Which GLP-1 and Probiotic Trials Have Results?

GLP-1 and Probiotic Clinical Trials: Which Studies Have Results?

Three published human reports discussed here pair a GLP-1 drug with a probiotic or fiber product. None is a placebo-controlled test of gastrointestinal side effects. Other registered studies cover several combinations, but a registration is not a result, and the cited evidence does not establish a benefit for a WonderBiotics product taken with a GLP-1 drug.

Below, each study gets its own row, listed by registration number where one exists and sorted into published, completed without results, and registered or ongoing, with the drug, formula, population, primary endpoint, and results link. For managing GLP-1 stomach symptoms, see our GLP-1 gut-support evidence map.

Which Studies Count as GLP-1 Combination Evidence?

The relevant studies involve people taking, starting, or recently stopping a GLP-1 receptor agonist and receiving a probiotic, prebiotic, fiber, or Akkermansia-based product. A study of a supplement that changes the body's own GLP-1 hormone answers a different question from a study involving semaglutide, tirzepatide, or another prescribed drug.

ClinicalTrials.gov records describe planned interventions, participants, endpoints, and study status. They distinguish results submitted to the registry from a study that is simply marked completed. The WHO International Clinical Trials Registry Platform also brings together registrations from national registries, including China's ChiCTR.¹² A registration number helps connect a paper to its original plan and prevents two descriptions of the same study from being mistaken for separate evidence.

For each study, the useful questions are whether there was a control group, which outcome was primary, and whether results have actually been published. The status column reproduces the cited registry record; it is not a guarantee that a study is still enrolling. Estimated completion dates are plans, and older records can lag behind what the study team is doing.

Which GLP-1 and probiotic studies have published results?

Two reports tested a probiotic, and one tested a protein shake that contains fiber.

In the dulaglutide trial, 60 adults with type 2 diabetes (HbA1c 6.5% to 11%) were randomized to dulaglutide plus placebo or dulaglutide plus B. longum for 12 weeks. The abstract reports a larger HbA1c drop with the probiotic, 1.06 points vs 0.35 points (P=0.028), along with lower inflammatory markers.³ The abstract does not name a primary endpoint or the analysis population, and neither the PubMed record nor the publisher's preview lists a trial registration number. The study measured blood sugar and cardiovascular risk markers, not GI side effects or weight loss.

The liraglutide report is a retrospective observational study, not a randomized trial. Its authors gave a lower liraglutide dose together with a multispecies probiotic and compared the outcomes with published results from higher-dose liraglutide. It had no liraglutide-only comparison group.⁴ That design cannot separate the probiotic's effect from the drug's, and the cited report does not establish a prospectively registered comparison.

The semaglutide pilot was single-arm and open-label. Each shake held 25 g of protein and 6 g of fiber from pea, agave inulin, acacia, and oat hull.⁵ Within participants, bloating and constipation scores were lower two hours after the first shake than before it (P<0.05). The seven-day composite GI score, the registered primary comparison, did not change significantly (2.55 vs 1.98, P=0.21), and the authors did not correct for multiple comparisons.⁵,⁶ Kate Farms funded the study. Three authors work for the company, and a fourth consults for it.

None of the three is a placebo-controlled test of whether a probiotic reduces nausea, constipation, or bloating during GLP-1 dose escalation.

Which GLP-1 probiotic and fiber trials are finished but have no results?

The five cited records list completed studies. The records and papers cited here do not provide their outcome results; completion alone cannot establish whether a supplement helped.

NCT07847593 measures GI adverse events during semaglutide escalation. Participants began the four-strain probiotic (B. animalis subsp. lactis AZHx1, Limosilactobacillus reuteri AZHx2, Lacticaseibacillus casei AZHx3, and L. rhamnosus AZHx4) or a placebo two weeks before their first semaglutide dose and continued through 12 weeks of dose escalation. Participants, investigators, care providers, and assessors were masked.⁷ The trial ended in July 2026, and the record was first posted that September, so it was registered after the fact. Secondary endpoints include symptom severity, quality of life, weight change, and staying on the planned dose schedule.

The two Soloways trials finished in 2023, with records posted in January 2024. The General Mills study compares GI responses to fiber bars in people already on a maintenance dose. The Olipop study compares GI symptom changes on prebiotic soda vs usual fluids in people who started treatment within the past month.

Which trials are still recruiting or have not started?

The single-arm Metagenics study (NCT07130396) also measures bowel symptoms, in people already on a GLP-1 drug. The Xiamen trial listed here pairs live A. muciniphila capsules with semaglutide, while the Nature's Sunshine study uses an Akkermansia-derived postbiotic and was designed mainly around safety.

Both Metagenics records still report "not yet recruiting," although their estimated completion dates have passed. The two records were last updated in August and October 2025.¹⁵,¹⁶ Their current status would need confirmation from the study teams.

Which studies get cited for GLP-1 and probiotics but test something else?

These four come up in searches for GLP-1 and probiotics, but none has a registry record showing a probiotic or fiber supplement taken alongside a GLP-1 drug.

NCT06989177 compares the probiotic and the drug in separate arms, so it cannot show what taking both does. The Pendulum study enrolls healthy adults who are not on a GLP-1 drug. Fecal transplant is a medical procedure using donor stool, so it falls outside a supplement comparison. The AG1 study mentions gut health in its title, but its record does not say what the product contains.

Where WonderBiotics fits while these trials report

The trials and papers cited here do not test a WonderBiotics finished product alongside a GLP-1 medication. We built WonderBiotics Probiotics for Weight Management, the formula we call Supports GLP-1 Journey, around ingredients that each have their own human research, with clearly specified amounts. B420 matches its study dose, HN019 falls within an earlier studied range, and the dihydroberberine pilot tested absorption rather than long-term clinical benefit. Per daily capsule, that means B420 at 10 billion CFU, HN019 at 2 billion CFU, and dihydroberberine at 100 mg, with 20 billion CFU in total at expiration.²² The formula also includes lemon fruit extract standardized to 70% eriocitrin. You take one capsule daily, ideally within 30 minutes after a meal.²³

The studies behind those ingredients tested each strain or compound on its own, without a GLP-1 drug, and our Lab of Biotics page lays that out ingredient by ingredient. WonderBiotics Probiotics for Weight Management combines those ingredients in one daily capsule. That makes the serving easy to track, but it does not establish improved appetite, waist size, or digestive symptoms specifically in GLP-1 users. It is a dietary supplement, not a treatment for GLP-1 side effects and not a substitute for your prescription. Because it contains dihydroberberine, a form of berberine, check with your prescriber first if you also take diabetes medication.

If your main concern during dose changes is digestive comfort and regularity, WonderBiotics Probiotics for Gut Health is the formula we built for that. It provides 60 billion CFU across 12 named strains, including HN019, NCFM, and LGG, plus the DigeZyme enzyme blend.²²

Results from NCT07847593 and NCT07213323 would help answer the practical question more directly: whether the tested probiotic changes gastrointestinal symptoms during dose escalation.

What to watch for next, and what to ask your prescriber

The Nordic Biotic trial (NCT07847593) is a completed, placebo-controlled test of a probiotic during semaglutide escalation in the cited registry record, and its GI adverse-event results have not been posted yet. The Lyon trial (NCT07213323) will add a second test that includes tirzepatide, with primary completion estimated for late 2027.

Tell your prescriber about any supplement you add, and keep your GLP-1 dose and schedule exactly as prescribed. Do not stop or change the drug on your own. Severe or persistent vomiting, diarrhea, or abdominal pain, or signs of dehydration such as dizziness or very little urine, need a call to your clinician the same day.

As a precaution, do not use our dihydroberberine-containing Weight Management formula during pregnancy or breastfeeding; safety in these groups has not been established.²⁴

References

1. ClinicalTrials.gov. ClinicalTrials.gov API (version 2). National Library of Medicine.
2. World Health Organization. International Clinical Trials Registry Platform (ICTRP) Search Portal.
3. Tian J, Yang Y, Yu Z, et al. Comparative evaluation of dulaglutide alone vs. dulaglutide combined with probiotics on cardiovascular risk factors in T2DM. Hormones (Athens). 2025;24(3):643-650. PMID 40214965.
4. Mattioli M, D'Agostino E, Valerii L, Angelino D, Serafini M, De Cristofaro P. Probiotics In Incretin-Based Therapy for Patient Living with Obesity: A Synergistic Approach. J Pharm Pharmacol Res. 2024;8(4). doi:10.26502/fjppr.0102.
5. Withrow NA, Hsueh EE, Wolever T, et al. Plant-Based Nutrition Alleviates Gastrointestinal Symptoms and Enhances Protein Intake during GLP-1 Therapy. Curr Dev Nutr. 2026;10(7):109393. PMID 42388893.
6. ClinicalTrials.gov. Tolerance of a High Protein Nutrition Shake in Individuals on GLP-1 (NCT07096739).
7. ClinicalTrials.gov. Probiotics in Obese Patients Treated With Semaglutide (NCT07847593).
8. ClinicalTrials.gov. Effectiveness and Safety of Semaglutide Combined With Dietary Fiber (Soloways) in Adults With Overweight or Obesity (NCT06215196).
9. ClinicalTrials.gov. Preventing Weight Regain Post-Semaglutide Treatment With Active Fiber Supplement (Soloways) (NCT06221696).
10. ClinicalTrials.gov. A Trial to Assess Gastrointestinal Responses to Dietary Fibers in Adults Using Weight Loss Medications (NCT07012317).
11. ClinicalTrials.gov. A Pilot Study Evaluating the Impact of a Prebiotic Soda on Gastrointestinal Symptoms in Users of GLP-1 Agonists (NCT07744360).
12. ClinicalTrials.gov. Probiotic Intervention for Digestive Health in Obese Patients Initiating GLP-RA Treatment (NCT07213323).
13. WHO ICTRP. The Effects of Semaglutide Combined with Akkermansia muciniphila on Glucose and Lipid Metabolism and Body Weight in Obese Patients with Type 2 Diabetes Mellitus (ChiCTR2500101690).
14. ClinicalTrials.gov. Effects of Inulin on Cardiometabolic Risk Factors in Individuals Using GLP-1 RA Medications for Weight Loss (NCT07611552).
15. ClinicalTrials.gov. Impact of Multivitamin (PhytoMulti) and a Probiotic (UltraFlora Balance Probiotic) on Gut Health of People Taking GLP-1 Medication (NCT07130396).
16. ClinicalTrials.gov. Impact of Probiotic (UltraFlora Triplebiotic) on Weight Evolution on People After Discontinuation of GLP-1 Treatment (NCT07209046).
17. ClinicalTrials.gov. Safety and Tolerability of a Nutritional Formula Designed to Aid in Maintenance of Muscle During Periods of Caloric Restriction in Adults (NCT07447843).
18. ClinicalTrials.gov. Probiotic Intervention on Body Weight (NCT06989177).
19. ClinicalTrials.gov. Safety and Tolerance of a Novel Three-Strain Probiotic in Healthy Adults (NCT07566884).
20. ClinicalTrials.gov. Fecal Microbiota Transplantation (FMT) Combined With Calorie-Restricted Diet and Semaglutide in Patients With Obesity and Type 2 Diabetes (NCT07599046).
21. ClinicalTrials.gov. A Randomized, Triple-blind, Placebo-controlled Study to Evaluate the Effects of a Supplement on Nutrient Gaps and Gut Health Among Individuals Utilizing GLP-1 RAs (NCT07437911).
22. WonderBiotics. Lab of Biotics.
23. WonderBiotics. Probiotics for Weight Management, Supports GLP-1 Journey.
24. Memorial Sloan Kettering Cancer Center. Berberine: pregnancy, breastfeeding, and medication precautions. These berberine precautions do not establish identical clinical risks for dihydroberberine.