In a previous GMFH article, ‘PROBIOTICS’ PART I: A BRANCHING DEFINITION, we covered recent updates to the definition of probiotics as discussed at the October 2013 meeting organized by The International Scientific Association for Probiotics and Prebiotics (ISAPP). Three of the scientific experts on the ISAPP panel – Dr. Francisco Guarner (University Hospital Vall d’Hebron, Barcelona, Spain), Dr. Mary Ellen Sanders (Dairy & Food Culture Technologies, Colorado, USA), and Dr. Lorenzo Morelli (Istituto di Microbiologia Università Cattolica S.C., Piacenza, Italy) – continue here by describing the future they see for scientific studies on probiotics.

As laboratories around the world continue to carry out probiotics research, the experts say not every study will fit neatly into one of the three probiotic categories that ISAPP identified: (1) Well-known probiotic species that provide general health benefits, (2) Probiotic strains that treat specific pathologies, and (3) Human commensal-derived probiotics used therapeutically as drugs.

“One issue is the ongoing scientific substantiation of what kind of effects probiotics have,” says Sanders. “I think there [are] differences of opinion in the medical world, and in the nutrition community, about what their value is and what that’s going to look like. Are these products going to be only valuable as drugs and not so much as foods? Or do they potentially play a role when you look at endpoints that have an importance in public health, like reducing the incidence of upper respiratory tract infections or things along that line?”

Morelli hopes to see two paths for probiotics develop in parallel: “One [path] is the food and the other one is the drugs,” he explains. “We have to learn how to use viable bacteria as a therapeutic agent (i.e. a drug) on one side. On the [other] side we have to refine the use of probiotics in food and food supplements for healthy people in order to reduce [the] risk of illness and to maintain… wellbeing.”

Early in Morelli’s career, he came to study probiotics in food for their possible role in improving “chronic but not lethal” health problems. “I was told by a scientific official in Brussels, ‘Listen Morelli, we have a strategy. The national health services throughout Europe have a lot of financial problems. They are spending a lot of money. We have to encourage research that could develop new foods able to support the well-being of [people].’,” he says.

As a gastroenterologist, Guarner is convinced by the current level of science behind ISAPP’s first category of probiotics, which are used to promote health in ‘healthy’ people. “These are…food products that contain live microorganisms that are…species of bacteria or species of fungi that are very well known,” he says. He explains that an abundance of studies show the benefits of Streptococcus thermophilus and Lactobacillus bulgaricus, for example, on the functioning of the gastrointestinal tract.

Morelli acknowledges that probiotics for healthy people may require future scientific studies to be conducted under a new framework. “Most of the research has been done in human subjects with pathological conditions,” he says. “But at the beginning, and still today, the area of probiotics [includes] a food area. Food or food supplements.”

Sanders, who is from the USA, and Morelli, who is from Europe, spoke about the different regulatory issues faced by the first category of probiotics in their respective parts of the world. Both, however, expressed a hope that the regulatory bodies will, first and foremost, look to science to resolve their uncertainties.

Part of the difficulty is that a ‘general’ health benefit, as conveyed by a food product, is not easy to define. “The regulators might say that if you help prevent upper respiratory tract infections or the common cold, that makes you a drug, and I could make a reasonable scientific argument that, no, foods can improve immune function and therefore foods can reasonably have the function of reducing the risk of upper respiratory tract infections,” says Sanders.

She says, “If you just cast your net quite broadly and look at all GI benefits, there’s a plethora of information that says that [the first category of probiotics] benefit people. They’re not going to benefit everybody. Someone who doesn’t have any GI problems may not benefit at all. But we felt that the evidence was strong enough to say that you could use the word ‘probiotic’ on a product that was delivering an adequate level of some well-defined species, and really not be misleading.”

“We wanted to offer a scientific opinion [at the ISAPP meeting],” Sanders underlines. “There’s enough combined evidence to say within the well-studied species that [‘probiotic’] is probably a reasonable word to use, because the evidence is strong across a variety of endpoints.”

Sanders adds that this area of research elicits keen public interest: “We’re really a society that’s very interested in knowing how to choose foods to maximize our health.”