Case studies
Use of novel and natural ingredients
Exploring ways of delivering probiotic organisms through non-milk based products
To maintain good health, our gut needs to contain a range of health maintaining, friendly bacteria. To supplement these bacteria, the beneficial health effects of fermented milks have been recognised for many years and the development of the yoghurt market has grown on the back of this approach. However, those who are allergic or intolerant to milk and milk-based products, will miss out on the health benefits of such products.
Our researchers set out to look at other possible methods of providing these beneficial organisms, other than through milk products.
A healthy lower gut contains around 40 billion bacteria which are responsible for the production of certain B vitamins and a range of fatty acids that help maintain the body's immune system. They also control the growth and development of potential food poisoning bacteria.
The health benefits from live yoghurt, containing many millions of gut friendly bacteria, is an easy top-up source of bacteria for the lower gut. Some 400 species of gut microorganisms have been identified, but three groups are most common and give the greatest health benefits - the Lactobacilli, the Streptococci and the Bifidobacteria.
Many commercial yoghurt products contain these organisms and are often referred to as lactic acid bacteria products (LAB products). They are excellent fermenters of lactose (the sugar found in abundance in milk) to lactic acid. The common name for these organisms is probiotics (meaning for life). The most common method of delivering them to the lower gut is via a fermented milk product such as yoghurt.
But what about those people who do not like the taste of fermented milk and indeed some who are allergic to milk and milk products? The aim of this exploratory project was to look at other possible food based delivery methods for providing these organisms.
Added benefits
Functional foods are foods that have some beneficial function in addition to their normal nutritional benefit. Those which supply the gut with friendly bacteria are one of the fastest growth sectors in the total functional food market.
One of the difficulties for any probiotic food is to ensure that the gut friendly micro-organisms can pass through the upper part of the gut (the stomach and small inappropriate pH or by the enzymes present. Milk products are ideal for this as they not only provide the right medium for the growth of the bacteria, but the fat present helps to protect the organisms during their journey to the lower gut.
Preserving organisms
Some milk products are less effective than others at transporting the organisms. Low fat products and those that are pasteurised for a long shelf-life will be more susceptible to destruction of the organisms or contain no live bacteria at all. However, such products should not be dismissed completely, as recent work has indicated that some of the metabolites of the LAB fermentation may be beneficial, even when there are no live bacteria present.
There is good evidence that probiotics do have an important role to play in the mediation of a number of disease conditions. Literature reports suggest irritable bowel syndrome and certain food allergies can be alleviated. Other benefits can include a strengthened immune system function, reduction in risk factor for colon cancer as well as suppression of exogenous pathogens, such as traveller's diarrhoea.
Despite this evidence, recent press coverage has reported some possible adverse effects of probiotics. These have been in patients with terminal illnesses, such as pancreatic cancer and when delivering the probiotics by nasalgastric tube feeding. Thus the overall conclusion, after hundreds of years of beneficial use, is that such products do have a definite positive health benefit.
To date, the team have only just begun to explore this novel approach to probiotic delivery. This exploratory project has begun to look at
- the most suitable species of bacteria to use in non-milk based delivery systems
- the possibility of incorporating the selected micro-organisms into a range of fruit and vegetables
- the best methods of preserving the organisms through the shelf-life of the product
- preserving the organisms on their journey to the lower gut after consumption
Initial findings suggest the potential to go further and the team is looking to engage a research student to progress this innovative research. There is scope for a partnership with an interested food company to jointly develop this new and exciting approach that links food and health.
