Scientific Opinion on the substantiation of health claims related to acacia gum (gum Arabic) and decreasing potentially pathogenic gastro-intestinal
microorganisms (ID 758), changes in short chain fatty acid (SCFA) production and pH in the gastro-intestinal tract (ID 759), changes in bowel
function (ID 759), reduction of gastro-intestinal discomfort (ID 759), maintenance of faecal nitrogen content and/or normal blood urea concentrations (ID 840, 1975), and maintenance of normal blood
LDL-cholesterol concentrations (ID 841) pursuant to Article 13(1) of Regulation (EC) No 1924/2006[sup]1[/sup]
EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA)2, 3
European Food Safety Authority (EFSA), Parma, Italy
Słowa kluczowe:
Acacia gum (gum Arabic)
LDL-cholesterol
SCFA production
blood urea
bowel function
faecal nitrogen
gastro-intestinal discomfort
health claims
pH
potentially pathogenic microorganisms
1. Charakterystyka żywności / składnika
The food constituent that is the subject of the health claim is acacia gum (gum Arabic).
Acacia gum is a water-soluble type of fibre made of hardened sap taken from two species of the acacia tree: Acacia senegal (L.) Willd. and Acacia seyal Delile. Acacia gum is a complex mixture of polysaccharides and glycoproteins, namely branched galactan composed of a backbone of D-galactose units and side chains of D-glucuronic acid with terminal L-rhamnose or L-arabinose units. Acacia gum is non-digestible in the human small intestine. The molecular weight of acacia gum is between 200 and 600 kDa. Acacia gum does not occur naturally in foods, and is used primarily in the food industry as a stabiliser (E414).
The Panel considers that the food constituent, acacia gum, which is the subject of the health claims, is sufficiently characterised.
2. Znaczenie oświadczenia dla zdrowia człowieka
2.1. Zmniejszenie ilości potencjalnie patogennych mikroorganizmów przewodu pokarmowego (ID 758)
The claimed effect is “prebiotic action: increase in beneficial bacteria in the colon”. The Panel assumes that the target population is the general population.
The Panel assumes that the claimed effect refers to increasing numbers of bacteria which are considered to be “beneficial”.
The numbers/proportions of bacterial groups which would constitute a “beneficial” colon/intestinal flora have not been established. Increasing the number of any group of microorganisms, including lactobacilli and/or bifidobacteria, is not in itself considered to be a beneficial physiological effect. The Panel considers that the evidence provided does not establish that increasing numbers of gastro- intestinal microorganisms is a beneficial physiological effect.
The Panel considers that the claimed effect, in the context of decreasing potentially pathogenic gastro- intestinal microorganisms, might be a beneficial physiological effect.
2.2. Zmienia produkcję krótkołańcuchowych kwasów tłuszczowych (SCFA) i odczyn pH w przewodzie pokarmowym (ID 759)
The claimed effect is “improved intestinal conditions (pH, SCFA production) and intestinal functions”. The Panel assumes that the target population is the general population.
The Panel notes that the claimed effect refers to changes in short chain fatty acid (SCFA) production and pH in the gastro-intestinal tract.
The Panel considers that changes in SCFA production and pH in the gastro-intestinal tract are not beneficial physiological effects per se, but need to be linked to a beneficial physiological or clinical outcome. No evidence has been provided to indicate the context in which the claimed effect could be considered as a beneficial physiological effect.
The Panel concludes that a cause and effect relationship has not been established between the consumption of acacia gum and a beneficial physiological effect related to changes in SCFA production and pH in the gastro-intestinal tract.
2.3. Zmiany w funkcjach jelita (ID 759)
The claimed effect is “improved intestinal conditions (pH, SCFA production) and intestinal functions”. The Panel assumes that the target population is the general population.
In the context of the proposed wording, the Panel assumes that the claimed effect refers to changes in bowel function.
The Panel considers that changes in bowel function, such as reduced transit time, more frequent bowel movements, increased faecal bulk or softer stools, may be a beneficial physiological effect, provided these changes do not result in diarrhoea.
2.4. Zmniejszenie dolegliwości ze strony przewodu pokarmowego (ID 759)
The claimed effect is “improved intestinal conditions (pH, SCFA production) and intestinal functions”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings, the Panel assumes that the claimed effect refers to reducing gastro-intestinal discomfort.
The Panel considers that reduction of gastro-intestinal discomfort is a beneficial physiological effect.
2.5. Utrzymanie prawidłowej zawartości azotu w kale i/lub prawidłowego stężenia mocznika we krwi (ID 840,1975)
The claimed effect is “acacia gum and renal function”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings, the Panel assumes that the claimed effect refers to the maintenance of faecal nitrogen content and/or blood urea concentrations.
The Panel considers that the evidence provided does not establish that maintenance of faecal nitrogen content and/or blood urea concentrations are beneficial physiological effects for the general healthy population.
The Panel concludes that a cause and effect relationship has not been established between the consumption of acacia gum and a beneficial physiological effect related to the maintenance of faecal nitrogen content and/or normal blood urea concentrations.
2.6. Utrzymanie prawidłowego stężenia cholesterolu LDL we krwi (ID 841)
The claimed effect is “acacia gum and cholesterol”. The Panel assumes that the target population is the general population.
In the context of the clarifications provided by Member States, the Panel assumes that the claimed effect refers to the maintenance of normal blood LDL-cholesterol concentrations.
A claim on acacia gum and the maintenance of normal blood cholesterol concentrations has already been assessed with an unfavourable outcome (EFSA Panel on Dietetic Products Nutrition and Allergies (NDA), 2009), and the references cited for this claim did not provide any additional scientific data which could be used to substantiate the claim.
3. Naukowe uzasadnienia wpływu na zdrowie człowieka -
3.1. Zmniejszenie ilości potencjalnie patogennych mikroorganizmów przewodu pokarmowego (ID 758)
The vast majority of the references provided for the scientific substantiation of this claim were narrative reviews, and human, animal and in vitro studies, on acacia gum and effects other than decreasing potentially pathogenic gastro-intestinal microorganisms. These included references on the fermentation of acacia gum by colonic bacteria, on the biological activity of two different acacia gums, on the digestive tolerance of acacia gum and on the digestive adaptation to acacia gum intake, as well as references on the effect of acacia gum on gastro-intestinal microbiota which did not address pathogens. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
In a randomised, double-blind study (Calame et al., 2008), healthy volunteers (n=54) consumed between 5 and 40 g per day of acacia gum dissolved in water or water as a control for four weeks. No significant differences in the numbers of Clostridium difficile during the intervention were noted between the test and the control group.
Two in vitro studies addressed the effect of acacia gum on the growth of clostridia and Clostridium difficile, and on the production of Clostridium difficile toxin A (May et al., 1994; Michel et al., 1998). The Panel considers that evidence provided in in vitro studies is not sufficient to predict the occurrence of an effect of acacia gum consumption on decreasing potentially pathogenic gastro- intestinal microorganisms in humans.
The Panel notes that the only human intervention study provided from which conclusions could be drawn for the substantiation of the claimed effect did not show an effect of acacia gum on decreasing potentially pathogenic gastro-intestinal microorganisms.
The Panel concludes that a cause and effect relationship has not been established between the consumption of acacia gum and decreasing potentially pathogenic gastro-intestinal microorganisms.
3.2. Zmiany w funkcjach jelita (ID 759)
The references provided for the scientific substantiation of the claim included textbooks, publications by authoritative bodies and general reviews that did not provide any primary data which could be used for the scientific substantiation of the claimed effect. The majority of human, animal and in vitro studies were unrelated to the food constituent that is the subject of the health claim, and/or were unrelated to the claimed effect. The latter included references on the digestive tolerance of acacia gum, on digestive adaptation to acacia gum intake, and on the effect of acacia gum on abdominal comfort, human gastro-intestinal microbiota, water and nutrient absorption, and NF-kappaB p65 activity. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
The effect of acacia gum on bowel function was evaluated in three of the presented human intervention studies.
McLean Ross et al. (1983) used 25 g of acacia gum per day in a non-controlled study in five male volunteers for three weeks to assess the effect of acacia gum on transit time and faecal weight. The Panel considers that no conclusions can be drawn from this uncontrolled study for the scientific substantiation of the claimed effect.
In a randomised, single-blind, cross-over study Bliss et al. (1996) evaluated the effect of acacia gum (50 g/day) vs. pectin on faecal nitrogen excretion and serum urea nitrogen in 16 patients with chronic renal insufficiency. Assessment of faecal weight and stool frequency were secondary endpoints of the study. During consumption of acacia gum the mean wet and dry faecal weight was significantly higher compared to pectin (p<0.001). No effect of acacia gum on stool frequency was found. The Panel notes the small study size, that the assessment of faecal weight and stool frequency was a secondary endpoint, and that acacia gum was used in this study in a dose many times (8-10 times) higher than the one proposed in the conditions of use.
The same team administered in a randomised, single-blind, parallel study acacia gum (25 g/day, 31 days) vs. Psyllium and pectin to a group of patients (n=13 in each group) with faecal incontinence (Bliss et al., 2001). Changes in stool frequency, and in wet and dry faecal weight, were not statistically significant during the intervention. The Panel notes that this study did not show an effect of acacia gum on bowel function.
In weighing the evidence, the Panel took into account that one study did not show an effect of acacia gum on stool frequency, or on wet and dry faecal weight, and that the one study showing an effect of acacia gum on faecal weight, but not on stool frequency, was a small study in which the assessment of faecal weight and stool frequency was a secondary endpoint.
The Panel concludes that a cause and effect relationship has not been established between the consumption of acacia gum and changes in bowel function.
3.3. Zmniejszenie dolegliwości ze strony przewodu pokarmowego (ID 759)
The references provided for the scientific substantiation of the claim included textbooks, publications by authoritative bodies and general reviews that did not provide any primary data which could be used for the scientific substantiation of the claimed effect. One human intervention study investigated the effects of acacia gum in combination with another food constituent on abdominal comfort (Goetze et al., 2008). The Panel considers that no conclusions can be drawn from a study using a fixed combination for the scientific substantiation of a claim on acacia gum alone. The remaining human, animal and in vitro studies were unrelated to the food constituent that is the subject of the health claim, and/or were unrelated to the claimed effect. The latter included references on the digestive tolerance of acacia gum, on digestive adaptation to acacia gum intake, on the effect of acacia gum on human gastro-intestinal microbiota, on water and nutrient absorption, on faecal incontinence, on faecal nitrogen excretion, on serum urea nitrogen concentrations, and on NF-kappaB p65 activity. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
The Panel concludes that a cause and effect relationship has not been established between the consumption of acacia gum and reduction of gastrointestinal discomfort.
Wnioski
On the basis of the data presented, the Panel concludes that:
The food constituent, acacia gum (gum Arabic), which is the subject of the health claims, is sufficiently characterised.
Decreasing potentially pathogenic gastro-intestinal microorganisms (ID 758)
The claimed effect is “prebiotic action: increase in beneficial bacteria in the colon”. The target population is assumed to be the general population. Decreasing potentially pathogenic gastro- intestinal microorganisms might be a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of acacia gum and decreasing potentially pathogenic gastro-intestinal microorganisms.
Changes in short chain fatty acid (SCFA) production and pH in the gastro-intestinal tract (ID 759)
The claimed effect is “improved intestinal conditions (pH, SCFA production) and intestinal functions”. The target population is assumed to be the general population. Changes in SCFA production and pH in the gastro-intestinal tract are not beneficial physiological effects per se, but need to be linked to a beneficial physiological or clinical outcome. No evidence has been provided to indicate the context in which the claimed effect could be considered as a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of acacia gum and a beneficial physiological effect related to changes in SCFA production and pH in the gastro-intestinal tract.
Changes in bowel function (ID 759)
The claimed effect is “improved intestinal conditions (pH, SCFA production) and intestinal functions”. The target population is assumed to be the general population. In the context of the proposed wordings, it is assumed that the claimed effect refers to changes in bowel function. The Panel considers that changes in bowel function, such as reduced transit time, more frequent bowel movements, increased faecal bulk or softer stools, may be a beneficial physiological effect, provided these changes do not result in diarrhoea.
A cause and effect relationship has not been established between the consumption of acacia gum and changes in bowel function.
Reduction of gastro-intestinal discomfort (ID 759)
The claimed effect is “improved intestinal conditions (pH, SCFA production) and intestinal functions”. The target population is assumed to be the general population. In the context of the proposed wordings, it is assumed that the claimed effect refers to reducing gastro-intestinal discomfort. Reduction of gastro-intestinal discomfort is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of acacia gum and reduction of gastro-intestinal discomfort.
Maintenance of faecal nitrogen content and/or normal blood urea concentrations (ID 840, 1975)
The claimed effect is “acacia gum and renal function”. The target population is assumed to be the general population. In the context of the proposed wordings, it is assumed that the claimed effect refers to the maintenance of faecal nitrogen content and/or blood urea concentrations. The evidence provided does not establish that maintenance of faecal nitrogen content and/or normal blood urea concentrations are beneficial physiological effects for the general healthy population.
A cause and effect relationship has not been established between the consumption of acacia gum and a beneficial physiological effect related to maintenance of faecal nitrogen content and/or normal blood urea concentrations.
Maintenance of normal blood LDL-cholesterol concentrations (ID 841)
The claimed effect is “acacia gum and cholesterol”. The target population is assumed to be the general population.
A claim on acacia gum and the maintenance of normal cholesterol concentrations has already been assessed with an unfavourable outcome, and the references cited for this claim did not provide any additional scientific data which could be used to substantiate the claim.
