Mycotoxins are contaminants of agricultural products both in the field and during storage and
can enter the food chain through contaminated cereals and foods (milk, meat, and eggs)
obtained from animals fed mycotoxin contaminated feeds. Mycotoxins are genotoxic
carcinogens that cause health and economic problems. Ochratoxin A and fumonisin B1 have
been classified by the International Agency for Research on Cancer in 1993, as “possibly
carcinogenic to humans” (class 2B).
To control mycotoxins induced damages, different strategies have been developed to reduce
the growth of mycotoxigenic fungi as well as to decontaminate and/or detoxify mycotoxin
contaminated foods and animal feeds. Critical points, target for these strategies, are:
prevention of mycotoxin contamination, detoxification of mycotoxins already present in food
and feed, inhibition of mycotoxin absorption in the gastrointestinal tract, reduce mycotoxin
induced damages when absorption occurs. Decontamination processes, as indicate by FAO,
needs the following requisites to reduce toxic and economic impact of mycotoxins: it must
destroy, inactivate, or remove mycotoxins; it must not produce or leave toxic and/or
carcinogenic/mutagenic residues in the final products or in food products obtained from
animals fed decontaminated feed; it must be capable of destroying fungal spores and
mycelium in order to avoiding mycotoxin formation under favorable conditions; it should not
adversely affect desirable physical and sensory properties of the feedstuff; it has to be
technically and economically feasible. One important approach to the prevention of
mycotoxicosis in livestock is the addition in the diets of the non-nutritionally adsorbents that
bind mycotoxins preventing the absorption in the gastrointestinal tract. Activated carbons,
hydrated sodium calcium aluminosilicate (HSCAS), zeolites, bentonites, and certain clays, are
the most studied adsorbent and they possess a high affinity for mycotoxins. In recent years,
there has been increasing interest on the hypothesis that the absorption in consumed food can
be inhibited by microorganisms in the gastrointestinal tract. Numerous investigators showed
that some dairy strains of LAB and bifidobacteria were able to bind aflatoxins effectively.
There is a strong need for prevention of the mycotoxin-induced damages once the toxin is
ingested. Nutritional approaches, such as supplementation of nutrients, food components, or
additives with protective effects against mycotoxin toxicity are assuming increasing interest.
Since mycotoxins have been known to produce damages by increasing oxidative stress, the
protective properties of antioxidant substances have been extensively investigated.
Purpose of the present study was to investigate in vitro and in vivo, strategies to counteract
mycotoxin threat particularly in swine husbandry. The Ussing chambers technique was
applied in the present study that for the first time to investigate in vitro the permeability of
OTA and FB1 through rat intestinal mucosa. Results showed that OTA and FB1 were not
absorbed from rat small intestine mucosa. Since in vivo absorption of both mycotoxins
normally occurs, it is evident that in these experimental conditions Ussing diffusion chambers
were not able to assess the intestinal permeability of OTA and FB1. A large number of LAB
strains isolated from feces and different gastrointestinal tract regions of pigs and poultry were
screened for their ability to remove OTA, FB1, and DON from bacterial medium. Results of
this in vitro study showed low efficacy of isolated LAB strains to reduce OTA, FB1, and
DON from bacterial medium. An in vivo trial in rats was performed to evaluate the effects of
in-feed supplementation of a LAB strain, Pediococcus pentosaceus FBB61, to counteract the
toxic effects induced by exposure to OTA contaminated diets. The study allows to conclude
that feed supplementation with P. pentosaceus FBB61 ameliorates the oxidative status in
liver, and lowers OTA induced oxidative damage in liver and kidney if diet was contaminated
by OTA. This P. pentosaceus FBB61 feature joined to its bactericidal activity against Gram
positive bacteria and its ability to modulate gut microflora balance in pigs, encourage
additional in vivo experiments in order to better understand the potential role of P.
pentosaceus FBB61 as probiotic for farm animals and humans. In the present study, in vivo
trial on weaned piglets fed FB1 allow to conclude that feeding of 7.32 ppm of FB1 for 6
weeks did not impair growth performance. Deoxynivalenol contamination of feeds was
evaluated in an in vivo trial on weaned piglets. The comparison between growth parameters of
piglets fed DON contaminated diet and contaminated diet supplemented with the commercial
product did not reach the significance level but piglet growth performances were numerically
improved when the commercial product was added to DON contaminated diet. Further studies
are needed to improve knowledge on mycotoxins intestinal absorption, mechanism for their
detoxification in feeds and foods, and nutritional strategies to reduce mycotoxins induced
damages in animals and humans. The multifactorial approach acting on each of the various
steps could be a promising strategy to counteract mycotoxins damages.
| Identifer | oai:union.ndltd.org:unibo.it/oai:amsdottorato.cib.unibo.it:1061 |
| Date | 10 April 2008 |
| Creators | Pizzamiglio, Valentina <1979> |
| Contributors | Piva, Andrea |
| Publisher | Alma Mater Studiorum - Università di Bologna |
| Source Sets | Università di Bologna |
| Language | English |
| Detected Language | English |
| Type | Doctoral Thesis, PeerReviewed |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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