An interventional study of Placebo and Calcium butyrate in Obesity, sponsored by Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran. Not yet recruiting at 1 site in Mexico. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-13.
Sponsored by Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran · Not applicable, Interventional, and Treatment
Obesity is characterized by gut microbiota dysbiosis, in which beneficial metabolites such as butyrate are reduced. Butyrate is a short-chain fatty acid produced by microbial fermentation that plays a key role in maintaining intestinal barrier integrity, regulating immune responses, and supporting mitochondrial function. Its depletion contributes to disruption of the intestinal barrier, facilitating the translocation of bacterial components and promoting systemic inflammation mediated by immune cell activation, like monocytes. This chronic inflammatory state is associated with mitochondrial dysfunction and impaired cellular bioenergetics. Butyrate has been investigated for its anti-inflammatory and metabolic effects, however, its direct impact on monocyte mitochondrial function and its relationship with gut microbiota composition in humans remains unclear.
This randomized, double-blind, placebo-controlled trial will evaluate the effect of oral calcium butyrate supplementation (1000 mg/day) compared with placebo for 4 weeks in adults with obesity. The primary objective is to determine the change in monocyte mitochondrial maximal respiration baseline to week 4.
The study will consist of a screening phase (pre-admission) and two visits, followed by asynchronous follow-up.
Pre-admission visit Participants meeting inclusion criteria (presence of obesity) will be recruited through advertisements published on official institutional platforms.
Informed consent will be explained and signed prior to any study-related procedures.
Participants will be informed about the study characteristics, procedures, risks, and expected benefits, including dietary intervention and biochemical assessments.
A clinical history will be obtained, including identification data, contact information, medical history, and current or recent use of medications and supplements.
Anthropometric measurements (weight and height) will be obtained for BMI calculation.
Blood pressure will be measured after at least 5 minutes of rest, with two readings per arm separated by 3 minutes and averaged.
A blood sample will be collected to determine glucose, creatinine, and liver function tests.
Eligible participants will receive a stool collection kit with instructions for microbiota analysis and will be instructed to return the sample at the next visit.
Visit 1: Baseline Anthropometric measurements will be recorded (weight, height, waist circumference).
Body composition will be assessed using bioimpedance (fat mass, lean mass). Blood pressure will be measured following standardized procedures. A 24-hour dietary recall will be administered. The International Physical Activity Questionnaire will be applied. A blood sample will be collected to assess: Glucose, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, insulin, liver enzymes, C-reactive protein, interleukin 6 and mitochondrial function.
The stool sample collected will be received for microbiota and short-chain fatty acids analysis.
Intervention Participants will be randomly assigned to either: Butyrate supplement group, or placebo group. An isocaloric maintenance diet will be prescribed (50% carbohydrates, 20% protein, 30% fat, 25 g/day fiber), including menus and food lists. Study capsules will be provided along with: Instructions for administration, adherence logbook, identification of adverse event monitoring (nausea, vomiting, abdominal discomfort, diarrhea, constipation, headache, dizziness, fatigue)
Visit 2: Final (After 4 weeks of intervention) Nutritional and Clinical Assessment Anthropometric measurements will be recorded (weight, height, waist circumference).
Body composition will be assessed using bioimpedance (fat mass, lean mass). Blood pressure will be measured following standardized procedures. A 24-hour dietary recall will be administered. The International Physical Activity Questionnaire will be applied. A blood sample will be collected to assess: Glucose, A blood sample will be collected to assess: Glucose, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, insulin, liver enzymes, C-reactive protein, interleukin 6 and mitochondrial function and mitochondrial function.
The stool sample collected will be received for microbiota and short-chain fatty acids analysis.
Capsule count and adherence log review will be conducted. The adverse events questionnaire will be administered.
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
This study's planned enrollment of 42 is below the median of 67 across 9,006 interventional studies indexed under Obesity.
Browse Obesity studies →Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran is the lead sponsor of 144 studies on the registry; 16 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:
Drug treatment:
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.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
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.
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.
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.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
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.
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.
Participants will receive oral placebo capsules containing maltodextrin at a dose of 600 mg/day, administered as two 300 mg capsules once daily for 4 weeks. Furthermore, the participants will follow the same standardized isocaloric maintenance diet (50% carbohydrates, 20% protein, 30% fat) throughout the study.
Dietary Supplement: Placebo
Participants will receive calcium butyrate capsules at a dose of 1000 mg/day (2 capsules of 500 mg) by oral administration once daily for 4 weeks. Furthermore, the participants will follow the same standardized isocaloric maintenance diet (50% carbohydrates, 20% protein, 30% fat) throughout the study.
Dietary Supplement: Calcium butyrate
Oral placebo capsules containing maltodextrin, 300 mg per capsule. Participants assigned to the placebo comparator arm will take two capsules once daily, for a total dose of 600 mg/day, for 4 weeks.
Oral calcium butyrate capsules, 500 mg per capsule. Participants assigned to the experimental arm will take two capsules once daily, for a total dose of 1000 mg/day, for 4 weeks.
Monocyte mitochondrial maximal respiration in pmol O₂/min/10⁶
Change in maximal respiration measured in Cluster of differentiation 14 (CD14+) monocytes using extracellular flux mitochondrial stress testing. Maximal respiration will be calculated as peak oxygen consumption rate (OCR) after Carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP) stimulation minus non-mitochondrial respiration, and compared between the intervention and placebo groups.
Time frame: From baseline to week 4 of the intervention
Gut microbiota composition as relative abundance percentage
Changes in gut microbiota composition will be assessed by 16 svedberg unit (16S) ribonucleic acid ribosomal (rRNA) sequencing, including alpha diversity (Chao1, Shannon), beta diversity, and relative taxonomic. and compared between the intervention and placebo groups.
Time frame: From baseline to week 4 of the intervention
Monocyte mitochondrial reserve respiratory capacity in pmol O₂/min/10⁶ cells
Change in reserve respiratory capacity measured in CD14+ monocytes using extracellular flux mitochondrial stress testing, will be calculated as the difference between maximal oxygen consumption rate and basal oxygen consumption rate, and compared between the intervention and placebo groups.
Time frame: From baseline to week 4 of the intervention
Monocyte Bioenergetic Health Index (BHI) score
Change in Bioenergetic Health Index measured in CD14+ monocytes using extracellular flux mitochondrial stress test. BHI will be calculated as (ATP-linked respiration × spare respiratory capacity) / (proton leak × non-mitochondrial respiration), and compared between the intervention and placebo groups.
Time frame: From baseline to week 4 of the intervention
Fecal butyrate concentration in µmol/g
Change in fecal butyrate concentration measured in stool samples by gas chromatography, and compared between the intervention and placebo groups.
Time frame: From baseline to 4 week of the intervention
Body mass index in kg/m²
Change in body mass index calculated as weight in kilograms divided by height in meters squared, and compared between the intervention and placebo groups.
Time frame: From baseline to 4 week of the intervention
Skeletal muscle mass percentage
Change in skeletal muscle mass measured by bioimpedance, and compared between the intervention and placebo groups.
Time frame: From baseline to 4 week of the intervention
Waist circumference in centimeter
Change in waist circumference measured at the midpoint between the lower costal margin and the iliac crest at the end of a normal expiration, and compared between the intervention and placebo groups.
Time frame: From baseline to 4 week of the intervention
Lean body mass percentage
Change in lean body mass measured by bioimpedance, and compared between the intervention and placebo groups.
Time frame: From baseline to 4 week of the intervention
Fat body mass percentage
Change in fat mass percentage measured by bioimpedance, and compared between the intervention and placebo groups.
Time frame: From baseline to week 4 of the intervention
Body weight in kilograms
Change in body weight measured using a calibrated scale under fasting conditions and light clothing, and compared between the intervention and placebo groups.
Time frame: From baseline to week 4 of the intervention
Systolic and diastolic blood pressure in mmHg
Change in systolic and diastolic blood pressure with an appropriately sized cuff, and compared between the intervention and placebo groups.
Time frame: From baseline to 4 week of the intervention
Serum glucose concentration in mg/dL
Changes in the concentration of serum glucose measured by automated analyzer, and compared between the intervention and placebo groups.
Time frame: From baseline to week 4 of the intervention
Total cholesterol serum concentration in mg/dL
Changes in total cholesterol concentrations measured by automated analyzer, and compared between the intervention and placebo groups.
Time frame: From baseline to week 4 of the intervention
High-density lipoprotein cholesterol serum concentration in mg/dL
Changes in H igh-density lipoprotein cholesterol concentrations measured by automated analyzer, and compared between the intervention and placebo groups.
Time frame: From baseline to week 4 of the intervention
Serum alanine aminotransferase concentration in IU/mL
Changes in Serum alanine aminotransferase measured by automated analyzer, and compared between the intervention and placebo groups.
Time frame: From baseline to 4 week of the intervention
Serum aspartate aminotransferase concentration in IU/mL
Change in serum aspartate aminotransferase measured by automated analyzer, and compared between the intervention and placebo groups.
Time frame: From baseline to week 4 of the intervention
Serum high-sensitivity C-reactive protein concentration in mg/dL
Changes in high-sensitivity C-reactive protein determined by autoanalyzer, and compared between the intervention and placebo groups.
Time frame: From baseline to 4 week of the intervention
Serum interleukin-6 (IL-6) concentration in pg/mL
Changes in IL-6 concentrations measured by enzyme-linked immunosorbent assay, and compared between the intervention and placebo groups.
Time frame: From baseline to 4 week of the intervention
Low-density lipoprotein cholesterol serum concentration in mg/dL
Changes in High-density lipoprotein cholesterol concentrations measured by automated analyzer, and compared between the intervention and placebo groups.
Time frame: From baseline to week 4 of the intervention
Plan to share: No
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