Mother’s milk has been found to contain natural antibiotics that could be used in the battle to fight drug-resistant diseases, a study has found.
Milk produced by breastfeeding mothers has long been known to include a special cocktail of ingredients that, as well as offering nutrition, helps babies to fight infection.
While scientists previously focused on how certain proteins in milk killed bugs, now they have found that sugars in the milk also have an anti-bacterial effect.
Scientists will now need to carry out further studies with the hope of harnessing the properties in breast milk to develop new antibiotic drugs.
Researchers at Vanderbilt University, in the US, said one of the advantages of breast-milk antibiotics is that they are very safe to take and have found that sugars in the milk also have an anti-bacterial effect
Worldwide antibiotic-resistant bacteria infects and kills hundreds of thousands of people each year – making the hunt for new antibiotics an urgent priority.
The Government has created a specialist panel to tackle antibiotic resistant bugs which kill 700,000 people a year worldwide and 10,000 in Britain.
Researchers at Vanderbilt University, in the US, said one of the advantages of breast-milk antibiotics is that they are very safe to take.
Assistant professor of Chemistry Steven Townsend said of the findings: ‘This is the first example of generalized, antimicrobial activity on the part of the carbohydrates in human milk.
‘One of the remarkable properties of these compounds is that they are clearly non-toxic, unlike most antibiotics.’
The results were presented yesterday at the annual meeting of the American Chemical Society in Washington DC, and published in the journal ACS Infectious Diseases.
Two proteins isolated from breast milk are showing promise as antibiotics: lactoferrin and HAMLET, which is active against tumour cells
Professor Townsend said: ‘We started to look for different methods to defeat infectious bacteria. For inspiration, we turned to one particular bacteria, Group B Strep.
‘We wondered whether its common host, pregnant women, produces compounds that can either weaken or kill strep, which is a leading cause of infections in newborns worldwide.
The sugars in breast milk have received little attention.
Testing different breast milks donated they analysed the different sugar compounds – called oligosaccharides – which had varying levels of effectiveness, and worked in a variety of different ways to attack bacteria.
Some worked by directly killing the bacteria.
Others attacked the ‘biofilm’. Biofilms are created when a number of different bacteria huddle together – creating a slimy substance called a biofilm which acts to protect the bacteria.
Professor Townsend said: ‘Our results show that these sugars have a one-two punch.’
‘First, they sensitize the target bacteria and then they kill them. Biologist sometimes call this ‘synthetic lethality’ and there is a major push to develop new antimicrobial drugs with this capability. ‘Sensitising’ helps weaken bacteria’s resistance to antibiotics.
Two proteins isolated from breast milk are showing promise as antibiotics: lactoferrin, which is also active against viruses and fungal infections as well as bacteria, and HAMLET – Human Alpha-lactalbumin Made Lethal to Tumor Cells, which is active against tumour cells.