Trust your gut: proboiotics and digestive health

Probiotics are live bacteria and yeasts that can be added to functional beverages, but are the health claims scientifically proven? Sonia Sharma finds out more


Image: Despite a lack of scientific evidence, probiotics have been promoted as a digestive aid. Image courtesy of 5PH


The probiotic market today is estimated to be worth almost £20bn globally, with the most developed markets being Asia Pacific and Europe, however the introduction of probiotics into the food industry has been an age old notion, which started in the early 1900s. The intake of fermented dairy foods and beverages containing live lactic acid-producing bacteria was spear headed by Professor Élie Metchnikoff, who believed probiotics could reduce the number of harmful gut microbes. However, it wasn’t until 30 years later in Japan, that Metchnikoff’s theory was put into practice when Dr Minoru Shirota produced a fermented milk drink containing high numbers of a live Lactobacillus strain, which was strong enough to survive within the gut.

Introducing this ‘friendly’ bacteria to the gut has been claimed to help with a number of health ailments including IBS and asthma and today probiotics are most widely known to consumers through yoghurt drinks, such as Yakult or Actimel. These beverages claim to promote a ‘healthy gut’ through the good bacteria with six out of ten UK households buying probiotic beverages regularly. But what should consumers be looking for and what lies ahead for the future of probiotics in functional beverages?

Scientific evidence to support the benefits of probiotics

"These beverages claim to promote a ‘healthy gut’."

In the digestive health and immune system support area, there have been many claims that use of probiotics can be beneficial. The term ‘probiotic’ was first formally proposed in 1965 and after growing commercial interest in the sector, the Food and Agriculture Organisation (FAO) and the World Health Organisation (WHO) spoke in partnership to industry experts to create an official term for the bacteria saying: “Probiotics are live microorganisms which, when administered in adequate amounts confer a health benefit on the host.”

Although the health benefits of probiotics are widely commercialised, the promotion has outpaced the research. The industry is cautious in promoting them too highly which is evident through the European Union’s decision in not giving approval to them due to a lack of supporting evidence. However, this hasn’t halted innovation within the sector, which has spread to other functional food products.

Probiotics beverage manufacturer Yakult gave their recommendations about what the industry should be looking for in a probiotic starting with the label and quality. The first thing that should be checked is whether the label states the full strain name of the microorganism or microorganisms, which should comprise of three components: genus, species, and strain identifier. The label should also state the number of live cells of the probiotic strain, for instance Yakult contains 1010 Lactobacillus casei Shirota per 100ml which is equivalent to 6.5 billion live cells per 65ml. Finally, if in doubt, the person should contact the company to ask whether quality control procedures are in place to ensure the product contains the correct strains and that the number of live microbial cells is the same as stated on the label.

Yakult also suggest checking the scientific evidence by speaking to the producer or accessing their HCP website to find the supporting research. The scientific evidence can back up the claims and healthcare professions should be checking for GI tract survival. In the case of oral probiotics, human intervention trials showing survival of the probiotic strain through the gut should be sought out. Trials and studies will also prove the efficacy of the strain which is a crucial element in the assessment of safety and in curbing over-enthusiastic claims.

Health claims surrounding ‘friendly bacteria’

"The term ‘probiotic’ was first formally proposed in 1965."

Although there is little evidence to back up the numerous claims made about the health benefits of probiotics, the National Health Service (NHS) does say drinking a functional probiotic beverage could be helpful in some cases.

Yakult itself says: “The advertising and sale of probiotics have to abide by several UK regulations including those governing trading standards and commercial communications covering health or medical claims.

“When probiotics were first introduced in the UK, a survey raised concerns about poor and inaccurate labelling. Some contained lower-than-labelled microbial numbers and even the wrong strains. Most products have best by dates. Even though the product may be safe to consume after this fate, it will not be at optimum quality (i.e. the cell count may drop). Fermented dairy products normally have a shelf life of 4 weeks if stored correctly; the shelf life of tablets or capsules is usually much longer.”

Proceed with caution

"Fermented dairy products normally have a shelf life of four weeks."

The NHS also states that probiotics are generally classed as food rather than medicine, which means they do not undergo the rigorous testing that medicines do. One of the more widely known strains – Lactobacilli – has been consumed in fermented foods such as yoghurts and milks, for centuries, “Most of the strains used as probiotics have a good record of safe use” Yakult says.

Having being used as a health addition for years, it is no wonder the popularity of probiotic drinks has continued to increase, however with evidence being sparse, brands agree that it should not be a substitute for proven medication.