1806.pdf

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Scientific Opinion on the substantiation of health claims related to lactulose and decreasing potentially pathogenic gastro-intestinal microorganisms (ID 806) and reduction in intestinal transit time (ID 807) 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 This scientific output, published on 9 December 2010, replaces the earlier version published on 19 October 20104.
Słowa kluczowe: Lactulose   health claims   intestinal transit time   potentially pathogenic microorganisms  
ID:    807      806  
Produkty: Laktuloza  

1. Charakterystyka żywności / składnika

The food constituent that is the subject of the health claims is lactulose which is an artificial disaccharide with the chemical formula 4-O-β-D-Galactopyranosyl-β-D-fructofuranose. Lactulose can be generated by alkaline isomerisation of lactose or by enzyme-catalysed synthesis (Schuster-Wolff- Buhring et al., 2010). Lactulose is a well-characterised food constituent.
The Panel considers that the food constituent, lactulose, 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 806)

The claimed effect is “probiotic/bifidogenic”. 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 capacity of the food constituent to increase the numbers of bacteria that are considered to be “healthy/balanced/good”.
The numbers/proportions of bacterial groups that would constitute a “healthy/balanced/good gut flora or microflora” have not been established. Increasing the number of any groups of microorganisms, including lactobaccilli 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 the numbers of gastro-intestinal microorganisms is a beneficial physiological effect.
The Panel considers that decreasing potentially pathogenic gastro-intestinal microorganisms might be a beneficial physiological effect.

2.2. Skrócenie czasu pasażu jelitowego (ID 807)

The claimed effect is “transit effect”. 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 reduction in intestinal transit time.
The Panel considers that a reduction in intestinal transit time within the normal range might be a beneficial physiological effect.

3. Naukowe uzasadnienia wpływu na zdrowie człowieka


3.1. Zmniejszenie ilości potencjalnie patogennych mikroorganizmów przewodu pokarmowego (ID 806)

The references cited consisted of seven studies in human subjects. Two human studies investigated yoghurt supplemented with a specific Bifidobacterium strain and lactulose, while two other human studies related to lactulose did not address changes in pathogens. The Panel notes that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
In the study by Terada et al. (1992), the effect of dietary lactulose was evaluated in eight healthy volunteers at the level of 3 g/day. The study reported on potentially pathogenic bacteria (lecithinase- positive Clostridium perfringens). However, the Panel notes the weaknesses of the study including the methodology used for microbiological analyses, the small number of subjects, and that the study was not blinded, which limits its value as a source of data to substantiate an effect of the consumption of lactulose on decreasing potentially pathogenic gastro-intestinal microorganisms.
In the study by Tuohy et al. (2002), 10 g of lactulose was given to 10 healthy volunteers and a further 10 healthy volunteers received a 5 g glucose and 5 g lactose dose for 22-33 days. The dose of lactulose used in the study was significantly higher than the dose proposed in the conditions of use. Using culture methods, clostridia were analysed. No other changes were reported. The Panel notes that clostridia represent a large group of bacteria that are part of the commensal intestinal microbiota and that the study did not provide evidence of their characterisation as pathogens. In another study in 36 healthy volunteers (Ballongue et al., 1997), the effects of lactulose, lactitol, and placebo consumption (2 x 10 g/day) on the composition of the faecal microbiota were determined, including analyses of the following bacterial groups Bacteroides, Clostridium, Bifidobacterium, coliforms, Eubacterium, Lactobacillus and Streptococcus. The Panel notes that the bacterial groups analysed in this study are also part of the commensal intestinal microbiota and the study did not provide evidence of the characterisation of any of these groups as pathogens. The Panel considers that no conclusions can be drawn from these studies 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 lactulose and decreasing potentially pathogenic gastro-intestinal microorganisms.

3.2. Skrócenie czasu pasażu jelitowego (ID 807)

The references cited consisted of seven studies in human subjects. The study by Terada et al. (1992) measured the effect of lactulose on some biochemical parameters of faeces and faecal microbiota. The Panel considers that no conclusions can be drawn for the scientific substantiation of the claimed effect.
The study by Miller et al. (1997) focused on determining the impact of 10 g of lactulose or placebo with a radiolabeled test meal on orocaecal transit in eight normal human subjects. The study reported that 10 g of lactulose had a direct accelerating effect on small intestinal transit.
A double-blinded cross-over study was performed on 42 normal healthy volunteers and 24 chronically constipated subjects (Bass and Dennis, 1981). Lactulose at the dose level of 20 g or 40 g/day (in syrup form) produced clinically and statistically significant increases in the frequency, weight, volume and water content of stools in both the normal and constipated subjects. The results in normal subjects demonstrated that there was a dose-response laxative effect in both healthy normal subjects and subjects with chronic constipation.
Another study focused on the impact of lactulose on transit time and reported that lactulose at a dose of 10 g per day accelerates small bowel transit in comparison with inulin (Geboes et al., 2003). Wutzke et al. (1997) demonstrated in a study in 12 healthy volunteers that lactulose given in a dose of 10 g per day caused a small but significant effect on breath hydrogen and that this effect was associated with decreased transit time. Pontes et al. (1995) studied patients admitted to the hospital due to reasons other than constipation. These patients were administered daily 10 g of liquid or crystalline lactulose, lactitol or placebo. The treatment resulted in shorter transit times in both lactulose groups compared with the untreated controls.
Lactulose as a synthetic sugar is used in the treatment of constipation. In the colon, lactulose is broken down to lactic acid and to small amounts of acetic and formic acids by the action of beta- galactosidases from colonic bacteria. This process leads to an increase in osmotic pressure and slight acidification of the colonic content causing an increase in stool water content and softening of the stools (Drugbank, 2009).
In weighing the evidence, the Panel took into account that all studies provided showed a consistent statistically significant effect of lactulose at a dose of 10 g per day on reduction in intestinal transit time, and that the mechanism by which lactulose could exert the claimed effect is established.
The Panel concludes that a cause and effect relationship has been established between the consumption of lactulose and a reduction in intestinal transit time.

4. Uwagi do zaproponowanego brzmienia oświadczenia


4.1. Skrócenie czasu pasażu jelitowego (ID 807)

The Panel considers that the following wording reflects the scientific evidence: “Lactulose contributes to a reduction in intestinal transit time”.

5. Warunki i możliwe ograniczenia stosowania oświadczenia

The Panel considers that in order to obtain the claimed effect at least 10 g of lactulose per day should be consumed in a single serving. The target population is the general population.

Wnioski

On the basis of the data presented, the Panel concludes that:
The food constituent, lactulose, which is the subject of the health claims, is sufficiently characterised.
Decreasing potentially pathogenic gastro-intestinal microorganisms (ID 806)
The claimed effect is “probiotic/bifidogenic”. 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 lactulose and decreasing potentially pathogenic gastro-intestinal microorganisms.
Reduction in intestinal transit time (ID 807)
The claimed effect is “transit effect”. The target population is assumed to be the general population. A reduction in intestinal transit time within the normal range might be a beneficial physiological effect.
A cause and effect relationship has been established between the consumption of lactulose and a reduction in intestinal transit time.
The following wording reflects the scientific evidence: “Lactulose contributes to a reduction in intestinal transit time”.
In order to obtain the claimed effect at least 10 g of lactulose per day should be consumed in a single serving.