Managing the health risks of emerging mycotoxins

In recent years, advances in analytical techniques and food safety monitoring have led to a growing body of research focused on emerging mycotoxins (EMs)—a group of lesser-known fungal metabolites. These EMs can negatively affect animal health and performance, even at low concentrations, especially when co-occurring. There is an urgent need for cumulative risk assessments and effective mitigation strategies to manage the health risks associated with simultaneous exposure to multiple mycotoxins.

Josep Garcia-Sirera
Category Specialist Toxin Binders
Agrimprove

Fumonisins (FUMs), deoxynivalenol (DON), aflatoxins (AFs), zearalenone (ZEN), T-2/HT-2 toxins, and ochratoxins (OTs) remain the most significant mycotoxins from a food and feed safety perspective. This is largely due to their widespread presence in agricultural products, their well-documented toxic effects on both human and animal health, and their strict regulation across many regions of the world.

In recent years, advances in analytical techniques and food safety monitoring have led to a growing body of research focused on emerging mycotoxins (EMs)—a group of lesser-known fungal metabolites. The term ‘emerging mycotoxins’ was first introduced in 2008 to describe compounds such as fusaproliferin (FP), beauvericin (BEA), enniatins (ENNs), and moniliformin (MON), all produced by Fusarium species. Today, EMs are broadly defined as mycotoxins that are not routinely tested for or regulated, yet they are increasingly detected in food and feed samples.

Although once considered of minor importance, EMs are now being found in high concentrations and at notable frequencies in cereals, cereal-based products, fruits, animal feed, and both processed and raw foods. Their frequent co-occurrence with regulated mycotoxins has raised growing concerns regarding their potential health risks and the need for broader surveillance and risk assessment.

PREVALENCE OF EMERGING MYCOTOXINS
The emerging mycotoxins most frequently detected worldwide include: fusaric acid (FUS), enniatins (ENNs), culmorin, apicidin, butenolide, fusaproliferin, alternaria toxins, aurofusarin, emodin, nivalenol (NIV), beauvericin (BEA), diacetoxyscirpenol (DAS), patulin (PAT), moniliformin (MON), and sterigmatocystin (STG).

These EMs are generally not regulated, nor are they routinely included in mycotoxin monitoring programs. Nevertheless, large-scale surveys show that EMs are becoming frequent contaminants in crops and animal feed. Their prevalence is largely influenced by environmental conditions, such as the weather, and they often co-occur with regulated mycotoxins.

The most common EMs found in agricultural commodities are nivalenol, enniatins (A, A1, B, and B1), beauvericin, diacetoxyscirpenol, fusaric acid, patulin, moniliformin, and sterigmatocystin. The most prevalent are nivalenol, beauvericin, and enniatins – and these are sometimes found at exceedingly high concentrations. For instance, nivalenol occurs in concentrations of 0.1 to 15,600 mg/kg, beauvericin at 0.01 to 8,854 mg/kg, and enniatins at 0.25 to 10,000 mg/kg.

Samples from Europe, Africa, and Asia, in particular, have shown high occurrence rates of nivalenol, beauvericin, and enniatins. High levels of EMs (excluding patulin) have been found in cereals like wheat, oats, barley, maize, and sorghum. Finished feeds for poultry, ovine, pig, cattle, and fish have also shown contaminations, predominantly with sterigmatocystin, beauvericin, patulin, moniliformin, nivalenol, and enniatins. Silage samples have also shown high levels of fusaric acid, enniatins, nivalenol, and beauvericin.

As is the case with regulated mycotoxins, EMs are usually found in combination. Analysis of data from multiple studies reveals various EM combinations. Over 90% of the analyzed studies detected 2 or more EMs per sample. The most frequent combinations are:
1. BEA + ENNs
2. BEA + ENNs + MON
3. BEA + ENNs + NIV

TOXICITY OF EMERGING MYCOTOXINS
The toxicity of EMs can be considered individually, in combination with other EMs, or in combination with regulated mycotoxins. Although EMs are less studied than regulated mycotoxins, several have demonstrated significant toxic potential.

Beauvericin (BEA) and enniatins (ENNs) may not affect feed consumption or body weight in monogastrics at 10,000 mg/kg, but, due to lipophilicity and rapid absorption, these toxins may accumulate in animal-derived products like meat, liver, skin, and eggs. To date, human toxicity data is limited.

Diacetoxyscirpenol (DAS) causes intestinal toxicity in pigs at concentrations of 2 mg/kg. In poultry, 0.3–20 mg/kg can even lead to oral lesions, reduced feed conversion, and reproductive issues. Moniliformin (MON) affects body weight, feed intake, egg production, and hematological parameters in monogastrics at 25–100 mg/kg. Limited data is available for Nivalenol (NIV), Sterigmatocystin (STG), and Patulin (PAT) regarding livestock effects.

On top of that, we know that co-contamination between regulated mycotoxins and EMs (e.g., DON, ZEN, BEA, ENNs, and NIV) significantly reduces weight gain and feed efficiency and induces organ damage. For example, pigs fed beauvericin (3578 mg/kg), enniatins (1830 mg/kg), and deoxynivalenol (2524 mg/kg) had reduced weight gain and microbial shifts.

Poultry studies have shown that long-term exposure to mixtures of deoxynivalenol, zearalenone, FBs, beauvericin, enniatins, and diacetoxyscirpenol impairs feed conversion significantly. Combinations of DAS, T-2, and AFs have also caused diarrhea, reduced growth, and feed inefficiency.

Another study has shown that equine liver disease outbreaks can be linked to the consumption of forages contaminated with mixed EMs and regulated mycotoxins.

In general, studies of EMs toxicity in livestock animals show that adverse effects in farm animals are often caused only at concentrations well above the levels commonly found in the field. Nevertheless, exposing livestock to feeds with co-occurring EMs and regulated mycotoxins at moderate to low levels can yield synergistic or additive effects.

MITIGATION STRATEGIES
Strategies to protect animal production from the effects of emerging mycotoxins largely mirror those used against traditional mycotoxins. The 2 primary approaches are biotransformation and binding:
• Biotransformation involves breaking down the mycotoxin molecule into metabolites that are either non-toxic or significantly less harmful to the animal. However, due to the relatively recent attention being given to emerging mycotoxins, there are currently no commercial products that specifically target these compounds through biotransformation.

• Binding agents have shown some success in mitigating the effects of traditional mycotoxins. However, the lipophilic nature of many EMs makes them poorly suited for adsorption by common natural clay-based binders. As an alternative, organic or inorganic binders already available on the market—designed for more lipophilic traditional mycotoxins—may offer a promising solution for mitigating the impact of EMs. An anti-mycotoxin functional feed ingredient like Agrimprove’s Mycoad AZ or the Vitafix range prevents absorption into the animal’s gastrointestinal tract and the consequent toxic effects.

In conclusion, even at low concentrations, EMs—especially when co-occurring—can negatively affect animal health and performance. There is an urgent need for cumulative risk assessments and effective mitigation strategies to manage the health risks associated with simultaneous exposure to multiple mycotoxins. A binder like Mycoad AZ or the Vitafix range offers significant organ protection against a wide range of traditional and emerging mycotoxins.

About Josep Garcia-Sirera
Josep Garcia-Sirera is a Technical Support Manager in the animal nutrition industry with over 20 years of experience. He holds a Ph.D. in Animal Science and a Master’s degree in Animal Science from Michigan State University, USA, and a D.V.M. from Universitat Autónoma Barcelona, Spain. Garcia-Sirera is a licensed veterinarian in the Col·legi Oficial de Veterinaris de Barcelona, Spain, and a member of the American Society of Animal Science (ASAS). He has held various managerial positions and is currently the Category Specialist Toxin Binders at Agrimprove. There, Josep Garcia-Sirera combines the responsibilities of supporting awareness of mycotoxins’ impact on animal health as well as expanding the current understanding of endotoxins in agriculture.