Specific sugar structures potential alternative to antibiotics in lung infection

Certain non-digestible sugar structures used in nasal sprays can reduce bacterial infections in the lungs. This makes the sugars a potential alternative to antibiotics, of which large-scale use might lead to bacterial resistance in both humans and animals. Pharmacologists from Utrecht University published their results in the scientific journal Biomaterials last week.

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"Respiratory diseases are one of the main reasons for a high antibiotic use in veal production in the Netherlands," says researcher Saskia Braber of the Utrecht Institute of Pharmaceutical Sciences (UIPS). "Calves of only a few weeks old from different farms in Europe are transported to specialised farms in the Netherlands. Due to stress during transport, mixing of calves from different places and dietary changes, these young animals are more susceptible to a variety of pathogens resulting in an increased incidence of respiratory infections."

The bacterium Mannheimia haemolytica is one of the major pathogens associated with these lung infections. Therefore, calves are frequently treated with antibiotics. However, this is resulting in the emergence of bacterial strains that are resistant to antibiotics. Therefore, there is an urgent need for antibiotic alternatives in the livestock industry to tackle antimicrobial resistance.

Also in mother's milk

Recently, Braber's research group discovered that supplementation of specific non-digestible sugars to milk replacers of the calf protects against lung infections. “In these studies, so-called galacto-oligosaccharides (GOS) were used. They can induce several effects that are comparable to the effects described for certain human milk oligosaccharides, as they support the immune system by, among others, stimulating the growth and activity of beneficial health promoting bacteria.”

Decreasing antibiotic use in animals by oligosaccharide administration, might contribute to advanced healthcare in the 21st century.

Dr. Saskia Braber

Antibacterial effect

However, when GOS is provided as a dietary supplement, it must pass through the intestines before it can be effective in the lungs. “Therefore, we thought it would be interesting to investigate whether lung inflammation will decrease, when oligosaccharides would be introduced directly into the lungs", says Braber. "We administered GOS intranasally via a spray and indeed it appears to work."

In collaboration with the Animal Nutrition Group at Wageningen University & Research and the Faculty of Veterinary Medicine at Utrecht University, UIPS researchers showed that direct administration of GOS into the airways during the first eight weeks of life diminishes lung inflammation in calves. In addition, they confirmed the direct antibacterial effect of GOS on Mannheimia haemolytica and, moreover, that GOS could enhance the antibiotic efficacy.

One Health Concept

The results of Braber and her colleagues are important for the so-called One Health Concept that recognises the connection between human health and the health of animals and the environment. Braber: "Because One Health is a global concept, decreasing antibiotic use in animals by oligosaccharide administration, might contribute to advanced healthcare in the 21st century. If some of the antibiotics can be replaced or diminished using non-digestible sugars, it will also reduce the risk of bacterial resistance in animals, and hopefully in humans.”

In addition to calves, the scientists used human airway cells in the lab. "The anti-inflammatory effect of GOS were present in these human cells also ", Braber said. "We now investigate the use of GOS in children suffering from respiratory infections in collaboration with Erasmus MC.

Hopefully, oligosaccharides as anti-infective agent can be used in the future as alternative or add-on therapy in animals and humans."