An interventional study of Probiotic Supplement (1C-01) in Probiotic Intervention and Healthy Adult Participants, sponsored by OneCarbon. Not yet recruiting at 1 site in United Kingdom. Open to participants aged 50 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-09.
Sponsored by OneCarbon · Not applicable, Interventional, and Basic science
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This study is a pre-post, open-label pilot feasibility study designed to investigate how a food-grade probiotic supplement affects biological measurements and wellbeing in healthy adults. Participants will take one capsule daily for 1 month. During the study, participants will complete online cognitive tasks and provide blood and stool samples collected during home visits by trained staff. The samples will be analysed to explore changes in gut bacteria and other biological markers.
This study aims to understand whether the supplement is well tolerated and whether measurable biological changes occur. The study does not involve any experimental drugs or invasive procedures beyond blood sampling and stool collection, and participants will not be asked to change any current prescribed medications or treatments; with eligibility exclusions applying for recent antibiotics or immunosuppressants. The supplement is being studied for research purposes only and is not intended to diagnose, treat, or prevent disease.
Participants self-administer one capsule of 1C-01 daily for 28 days. 1C-01 is a live-culture food supplement.
Biological sampling occurs at two timepoints, baseline and end of intervention. Blood and stool is self-collected by the participant using a supplied kit and transported by study staff. Stool undergoes shotgun metagenomic sequencing; plasma undergoes untargeted metabolomic and proteomic profiling. Samples are rendered acellular on receipt and held at the sponsor's primary site.
Remote assessments are delivered through a browser-based study application and are completed together in a single session at baseline and at scheduled fortnightly intervals thereafter. Each session comprises the seven-task cognitive battery, the sleep questionnaire, the mood and stress ratings, and the adherence record for the preceding interval. The cognitive battery is modelled on the UK Biobank assessments using original task content; trial-level response data are retained alongside summary scores. The exit questionnaire is presented once, at the end of the intervention period.
The study is conducted in a hybrid format, with remote assessment and in-person sample collection at participants' homes.
OneCarbon is the lead sponsor of 2 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
4 week course of 1C-01
Dietary Supplement: Probiotic Supplement (1C-01)
Proprietary probiotic supplement
Also known as: HSB001, 1C-01
Stool metagenome
Change from baseline in stool metagenomic markers, representing stool microbiome.
Time frame: From enrolment to end of treatment at 4 weeks
Plasma Metabolome, Proteome
Change from baseline in plasma metabolomic and proteomic markers, representing cellular metabolism and circulating protein levels. Reported as change in normalised relative abundance for each analyte. Continuous measure.
Time frame: From enrolment to end of treatment at 4 weeks
Cognitive Task Performance
Self-administered web-based battery of seven tasks modelled on the UK Biobank cognitive assessments. Components and scoring: reaction time (mean response latency in milliseconds across matching trials; lower is better); numeric memory (longest digit span correctly recalled; higher is better); symbol-digit matching (number of correct substitutions in 60 seconds; higher is better); word-pair memory (number of pairs correctly recalled out of 6; higher is better); matrix reasoning (number of puzzles solved correctly out of 5; higher is better); Trail Making A and Trail Making B (time to complete the sequence in milliseconds; lower is better). Each component is reported independently.
Time frame: From enrolment to end of treatment at 4 weeks.
Self-reported Sleep
Change from baseline on a study-specific sleep questionnaire covering six domains. Sleep duration: hours of sleep per 24 hours including naps, 0 to 16 in half-hour steps; higher indicates longer sleep. Sleep quality: 5-point ordinal scale (very poor, poor, average, good, very good); higher is better. Daytime sleepiness: 4-point ordinal scale (never, sometimes, often, always); higher is worse. Difficulty falling asleep and difficulty staying asleep, each a 4-point ordinal scale (no, occasionally, yes often, every night); higher is worse. Sleep-onset latency: 4 ordered categories (under 15 minutes, 15 to 30 minutes, 30 to 60 minutes, over 60 minutes); longer is worse. Causes of night-time waking: multi-select checklist of 8 options, reported descriptively as the proportion of participants endorsing each cause, not scored. Each domain is reported separately; no total score is used as an outcome measure.
Time frame: From enrolment to end of treatment at 4 weeks.
Wellbeing
Change from baseline in self-reported wellbeing, assessed by two single-item ratings collected at each study assessment. Mood: "How are you feeling today?", 5-point ordinal scale (very low, low, neutral, good, very good); higher is better. Stress: "Stress level today", 4-point ordinal scale (none, mild, moderate, high); higher is worse. Each item is analysed and reported separately; no composite score is derived.
Time frame: Enrolment to end of treatment at 4 weeks.
Adherence
Self-reported number of days on which the study supplement was taken during each consecutive 14-day period, recorded by participants at the end of each period. Integer count from 0 to 14 per period; higher indicates greater adherence. Reported as the count per period and as percentage adherence (days taken divided by 14, multiplied by 100).
Time frame: Enrolment to end of treatment at 4 weeks.
Adverse Events
Count of adverse events reported by participants, and the severity of each event graded as mild, moderate or severe. Reported as the number of participants with at least one adverse event, the total number of events, and the number of events at each severity grade. Higher counts indicate a less favourable tolerability profile.
Time frame: Enrolment to end of treatment at 4 weeks.
Acceptability of study procedures
Participant-rated acceptability of five study procedures, assessed once at the Week 4 end-of-intervention visit using a study-specific questionnaire. Each procedure is rated on a 5-point ordinal scale: 1 = not at all acceptable, 2 = slightly acceptable, 3 = moderately acceptable, 4 = very acceptable, 5 = completely acceptable. Higher scores indicate greater acceptability. Each item is reported separately; no total or composite score is derived. Three optional free-text questions are collected and reported descriptively. Feasibility is additionally assessed as recruitment rate (participants enrolled as a proportion of those screened, and mean enrolled per month across recruitment) and outcome completion (proportion of scheduled assessments and biological samples completed and usable, reported separately for stool samples, blood samples, cognitive batteries, and mood and stress ratings).
Time frame: Assessed at week 4 (end of treatment)
Plan to share: No
Start is estimated for Jan 2027; primary completion for Jun 2027, 5 months later.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Probiotic
OneCarbon