Super poo: the emerging science of stool transplants and designer gut bacteria

The collective genetic material in the microbiome performs myriad functions that affect our mood, our immunity, and our physical and mental health.

Restoring them to health has become a very serious scientific endeavour, as the diversity of our gut bacteria is linked to everything from depression to how we respond to cancer treatment.

But as scientific understanding of the microbiome improves, the possibilities of faecal transplants are expanding.

Those who make it through all the assessments are enrolled for an eight-week program where they have to turn up on time, fill out a questionnaire, then (ahem) make a deposit inside a special room.

People are building libraries of the very best that poo has to offer, and BiomeBank is part of the effort to categorise premium stool strains.

Costello, a gastroenterologist, says that humans historically had much more diverse microbiota. We lived more closely with other people and with animals, and we ate more unprocessed food.

Patients can take it orally to treat specific infections. This generation has already been rolled out in hospitals, and, if approved by the Therapeutic Goods Administration, it will be the first microbial therapy in the world approved as a biologic (it currently has provisional approval).

Babies born by caesarean section have a different mix to those delivered vaginally, a major study has found. The C-section babies pick up more strains from the hospital, which could explain higher rates of immune problems such as asthma and allergies in those babies.

A team from the Imperial College London and the University of Pittsburgh compared African Americans to rural South Africans. The volunteers were tested, then swapped diets and were tested again.

After just two weeks on the fibre-rich rural diet, the Americans had significantly less colon inflammation and a lower cancer risk. Unfortunately, the rural group went the other way.

The Food and Mood Centre is studying nutrition and its effect on depression, on muscle and heart health, on psychotic disorders, on post-traumatic stress disorder, eating disorders and a host of other health concerns.

Jacka nominates cancer research as one of the most exciting fields in microbiome studies. Data show better responses to treatment, particularly immunotherapy, in people with more diverse gut microbes.

He says the the number of genes in these microorganisms dwarfs that of the human genome.

Jacka says for most people changing their diet is enough to change their bacteria.

Think kimchi, kombucha and sauerkraut. And think fibre.

You have to start gently, she says. Increase the amount and type of fibre gradually.