Probiotics one of the ‘last remaining tools’ to fight antimicrobial resistance

While much has been made of the potential of probiotics in human health, there has been considerably less focus on the benefit that their use could bring to the farming sector. [SHUTTERTSTOCK]

As the EU moves to tighten restrictions on the use of antibiotics in the livestock sector, probiotics are rapidly becoming one of the last tools remaining in the toolbox for producers. But prohibitive prices continue to impede their uptake, according to an expert.

On the back of rising concern over disease resistance to antibiotics, the EU has stepped up efforts to slash the use of antimicrobials via the EU’s flagship food policy, the Farm to Fork strategy (F2F), which aims to reduce overall EU sales of antimicrobials for farmed animals and in aquaculture by 50% by 2030. 

But as the use of antibiotics becomes more restrictive, there is a “new ecological niche in poultry flocks that pathogens can occupy,” according to a recent study that explored the potential of probiotics to improve the sustainability of the poultry industry.

This is where probiotics can come in, says Todd Callaway, an animal microbiome expert with the department of animal and dairy science at the University of Georgia and co-author of the study.

Probiotics are live microorganisms thought to provide health benefits when consumed, generally by improving or restoring the gut microbiome. 

Much has been made of the potential of probiotics in human health recently, resulting in a boom in fermented drinks and foods, including kombucha and kimchi, and probiotic supplements.

But their benefits go far beyond human use, Callaway told EURACTIV in an interview, pointing out that generic probiotic type approaches in livestock farming can “often work almost as well or just as well as antibiotics”.

Besides helping to reduce the use of antibiotics, Calloway stressed that maintaining a “healthy” intestinal microbiota has a number of demonstrable animal welfare and food safety benefits, including improved growth rates, nutrient absorption and intestinal barrier function.

Meanwhile, the use of probiotics carries minimal risks, he pointed out. 

“Most farmers are okay with the idea of adding a new bacteria, because they know that their animals are full of bacteria – you’re adding one in a population of 100 million. So it’s a very low risk proposition,” he said.

The use of probiotics is also particularly relevant in view of the Commission’s plans to phase out the use of cages for farmed animals by 2027, Callaway pointed out, given that this throws up a number of biosecurity and disease control concerns.  

“It’s going to be one of the few tools that we have left,” he said.

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While the idea of probiotics is not a new one, the industry was overtaken in favour of chemically synthesised antibiotics, Calloway explained, since they offered a more consistently predictable outcome and were cheaper.

But while over time, scientists have refined and standardised production techniques to produce more consistent probiotic cultures, price continues to be a major barrier for their uptake.

“The problem has always been, [probiotics] are more expensive, as there is not the same economies of scale as you can have with chemically synthesised antibiotics,” said Calloway.

He offered the example of one study, which explored the supplementation of one-day-old chicks’ diets with probiotics.

This is a concept known as ‘competitive exclusion’ whereby a sterile gut is colonised with ‘healthy’ strains of bacteria which outcompetes pathogenic bacteria, and was shown to be highly effective – but came at a price.

“By using this exclusion culture, you’re helping to prevent pathogens, and it worked great in million-plus birds that we ran through in the US and Puerto Rico. But the problem is, it cost about a penny a bird a day, versus a 10th of a penny, or a 100th of a penny per bird per day for antibiotics,” he explained.

This has led poultry producers to often use probiotics as a last resort, rather than employing a consistent probiotic strategy.

“When companies have a lot of salmonella positive birds, they will try everything they know. When that doesn’t work, they give up and bring in the competitive exclusion culture, which helps the birds until they pass their test,” he explained.

But once their salmonella numbers are down, companies then start “looking at that bottom line” again, and revert back to their previous competitive exclusion, he pointed out.

As such, the trick is now to find a way to encourage the routine use of probiotics to keep the use of antibiotics as low as possible. 

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Callaway also pointed to a lack of regulation as a barrier for their uptake.

“This is the area where regulation is somewhat limited,” he pointed out. 

“There are some companies that are fantastic for sharing data with scientists and the public, but there are others that are snake-oil salesmen,” he said, adding that it can be a challenge for prospective users to distinguish the good from the bad.

He pointed to open sharing of information and data as a way to ensure quality in the products on the market.

“When someone asks me to recommend a probiotic to like animals, I’m typically going to go to those companies that have been open about their research and what they’ve done so I can look at that data and say, okay, this makes sense, or this doesn’t make sense,” he said.

US-UK imports of meat raised with antibiotics risk undermining EU farmers

Trade of meat from animals raised with antibiotics between the United Kingdon and the United States threatens the progress recently made on antibiotic resistance and risks adversely affecting both British and EU meat producers, warns a new report published on Tuesday (1 December).

[Edited by Benjamin Fox]

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