Assessment of the efficacy of a feed additive consisting of Bifidobacterium longum CNCM I‐5642 (PP102I) for dogs (Nestlé Enterprises S.A.)

TL;DR

This paper evaluates the effectiveness and safety of a probiotic additive for dogs, finding it potentially effective at a specific dosage but irritating to the eyes.

Contribution

The study provides new evidence on the efficacy and safety profile of Bifidobacterium longum CNCM I-5642 for use in dog feed.

Findings

The additive is irritant to the eyes but not to the skin.

The additive may be effective at 1 × 109 CFU per dog per day.

Safety for users remains a concern due to potential sensitisation.

Abstract

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the efficacy of Bifidobacterium longum CNCM I‐5642 (PP102I) as a zootechnical feed additive (functional group: physiological condition stabiliser) for dogs. In a previous opinion, the FEEDAP Panel concluded that PP102I was safe for dogs and the environment. Regarding the safety for the users, the Panel concluded that the additive should be considered a skin and respiratory sensitiser. Due to the lack of data, no conclusions could be drawn on the potential for skin/eye irritancy of the additive. Due to the lack of sufficient data, the Panel could not conclude on the efficacy of the additive for dogs at the proposed conditions of use. The applicant submitted in vitro eye and skin irritation tests and one efficacy trial in dogs to address the inconclusive aspects of the previous assessment. Based on the data provided, the Panel considers that the additive is irritant to the eyes but not to the skin. The additive has the potential to be efficacious when included in feed for dogs at 1 × 109 colony forming unit (CFU)/dog per day (which would correspond approximately to 3.5 × 109 CFU/kg complete feed).

Tables

TABLE 1. Description of the additive.

Category of additive	Zootechnical additives
Functional group of additive	Physiological condition stabiliser
Description	Bifidobacterium longum (CNCM I‐5642)
Target animal category	Dogs
Applicant	Nestlé Enterprises S.A., (NESA), Nestlé Purina PetCare EMENA Division represented in the EU by Centres de Recherche et Développement Nestlé
Type of request	New opinion – Request for scientific opinion pursuant to Article 29(1)(a) of Regulation (EC) No 178/2002

TABLE 2. Effects of the dietary supplementation with the additive (PP102I) on relevant physiological and behavioural parameters measured in dogs.

Groups	Control	PP102I
CFU/dog per day	0	109
First veterinary clinic visit
Tympanic temperature (°C)	38.4a	38.1b
LF/HF*	0.33a	0.22b
Car ride
Standing (s)	28.9a	13.9b
Lying down (s)	278b	345a
Lip licking Frequency score	2.9a	2.6b
Panting score	2.6a	2.2b
Yawning (frequency)**	0.23b	0.42a
Recovery period
HF (ms2)*	3582b	5134a
RMSSD (ms)*	83b	102a
pNN50 (%)*	23.5b	34.4a

Full text

INTRODUCTION

1

Background and Terms of Reference as provided by the requestor

1.1

Regulation (EC) No 1831/2003 establishes the rules governing the Union authorisation of additives for use in animal nutrition; in particular, Article 9 defines the terms of the authorisation by the Commission.

The applicant is seeking a Union authorisation of the feed additive described in Table 1.

On 29.06.2022, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP), in its opinion on Safety and efficacy of a feed additive consisting of Bifidobacterium longum CNCM I‐5642 (PP102I) for cats and dogs (Nestle Enterprises S.A.) could not conclude on the efficacy of the additive. Subsequently, the applicant withdrew the application for cats. The European Commission gave the possibility to the applicant to submit supplementary information and data to complete the assessment and to allow a revision of the EFSA's opinion. The new supplementary information and data have been transmitted by the applicant using the E‐Submission Food Chain Platform (application number FEED‐2024‐27056).1

In view of the above and in accordance with Article 29(1)(a) of Regulation (EC) No 178/2002, the European Commission requests EFSA to deliver a new scientific opinion on the efficacy of the feed additive consisting of Bifidobacterium longum CNCM I‐5642 for dogs under the conditions of Regulation (EC) No 1831/2003, based on the supplementary information and data submitted by the applicant.

DATA AND METHODOLOGIES

2

Data

2.1

The present assessment is based on data submitted by the applicant in the form of supplementary information2 to a previous application on the same product.3 The dossier was received on 8/8/2024, and the general information and supporting documentation are available on Open.EFSA at https://open.efsa.europa.eu/questions/EFSA‐Q‐2024‐00522.

Methodologies

2.2

The approach followed by the FEEDAP Panel to assess the safety and efficacy of B. longum CNCM I‐5642 (PP102I) is in line with the principles laid down in Regulation (EC) No 429/20084 and the relevant guidance documents: Guidance on the assessment of the safety of feed additives for the users (EFSA FEEDAP Panel, 2023) and Guidance on the assessment of the efficacy of feed additives (EFSA FEEDAP Panel, 2024).

ASSESSMENT

3

The additive under assessment (referred to by the commercial name: PP102I) consists of a powder preparation containing viable cells of B. longum CNCM I‐5642 (minimum guaranteed content of 5 × 10^10^ colony forming units (CFU) per gram of additive) and ■■■■■. The additive is intended for use as a zootechnical additive (functional group: physiological condition stabilisers) in feed for dogs at the minimum recommended daily dose of 1 × 10^9^ CFU of B. longum per dog, which would be equivalent to 3.5 × 10^9^ CFU/kg complete feed.

The species B. longum is considered by EFSA to be suitable for the qualified presumption of safety (QPS) approach to safety assessment. In the previous application, the strain was shown to meet the QPS requirements. Considering the QPS status of the strain and the fact that no concerns are expected from maltodextrin, PP102I was deemed safe for the target animals and the environment (EFSA FEEDAP Panel, 2022). Regarding the safety for the users, the Panel concluded that the additive should be considered a skin and respiratory sensitiser. Due to the lack of data, no conclusions could be drawn on the potential for skin/eye irritancy of the additive. The Panel could not conclude on the efficacy of the additive for dogs.

The applicant submitted new data to address the potential for skin/eye irritancy and the efficacy of the additive.

Safety for the user

3.1

The applicant provided one in vitro skin and one eye irritation test performed following OECD Guidelines 439 and 492, respectively. The skin irritation study showed that the additive is classified as non‐irritant to the skin (UN GHS ‘No Category’). Regarding eye irritation, the study's results showed that the additive reduced cell viability to 33% compared to relevant controls; therefore, the additive is considered irritant to the eyes, but no prediction can be made on its classification.

Therefore, the additive is considered not to be an irritant to the skin but an irritant to the eyes and, being a microorganism, a skin and respiratory sensitiser. Therefore, any exposure to it is regarded as a risk.

Efficacy

3.2

The additive is proposed as a zootechnical additive (functional group: physiological condition stabiliser) to improve the stress resilience of dogs. The minimum inclusion rate is 1 × 10^9^ CFU/dog daily (equivalent to 3.5 × 10^9^ CFU/kg complete feed). In its previous opinion (EFSA FEEDAP Panel, 2022), the Panel concluded that the additive showed positive effects when the dogs were exposed to stressful situations in two of the trials. Due to the lack of effects on physiological key endpoints and the limited changes in the behavioural parameters measured in the third trial, the Panel could not conclude on the efficacy of the additive for dogs.

The applicant submitted a new trial in dogs to support the efficacy of the additive. A total of 20 adult (2.2–6.1 years) dogs from both sexes (11 females and 9 males; all neutered) and mixed breeds5 were housed in groups of two animals and allocated to the two experimental groups based on sex, age and/or body size. The trial followed a cross‐over design, each dog acting as its own control. The study lasted 107 days and was distributed in three phases: phase I – half of the dogs received a basal diet, whereas the other half received the same basal diet supplemented with the additive for 42 days; washout phase – all dogs received the basal diet for 23 days; phase II – the dogs previously receiving the basal diet were supplemented with the additive for 42 days and vice versa. Dogs were fed a commercial extruded feed top‐dressed with 1 g of a complementary feed without (control) or with PP102I at an intended level of 1 × 10^9^ CFU/dog per day. The count of B. longum in the complementary feed was analytically confirmed.6 Water was available ad libitum in all cases.

Feed intake and health status were recorded daily during the experimental period in all trials. Dogs were weighed at the start (days 1 and 65) and at the end of each phase (days 42 and 107). At the end of each phase, all dogs underwent a formal behavioural challenge, consisting of a visit to the on‐site veterinary clinic, in which a cardiac monitor was fitted, the tympanic temperature was recorded and a blood sample was taken, followed by a 10‐min car ride and a second consecutive visit to the clinic to perform the same measurements (tympanic temperature and blood sampling). After this, the dogs were taken to a holding kennel and allowed to recover for 30 min. The cardiac monitor was removed after the recovery time.

The blood samples were analysed for the content of serum cortisol. The heart rate (HR) and the heart rate variability (HRV) were recorded during the visit to the clinic (tympanic temperature measurement and blood sampling), continuously throughout the car ride and for an additional 30 min in the recovery kennel environment after the completion of the car ride.7 A series of behavioural parameters were evaluated during the car ride using video recording.8

The experimental data were analysed with a generalised linear mixed model considering the diet, order and the interaction between them as fixed effects and the animal as a random effect. The significance level was set at 0.10.

At the time of the first stressful event (veterinary visit), the dogs supplemented with PP102I showed a lower tympanic temperature and a lower LF/HF ratio than the control animals (Table 2). Out of the 10 behavioural parameters recorded during the car ride, the dogs supplemented with PP102I showed a lower standing time, a higher lying down time and a lower lip licking and panting frequency than the control ones, while the yawning frequency was higher in the supplemented group. No differences between groups were observed in the remaining four behavioural parameters measured. During the recovery period, the supplemented dogs showed higher high frequency (HF), root mean square of successive differences between heartbeats (RMSSD) and percent of heartbeats where differences between the RR interval and the previous RR interval are greater than 50 (pNN50) values than the control ones.

The dogs' body weight and feed intake were unaffected by the dietary supplementation with the additive during the experimental period. Moreover, no difference in serum cortisol was observed before or after the car ride between the groups.

The physiological parameters affected by the additive supplementation are primarily indicators of parasympathetic system dominance compared to the sympathetic system, suggesting a higher level of tranquillity and lower stress. The direction of the affected behavioural parameters (standing time, lying down time, lip licking, panting) are generally correlated with a state of calm. The only exception is the yawning frequency, which was increased.

Based on the positive changes observed in relevant physiological and behavioural parameters, the FEEDAP Panel concludes that the dogs supplemented with the additive at the proposed conditions of use showed higher stress resilience when exposed to stressing factors representing realistic situations of the animals' lives.

Conclusions on efficacy

3.2.1

Considering the data provided in the previous and current submissions, the FEEDAP Panel concludes that the additive has the potential to be efficacious in dogs as a physiological condition stabiliser when added to feed at 1 × 10^9^ CFU/dog per day (which would correspond approximately to 3.5 × 10^9^ CFU/kg complete feed).

Post‐market monitoring

3.3

The FEEDAP Panel considers that there is no need for specific requirements for a post‐market monitoring plan other than those established in the Feed Hygiene Regulation9 and Good Manufacturing Practice.

CONCLUSIONS

4

The additive PP102I consisting of B. longum CNCM I‐5642 is not an irritant to the skin, but it is considered an irritant to the eyes and a skin and a respiratory sensitiser. Therefore, any exposure of users to the additive is considered a risk.

The FEEDAP Panel concludes that the additive has the potential to be efficacious in dogs as a physiological condition stabiliser when added to feed at the minimum recommended use level of 1 × 10^9^ CFU/dog per day, corresponding to 3.5 × 10^9^ CFU/kg complete feed.ABBREVIATIONSCFUcolony forming unitFEEDAPEFSA Scientific Panel on Additives and Products or Substances used in Animal FeedLF/HFlow to high‐frequency ratioOECDOrganisation for Economic Co‐operation and DevelopmentpNN50Percent of heartbeats where differences between the RR interval and the previous RR interval are greater than 50 msRMSSDroot mean square of successive differences between heartbeats

REQUESTOR

European Commission

QUESTION NUMBER

EFSA‐Q‐2024‐00522

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PANEL MEMBERS

Roberto Edoardo Villa, Giovanna Azimonti, Eleftherios Bonos, Henrik Christensen, Mojca Durjava, Birgit Dusemund, Ronette Gehring, Boet Glandorf, Maryline Kouba, Marta López‐Alonso, Francesca Marcon, Carlo Nebbia, Alena Pechová, Miguel Prieto‐Maradona, Ilen Röhe, and Katerina Theodoridou.

LEGAL NOTICE

Relevant information or parts of this scientific output have been blackened in accordance with the confidentiality requests formulated by the applicant pending a decision thereon by EFSA. The full output has been shared with the European Commission, EU Member States (if applicable) and the applicant. The blackening may be subject to review once the decision on the confidentiality requests is adopted by EFSA and in case it rejects some of the confidentiality requests.