Safety and Tolerability Evaluationof Phascolarcobacterium Faecium

NCT07285317 | Completed Phase 1

• 1 other identifier: 217/2023
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this interventional study is to assess the safety and tolerability of the daily administratrion of bacterium Phascolarctobacterium faecium in healthy adults with normal weight, and in individuals with overweight and alterations in glucose metabolism. The main questions this study aims to answer are: Is the bacterium intake safe? Is the bacterium intake well tolerated? The objecitves are to assess if the intake of the bacterium is well tolerated by assessing gastrointenstinal symptoms, and safe, by assessing biochemical markers, incidence of adverse events and the general health status. Participants will take daily the bacterium for 15 days. Study assessments include stool collection for microbiota analysis; blood sampling form biochemical tests, anthropometric measurements, and validated questionnaires on diet, physical activity, and perceived health.

Conditions

Obesity & Overweight; Health; Obesity Type 2 Diabetes Mellitus

Keywords

Gut microbiota; Obesity; Metabolic health; Probiotic; Phascolarctobacterium faecium

Outcome Measures

Primary Outcomes (9)

• Incidence of adverse events and general health status

  Participants will have access to a 24-hour contact number to report any inconvenience or adverse effects. All adverse effects will be recorded throughout the intervention period and for one additional week after completion. Outcomes will be reported as the presence or absence of adverse effects.

  21 days

• Systemic safety of P. faecium intake assessed in all the clinical trial participants by biochemical markers

  Complete hemogram and biochemical analysis will be permormed at baseline and after bacterum intervention and includes red blood cells, white blood cells, and assessments of lipid profile (triglycerides, total cholesterol, LDL cholesterol, HDL cholesterol, and non-HDL cholesterol), renal function (urea, creatinine, and uric acid), hepatic function (total protein, AST, and ALT), and glucose homeostasis (glucose, insulin, HbA1c, and HOMA-IR). All parameters will be measured using standard units commonly applied in clinical practice, and results will be compared before and after the intervention. It will be interpreted as either unchanged or altered relative to baseline values.

  15 days

• Tolerability assessment measured by stool habit

  To assess the tolerability of P. faecium, participants will complete gastrointestinal symptom questionnaires before and after the intervention, capturing both weekly bowel movement frequency and stool consistency using the Bristol Stool Scale. Stool habits will be evaluated by integrating these two variables: a normal habit will be defined as 4-14 bowel movements per week together with a Bristol score of 3-5, whereas any deviation from these ranges will be classified as an altered stool habit.

  15 days

• Tolerability assessment measured by the frequency of heartburn.

  Use of probiotic bacteria may occasionally elicit mild gastrointestinal discomfort, including bloating, gas or abdominal cramps. To assess the tolerability of the tested bacterium, participants will complete gastrointestinal symptom questionnaires before and after the intervention, which also capture the frequency of heartburn. Response options include: "all the time," "most of the time," "sometimes," "a few times," and "never." Changes in frequency will be compared between pre- and post-treatment assessments.

  15 days

• Tolerability assessment measured by the frequency of abdominal bloating.

  Use of probiotic bacteria may occasionally elicit mild gastrointestinal discomfort, including bloating, gas or abdominal cramps. To assess the tolerability of the tested bacterium, participants will complete gastrointestinal symptom questionnaires before and after the intervention, which also capture the frequency of abdominal bloating. Response options include: "all the time," "most of the time," "sometimes," "a few times," and "never." Changes in frequency will be compared between pre- and post-treatment assessments.

  15 days

• Tolerability assessment measured by the frequency of constipation.

  Use of probiotic bacteria may occasionally elicit mild gastrointestinal discomfort, including bloating, gas or abdominal cramps. To assess the tolerability of the tested bacterium, participants will complete gastrointestinal symptom questionnaires before and after the intervention, which also capture the frequency of constipation. Response options include: "all the time," "most of the time," "sometimes," "a few times," and "never." Changes in frequency will be compared between pre- and post-treatment assessments.

  15 days

• Tolerability assessment measured by the frequency of diarrhea.

  Use of probiotic bacteria may occasionally elicit mild gastrointestinal discomfort, including bloating, gas or abdominal cramps. To assess the tolerability of the tested bacterium, participants will complete gastrointestinal symptom questionnaires before and after the intervention, which also capture the frequency of diarrhea. Response options include: "all the time," "most of the time," "sometimes," "a few times," and "never." Changes in frequency will be compared between pre- and post-treatment assessments.

  15 days

• Tolerability assessment measured by the frequency of nausea.

  Use of probiotic bacteria may occasionally elicit mild gastrointestinal discomfort, including bloating, gas or abdominal cramps. To assess the tolerability of the tested bacterium, participants will complete gastrointestinal symptom questionnaires before and after the intervention, which also capture the frequency of nausea. Response options include: "all the time," "most of the time," "sometimes," "a few times," and "never." Changes in frequency will be compared between pre- and post-treatment assessments.

  15 days

• Tolerability assessment measured by the frequency of flatulence.

  Use of probiotic bacteria may occasionally elicit mild gastrointestinal discomfort, including bloating, gas or abdominal cramps. To assess the tolerability of the tested bacterium, participants will complete gastrointestinal symptom questionnaires before and after the intervention, which also capture the frequency of flatulence. Response options include: "all the time," "most of the time," "sometimes," "a few times," and "never." Changes in frequency will be compared between pre- and post-treatment assessments.

  15 days

Study Arms (2)

P. faecium in healthy normal weight individuals

EXPERIMENTAL

Healthy normal weight individuals will receive a daily dose of P. faecium for 15 days to evaluate the tolerability and safety of short-term administration.

Dietary Supplement: Bacterium P. faecium

P. faecium in overweight individuals with mild alterations in glucose homeostasis

EXPERIMENTAL

Overweight individuals with mild alterations in glucose homeostasis will receive P. faecium for 15 days to evaluate its safety and tolerability in the target population.

Dietary Supplement: Bacterium P. faecium

Interventions

Bacterium P. faecium DIETARY_SUPPLEMENT

The participants will be given Phascolarctobacterium faecium orally (pill form) for 15 consecutive days.

P. faecium in healthy normal weight individuals; P. faecium in overweight individuals with mild alterations in glucose homeostasis

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• years
• stable body weight and dietary habits during the previous three months
• written informed consent

You may not qualify if:

• the presence of gastrointestinal disorders
• immunodeficiency
• eating disorders
• antibiotic use within one month before the study
• chronic antidiabetic therapy
• substance (drug) abuse
• restrictive diets
• any other condition deemed inappropriate for participation by the clinician

Sponsors & Collaborators

• Spanish National Research Council: lead

Study Sites (1)

Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC)

Valencia, Spain

Location

Related Publications (1)

• Liebana-Garcia R, Lopez-Almela I, Olivares M, Romani-Perez M, Manghi P, Torres-Mayo A, Tolosa-Enguis V, Flor-Duro A, Bullich-Vilarrubias C, Rubio T, Rossini V, Segata N, Sanz Y. Gut commensal Phascolarctobacterium faecium retunes innate immunity to mitigate obesity and metabolic disease in mice. Nat Microbiol. 2025 Jun;10(6):1310-1322. doi: 10.1038/s41564-025-01989-7. Epub 2025 May 6.

  PMID: 40328980 BACKGROUND

MeSH Terms

Conditions

Obesity; Overweight

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Yolanda Sanz, Professor

  Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC)

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Model Details: This study uses a parallel interventional model with two predefined groups: normal-weight individuals and individuals with overweight and mild alterations in glucose metabolism. All participants receive Phascolarctobacterium faecium. All participants follow the same intervention and assessment schedule, allowing for within-group comparisons before and after supplementation, as well as exploratory analyses between the two population subgroups.

Study Record Dates

• First Submitted: November 14, 2025
• First Posted: December 16, 2025
• Study Start: February 1, 2024
• Primary Completion: January 30, 2025
• Study Completion: January 31, 2025
• Last Updated: December 16, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

ES (1)