Natural sugars found in breast milk that are now included in prebiotic foods may help in the fight against Salmonella and other food poisoning bacteria, scientists heard at the Society for General Microbiology's 162nd meeting being held this week at the Edinburgh International Conference Centre.
The sugars, or oligosaccharides, are called galacto-oligosaccharides and are already known to improve the health of breast-fed infants. They may also reduce the chances of Salmonella bacteria damaging the gut during a food poisoning episode, reducing the overall damage and severity of the infection.
“Salmonella Typhimurium is a disease-causing bacterium capable of infecting a wide range of animals including humans. It is responsible for outbreaks of serious illness every year,” says Laura Searle of the Department of Food and Environmental Safety at the Veterinary Laboratories Agency in Weybridge, Surrey, UK. “We are particularly concerned about it as we can trace people being infected through direct contact with animals or through the food chain.”
Symptoms of Salmonella food poisoning in people include diarrhoea, nausea, vomiting, stomach cramps, fever and headaches and in rare cases the disease can attack the whole system and can be fatal.
"Antibiotics are used to treat particularly severe Salmonella infections,” says Laura Searle. “But their effectiveness has been undermined by their systematic use both as growth promoters in animals and as therapeutic agents, which has been implicated in widespread antibiotic resistance. In an attempt to overcome this problem the European Union banned the use of antibiotics as growth promoters in 2006, so now alternatives are urgently being investigated.”
One possibility is to use prebiotics made from natural complex sugars that are already known to improve gastrointestinal health. There have been many theories put forward about the way they actually work, including the suggestion that they may stimulate our natural gut bacteria to multiply, allowing them to fight off invading pathogens trying to colonise our guts.