Scientific Opinion on the substantiation of health claims related to
Bifidobacterium longum BB536 and improvement of bowel regularity
(ID 3004), normal resistance to cedar pollen allergens (ID 3006), and
decreasing potentially pathogenic gastro-intestinal microorganisms
(ID 3005) 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:
Bifidobacterium longum BB536
allergy
bowel regularity
cedar pollens
health claims
potentially pathogenic gastro-intestinal microorganisms
3. Naukowe uzasadnienia wpływu na zdrowie człowieka
3.1. Poprawa regularności pracy jelit (ID 3004)
The references provided for the scientific substantiation of the claim included a review article and a publication from an authoritative body, which did not contain any primary data which could be used for the scientific substantiation of the claimed effect, and one publication in Japanese of which no English translation was available to the Panel. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
Five human intervention studies were cited in the consolidated list, all of which were included in an internal report (Cantox Health Sciences International, 2009, unpublished) which was also provided.
In a human intervention study (Ogata et al., 1999), 250 mL of a test yoghurt supplemented with Bifidobacterium longum BB536 (2×107 viable BB536 cells per mL, 5x109 cells per day, containing also Streptococcus thermophilus STH450 and Lactobacillus delbrueckii subsp. bulgaricus LBU108) or a control yoghurt (with the same bacterial cultures but without Bifidobacterium longum BB536) were administered daily for two weeks to six healthy volunteers. The effects on faecal microbiota, faecal putrefactive substances, faecal enzymatic activities and faecal properties were examined. The Panel notes that the study did not address outcomes related to the improvement of bowel regularity.
In another study by the same group (Ogata et al., 1997), the effect of Bifidobacterium longum BB536 administered in 200 mL of milk per day for three weeks (2 x109 CFU/day) to adult volunteers was studied in a sequential design. Defecation frequency and faecal characteristics were investigated in 40 women suffering from constipation. Milk without Bifidobacterium longum BB536 was used as placebo. The Panel notes that the intervention order was not randomised, that the study design did not allow the exclusion of a time effect, that no information on blinding was provided, and that the statistical evaluation did not correct for multiple repeated measures. The Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claimed effect.
In another study, adult volunteers were administered a test yoghurt containing Bifidobacterium longum BB536 (100 g of yoghurt, >2x107 viable BB536 cells per mL, containing also Streptococcus thermophilus STH450 and Lactobacillus delbrueckii subsp. bulgaricus LBU108) or a control yoghurt (containing Streptococcus thermophilus STH450 and Lactobacillus delbrueckii subsp. bulgaricus LBU108), and their effects on faecal microbiota, ammonia concentrations, faecal characteristics (colour, consistency) and defecation frequency were examined (Yaeshima et al., 1997). Eleven women were assigned as subjects to test the effects of Bifidobacterium longum BB536 on the intestinal environment, and 39 women were assigned as subjects to test the effects on faecal characteristics and defecation frequency. After a two-week run-in period, in which the subjects consumed control yoghurt, the subjects consumed 100 g of Bifidobacterium longum BB536 yoghurt per day for the subsequent test period, which was two weeks for testing effects on the intestinal microbiota, and three weeks for testing effects on faecal characteristics and defecation frequency. The Panel notes that the intervention order was not randomised, that the study design did not allow the exclusion of a time effect, that no information on blinding was provided, and that the statistical evaluation did not correct for multiple repeated measures. The Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claimed effect.
The same group (Yaeshima et al., 2001) analysed the defecation frequency and faecal characteristics in 43 healthy female volunteers with constipation. A daily dose of 180 mL of a non-fermented milk (1×107 CFU/mL of Lactobacillus gasseri, >1.2×107 CFU/mL of Bifidobacterium longum BB536, and fortified with 376 mg calcium per bottle (180 mL)) was administered for two weeks. The effects on defecation frequency and faecal characteristics were examined and compared with the effects of placebo non-fermented milk. The placebo milk contained Lactobacillus gasseri, and was also fortified with calcium. The total study duration was eight weeks divided into four consecutive periods: milk- free period 1 (1st and 2nd week), Bifidobacterium longum BB536 milk administration period (3rd and 4th week), milk-free period 2 (5th and 6th week), and placebo milk administration period (7th and 8th week). Defecation frequency and number of days without defecation were reported. The Panel notes that the intervention order was not randomised, that the study design did not allow the exclusion of a time effect, that no information on blinding was provided, and that the statistical evaluation did not correct for multiple repeated measures. The Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claimed effect.
A sweet yoghurt containing Bifidobacterium longum BB536 was administered to 41 healthy women volunteers (Yaeshima et al., 1998), and the effects on defecation frequency and faecal characteristics were examined. The study duration was eight weeks, which was divided into four consecutive periods: yoghurt-free period 1 (1st and 2nd week), Bifidobacterium longum BB536 yoghurt (100 g per day, 2x107 CFU/g) administration period (3rd and 4th week), yoghurt-free period 2 (5th and 6th week), and placebo standard sweet yoghurt administration period (7th and 8th week). Changes in defecation frequency were investigated. The Panel notes that the intervention order was not randomised, and that the study design did not allow for the possibility of a time effect. Furthermore, the study was not blinded and the statistical evaluation did not correct for multiple repeated measures. The Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claimed effect.
The Panel concludes that a cause and effect relationship has not been established between consumption of Bifidobacterium longum BB536 and improvement of bowel regularity.
3.2. Prawidłowa odporność na wywołujące alergię pyłki cedru (ID 3006)
The references provided for the scientific substantiation of the claim included a review article, an in vitro study and three animal studies which were not directly related to the claimed effect. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
Three human intervention studies which addressed outcome measures related to the claimed effect were provided (Xiao et al., 2006a; Xiao et al., 2006b; Xiao et al., 2007). These studies were focused on allergic pollinosis, mainly Japanese Cedar Pollinosis. Japanese Cedar Pollinosis (JCPsis) is an immunoglobulin E (IgE)-mediated type I allergy caused by exposure to Japanese cedar (Cryptomeria japonica (L. f.) D. Don) pollen (JCP) which is normally released from early February until the end of April. Subjects included in these studies had at least a two-year clinical history of JCPsis with presence of serum JCP-specific IgE.
In a randomised, double-blind, placebo-controlled pilot study of 40 subjects (17 men, 23 women), the
effect of a yoghurt supplemented with BB536 ( 2x107 CFU/g) given at a dose of 2x100 g per day for 14 weeks in the treatment of Japanese Cedar Pollinosis (JCPsis) was tested by Xiao et al. (2006a). Subjective symptoms and self-care measures were recorded daily, and blood samples were taken before and during the intervention to measure blood concentrations of parameters related to JCPsis. The primary outcome measures were the scores of subjective symptoms. Nasal blockage and nasal itching, eye symptoms and throat symptoms were evaluated using a 0 to 4 point rating scale in accordance with the guidelines of the Japanese Nasal Allergy Clinic. The Panel notes that the study design allowed subject drop-outs when they were prescribed medications for their allergy, instead of leaving these subjects in the study and adjusting for the prescribed medication in the statistical analysis. Because of a possible bias in handling missing data, the Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claimed effect.
In a randomised, double-blind, placebo-controlled trial performed by the same group (Xiao et al., 2006b) in 44 JCPsis subjects (26 men, 18 women), the effect of BB536 (~5x1010 CFU/2 g powder to be ingested with milk) was compared to placebo powder (dextrin) consumed twice daily for 13 weeks during the pollen season. Subjective symptoms were scored according to the guidelines of the Japanese Nasal Allergy Clinic, self-care measures were recorded daily, and blood samples were taken before and during the intervention to measure blood concentrations of parameters related to JCPsis. Two out of 22 subjects in the test group, and 9 out of 22 in the placebo group, prematurely dropped out of the study. The authors attributed the drop-out to severe reactions to pollen, but no further information on these subjects was available. The Panel notes that the study design allowed subject drop-outs, instead of leaving these subjects in the study and adjusting for the prescribed medication that they presumably received, and that the area-under-the-curve analysis performed for each clinical score is not an appropriate method given the missing data. Because of a possible bias in the statistical methods and analyses used for handling missing data, the Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claimed effect.
A double-blind, two-way cross-over study performed by the same group (Xiao et al., 2007) evaluated the effect of BB536 on symptoms in 24 JCPsis patients (10 men, 14 women) experimentally exposed to Japanese cedar pollen in an environmental exposure unit (EEU) outside the normal JCP season. After a one-week run-in period, subjects were randomised to receive either BB536 (~5x1010 CFU/2 g powder to be ingested with milk) or a placebo (dextrin) twice a day for 4 weeks. After a 2-week wash- out period, subjects were crossed over to the other intervention for a period of 4 weeks. At the end of each intervention period, subjects were exposed to JCP in a controlled manner (4 hours). Symptoms were self-rated 30 minutes before exposure, and every 30 minutes during the exposure. After exposure, subjects were instructed to record daily delayed subjective symptoms and medications used from the day of exposure for 5 days. Nasal blockage, eye itching, watery eyes, throat symptoms and disruption of normal activities were evaluated using self-reported questionnaires. The Panel notes the small sample size of the study and the lack of information on the scoring system used to conclude on the allergic nature of the symptoms. The Panel considers that no conclusions can be drawn from this study 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 Bifidobacterium longum BB536 and normal resistance to cedar pollen allergens.
3.3. Zmniejszenie ilości potencjalnie patogennych mikroorganizmów przewodu pokarmowego (ID 3005)
The references provided for the scientific substantiation of the claim included a review article and a publication from an authoritative body, which did not contain any primary data which could be used for the scientific substantiation of the claimed effect, and a paper on the isolation/identification of bifidobacteria which is not related to the claimed effect. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
Seven studies assessed the relationship between dietary intakes of Bifidobacterium longum BB536 and gastro-intestinal microbiota (Ballongue et al., 1993; Odamaki et al., 2007a; 2007b; Ogata et al., 1997; 1999; Tomoda et al., 1991; Yaeshima et al., 1997), all of which were included in an internal report (Cantox Health Sciences International, 2009, unpublished) which was also provided. Faecal levels of the Bacteroides group and Clostridium perfringens were measured in a number of early human intervention studies using traditional culture methods. Several different groups of Bacteroides and clostridia have been analysed, but consistent comparisons are not possible between the reports because of the use of different methodologies. The Panel notes that Bacteroides and clostridia represent a large group of bacteria that are part of the commensal intestinal microbiota, and that the studies did not provide evidence for their characterisation as pathogens. The Panel considers that no conclusions can be drawn from these studies for the scientific substantiation of the claimed effect.
One in vitro study investigated the effect of Bifidobacterium longum BB536 on intestinal pathogens in co-cultivation experiments (Araya-Kojima et al., 1995), and one animal study examined the resistance of Bifidobacterium-monoassociated mice to Escherichia coli challenge (Yamazaki et al., 1982). The Panel considers that evidence provided in animal and in vitro studies is not sufficient to predict the occurrence of an effect of Bifidobacterium longum BB536 consumption on the reduction of potentially pathogenic gastro-intestinal microorganisms in humans.
The Panel concludes that a cause and effect relationship has not been established between the consumption of Bifidobacterium longum BB536 and decreasing potentially pathogenic gastro- intestinal microorganisms.