METHOD FOR DECREASING ABDOMINAL GIRTH BY ADMINISTERING A BIFIDOBACTERIUM BACTERIA

The present invention relates to a method for decreasing abdominal girth in a subject by administering a bacteria of the Bifidobacterium genus, Bifidobacterium animalis said method being on one aspect of the invention a non therapeutic method, and according to another aspect of the invention being a method for treating IBS.

Abdominal girth changes during the day in normal healthy individuals and seems to follow a particular pattern-namely that it increases as the day progresses, is more pronounced after meals and subsides at night.

Increase of abdominal girth, especially after meals, is, for a lot of people, an everyday or punctual discomfort that they would like to make disappear or at least to reduce.

Important increase of abdominal girth may also indicate functional bowel disorder like irritable bowel syndrome (IBS).

Irritable bowel syndrome (IBS) is a functional bowel disorder in which abdominal pain or discomfort is associated with defecation or change in bowel habit and with features or disordered defecation.

Patients can present with either constipation (IBS-C) or diarrhoea (IBS-D), or a mixture of both (IBS-M) or none of these three characteristics (IBS-U; U means “Unsubtype”) (1). IBS affects between 10% and 20% of the population (1-4), and results in significant work absenteeism and reduced quality of life (5-6). Although it accounts for nearly half of gastroenterology clinic referrals (7), the treatment available is far from adequate (1, 7).

Thus there is need for means to reduce partially or totally small increases of abdominal girth for healthy subject but also to reduce partially or totally more important increases of abdominal girth for IBS patients.

It has been shown that the use of certain probiotic preparations, containing bacteria such as propionic bacteria, lactobacilli and/or bifidobacteria, makes it possible to modify the flora in the colon of certain patients (8, 9, 9bis). Moreover, in both man and animal models, a number of probiotics have been shown to modify gastrointestinal contractility or excessive flatulence, meteorism, or abdominal pain (10).

However, to date, no study has investigated the effect of using a probiotic on abdominal distension, or examined the relationship of the symptom of bloating, distension and/or gastrointestinal transit to modification of intestinal microflora composition in patients with IBS-C.

Surprisingly, it has been found that administration of at least about 1×10⁹ cfu of probiotic per day during at least 15 days can reduce significantly abdominal girth in a subject.

An object of the present invention is therefore a method for decreasing abdominal girth in a subject comprising the step of administering to said subject at least about 1×10⁹ cfu of a bacteria chosen in the group of bacteria of the Bifidobacterium genus per day.

In a preferred embodiment of the invention said bacteria is administered during at least 15 days.

The term “abdominal girth” is intended to mean the measurement of the distance around the abdomen at a specific point, usually at the level of the belly button (navel). Abdominal inductance plethysmography can be used to measure abdominal girth.

The measurement of the abdominal girth may also be helpful in determining objective abdominal distention.

For the comprehension of the invention, it has to be understood that increase of abdominal girth and bloating are not synonymous for the man state in the art, specialist in gastroenterology.

Until recently research into bloating and distention has been sparse and largely empirical as well as being based on the assumption that the two descriptors were describing the same phenomenon. Thus interpreting the data from older studies is difficult and even today patients and their physicians often use the terms synonymously. However, with the development of more objective ways of assessing it such as the gas challenge technique or abdominal inductance plethysmography, there is increasing evidence that bloating and distention may have different pathophysiological mechanisms.

While bloating is a subjective sensation measured by a questionnaire submitted to the patient, increase of abdominal girth can be measured by objective ways, such as abdominal inductance plethysmography. Numerous studies have shown that only approximately half of patients reporting the sensation of bloating exhibit objective abdominal distension beyond a 90% control range, as measured by the recently validated technique of Abdominal Inductance Plethysmography.

Sensory mechanisms appear to be more important in bloating and thus this symptom may be eased by drugs affecting this modality (for example, tricyclic antidepressants have been suggested to be tested (11). In contrast, abdominal distension have more mechanical basis and it has been suggested to test laxatives and prokitenics, which are a class of drugs used on the digestive system (e.g. Alosetron or Tegaserod) (11).

Thus it has become apparent that not all individuals who feel bloated necessarily exhibit an increase in abdominal girth. This has led that the term bloating should be used to describe the sensation of increased abdominal pressure and the descriptor distension and abdominal girth should only be used when there is an actual change in abdominal circumference (11).

Complex mechanisms which sometimes overlapping seem to be involved in abdominal distension (11). Increase of abdominal girth is observed in both IBS-C and IBS-D, which are associated with opposite transit conditions, i.e. slow and rapid respectively (13). This is also supported by the fact that other mechanisms than transit are involved in the abdominal girth increased such as visceral sensation or gas handling as well as sex-related mechanisms that may have a role as higher prevalence is observed than in men among IBS patients (11).

The term “administering” is intended to mean “administering orally” i.e. that the subject will orally ingesting a bacteria according to the present invention or a composition comprising the bacteria according to the present invention, or “administering directly” i.e. that a bacteria according to the present invention or a composition comprising the bacteria according to the present invention will be directly administered in situ, in particular by coloscopy, or rectally via suppositories.

Oral administration of composition comprising the bacteria according to the present invention may be in the form of gelatin capsules, of capsules, of tablets, of powders, of granules or of oral solutions or suspensions.

In a preferred embodiment of the invention, said composition is a food composition which can be used in the production of new foods or food ingredients as defined in EC Regulation No. 258/97, and in particular in the manufacture of functional foods. A food may be considered to be functional if it is demonstrated satisfactorily that it exerts a beneficial effect on one or more target functions in the organism, beyond the usual nutritional effects, improving the state of health and of well-being and/or reducing the risk of a disease (12).

In a preferred embodiment of the invention, said bacteria is administered in the form of a dairy product. In particular, the dairy product is a fermented dairy product and more particularly the fermented dairy product is a yoghurt.

Said composition may in particular constitute a probiotic packaged, for example, in the form of a capsule or a gelatin capsule.

In another preferred embodiment of the invention, said composition is a pharmaceutical composition, also combined with a pharmaceutically acceptable carrier, which may comprise excipients.

Preferably, the pharmaceutical composition also comprises at least one other agent active against IBS.

The term “pharmaceutical composition” is intended to mean “drug” or “OTC (Over The Counter)”.

According to the invention, the decrease of abdominal girth of the subject is at least about 1 cm.

Preferably, the decrease of abdominal girth of the subject is at least about 1.5 cm.

It is also possible to quantify the decrease of abdominal girth of the subject in percentage of decrease of the abdominal girth of the subject.

According to experiments done by the inventors (see “Examples” part), the mean values of abdominal girth in the subjects observed are about 81.5 cm in baseline conditions at the beginning of the day (i.e. morning) and the mean increase of abdominal girth during the day is 3.5 cm (FIG. 2A).

In an embodiment of the invention, the decrease of abdominal girth is a decrease in the relative maximum abdominal distension.

The term “relative decrease in maximum abdominal distension” is intended to mean “percentage of maximum abdominal distension reduction”.

The “Maximum distension” or “maximum abdominal distension” or “maximum abdominal girth increase” is defined as the mean abdominal girth over one hour of recording at which girth was at its greatest.

For example, a patient having an abdominal girth of 81.5 cm in baseline conditions, and having a maximum abdominal girth increase of 6 cm, which would have a decrease of abdominal girth of 3 cm (i.e 3.7% of the abdominal girth) will show a decrease of the relative maximum abdominal distension of 50% (3 cm/6 cm).

Preferably, the decrease in the relative maximum abdominal distension is at least about 50%.

Moreover, it has to be noted that increases of this abdominal girth have been observed until 12 cm in some patients with IBS (13).

The bacteria is chosen in the group of bacteria of the Bifidobacterium genus and is considered as a probiotic.

The term “probiotics” is intended to mean dietary supplements containing potentially beneficial bacteria or yeasts. According to the currently adopted definition by FAO/WHO, probiotics are: ‘Live microorganisms which when administered in adequate amounts confer a health benefit on the host’. Lactic acid bacteria are the most common type of microbes used. Lactic acid bacteria have been used in the food industry for many years, because they are able to convert sugars (including lactose) and other carbohydrates into lactic acid. This not only provides the characteristic sour taste of fermented dairy foods such as yoghurt, but also by lowering the pH may create fewer opportunities for spoilage organisms to grow, hence creating huge health benefits on preventing gastrointestinal infections. Strains of the genera Lactobacillus and Bifidobacterium, are the most widely used probiotic bacteria.

Probiotic bacterial cultures are intended to assist the body's naturally occurring gut flora to reestablish themselves. They are sometimes recommended by doctors, and, more frequently, by nutritionists, after a course of antibiotics, or as part of the treatment for gut related candidiasis. Claims are made that probiotics strengthen the immune system to combat allergies and other immunal diseases.

Preferably the bacteria is chosen in the group of Bifidobacterium animalis, Bifidobacterium infantis and Bifidobacterium lactis species.

More preferably the bacteria is chosen in the group of B. infantis UCC 35624 (NCIMB 4100), B. animalis CNCM I-2494, B. lactis ATCC 27536 (other deposit numbers: NCC 2818, CNCM I-3446, DSM 20215, DSM 10140).

The B. infantis UCC 35624 has been deposited at the National Collections of Industrial and Marine Bacteria Limited (NCIMB) on Jan. 13, 1999 under the accession number NCIMB 4100.

The B. lactis has been deposited at the german culture collection (Deutsche Sammlung von Mikroorganismen and Zellkulturen GmbH) under the numbers DSM20215 and DSM 10140, at CNCM (Collection Nationale de Cultures de Microorganismes—Institut Pasteur—28, rue du Dr. Roux—75724 Paris Cedex 15—France) on Jun. 7, 2005, under the number CNCM I-3446 and at ATCC (American Type Culture Collection) under the number ATCC 27536. This strain is often associated to the species Bifidobacterium animalis.

More preferably, the bacteria according to the present invention is a Bifidobacterium animalis.

More preferably, the bacteria according to the present invention is a Bifidobacterium animalis deposited under the number I-2494 at CNCM on Jun. 20, 2000. This strain is known under the code DN-173 010 and is protected, with its use as glycosylation modulator of intestinal cell surface, by European Patent EP 1 297 176.

In a preferred embodiment of the invention, at least 1×10¹⁰ cfu of bacteria per day is administered to the subject.

In a preferred embodiment of the invention, about 1×10¹⁰ cfu of bacteria per day is administered to the subject during at least 15 days, preferably at least 28 days.

More preferably, 1.25×10¹⁰ cfu of bacteria is administered to the subject two times per day during at least 15 days, preferably at least 28 days.

According to the invention, the subject can be a child, an adult or an elderly, preferably an adult.

In a preferred embodiment of the invention the subject is a female.

Indeed it has been shown that female subjects has predisposition for increase of abdominal girth, abdominal distension and irritable bowel syndrome (1, 13).

In a preferred embodiment, the subject has or is subjected to abdominal girth increase.

According to an embodiment of the invention, the method is a non therapeutic method.

The purpose of said non therapeutic method is to decrease the abdominal girth of healthy subjects of the population, in particular after meals. Preferably, said non therapeutic method is to decrease the relative maximum distension of abdominal girth of said subjects.

Healthy subjects of the population according to the present invention are defined as subject in a population having increase of abdominal girth, and which cannot be classified as suffering from irritable bowel syndrome (IBS). People classified as suffering from IBS are people, when compared to the general population, which have a higher frequency and a higher severity of gastro-intestinal symptoms (17) and have a higher sensitivity to the physiological digestive events (7). These frequency and sensitivity can be evaluated by using the methods described in the publications from Leibbrand et al (17) and Spiller et al (7).

According to another embodiment of the invention, the method is for treating irritable bowel syndrome (IBS).

In gastroenterology, irritable bowel syndrome (IBS) or spastic colon is a functional bowel disorder characterized by abdominal pain and changes in bowel habits which are not associated with any abnormalities seen on routine clinical testing. It is fairly common and makes up 20-50% of visits to gastroenterologists. Lower abdominal pain, and bloating associated with alteration of bowel habits and abdominal discomfort relieved with defecation are the most frequent symptoms. It has to be understood for the good comprehension of the present invention that IBS is a syndrome and that under this expression are collected several symptoms observed on patients suffering from the gastrointestinal area. Thus there is not one disease (IBS) to treat but several types of diseases, and most of all, one or several symptoms to treat or decrease.

According to one embodiment of the present invention, the method according to the invention is for reducing a symptom of abdominal girth increase of patients diagnosed as suffering from IBS.

The stop of administration to the subject of bacteria of Bifidobacterium animalis species according to the method of the present invention is associated in the subject with a return after a few weeks to value of abdominal girth increase similar of the one before the administration of the bacteria.

Moreover, Inventors have shown that bacteria of Bifidobacterium animalis species, in particular B. animalis DN-173010 are not able to colonise the gastrointestinal tract (18).

Concerning the several types of IBS, the abdominal pain type is usually described in a patient as either constipation-predominant (IBS-C) or diarrhoea-predominant (IBS-D), or a mixture of both (IBS-M) or none of these three characteristics (IBS-U; U means “Unsubtype”).

Preferably, the method according to the invention is for treating IBS-C (constipation-predominant).

Most preferably, the method according to the invention is for reducing abdominal girth increase of patients diagnosed as suffering from IBS-C.

Preferably, the method according to the invention is for treating subjects diagnosed according to ROME III criteria.

Most preferably, the method according to the invention is for reducing abdominal girth increase of patients diagnosed as suffering from IBS-C, according to ROME III criteria.

ROME is a process developed to classify the functional gastrointestinal disorders based on clinical symptoms.

The term “ROME III* criteria” is intended to mean criteria for irritable bowel syndrome as follows:

Recurrent abdominal pain or discomfort** at least 3 days per month in the last 3 months associated with 2 or more of the following: * Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis.** “Discomfort” means an uncomfortable sensation not described as pain.

• • 1. Improvement with defecation
  • 2. Onset associated with a change in frequency of stool
  • 3. Onset associated with a change in form (appearance) of stool

Other symptoms that are not essential but support the diagnosis of IBS:

• • Abnormal stool frequency (greater than 3 bowel movements/day or less than 3 bowel movements/week);
  • Abnormal stool form (lumpy/hard or loose/watery stool);
  • Abnormal stool passage (straining, urgency, or feeling of incomplete bowel movement);
  • Passage of mucus;
  • Bloating or feeling of abdominal distension.

Some or all of IBS symptoms can occur at the same time—some symptoms may be more pronounced than others.

All the criteria which are required to be diagnosed as IBS-C are described by the Rome III criteria (Longstreth et al., 2006).

In particular, the method according to the invention is for reducing the symptom of abdominal girth increase of patients suffering from IBS. The purpose is to decrease the abdominal girth of subjects of the population suffering of IBS. Preferably, said method is to decrease the relative maximum distension of abdominal girth of said subjects.

DESCRIPTION OF THE FIGURES

FIG. 1 describes the flow of patients through the protocol. From the 41 enrolled patients, 38 were randomised giving an ITT population of 38. Six patients have been excluded from the PP population (n=32).

FIG. 2A: shows that the mean distension was lower in the product group vs control at the end of the product consumption period (−1.5; 95% CI (−3.3, 0.3); p=0.096). A trend (p=0.069) was also observed in PP population (−1.7; 95% CI (−3.6, 0.1). Data are expressed as mean girth distension (cm)±SD. These data correspond to AUC values over these standardized 12 h period for each of the 2 days of recording (pre and postintervention).

FIG. 2B: Relative changes in maximum abdominal distension in ITT population. Data are expressed as relative change in maximal girth distension (cm) at the end of product comsumption vs baseline. Analysis of the difference between groups was done with Mann-Whitney-U test (* p<0.05).

FIG. 3 A-B: Subjective bloating over a standardized period of 12 h before starting product consumption (baseline test, A) and at the end of study (B) in ITT population. Data are expressed as mean bloating score from hour 1 to hour 13 allowing the determination of bloating score over the 13 h period of the day. Bloating score was assessed with a 6-point likert scale (from none=1 to very severe=6).

FIG. 3 C: Mean bloating score (AUC 24 h) in ITT population. Data are expressed as bloating score±SD. These data correspond to the mean bloating score over the standardized 13 h period for each of the 2 days of recording (pre and post-intervention).

FIG. 4 A-B: Subjective abdominal pain/discomfort over a standardized period of 12 h before starting product consumption (baseline test, A) at the end of the study (B) in ITT population. Data are expressed as mean abdominal pain/discomfort score from hour 1 to hour 13 allowing the determination of abdominal pain/discomfort score over the 13 h period of the day. Abdominal pain/discomfort score was assessed with a 6-point likert scale (from none=1 to very severe=6).

FIG. 4 C: Abdominal pain/discomfort score (AUC 24 h) in ITT population. Data are expressed as abdominal pain/discomfort score±SD. These data correspond to the mean abdominal pain/discomfort score over the standardized 13 h period for each of the 2 days of recording (pre and post-intervention).

FIG. 5: Abdominal bloating score over 4-week period of product consumption in ITT population. Data are expressed as mean weekly bloating score±SD. Bloating score was assessed with a 6-point likert scale (from none=1 to very severe=6). Ancova test (* p<0.05).

FIG. 6: Abdominal pain/discomfort score over 4-week period of product consumption in ITT population. Data are expressed as mean weekly abdominal pain/discomfort score±SD. Abdominal pain/discomfort score was assessed with a 6-point likert scale (from none=1 to very severe=6).). Ancova test (* p<0.05).

FIG. 7: Flatulence score over 4-week period of product consumption in ITT population. Data are expressed as mean weekly flatulence score±SD. Flatulence score was assessed with a 6-point likert scale (from none=1 to very severe=6).). Ancova test (* p<0.05).

FIG. 8: Overall IBS symptoms score over 4-week period of product consumption in ITT population. Data are expressed as mean weekly overall IBS symptoms score±SD. Overall IBS symptoms score was assessed with a 6-point likert scale (from none=1 to very severe=6). Ancova test (* p<0.05).

FIG. 9: Satisfaction with bowel habits over 4-week period of product consumption in ITT population. Data are expressed as percentage of patients satisfied with their bowel habits (slightly, moderately or completely) at each week. Chi-square test (** p<0.005; * p<0.05).

FIG. 10: Overall well being over 4-week period of product consumption in ITT population. Data are expressed as percentage of patients satisfied with their overall well-being (slightly, moderately or completely) at each week.

EXAMPLES

Material and Methods

Study Population

The study was carried out in 38 female patients with IBS-C aged 18-70 years, diagnosed according to Rome III criteria (1) (19 per treatment group). Randomised patients who dropped out before the second AlP and transit assessment, as planned in the protocol were replaced in order to reach a total number of 34 patients with main criterion (i.e. abdominal distension) and transit assessment available for product efficacy analysis. Patients were recruited from the out patients departments of the University Hospitals of South Manchester (tertiary patients excluded), local general practices, advertisement in regional newspapers, and from an existing departmental volunteer pool of patients.

Patients fulfilled the Rome III criteria for IBS with predominant constipation based on the stool consistency pattern (1). Patients had to have a bowel frequency of at least 2 per week in order to exclude patients with severe constipation. Patients were excluded from the study if they had any significant illness other than IBS. Patients with history of laxative abuse were also excluded as well as patients taking antidepressive or analgesic drugs. Patients having taken antibiotics within 60 days prior the entry in the study were also excluded. Detailed inclusion and non inclusion criteria are described below:

Inclusion Criteria

• • Females between the ages of 18 and 70 years.
  • Diagnostic criteria (Rome III)* for IBS-C will be as follows: Recurrent abdominal pain or discomfort** at least 3 days per month in the last 3 months associated with 2 or more of the following:

    • Improvement with defecation.
    • Onset associated with a change in frequency of stool.
    • Onset associated with a change in form (appearance) of stool.
    • Hard and lumpy stools (Bristol Stool scale 1 and/or 2)>25% and loose (mushy) or watery stools (Bristol Stool scale 6 and/or 7—fluffy pieces with ragged edges, a mushy stool or watery, no solid pieces, entirely liquid)<25% of bowel movements.*** * Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis. Only patients with ‘active IBS’ at the time of screening will be studied; defined as those who report pain/discomfort on at least 2 days of the baseline symptom diary assessment (see below).** Discomfort means an uncomfortable sensation not described as pain.*** In the absence of use of laxatives.

  • Patients who are able to communicate well with the investigator and to comply with the requirements for the entire study.
  • Patients who provide written informed consent before participating in the study after being given a full description of the study.
  • Patients of normal body weight or overweight ie. not obese (body mass index between 18 and 30 kg/m2).

Exclusion Criteria

• • Any significant illness other than IBS will exclude patients from the study.
  • Patients with severe constipation, defined as a bowel frequency of <2 bowel movements per week. The patients must have a bowel frequency of at least 2 per week.
  • Patients with evidence of cathartic colon or a history of laxative abuse, that in the Investigator's opinion is consistent with severe laxative dependence such that the patient is likely to require or use laxative during the study.
  • Taking drugs that might modify gastrointestinal function.
  • Taking antidepressive or analgesic drugs.
  • Taking antibiotics within 60 days prior to entry into the study.
  • Taking an investigational drug within the 30 days prior to entry into the study.
  • Drinking alcohol above the recommended safe alcohol limit (<21 units/week).
  • Fertile women* who are not currently taking oral birth control pills (at least 1 full monthly cycle prior to study medication administration and continued until 1 month following the last dose of study medication) should be using or complying with one of the other medically approved methods of contraception such as, but not exclusively, one of the following:

    • Intra-uterine device (IUD)
    • Double barrier methods (such as condoms and spermicide)
    • Abstinence, when in the opinion of the investigator, their occupation or life style gives sufficient evidence that abstinence will be maintained throughout the study and for 1 month thereafter. In the case of abstinence, it should be recorded in the source documents that the patient was appropriately counseled. * Fertile woman is defined as a woman who is not surgically sterile (i.e. hysterectomy, bilateral oophorectomy or bilateral tubal ligation), or is not post-menopausal (a post-menopausal patient is defined as a patient who has not menstruated for 12 months or more). A urine pregnancy test will be performed at visit V1 and prior to each abdominal x-ray.

  • All medications and cigarette smoking will be prohibited for 48 hours prior to the study, whilst alcohol and caffeine containing drinks will be stopped for 24 hours before the study.
  • Strenuous physical activity will be prohibited for 24 hours prior to the study.
  • Patient with allergy or hypersensitivity to milk proteins.
  • Patient having undergone a surgery in the month prior to inclusion.

Throughout the study, the patients had not to consume any probiotic or fermented dairy products other than those provided. They were encouraged to continue with all the other aspects of their dietary and physical exercise habits.

Study Design

The study was single-centre, randomized, double-blind, placebo-controlled, parallel-group in female patients with IBS-C assessing the effect of daily consumption of a fermented milk containing B. animalis DN-173 010 (Activia®, test group) vs a control group.

The individual's participation has lasted approximately 50 days. The first 11 days were used to obtain baseline values for the outcome parameters. The 4 subsequent weeks (D0 to D28) have constituted the experimental phase. During this period, the patients had to consume 2 products per day (during D0 to D27). The products must be consumed with a meal twice a day, preferably once at 8 am and once at 8 pm (with the exception of the first day of consumption (t=0), where the patients were asked to consume the 2 pots with their evening meal (i.e. 8 pm)). In the case of patients forgetting to eat the product they were advised to consume it with their next meal. They have ceased consumption of the study product at the end of week 4 (D27), and were then contacted by telephone on 7th day after last visit (D35).

The study protocol was conducted in accordance with the Declaration of Helsinki and approved by South Manchester Medical Research Ethics Committee. All subjects gave written informed consent before inclusion in the study.

Products

The test product was a fermented milk (Activia®, Danone), containing Bifidobacterium animalis DN-173 010 (1.25×10¹⁰ colony forming unit (cfu) per pot) together with the two classical yoghurt starters, S. thermophilus and L. bulgaricus (1.2×10⁹ cfu/pot). The test product was without flavour. The placebo control is a milk-based non-fermented dairy product without probiotics and with low content of lactose<4 g/pot as in the test product. Each serving (one pot) of either test or placebo control product contained 125 g.

Assessments and Study Endpoints

Abdominal Distension

Abdominal distension was measured using the technique of Abdominal Inductance Plethysmography (AIP) that has been described in detail elsewhere (13, 14-15) but briefly it works on the principle that a loop of wire forms an inductor, the inductance of which is dependent on the area enclosed by the loop. For the purposes of AIP, the wire is sewn into a band of elasticated fabric (approximately 8.5 cm wide) in zig-zag fashion to allow for expansion (Respitrace inductive sensor, Ambulatory Monitoring Inc., New York, USA) and is worn like a belt around the abdomen. Attached to the wire is a small electronic circuit unit, which incorporates an inductor in a resonant circuit whose output frequency varies with the area enclosed by the band, and a small battery operated microprocessor “data logger” which records and stores the average frequency of the oscillator circuit for 30 seconds each minute. The data logger simultaneously records posture (standing, sitting and lying) via sealed mercury tilt switches (ASSEMtech Europe Ltd., Essex, UK) taped to the subject's chest and thigh. The cross sectional area of the abdomen recorded by the equipment is then converted into a circumferential measurement, as described previously.

As previous studies have shown that there is no statistically significant difference between girth measurements taken in the standing and sitting positions, girth whether in the sitting or standing position will be averaged over one hour periods throughout day 1.

With regards standardisation of record time, for each subject, if the length of record was different between the two evaluations, the shorter time was used as reference for the two records.

The length of record was specific to each subject and was thus not the same for all the subjects. It has varied from 11 to 14 hours.

AUC values, over these hourly data, for each of the two days of recording (pre and post intervention respectively) from the first hour after fitting the belt to the hour of retiring to bed in the evening, were calculated. The analysis of AUC were made on the same period, i.e. 12 h period from hour 1 (baseline referenced as the beginning of the measurement at pre- or post-intervention sessions) to hour 13, in order to standardize the period of measurement for each patient and to have complete data for all time for all patients. This period corresponds to the minimal period with all AIP data available for all patients for pre- and post-intervention measurements. The main expression of this parameter was an incremental AUC.

In addition, mean abdominal girth from the beginning to end of day 1 referenced to the beginning of day 1 (i.e. mean abdominal girth from the second hour of the study to the end of day 1 minus mean girth for the first hour of the study) were determined.

Maximum distension was defined as the mean girth over one hour of recording at which girth was at its greatest. Whether maximal girth was associated with the end of day, meal ingestion or no specific identifiable event will be noted.

Global Assessment

The global assessment of IBS symptoms relief was done by one global question (“Do you consider that in the past week, you have had adequate relief of your IBS-symptoms (abdominal pain or discomfort, bloating or distension, altered bowel habit, overall well being) compared to the period before beginning the study yoghurt?”). If the answer to this question is yes, then the patient was asked to answer the following question: “How would you describe your relief?” “slight”, “moderate”, “a lot” or “complete”. This assessment was done every 7th day after the start of the consumption of the study product.

Satisfaction with Bowel Habit

The satisfaction with bowel habits or with overall wellbeing was assessed by answering to two independent questions (“How satisfied have you been with your bowel habit in the past week, compared to the period before beginning the study yoghurt?” and “How satisfied have you been with your overall well-being in the past week, compared to the period before beginning the study yoghurt?”). The answer to each question could be “not satisfied”, “slightly satisfied”, “moderately satisfied” or “completely satisfied”. This assessment was done every 7th day after the start of the consumption of the study product.

Statistical Methods

The trial sample size calculation was based on previous data obtained on abdominal girth studies (18, 14-15). With 17 patients per group (34 patients in all), the study will have an 80% power to detect differences (mean abdominal girth from the beginning to the end of day 1 referenced to the beginning of day 1) of 2 cm or more, assuming a common SD (16) of 2.0 and that a simple 2-sample t-test is used with the conventional 5% significance level. The randomisation was stratified by menstrual cycle/menopausal status Randomised patients who dropped out before the second AlP and transit time assessment were replaced in order to reach the number of 34 evaluable patients.

Two analyses will be carried out: one on the ITT population, and one on the PP population. The main analysis will be the analysis on the ITT. Baseline for criteria measured several times before study product consumption were the mean over the last 11 days before study product consumption, standardized for 7 days when needed. Age and body mass index (BMI) were taking into account as confounding factors in the covariate analysis according to data literature. Changes of parameters hourly assessed during 24-h periods (abdominal distension, i.e. AUC, mean, maximal, abdominal pain/discomfort, bloating, flatulence, overall IBS-symptom, bowel frequency, stool consistency, straining, urgency, incomplete evacuation) were compared between groups using analyses of covariance with baseline readings as covariate.

The main expression of abdominal distension is an incremental AUC over a standardized 12-h period which was considered as the main criterion. For daily assessment of parameters (recorded throughout the study in the dairies), a repeated measures analysis over 4-week was performed (time=week) as the main analysis (averaging over 7 days of recording where appropriate) to compare test and control groups. The analysis of the effect of each parameter at each week was performed with a ANCOVA, with appropriate adjustment for multiple testing, or a t-test if no covariate was taken into account. A longitudinal analysis over the time period using generalised estimating equations was also carried out.

IBS symptoms relief will be weekly assessed except for baseline time. First one with a binomial response (“Yes”/“No”) and if it is “Yes” with a multinomial response. Satisfaction with bowel habits and with overall well-being were also assessed each week. A repeated measures analysis was performed (time=week) as the main analysis. The analysis of the effect at each week was performed with a ANCOVA, or logistic regression models as appropriate, with appropriate adjustment for multiple testing, or a t-test if no covariate is taken into account.

Changes in IBS severity score between groups were compared using analyses of covariance with baseline readings as covariate. Comparison of the changes for bowel transit (small and large) between the two groups was carried out using ANCOVA.

Results

All results in tables and figures are the results on the ITT population. Results on PP population, when available, are given in the text following the description of the ITT results.

FIG. 1 describes the flow of patients through the protocol.

Abdominal Distension

Changes in maximal abdominal distension are shown in FIG. 2B. There is a significant (p=0.029) larger percentage decrease in the relative maximum distension in the product group vs the control group, −77.1% vs −28.6 respectively. The effect was similar in the PP population (−77.1% vs −15.8%, p=0.022).

IBS Symptoms

• • 24-hour AUC measurements

Results of the changes in abdominal bloating and abdominal pain/discomfort over the same period of recording of abdominal girth are shown in FIGS. 3A-C and 4A-C, respectively.

The mean score of abdominal bloating was lower in the product group as compared to the control group at the end of product consumption period (−0.5; 95% CI (−1.0, 0.1); p=0.084) (FIG. 4C). This effect was significant in the PP population (−0.5; 95% CI (−1.0, 0.0); p=0.042).

This lower abdominal pain/discomfort score was significantly different than the one observed in control group (−0.6; 95% CI (−1.2, −0.1); p=0.024) in the PP population.

• • 4 week assessment

Results of the changes in abdominal bloating, abdominal pain/discomfort, flatulence and overall IBS symptoms over the 4-week period of product consumption are shown in FIGS. 5, 6, 7 and 8, respectively.

Weekly analysis show that the improvement decrease in bloating score was significantly better (p=0.041, non-adjusted test) in product group at week 4 (FIG. 5).

Abdominal pain/discomfort score was significantly (p=0.044) improved in the test group over the 4-week period of product consumption (mean overall difference between groups=−0.5; 95% (−1.0, 0.0) (FIG. 6). A significant improvement (p=0.039, non-adjusted test) is also observed in test group at the end of product consumption, i.e. week 4, when weekly analysis was performed.

Weekly analysis showed that the improvement decrease in flatulence score is significantly better (p=0.030, non-adjusted test) in product group at week 1 (FIG. 7).

Overall IBS symptoms score was significantly (p=0.032) improved in the test group over the 4-week period of product consumption (mean overall difference between groups=−0.5; 95% (−1.0, −0.05) (FIG. 8). A significant improvement (p=0.031, non-adjusted test) was also observed in test group at the end of product consumption, i.e. week 4, when weekly analysis were done.

Satisfaction Symptoms Relief

Weekly change of IBS symptoms relief showed significant higher rate of patients which were satisfied with their bowel habits (FIG. 9) at week 1 (82.4% (14/17 patients) in test group vs 41.2% (7/17 patients) in control group; p=0.001) and week 2 (87.5% (14/16 patients) in test group vs 47.1% (8/17 patients) in control group; p=0.026).

Results of the analysis on overall 4-week period are not available yet. The mean rate of patients satisfied with their bowel habits over the 4-week period of product consumption was 85% (14/17 patients) vs 53% (9/17 patients), for test and control groups respectively.

Overall Well Being

The mean rate of patients satisfied with their overall well being over the 4-week period of product consumption was 82% (12/15 patients) vs 65% (10/16 patients), for test and control groups respectively (FIG. 10).

CONCLUSIONS

This study was designed to investigate the effect of the fermented dairy product containing the strain B. animalis DN-173 010 and a yoghurt symbiosis (i.e. Activia®) on abdominal distension that is a particular intrusive symptoms in IBS. Global assessment of IBS symptoms were also done to determine the global effect of the product in a well characterised population of IBS women.

The present study showed that the consumption of a fermented dairy product containing the strain B. animalis DN-173 010 and a yoghurt symbiosis (i.e. Activia®) improves abdominal distension and as well as the overall global symptomatology of IBS (abdominal bloating, abdominal pain/discomfort, flatulence and overall IBS symptoms) in women with IBS-C.

Primary endpoint, abdominal distension, showed a significant larger percentage decrease in the relative maximum distension in the product group vs the control group. Indeed, a striking effect was observed in the decrease (−77%) of the maximal abdominal distension (relative expression). It's the first time that a study reports a positive effect of probiotics on abdominal distension. Interestingly, this effect on abdominal distension is associated with an improvement of both sensations of abdominal bloating and abdominal pain/discomfort during the same 12-h period of assessment.

Analysis on PP population, which could be considered as analysis of sensitivity, showed a significant improvement of abdominal bloating and abdominal pain/discomfort. The analysis of the 4-week period of product consumption demonstrated also beneficial effects on overall symptomatology of IBS as showed by the significant improvement of overall IBS symptoms over this period. This effect is supported by a significant reduction of abdominal pain/discomfort and a tendency to an improvement of abdominal bloating and flatulence.

Although for the evaluation of the clinical relevance the small sample size has to be kept in mind, global assessments of IBS-symptoms relief, satisfaction with bowel habits and with overall well-being are in favour of an important clinical change for the patients having consumed the product.

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