Closing in on microbiome therapy
The idea of manipulating the human microbiome to maintain or restore health is not new. Probiotics, or beneficial gut bacteria, have long been used to manage and prevent disease, even in the absence of conclusive evidence of their effectiveness.
Pharmaceutical companies are taking an increasing interest in the field, however, as our understanding of the human microbiome grows. Scientific research, including efforts from the International Human Microbiome Consortium (IHMC), is beginning to unravel the genetic make-up of the microbes that live within us and is shedding light on their potential in fighting a wide range of conditions.
For example, there is growing evidence to suggest that autism spectrum and eating disorders, cardiovascular disease and metabolic conditions such as obesity and type 2 diabetes may all be associated with microbial imbalances in the gut, explains Sandrine Claus, a lecturer in metabolomics at the University of Reading, UK.
"The microbiome field has produced some of the most exciting science discoveries of the last five years, and its potential impact on human health is just too big to ignore"
If confirmed, these findings could have an enormous impact on human health. The benefits for treating diabetes alone, which affects over 300 million people globally, could be transformational. “If we were able to prevent the disease’s complications by manipulating the gut microbiome in only 10 per cent of patients, this would still equate to millions of people with a preserved quality of life", says Dr Claus.
The microbial communities that live in our body also appear to have a role in protecting against certain rare conditions, such as hyperoxaluria, a kidney condition that is often treated with a transplant. “This may concern a very small population, but it means that these patients could keep their organs, which would be a tremendous achievement,” Dr Claus explains.
There are other potential applications, too. Researchers at Queens University and Kingston General Hospital, Kingston, Ontario, Canada, are investigating novel microbial therapies for various forms of intestinal conditions, including inflammatory bowel disease (IBD) and Clostridium difficile infection (CDI), an infectious diarrhoea that causes 14,000 deaths annually in America alone.
Elaine Petrof, associate professor at the university’s department of medicine and infectious diseases, leads the team. She says that some patients with an antibiotic-resistant form of CDI are already experiencing the benefits of one microbial therapy. Faecal microbial transplantation (FMT) involves the infusion of a faecal suspension obtained from a healthy donor into the colon of a CDI patient.
This is just the “tip of the iceberg,” says Dr Petrof. Researchers have found that some cancers are caused by infections, many of which result from the deterioration of microbial communities in the body. Microbial therapies may one day be able to treat or even prevent cancer.
Opportunities and challenges
As scientists gain greater knowledge about human microbial populations, pharmaceuticals companies are increasingly teaming up with research organisations and biotech start-ups to develop microbiome therapies, says Adi Reske, PhD, an analyst for research company Decision Resources Group.
In August 2014, for example, Pfizer’s Center for Therapeutic Innovation launched with the Crohn’s & Colitis Foundation of America a joint effort to advance research into treatment for inflammatory bowel disease. Two months earlier, the drug giant had partnered with Second Genome, an emerging US biotechnology firm based in San Francisco, to investigate the relationship between the human microbiome and metabolic disorders such as obesity. And, last year, Johnson & Johnson made an investment in Boston start-up Vedanta Biosciences to develop microbial therapies that address the human immune system.
According to a report published in September by MarketsandMarkets, the emerging microbiome market will reach $658 million in size by 2023 from $294 million in 2019, expanding at a compound annual growth rate (CAGR) of 22.3 per cent in the forecasted period. Europe is expected to have double-digit annual growth and to be the largest-growing region in 2019, followed by Asia, while North America’s growth will be slow due to lack of awareness of the potential benefits of probiotics.
Clearly, the impact of microbiome-derived therapies on human health could be huge, offering pharmaceutical companies and dedicated biotechnology firms strong opportunities for market access and growth – but not without challenges. As Dr Reske at Decision Resources Group points out, a major challenge will be to prove that such therapies are an improvement over current treatments, through clinical trials that demonstrate superior long-term efficacy and safety.
Currently, scientists are still trying to understand how the microbiome works. For example, while studies suggest a 92 per cent success rate for fecal microbial transplantation in Clostridioum difficile infections, the exact mechanism of action of FMT remains unknown, and clinical data on potential side effects are scarce. Another problem is the absence of guidelines from regulatory bodies such as the US Federal Drug Administration (FDA) concerning microbiome-based therapies. As Barbara Sosnowski, vice president of external research and development at Pfizer, New York, puts it: “This is such a new field, without any validated drugs. What is needed is solid data with a clear proof of mechanism.”
Scientists emphasise the crucial role of technology in advancing microbiome research. “The development of next-generation DNA sequencing has given us the unique opportunity to characterise the human microbiome and its genome,” she Dr Petrof. But there is always a need for more detailed information and more precise tools. “We now require molecular tools that accurately measure microbial gene expression, to be able to identify the specific metabolic functions of the various microorganisms in our body.”
Despite the uncertainties, both researchers and the pharmaceutical industry are optimistic. “The microbiome field has produced some of the most exciting science discoveries of the last five years, and its potential impact on human health is just too big to ignore,” says Bernat Olle, chief operating officer at Vedanta Biosciences. “As the scope of applications in the field is growing much faster than any one company alone can reach, there will be space for multiple winners.
“The fact that the first, albeit crude, therapeutic approaches to modulating the microbiome are already helping patients is an important accomplishment.”
