Healthy AdultAdHumanNCT07879079
AdHuman - Impact of Food Additives in Humans
A study testing Carrageenan baked in bread, Xanthan and guar-gum baked in bread and Gellan baked in bread in people with Healthy Adult, run by Siv K Bohn at 1 site in Norway.
Trial summary
Food additives, in particular hydrocolloids (thickening, gelling and stabilising agents), are widely used in the food supply. Concerns about carrageenan have led the food industry to replace it with alternative hydrocolloids, yet no one has compared these different commercial additives with respect to their effects on… Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Adult
- What is being tested?
- Carrageenan baked in bread, Xanthan and guar-gum baked in bread and Gellan baked in bread
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 160 participants
- Where
- 1 siteNorway
- Study dates
- 16 Oct 2026to 1 Apr 2027
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Sex: Both
- Age: 18-60 years
- BMI: 18.5-30 kg/m2
- able to understand the Norwegian questionnaires.
Who cannot join
- Chronic diseases (evaluated as impacting either safety or potentially impacting primary/secondary outcomes)
- history of inflammatory bowel disease, celiac disease, IBS diagnosis
- GI tract surgery affecting gut transition (i.e. not excluding appendectomy)
- Pregnancy
- treatment with oral antibiotics the past six months
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Stine S Strømland, PhD contact
About this study
Official title: AdHuman - Health Effects of Food Additives - Implications for the Gut-brain- and Gut-liver Axis
Food additives, in particular hydrocolloids (thickening, gelling and stabilising agents), are widely used in the food supply. Concerns about carrageenan have led the food industry to replace it with alternative hydrocolloids, yet no one has compared these different commercial additives with respect to their effects on health. Experimental studies indicate that hydrocolloids can interact with the intestinal barrier, gut microbiota and immune signalling, with possible implications for both the gut-liver and gut-brain axes, but how they compare in humans is unknown.
This study investigates how different food additives affect health in healthy adults. In an initial run-in period, all participants follow a standardised diet low in food additives to establish a common background diet. Participants are then randomised to receive foods containing different hydrocolloids - carrageenan and its commercial replacements - or a reference dietary fibre as comparator, on top of the shared background diet.
The study examines effects on the liver, gut microbiota and short-chain fatty acid production, as well as measures relevant to the gut-brain axis such as mood, gastrointestinal symptoms and sleep. By providing the first controlled human comparison of carrageenan and its replacements, the study addresses a timely public health and regulatory question: whether the reformulation already adopted by the food industry has any measurable consequences for gut, liver and brain health.
- Conditions
- Healthy Adult
- Being tested
- Carrageenan baked in bread, Xanthan and guar-gum baked in bread, Gellan baked in bread, Potatoe fiber baked in bread
- Keywords
- Food additives, hydrocolloids, carrageenan, gellan, guar-gum, xanthan gum, fiber, gut-brain, gut-liver, microbiota, gut flora
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Carrageenan baked in breadOther
Also called Kappa-carrageenan baked in bread
Carrageenan baked in bread
Xanthan and guar-gum baked in breadOther
Also called Xanthan, guar-gum
Xanthan and guar-gum baked in bread
Gellan baked in breadOther
Also called gellan
Gellan baked in bread
Potatoe fiber baked in breadOther
Also called Potatoe fiber
Potatoe fiber baked in bread
| Study group | Role | What they receive |
|---|---|---|
| Carrageenan, food grade | Experimental | 3 weeks Receives: Other: Carrageenan baked in bread |
| Xanthan gum + Guar gum, food grade | Experimental | 3 weeks Receives: Other: Xanthan and guar-gum baked in bread |
| Gellan, food grade | Experimental | 3 weeks Receives: Other: Gellan baked in bread |
| Potato fiber | Active comparator | 3 weeks Receives: Other: Potatoe fiber baked in bread |
What is being measured
The primary outcome is the main question the study is designed to answer.
Serum aspartate aminotransferase (AST)
Serum AST concentration (U/L) measured by standard clinical biochemistry.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Secondary outcomes (24)
Change in serum alanine aminotransferase (ALT)
Serum ALT (U/L) by standard clinical biochemistry, as a liver-specific secondary marker supporting the primary outcome (AST).
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Serum gamma-glutamyl transferase (GGT)
Serum GGT (U/L) by standard clinical biochemistry, as an additional liver marker.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Gut microbiota composition and function
Outcomes include alpha diversity, beta diversity, taxa abundance and functional pathways.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Faecal short-chain fatty acid (SCFA) concentrations
Concentrations of Short chain fatty acids in faeces, measured by gas chromatography.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Faecal inflammatory biomarkers (e.g. calprotectin)
Biomarkers of intestinal inflammation in fecal extracts.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Systemic inflammatory markers
Circulating markers of systemic inflammation, including high-sensitivity CRP and panels of cytokines.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Metabolic markers
Metabolic markers (e.g. fasting glucose, fasting insulin (with HOMA-IR), and fasting lipid profile).
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Appetite-regulating hormones
Fasting concentrations of appetite-regulating hormones (e.g. GLP-1, PYY, ghrelin), measured in blood.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Exploratory biomarkers of gut-liver and gut-brain signalling
Exploratory biomarkers of inflammation, intestinal integrity, metabolism, and gut-liver and gut-brain signalling, analysed in blood and faecal samples. These may be extended as additional analyses are performed on stored samples.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Stool consistency (Bristol Stool Scale)
Self-reported stool form assessed by the Bristol Stool Scale. Reported in connection with the fecal sampling.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7
Gastrointestinal symptoms (GSRS-IBS)
Self-reported gastrointestinal symptoms assessed by the Gastrointestinal Symptom Rating Scale for IBS (GSRS-IBS).
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Depression (PHQ9)
Self-reported symptoms assessed by PHQ-9 (depression)
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Anxiety (GAD-7)
Self-reported symptoms assessed by GAD-7 (anxiety)
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Obsessive-compulsive symptoms (OCI-R)
Self-reported symptoms assessed by OCI-R (obsessive-compulsive symptoms),
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Sleep (Bergen Insomnia Scale - BIS)
Self-reported symptoms assessed by (Bergen Insomnia Scale - BIS)
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Health-related quality of life (SF-36)
Health-related quality of life assessed by the SF-36 health survey.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Physical activity
Self-reported physical activity assessed by selected validated items.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Personality traits
Personality assessed by the BFI-20 (Norwegian short form of the Big Five Inventory)
Measured: Baseline
Dietary intake
Dietary intake assessed by 3-day dietary records (two weekdays and one weekend day) using household measures, including energy and macronutrient intake, micronutrient intake, dietary fibre, and intake of food groups.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Additive intake
Intake of food additives, including hydrocolloids, estimated from 3-day dietary records linked to a food additive composition database.
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
BMI
Self-reported body weight
Measured: Baseline, end of run-in (week 3), end of intervention (week 6/7)
Attitudes to additives in food
Self-reported on a 5 item Likerts scale
Measured: Baseline
Compliance to the intervention
Weekly reports on the intake of intervention food (2 slices of bread, 1 slice or none)
Measured: Week 4, 5, 6 (and 7)
Health problems
Self reported new health problems
Measured: Week 1-7
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Oct 2026
- Study start16 Oct 2026 (estimated)
- Primary completion1 Apr 2027 (estimated)
- Study completion1 Apr 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy AdultStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- The study comprises two phases. In an initial run-in phase, all participants follow a shared standardised diet low in food additives, with no group allocation. Participants are then randomised to one of four parallel arms for the intervention phase, each receiving a different hydrocolloid (or a reference fibre comparator) on top of the maintained background diet. Randomisation is stratified by sex.
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 160 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Siv K Bohn
- Sponsor type
- University, hospital or other
- Collaborators
- The Research Council of Norway, Nofima, Tine, MILLS AS, NORTURA SA, GRILSTAD AS, ANIMALIA AS, Norgesgruppen ASA
- Responsible party
- Sponsor-investigator, Siv K Bohn, Norwegian University of Life Sciences
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07879079
- Sponsor's protocol ID
- 353191_KBM_SKB_2026
- Other IDs
- 353191 - KSPSAMARBEID24
- Acronym
- AdHuman
- Status last verified
- Oct 2026
- First submitted
- 10 Oct 2026
- Last updated
- 16 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided