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A bacterium/enzyme combination to control the harmful  effects of mycotoxins in pigs

INRA researchers working with the company BIOMIN have demonstrated the efficacy of a bacterium/enzyme combination in controlling sub-clinical intoxications due to the ingestion of mycotoxins by pigs.  This approach enabled restoration of the biological parameters affected by deoxynivalenol combined with fumonisins.

Macroconidia of Fusarium graminearum, a fungus which contaminates cereals © CAHAGNIER Bernard
Updated on 01/20/2014
Published on 01/17/2014

Animals exposed to combinations of toxic compounds

Mycotoxins are fungal toxins of an extremely disparate chemical structure that are secreted by moulds present on cereals.  Toxic to both humans and animals, these compounds are responsible for a variety of pathologies that affect the digestive tract (liver, intestine), liver or nervous system.  Although there are no longer any fears of massive intoxication  because of the appropriate health management of cereal crops, animals are still exposed to low doses of the toxins.   

Deoxynivalenol and fumonisins B: a devastating cocktail

Among the mycotoxins present on cereals, deoxynivalenol (DON) and fumonisins B1 and B2 (FB) are produced by fungi belonging to the Fusarium genus (mainly F. graminearum and F. verticillioides,  respectively).  DON is known to decrease feed intake and to disturb intestinal epithelial functions (permeability, immunity and nutrient transport).  FBs interfere with the immune function, predisposing animals to pulmonary infections and colonisation of the intestine by pathogenic bacteria.  Recent studies have shown that animals can be exposed concomitantly to these substances, leading to hepatic lesions, and impaired intestinal and immune functions - notably the inefficacy of immunisation - which differ from the effects observed with each of the toxins separately.  "The whole is more toxic than the sum of its parts".

A successful protective strategy: the degradation of toxins

To fight against the harmful effects of toxins, feed additives capable of absorbing the mycotoxins were developed.  These neutralising matrices, based on clay and yeast or bacterial cell walls, are effective against toxins in the aflatoxin family, but have shown their limitations versus DON and FBs. To protect animals against these substances, it was therefore necessary to envisage another strategy: degradation into non-toxic by-products.
In the context of a CIFRE thesis project in collaboration with BIOMIN, researchers in the Joint Research Unit for Food Toxicology (TOXALIM) had the idea of associating a bacterium of bovine origin (a bacterium of a new type from the Coriobacteriaceae family, isolated in the rumen and given the identification number DSM 11798)  capable of degrading DON, with an enzyme (named fumD and produced by genetic engineering) that is able to hydrolyse FBs.  Recent studies by this team showed that these by-products obtained by hydrolysis were not toxic in the pig.

A probiotic and an enzyme: effective detoxification in the pig

The scientists analysed blood and tissue samples (liver, lungs, intestine) from pigs whose feed was contaminated by the mycotoxins (DON alone, FBs alone, DON and FBs), in the presence or absence of  the bacterium and enzyme combined in an additive.  They were able to show that this additive was able to restore the blood count (neutrophil count and the synthesis of sphinganine, which are generally affected by the toxins).  The lungs, livers and intestines from DON and FB animals whose feed had been supplemented with the additive displayed a marked reduction in the histological changes observed in the non-supplemented DON and FB groups.  Use of the additive also enabled a reduction in the inflammatory markers induced by the mycotoxins (reduction in the levels of interferon γ and TNF), and restoration of the immune response necessary to ensure vaccine efficacy.

Contact(s)
Scientific contact(s):

  • Isabelle OSWALD (+33 (0)5 61 28 54 80) Joint Research Unit for Food Toxicology (TOXALIM)
Associated Division(s):
Animal Health
Associated Centre(s):
Occitanie-Toulouse

For further information

  • Biotransformation Approaches To Alleviate the Effects Induced by Fusarium Mycotoxins in Swine. Grenier, B. ; Bracarense, A. P. ; Schwartz, H. E. ; Lucioli, J. ; Cossalter, A. M. ; Moll, W.-D. ; Schatzmayr, G. ; Oswald, I.P. Journal of Agricultural and Food Chemistry, 2013, 61 : 6711-6719.