Probiotics need more scientific backing

The scientists reviewed research that had looked at the ability of bacteria from dairy products such as yoghurt, fermented with probiotic bacterial cultures, to reduce the unpleasant symptoms associated with gastrointestinal conditions like lactose intolerance, constipation, diarrhoeal diseases, colon cancer, inflammatory bowel disease and food allergies.

Inconsistencies​

While they did not conclude that the reported results were incorrect or misleading, they found inconsistencies which they attributed to differences in the strains of bacteria used, the routes of administration, or a lack of an objective definition of 'gut health'.

Probiotics are based on the notion that there is such a thing as a normal healthy microflora. However, the Boston team led by Osker Adolfsson, noted that: "normal healthy microflora had not been defined except perhaps as a microflora without a pathogenic bacterial overgrowth."​

The group therefore advocated further studies to substantiate past findings either through animal models and clinical trials. They were specifically interested in ascertaining whether beneficial effects were age-specific and to investigate the mechanisms through which yoghurt works.

It would also be of particular interest to the burgeoing functional food industry, which markets probiotics as improving 'gut health', for scientists to discover what really are the defining characteristics of a healthy gut.

This research is published in the American Journal of Clinical Nutrition​ (Vol. 80 (2), 2004).

Probiotics and tumours​

Meanwhile, IA Abd El-Gawad and colleagues from Cairo University, Egypt, reported this week in the British Journal of Nutrition​, Vol. 92 (1), 2004, that probiotic yoghurt and soya yoghurt significantly prolonged the lives of mice with tumours.

The scientists found that the mice fed with yoghurt containing bifidobacterium lactis Bb-12 or B. longum Bb-46 out lived those fed products without the probiotic bifidobacteria.

Functional food market​

Probiotics is one of the fastest growing functional food markets worldwide. The US probiotics market is forecast to more than triple in value from $143.9 million currently to $394 million in 2010, according to recent statistics from Frost & Sullivan

However, the research company noted in its report last year that limited consumer awareness and scanty scientific research threatened to restrain the development of the probiotics market. Consumer knowledge of probiotics is still low in the US and restricted to a fairly small range of products.

"Increasing public knowledge of probiotics has been cited by most companies as their first priority. However, many probiotic manufacturers are not in direct contact with the consumer and must rely on marketing investment by end-users such as dairy companies,"​ explained Frost & Sullivan food industry analyst Lyndsey Greig.

The report also revealed that probiotics suppliers also need to enhance credibility through independent scientific studies. Products supported by comprehensive scientific documentation and proof of efficacy are likely to make the strongest gains, particularly when specific health claims are being made, given consumers' greater confidence in the products.