The human body is host to trillions of microbes – in the gut and on the skin, as well as in the mouth, urinary tract, vagina and lungs – and these microbiota have a symbiotic relationship with us. They help maintain a healthy body and help to keep potentially harmful bacteria in check. The market for probiotics – substances in food or supplements that help us to maintain a healthy microbiome – has grown quickly, as awareness of their potential benefits has grown.

According to a Global Markets Insight report, the market for probiotics in 2015 exceeded $34 billion, fuelled by growing concerns over lifestyle diseases and a greater understanding of the impact of nutrition on health. The same report suggests that by 2023, the market may well exceed $64 billion globally.

The gut – where more than 90% of our beneficial microbes are thought to reside – is now regularly referred to as our second brain, and research into the role of microbiota in health is drawing greater interest than ever, though there remain gaps in scientific knowledge. There is no consensus about what constitutes the ideal composition of gut microbiota, but food companies have nevertheless made probiotics a key influence in product development. Among scientists, there is talk of tailored therapies using probiotics, and there is potential for close collaboration with the food industry to make this a reality.

Market myths

For now, market growth is largely driven by food manufacturers trying to sell specific products, so the facts about probiotics are often obscured by marketing message. Perhaps more could be achieved in terms of consumer health benefits if people buying the products knew more about probiotics in general and could ensure that what they consume is right for the outcomes they seek.

“Prebiotics and probiotics are ways of influencing the normal colonising microbiota in the gut, but there is a lot of bad information about them out there.” says Dr Mary Ellen Sanders International Scientific Association for Probiotics and Prebiotics. “There are a lot of myths, particularly about probiotics, including the idea that they need to be refrigerated or that they are no good if they are killed in the stomach or that they are harmful if they are not from a human source. All of these are false. The fact is, their potential benefits to healthy and sick people are very complex, so they defy simple definition.”

Sanders is the executive science officer, and former founding president, of the ISAPP, a non-profit organisation. ISAPP supports the probiotic field through stewardship, advancing scientific research, and education. An internationally recognised consultant in the area of probiotic microbiology, she has spent 25 years helping food and supplement companies develop products.

“We focus on the science, so we need to get the facts to people in plain language and we are very excited about the new consumer-focused ISAPP materials. Companies want to distinguish their products in the market, so they each push their own agenda,” she says. “For instance, there are many room-temperature, shelf-stable products out there. Some products kept at room temperature and produced well can be better than badly prepared refrigerated products. Third-party communicators – think [TV personality] Dr Oz and others like him – run their own ratings of the top probiotic products and I rarely recognise anything on those lists. They may be ranked high because they have a higher number of strains, but often there are no scientific studies about them.”

No substitute for facts

ISAPP was created from the desire to have a multidisciplinary team of scientists – such as gastroenterologists and specialists in gut microbiology – working on the study of prebiotics and probiotics. Though it is funded by corporate entities, ISAPP’s strategy is defined by its board of directors, all of whom are academics, and it engages with industrial scientists rather than corporate CEOs to further the understanding of the science. As a result, it has generated a wealth of knowledge about probiotics and their interaction with gut microbiota.

“The organisation started out as a source of information, and a body for networking to match companies to the conduct of research studies. Then its focus expanded to address regulatory issues, looking at the approach of food safety authorities in the US and Europe. We feel they are off-base when it comes to prebiotics and probiotics. Now, we help to translate scientific information in this area for consumers and healthcare providers, who must have the right information to use these products in an evidence-based way,” says Sanders.

“People’s level of understanding depends, in part, on their geographic location. In the US, for instance, surveys have shown that some people know more about probiotics. They may know that it is a live microbe that is good for them, but they may not know how or why. The internet has a lot of information, but consumers would do well to stay true to the science. In the healthcare world, people do not understand the evidence when it comes to the wider benefits, and neither do some academics.”

The challenge for ISAPP partly derives from the fact that many factors dictate how individuals respond to different probiotics. This is why a detailed, evidence-based approach is so important. Many people are aware that some yogurts are a source of probiotics – though consumers should always check the label to ensure probiotics are listed – and some know that fermented foods can be a source of live bacteria. But to get the full health benefits, they may need to dig into the detail. For instance, they must first understand that not all live cultures are probiotics.

“Individuals respond differently to dietary factors. The behaviour of the colonising microbiota may vary, and host genetics play an important role. Also, the benefits may be quickly visible in a person with specific functional bowel symptoms or someone who has taken a course of antibiotics, but they may be harder to measure in someone who is healthy,” Sanders says.

“The general understanding of the role of microbes in health has certainly grown and a lot of information has come out of the Human Microbiome Project in the US. Patterns of colonisation can be matched to obesity, diabetes and other health conditions. In the past ten years, there has been a lot of humancontrolled science, but much more research is needed.

“There is a better sense of the role of probiotics in health, but it is all about the source of the information and the reliability of that source. You can’t recommend a product on anecdotal evidence. You must always come back to the science, and ISAPP information always shows where the strongest evidence is, which is very important when the details are so complex.”

The next big thing

A key focus for ISAPP now is the global regulatory environment, and its mission is to ensure that probiotic products are safe and are not misrepresented in advertising. One key question is whether the US should continue to regulate probiotics as drugs, or whether consumers would be better served if they came under food safety regulations. Another important issue is whether international regulations should be harmonised to ensure that probiotics are marketed and sold in a consistent way around the world.

On that front, a great deal of work lies ahead, given that the wheels of regulation turn slowly and the scope of the initiative is vast. For now, ISAPP’s key role is to disseminate reliable information based on scientific studies to ensure consumers and companies understand the potential benefits of probiotics in healthy people, as well as people with treatable conditions.

“We are reaching out to primary care physicians who could recommend probiotics as part of a treatment plan. Anecdotal evidence suggests that many people ask their physician about probiotics, so it would help to give them reliable information,” Sanders notes.

The future for probiotics – as an ingredient in food and as a supplement – looks bright, as the market continues to grow rapidly and new research takes its potential into new areas. There are studies under way, for instance, that focus on the creation of precision gut bacteria that could respond to specific chemical disturbances and combat disease in a targeted way. Those tailored treatments, however, lie in the future. In the near term, it is likely that the surge in interest in probiotics will bring their companion – prebiotics – into the spotlight.

Prebiotics are dietary fibres that are selectively fermented by beneficial microbes in the gut. They are found naturally in many foods or can be added as supplements, and they can have a significant effect on the composition and function of gut microbiota. They can improve mineral absorption and digestive function, support the immune system, and regulate glucose metabolism and appetite.

“For probiotics, there is a lot of information out there and many more studies are being done. However, prebiotics are poised to be the ingredient of the future. They don’t require organisms to be kept alive, but they can have a very positive impact on gut microbiota. We know they are mainly found in carbon-based food elements, but we need to find out more about the science of their interaction with gut microbiota,” Sanders says.

With more people turning to kimchee, kombucha, kefir and other probiotic foods to improve their digestion and boost their bodies’ defences, there is likely to be a similar growth in the consumption of onions, garlic, bananas, chicory root and other foods that deliver prebiotics. ISAPP will continue to look hard at the science in both areas, and provide a solid basis for decision-making among consumers, healthcare practitioners and food manufacturers.

The function of probiotics

Probiotics are live microorganisms that can be beneficial to health when consumed in sufficient amounts. They are naturally present in many foods or can be consumed in supplements. They support the bacteria that exist in the stomach and can improve their function if the bacteria have been compromised by factors such as poor diet or the use of antibiotics. The many potential benefits of probiotics include:

  • „supporting the proper function of the immune system
  • „aiding digestion by helping to break down food that is hard to digest
  • „helping to counteract harmful microorganisms
  • producing vitamins
  • supporting nutrient absorption.