Feeding antibiotics to livestock is putting human lives at risk as diseases become drug-resistant. But immune systems could hold the answer. By Nick Hughes.
What are antibodies? Antibodies are produced by the immune system and are part of the body’s natural protection against harmful bacteria and viruses.
Why are we talking about them now? They are being touted as a possible solution to the growing problem of anti-microbial resistance (AMR), which has been described as “one of the greatest threats to modern health” by the UK’s chief medical officer. Previously effective medicines are being rendered impotent because bacteria, present in either humans, animals or the environment, have become resistant to the drugs. In the UK, the leading economist Jim O’Neill warned in a 2016 report commissioned by the government that without policies to stop its spread, the 700,000 annual deaths attributable to AMR today will increase to 10m a year by 2050 – more people than currently die from cancer.
What’s the link with food? The majority of antibiotics produced globally are given to livestock, enabling drug-resistant bacteria to reach humans through our food. Antibiotics are not only administered to sick animals but are also used to prevent disease and, in many of the world’s largest meat-producing countries, to promote growth. It is these non-therapeutic uses in particular that are coming under increasing public scrutiny.
In the UK, the Food Standards Agency (FSA) recently commissioned a survey to assess the amount of AMR in bacteria in fresh pork mince and fresh and frozen chicken on sale in shops in the UK. The results showed AMR to be present in a proportion of all the types of bacteria examined, including Campylobacter and E coli, with resistance to the most clinically important drugs generally appearing to be more prevalent in chicken than pork.
Why could antibodies be the solution? A new study has found that naturally occurring antibodies can fight infections in much the same way as antibiotics. Antibodies could be captured from farm byproducts, such as the whey left over from milk production, and administered to animals through their feed. The study’s authors identified two antibodies with particularly strong potential as an alternative to antibiotics: immunoglobulins which can act as a barrier against infection, and peptides which can slow down the establishment of infection.
So why aren’t we using them already? Antibody treatments are still a long way from commercial use and will also require approval from regulators. The study’s authors conclude that unless specific legislation is imposed favouring alternative methods of treatment, adoption will depend on their comparable efficiency, ease of use and low cost versus traditional medication. Campaigners, meanwhile, argue that the priority should be to increase animal health through improved husbandry rather than developing new forms of medication.
Why is this relevant to food companies? There is growing pressure on businesses, from financiers as well as campaigners, to use their supply chain influence to accelerate the shift away from antibiotics for therapeutic use. Some are already doing just that. McDonald’s intends to phase out all use of antibiotics considered critically important to human health in its chicken supply chain by 2018, while Subway has announced plans to serve only antibiotic-free meat by 2025.
In the UK, the use of antibiotics in the poultry meat sector declined by 82% between 2012 and 2017 and antibiotic use in pigs halved between 2015 and 2017, according to the FSA.