The Big Read: Rethink that detox

It is fashionable to kick off the New Year with a detox, which supposedly clears the body of the waste products that have accumulated in it over the year. But detoxing is derided by doctors and dieticians.

However, scientists in the US have come up with the "anti-detox" - a treatment that involves putting waste back in. Welcome to the strange world of "poo-therapy".

A Boston biotechnology company has unveiled a bacteria pill designed to unleash a flood of live faecal microbes into the body. The pill, which entered clinical trials last month, is the first of a new class of drugs nicknamed "ecobiotics", which are intended to treat diseases by manipulating the balance between harmful and beneficial bacteria so that the good microbes always have the upper hand.

Though probiotic yogurts claim to promote good bacteria - claims not always backed up by research - they cannot pack the same bacterial punch as a tailored pill containing purified strains.

There is currently a lot of excitement about the human microbiome: the collection of trillions of microbes - a cocktail of bacteria, viruses and fungi - that teems inside and on the surface of the human body.

Researchers across the world are uncovering intriguing evidence that bacteria and other microbes might be implicated not only in causing but often in mitigating serious conditions.

Microbes play vital roles in digestion, metabolism, the production of vitamins, the regulation of immunity and responses to drug treatment.

The healthy female microbiome is particularly interesting: newborns are bathed in maternal flora during birth, and breastfed infants receive more maternal microbes through breast milk. Both these aspects of early infant life - vaginal delivery and breastfeeding - have been associated with better lifetime health.

In another study, Kenyan prostitutes were found to harbour cervical microbes that protected them from HIV, strengthening suspicions that the microbiome could be a promising reservoir of disease resistance.

Humans harbour about 10000 microbe species. The microbiome typically accounts for around 2% of an adult's total body weight - yes, one-fiftieth of you is bacteria.

The bacteria pill has been developed by Seres Health to tackle Clostridium difficile, a notorious germ and the enemy of hospitals everywhere.

Healthy people fend off C difficile without difficulty, but patients on antibiotics are vulnerable to infection because antibiotics target bacteria indiscriminately, and wipe out protective microbes and nasty ones with equal vigour. More than 1600 health service patients died from C difficile complications in England and Wales in 2012.

If the infections don't respond to potent antibiotics, patients can receive a faecal transplant, in which the diluted faeces of a healthy donor (usually a relative) are fed through the rectum or a nasal catheter into the colon to re-establish a healthy gut flora. The procedure, pioneered over the past two years, is successful, but there are downsides: it is invasive, not widely available, and carries a small risk of introducing harmful microbes. And not many patients find it a palatable procedure.

Dr Jeremy Sanderson, a UK gastroenterologist, said the poo pill was exactly the sort of treatment that scientists should be developing.

"The success of faecal transplants is fascinating. If we can deliver the same with a pill that can keep the bacteria alive long enough to reach the colon, which is 4m down, then that is more acceptable to a patient than a succession of enemas."

A Canadian researcher, Professor Elaine Petrof, spent two years creating RePOOPulate (yes, really) - a pill containing 33 purified bacterial strains extracted from a healthy donor's faeces. The pills worked, but the cost of manufacturing them led her to conclude that commercialising the process would be a thankless task.

That we share our bodies with trillions of microbes - and that we and they have evolved together, largely harmoniously, over millions of years - promises new therapies and should prompt us to rethink on how antibiotics are used.

Our bodies are not designed to be sterile, bacteria-free temples - they evolved as microbe-filled shrines, coated and stuffed with colonies of microorganisms designed to keep us well.

You might want to rethink that New Year detox.