits

In another trial with adults 70 years of age and older, HN019 was shown to increase helper T lymphocytes and natural kill cell activity in patients with low immune response.8

In a clinical trial comparing the effectiveness of various probiotic strains on immune responses, groups administered Lactobacillus acidophilus La-14 or Bifidobacterium animalis subsp. Lactis BL-04 was shown to significantly increase serum IgG, compared to controls.9 In a randomized, double-blind placebo controlled trial, Bifidobacterium animalis subsp. Lactis BL-04 was shown to reduce the incidence of respiratory tract infection and viral shedding after being administered during a rhinovirus infection and supplementing with the probiotic strain for an additional 28 days.10 In another double blind placebo controlled trial with 465 healthy adults, Bifidobacterium animalis subsp. Lactis BL-04 (at a dose of 2 billion CFU) was shown to be more effective than placebo and a multi-strain probiotic (19% reduction vs. 27% reduction) in reducing the incidence of respiratory tract infection and improving immunity.11

Metabolic Benefits

Chronic medical conditions like obesity and hypertension are modifiable cardiometabolic risk factors highly predictive of hospitalization.12 Many probiotic strains address the inflammatory biomarkers, hypercholesterolemia, and elevated BMI typically seen in people with reduced immune function.

In a randomized double-blind placebo controlled trial with 32 overweight and obese women, specific strains were shown to be significantly correlated with healthy BMI, weight, fat mass, lean mass, conicity index, protein intake, monounsaturated fat intake, glycated hemoglobin, TNF-α, and IL6/IL10.13 Bifidobacteria strains have also demonstrated specific cholesterol absorption properties, leading to decreases in serum total cholesterol and LDL-C.14

Heavily Clinically Researched Strains

Lactobacillus rhamnosus GG is among the world’s most heavily studied probiotic strains. Supplementation of rhamnosus GG has been clinically shown to reduce the risk of upper respiratory tract infections, rhinovirus-induced symptoms, acute otitis media, and antibiotic use in populations dealing with viral respiratory infections.15,16,17

In trials with hospitalized children in both India and Poland, supplementation with rhamnosus GG significantly reduced hospital stay, frequency & duration of diarrhea, and IV therapy requirements.18,19 In rotavirus-associated diarrhea, rhamnosus GG supplementation reduced the duration of symptoms, improved gastrointestinal function, and increased IgG.20,21

In patients with Ulcerative Colitis, rhamnosus GG was shown to be as effective as mesalazine in relapse rate after 6 months of supplementation. The probiotic had a better adverse event profile, and was more effective than the drug in promoting “relapse-free time”.22

In a randomized placebo-controlled trial tracking 6 month old infants to 13 years of age, use of lactobacillus rhamnosus GG resulted in significant risk reduction of ADHD and Asperger’s syndrome.23

In two separate clinical trials, rhamnosus GG supplementation starting in the second trimester of pregnancy reduced the severity of maternal allergic disease.24 During pregnancy and breastfeeding up to the first 2 years of an infant’s life, a study on maternal rhamnosus GG supplementation demonstrated a reduced risk of atopic dermatitis.25 Extending the benefits to immune and skin health even further, rhamnosus GG supplementation has also been shown to reduce the risk of a child developing atopic dermatitis (eczema), compared to placebo, when taken consistently in the first 7 years of life.26

The growing body of clinical research clearly supports the use of targeted probiotic and postbiotic strains to enhance human health across multiple domains—digestive, immune, metabolic, and even neurological. From the well-established benefits of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis HN019 to the promising potential of postbiotic producers like Pediococcus acidilactici UL5 and Lactococcus lactis MJC18, these microorganisms offer evidence-based tools for improving patient outcomes. As the understanding of the microbiome deepens, the integration of these clinically validated strains into therapeutic protocols provides a proactive, natural approach to support resilience, reduce disease risk, and promote optimal well-being.

References

  1. https://secureservercdn.net/198.71.233.206/lp0.a27.myftpupload.com/wp-content/uploads/2020/06/proacticin-pa-syneova-poster.pdf
  2. Silva CCG, Silva SPM, Ribeiro SC. Application of Bacteriocins and Protective Cultures in Dairy Food Preservation. Front Microbiol. 2018;9:594. Published 2018 Apr 9. doi:10.3389/fmicb.2018.00594 
  3. Ellis JC, Ross RP, Hill C. Nisin Z and lacticin 3147 improve efficacy of antibiotics against clinically significant bacteria. Future Microbiol. 2019;14:1573-1587. doi:10.2217/fmb-2019-0153 
  4. Fu, Y., Jaarsma, A.H. & Kuipers, O.P. Antiviral activities and applications of ribosomally synthesized and post-translationally modified peptides (RiPPs). Cell. Mol. Life Sci. 78, 3921–3940 (2021). https://doi.org/10.1007/s00018-021-03759-0 
  5. Bottacini F, Dal Bello F, Turroni F, et al. Complete genome sequence of Bifidobacterium animalis subsp. lactis BLC1. J Bacteriol. 2011;193(22):6387-6388. doi:10.1128/JB.06079-11 
  6. Holkem AT, Favaro-Trindade CS, Lacroix M. Study of anticancer properties of proanthocyanidin-rich cinnamon extract in combination with Bifidobacterium animalis subsp. lactis BLC1 and resistance of these free and co-encapsulated materials under in vitro simulated gastrointestinal conditions. Food Res Int. 2020;134:109274. doi:10.1016/j.foodres.2020.109274 
  7. Ibarra A, Latreille-Barbier M, Donazzolo Y, Pelletier X, Ouwehand AC. Effects of 28-day Bifidobacterium animalis subsp. lactis HN019 supplementation on colonic transit time and gastrointestinal symptoms in adults with functional constipation: A double-blind, randomized, placebo-controlled, and dose-ranging trial. Gut Microbes. 2018;9(3):236-251. doi:10.1080/19490976.2017.1412908.
  8. Gill HS, Rutherfurd KJ, Cross ML, Gopal PK. Enhancement of immunity in the elderly by dietary supplementation with the probiotic Bifidobacterium lactis HN019. Am J Clin Nutr. 2001;74(6):833-839. doi:10.1093/ajcn/74.6.833.
  9. Paineau D, Carcano D, Leyer G, et al. Effects of seven potential probiotic strains on specific immune responses in healthy adults: a double-blind, randomized, controlled trial. FEMS Immunol Med Microbiol. 2008;53(1):107-113. doi:10.1111/j.1574-695X.2008.00413.x 
  10. Turner et al., (2017) ‘Effect of probiotic on innate inflammatory response and viral shedding in experimental rhinovirus infection – a randomised controlled trial’ Beneficial Microbes, 8(2): 207-215.
  11. West NP et al., (2014), ‘Probiotic supplementation for respiratory and gastrointestinal illness symptoms in healthy, physically active individuals’, Clinical Nutrition, 33(4):581-7. 
  12. Simon M, Pizzorno J, Katzinger J. Modifiable Risk Factors for SARS-CoV-2. Integr Med (Encinitas). 2021;20(5):8-14.
  13. Gomes AC, Hoffmann C, Mota JF. Gut microbiota is associated with adiposity markers and probiotics may impact specific genera. Eur J Nutr. 2020;59(4):1751-1762. doi:10.1007/s00394-019-02034-0 
  14. Bordoni A, Amaretti A, Leonardi A, et al. Cholesterol-lowering probiotics: in vitro selection and in vivo testing of bifidobacteria. Appl Microbiol Biotechnol. 2013;97(18):8273-8281. doi:10.1007/s00253-013-5088-2 
  15. Davidson, Lisa E. et al. “Lactobacillus GG as an Immune Adjuvant for Live Attenuated Influenza Vaccine in Healthy Adults: A Randomized Double Blind Placebo Controlled Trial.” European journal of clinical nutrition 65 (2011): 501 - 507. 
  16. Wang B, Hylwka T, Smieja M, Surrette M, Bowdish DME, Loeb M. Probiotics to Prevent Respiratory Infections in Nursing Homes: A Pilot Randomized Controlled Trial. J Am Geriatr Soc. 2018;66(7):1346-1352. doi:10.1111/jgs.15396. 
  17. Liu, S., Hu, P., Du, X. et al. Lactobacillus rhamnosus GG supplementation for preventing respiratory infections in children: A Meta-analysis of Randomized, Placebo-controlled Trials . Indian Pediatr 50, 377–381 (2013) 
  18. Basu S, Paul DK, Ganguly S, Chatterjee M, Chandra PK. Efficacy of high-dose Lactobacillus rhamnosus GG in controlling acute watery diarrhea in Indian children: a randomized controlled trial. J Clin Gastroenterol. 2009 Mar;43(3):208-13. doi: 10.1097/MCG.0b013e31815a5780. PMID: 18813028. 
  19. Czerwionka-Szaflarska M, Murawska S, Swincow G. Evaluation of influence of oral treatment with probiotic and/or oral rehydration solution on course of acute diarrhoea in children. Gastroenterology Review/Przegląd Gastroenterologiczny. 2009;4(3):166-172.
  20. Sindhu KN, Sowmyanarayanan TV, Paul A, et al. Immune response and intestinal permeability in children with acute gastroenteritis treated with Lactobacillus rhamnosus GG: a randomized, double-blind, placebo-controlled trial. Clin Infect Dis. 2014;58(8):1107-1115. doi:10.1093/cid/ciu065. 
  21. Pieścik-Lech, Małgorzata et al. “Lactobacillus GG (LGG) and smectite versus LGG alone for acute gastroenteritis: a double-blind, randomized controlled trial.” European Journal of Pediatrics 172 (2012): 247 - 253.
  22. Zocco, M A et al. “Efficacy of Lactobacillus GG in maintaining remission of ulcerative colitis.” Alimentary pharmacology & therapeutics vol. 23,11 (2006): 1567-74. doi:10.1111/j.1365-2036.2006.02927.x. 
  23. Pärtty A, Kalliomäki M, Wacklin P, Salminen S, Isolauri E. A possible link between early probiotic intervention and the risk of neuropsychiatric disorders later in childhood: a randomized trial. Pediatr Res. 2015 Jun;77(6):823-8. doi: 10.1038/pr.2015.51. Epub 2015 Mar 11. PMID: 25760553.
  24. Ou CY, Kuo HC, Wang L, et al. Prenatal and postnatal probiotics reduces maternal but not childhood allergic diseases: a randomized, double-blind, placebo-controlled trial. Clin Exp Allergy. 2012;42(9):1386-1396. doi:10.1111/j.1365-2222.2012.04037.x
  25. Rautava S, Kalliomäki M, Isolauri E. Probiotics during pregnancy and breast-feeding might confer immunomodulatory protection against atopic disease in the infant. J Allergy Clin Immunol. 2002;109(1):119-121. doi:10.1067/mai.2002.120273 
  26. Kalliomäki M, Salminen S, Poussa T, Isolauri E. Probiotics during the first 7 years of life: a cumulative risk reduction of eczema in a randomized, placebo-controlled trial. J Allergy Clin Immunol. 2007;119(4):1019-1021. doi:10.1016/j.jaci.2006.12.608 

DOI: https://doi.org/10.14200/rmd.2025.0001