Effect of a bean extract on glucose metabolism in obesity

ISRCTN	ISRCTN67373128
DOI	https://doi.org/10.1186/ISRCTN67373128
Secondary identifying numbers	2021_01_26_10

Submission date: 07/04/2021
Registration date: 20/05/2021
Last edited: 20/05/2021

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Nutritional, Metabolic, Endocrine

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Background and study aims
Among the treatment options for obesity, diet plays a central role. Some foods derived from plants have shown activity in controlling blood glucose after a meal. These compounds are contained in some food supplements such as those based on extracts from common beans. It is demonstrated that this extract reduces the absorption of sugar, leading to an improved blood glucose level in normal weight and overweight people. The aim of this study is to evaluate the medium- to long-term effects of the administration of bean extracts on the capability of insulin to carry out its action in a group of people with severe obesity, compared with a group with similar characteristics treated with a placebo (dummy). The study also aims to evaluate the effects of the extract on food intake.

Who can participate?
People aged between 18 and 65 with a Body Mass Index greater than or equal to 35 kg/m² with altered blood sugar but without type 1 or type 2 diabetes

What does the study involve?
Participants will be randomly allocated into two groups. One group will be given a 100 mg dose of P.V. extract 15-30 minutes before lunch and dinner (total daily dose 200 mg) for a period of 12 weeks, while the control group will be given a placebo (dummy). Both groups follow a balanced low-calorie diet: 50% carbohydrates, 20% protein and 30% fat. Each participant will undergo a nutritional assessment and are assigned a low-calorie diet calculated according to his/her energy requirements (with comparable energy reduction for all participants). Participants will also be asked to perform moderate aerobic physical activity.

What are the possible benefits and risks of participating?
The use of bean extract could help people to control blood sugar levels and, in the long term, lead to improved weight loss. To date, no undesirable effects have been observed; chronic use may lead to digestive symptoms such as bloating or flatulence. These effects will be monitored during the study.

Where does the study run from?
Istituto Auxologico Italiano (Italy)

When is the study starting and how long is it expected to run for?
December 2020 to October 2022

Who is funding the study?
1. Regione Lombardia (Italy)
2. Istituto Auxologico Italiano (Italy)
3. Indena (Italy)

Who is the main contact?
Prof. Massimo Scacchi, massimo.scacchi@unimi.it
Prof. ssa Simona Bertoli, simona.bertoli@unimi.it

Contact information

Prof Massimo Scacchi
Scientific

via Cadorna 90
Oggebbio
28824
Italy

Phone	+39 (0)323514301
Email	massimo.scacchi@unimi.it

Prof Simona Bertoli
Scientific

Via Ariosto 13
Milan
20145
Italy

Phone	+39 (0)250316653
Email	simona.bertoli@unimi.it

Study information

Study design	Interventional randomized placebo-controlled double-blind trial
Primary study design	Interventional
Secondary study design	Randomised controlled trial
Study setting(s)	Hospital
Study type	Prevention
Participant information sheet	No participant information sheet available
Scientific title	In vivo effects of chronic administration of a Phaseolus vulgaris extract, containing alpha-amylase inhibitor and agglutinin, on glucometabolic status and the hunger-satiety circuit in subjects with severe obesity
Study acronym	MFHBB
Study objectives	Derangements of glucose metabolism, in particular pre-diabetic conditions, are among the most common comorbidities of severe obesity. The use of plant extracts such as Phaseolus vulgaris (P.V.), containing a glycoprotein able to inhibit pancreatic alpha-amylase and thus decrease intestinal absorption of complex carbohydrates, may be effective in these clinical conditions. In addition, Phaseolus extract contains agglutinins which have been shown to modulate the hunger-satiety circuit. The researchers hypothesize that supplementation with a standardized extract of P.V. could improve and modulate the glucometabolic profile compared to diet treatment alone in subjects suffering from severe obesity
Ethics approval(s)	Approved 26/01/2021, Ethics Committee Istituto Auxologico Italiano IRCCS (Via Ariosto 13, 20145, Milan, Italy; +39 (0)02619112237; comitato.etico@auxologico.it), ref: 2021_01_26_10
Health condition(s) or problem(s) studied	Glycometabolic control in patients with severe obesity
Intervention	Randomization: Block randomisation at https://www.sealedenvelope.com/. The population will be divided into two arms: to avoid any kind of bias the two arms will be comparable by age, gender and initial weight. One group will be given a 100 mg dose of P.V. extract 15-30 minutes before lunch and dinner for a period of 12 weeks, while the control group will be given a placebo identical in terms of excipient content with the exclusion of the active ingredient. Statistical analysis plan: Data will be reported as mean and standard deviation (SD) for continuous and normally distributed variables (median and interquartile range for non-normally distributed variables) and as absolute and relative frequency for categorical variables. The data from the experiment will be analysed using a repeated-measures ANOVA model by including the period effect, the treatment effect and the interaction between the two in the model. The variance-covariance matrix considered will be of the compound-symmetry type with a constant correlation between times. A sensitivity analysis will be conducted to assess the robustness of the results to changes in the structure of the variance-covariance matrix. Sample size: A sample size of 208 subjects, 104 for each arm in the study, will reach a power of 80% in detecting a statistically significant difference of 0.7 between the start and end of treatment in the experimental group and between the start and end of treatment in the placebo group assuming a significance level of 5%. This sample size was calculated by considering a standard deviation of 2 of the differences between the start and end of treatment between the two groups.
Intervention type	Supplement
Primary outcome measure	1. Insulin resistance measured using the HOMA Index before and after P.V. extract or placebo treatment at baseline (T0), after 2 weeks (T1), 4 weeks (T2) and after 12 weeks (T6) 2. Serum concentrations of glycated haemoglobin, glucose and insulin measured from blood samples taken before P.V. extract or placebo intake, baseline (T0), after 2 weeks (T1), 4 weeks (T2) and 12 weeks (T6) from the start of treatment
Secondary outcome measures	The following outcomes are measured before and after the P.V. extract or placebo treatment at specific time points: before P.V. extract/placebo intake (T0) and after 2 weeks (T1), 4 weeks (T2), 8 weeks (T4) and 12 weeks (T6): 1. Weight and waist circumference measured to the nearest 0.1 kg and 0.1 cm, respectively. Waist circumference will be measured midway to the lowest rib and the top of the iliac crest after gentle expiration; weight will be measured with a digital scale. The anthropometric data will be expressed as the mean of two measurements. 2. Satiation and satiety assessed using the Visual Analogue Scale questionnaire 3. Collection of faecal samples at baseline and after 2 weeks, 4 weeks and 12 weeks for: 3.1. Gut microbiota composition defined by 16S rRNA gene profiling on DNA extracted 3.2. Characteristics of the stool identified through the Bristol Stool Scale (BSS) 3.3. Short-chain fatty acids identified in faecal samples through qualitative and quantitative analysis in gas chromatography and pH measuring 3.4. Intestinal permeability and inflammatory processes investigated through the dosage of serum zonulin and faecal calprotectin through the ELISA test
Overall study start date	15/12/2020
Completion date	15/10/2022

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Sex	Both
Target number of participants	208
Key inclusion criteria	1. Obesity (BMI ≥35 kg/m²) with or without comorbidities 2. 18 to 65 years of age 3. Dysglycemia, altered fasting glycemia or insulin resistance (HOMA index >2.5) 4. Possibility to be followed in the follow up at Auxologico Via Ariosto (Milan) 5. Negative swab for COVID-19 at enlistment
Key exclusion criteria	1. Type 1 and 2 diabetes in treatment 2. Previous operations of bariatric surgery 3. Psychiatric illness 4. Inflammatory bowel disease 5. Untreated thyroid 6. Past or present history of malignant neoplasia
Date of first enrolment	15/04/2021
Date of final enrolment	15/04/2022

Locations

Countries of recruitment

Italy

Study participating centres

San Giuseppe Hospital - Piancavallo

Via Cadorna 90
Oggebbio
28824
Italy

San Michele Hospital

via Ariosto 13
Milano
20145
Italy

Sponsor information

Istituto Auxologico Italiano
Hospital/treatment centre

Via Ariosto 13
Milan
20145
Italy

Phone	+39 (0)2619112237
Email	seg.sci@auxologico.it
Website	http://www.auxologico.it/en/section/538/the_italian_institute_for_auxology#
"ROR"	https://ror.org/033qpss18

Funders

Funder type

Government

Istituto Auxologico Italiano
Private sector organisation / Other non-profit organizations

Alternative name(s): Auxologico
Location: Italy

Regione Lombardia
Government organisation / Local government

Alternative name(s): Lombardy Region, Region of Lombardy
Location: Italy

Indena

No information available

Results and Publications

Intention to publish date	30/09/2022
Individual participant data (IPD) Intention to share	Yes
IPD sharing plan summary	Available on request
Publication and dissemination plan	Planned publication in a high-impact peer-reviewed journal
IPD sharing plan	The datasets generated during and/or analysed during the current study are/will be available upon request from Sara Mambrini (s.mambrini@auxologico.it), a.bruno@auxologico.it; Simona Bertoli (simona.bertoli@unimi.it), Massimo Scacchi (massimo.scacchi@unimi.it). Data of the markers analysed will be available upon request at the end of the study. Data are anonymous and consent from participants was obtained.

Editorial Notes

20/05/2021: Internal review.
16/04/2021: Trial's existence confirmed by the ethics committee of Istituto Auxologico Italiano.