Overview of differences between microbial feed additives and probiotics for food regarding regulation, growth promotion effects and health properties and consequences for extrapolation of farm animal results to humans

Abstract

For many years, microbial adjuncts have been used to supplement the diets of farm animals and humans. They have evolved since the 1990s to become known as probiotics, i.e. functional food with health benefits. After the discovery of a possible link between manipulation of gut microflora in mice and obesity, a focus on the use of these beneficial microbes that act on gut microflora in animal farming was undertaken and compared with the use of probiotics for food. Beneficial microbes added to feed are classified at a regulatory level as zootechnical additives, in the category of gut flora stabilizers for healthy animals and are regulated up to strain level in Europe. Intended effects are improvement of performance characteristics, which are strain dependent and growth enhancement is not a prerequisite. In fact, increase of body weight is not commonly reported and its frequency is around 25% of the published data examined here. However, when a Body Weight Gain (BWG) was found in the literature, it was generally moderate (lower than or close to 10%) and this over a reduced period of their short industrial life. When it was higher than 10%, it could be explained as an indirect consequence of the alleviation of the weight losses linked to stressful intensive rearing conditions or health deficiency. However, regulations on feed do not consider the health effects because animals are supposed to be healthy, so there is no requirement for reporting healthy effects in the standard European dossier. The regulations governing the addition of beneficial microorganisms to food are less stringent than for feed and no dossier is required if a species has a Qualified Presumption of Safety status. The microbial strain marketed is not submitted to any regulation and its properties (including BWG) do not need to be studied. Only claims for functional or healthy properties are regulated and again growth effect is not included. However, recent studies on probiotic effects showed that BWG could also be observed in humans, or not, according to species and strains. Determining the significance of farm animal results for extrapolation to humans, especially regarding body weight improvement, was not easy because they do not use the same microbial strains nor always the same species. Furthermore, the framework for the management of microbials added to feed or to food differ, especially with regard to goal, timescale and lifestyle. So no one can exclude the possibility that beneficial microorganisms having probiotic effects may have long-term effects in humans that cannot be seen to date in animals, where short-term use is the rule. A possible link to obesity cannot be excluded in relation to timescale, species and strain specificity. To conclude, beneficial microorganisms added in feed are key factors stringently regulated for short-term improvement of zootechnical performances in animals and their use does not entirely parallel that of human probiotics. So extrapolation of farm animal results to humans is biased and not sufficient to be con...

Probiotics - the versatile functional food ingredients

“…and Lactobacillus spp. are more likely to be efficient in pigs and poultry (Bernardeau and Vernoux 2013); and in aquaculture practices the commonly used being Lactobacillus, Lactococcus, Leuconostoc, Enterococcus, Carnobacterium, Shewanella, Bacillus, Aeromonas, Vibrio, Enterobacter, Pseudomonas, Clostridium, and Saccharomyces species (Nayak 2010). But, it is important to note that the health benefits provided by probiotics are strain specific and not species or genus specific (Figueroa-Gonzalez et al 2011).…”

“…Then, microbial feed additives should also enhance the performance characteristics which include feed efficiency through improvement of feed conversion ratio, average daily weight gain through improvement of body weight gain (BWG), milk or egg production, improving carcass composition by increasing protein and muscle deposition while reducing fat deposition, and improving herd performance by bringing about improvement in the reproductive performance of the breeding females, lowering disease incidences, lowering the culling rates in case of dairy cattle, etc. (Bach et al 2008;Jacela et al 2009;Bernardeau and Vernoux 2013).…”

Chemical and Sensory Characteristics of Chicken Breast Meat After Dietary Supplementation With Probiotic Given in Combination With Bee Pollen and Propolis

“…In this view, supplementation of diet with the additives, such as probiotics, prebiotics, organic acids, enzymes, and herbal products, has been attempted to enhance the poultry feed for growth development and health (Hassan et al, 2010; Wati et al, 2015). Probiotics cover a wide range of living microorganisms with supposed positive effects on gut flora and producing many substances supporting many different effects (Bernardeau and Vernoux, 2013). Prebiotics are non-digestible food ingredients that selectively stimulate the growth and activity of microorganisms in the gut.…”

Effective valorisation of distillery stillage by integrated production of lactic acid and high quality feed

“…After the ban for application of antibiotics as growth promoters in September 2006, the role of microorganisms as valuable additives for feed has been intensively studied. Probiotic strains are classified as zootechnical additives for feed in the current EU legislative (Bernardeau & Vernoux, 2013). Probiotics used in animal diet could reduce intestinal colonisation by Salmonella sp.…”

“…Probiotics used in animal diet could reduce intestinal colonisation by Salmonella sp. in chickens or increase the feed utilization efficiency and prevent diarrhoea in pigs (Bernardeau & Vernoux, 2013). Beside their antimicrobial activity, probiotic strains could positively affect animal health by exopolysaccharide (EPS) production on different carbon sources present in animal diet.…”