Probiotics could treat autism, expert says

Carding, who is also a professor at the University of East Anglia, will tonight deliver a talk on the relationship between gut health and the brain at The Assembly House in Norwich, and will explain how fixing your brain starts by fixing your gut (see video above).

Speaking ahead of tonight’s lecture, Carding said: “The human gut is home to hundreds of trillions of microorganisms, collectively called the microbiome.

“Since the first reports of successful faecal microbiotic transplantation, there has been a tidal wave of interest

UEA professor Simon Carding

“They outnumber the cells that make up the body by more than 10-to-1.”

According to Carding, humans are “under the influence” of microorganisms present in the gut.

For instance, individuals that are prone to gaining weight and becoming obese have populations of microbes in the gut that are very effective in extracting maximum levels of calories from their diet.

“Interestingly, if you take the microbes present in the faeces of an obese individual and put them into a mouse, then the mouse will become obese,” Carding told Laboratorytalk.

“Likewise, if you do the opposite and put the microbes of a lean individual into a mouse, the mouse will stay lean. It will not gain excessive weight.”

Carding also claimed microbes get shared readily by animals that live together in cages, or else by humans that live in close proximity to one another.

“We can show that if you put a mouse with lean microbes into a cage that contains mice with microbes from an obese individual, that co-housing protects the mice given the obese microbes from becoming obese,” he said.

“So there is a transfer of some protective organisms from the lean mouse that stops, or reduces the weight gain in animals that have obese microbe populations.”

However, experts must analyse a variety of factors, particularly when studying the human microbiome, to fully understand microbe populations.

A recent report published in the Sunday Times newspaper looked at the effects of a high-fat diet on the gut microbiome over a period of 10 days.

“In analysing the microbes of the patient within that study, Tim Spector, professor of genetic epidemiology at King’s College London - the researcher in charge of the project - showed there was a drastic reduction in the diversity of microbe species present in the patient’s gut. This also resulted in a two kilogram weight gain,” Carding said.

“One interpretation is that highly-processed food contains ingredients that can be toxic to certain beneficial gut microbes and if you lose enough of them you are tipping the balance between them being beneficial to your health and detrimental to your health - in this case it’s weight gain and the propensity to be obese.”

What is also key, and what the study shows, is the importance of microbe diversity, Carding said.

“Healthy individuals generally have up to 3,000 species of microbes in the gut, and that number is growing.

“In the Times’ research article, the individual in question lost about 1,000 species of microbe over a period of 10 days.”

This can cause a number of adverse effects to an individual’s health, Carding said.

“[For example], understanding how gut microbes influence the brain, the ’gut-brain axis’, is becoming increasingly relevant to understanding aspects of human behaviour - particularly the causes and possible future treatments for serious neurodegenerative diseases, such as Parkinson’s disease and autism,” Carding said.

To that end, there is now a growing body of research, particularly with animal models, that suggests you can treat the symptoms of autism by consuming probiotic bacteria, Carding said.

According to Carding, the use of probiotics to treat certain diseases, such as autism, is becoming increasingly more important and unique.

“We are moving here into the realms of personalised medicine by finding out the relative health status of the gut microbes - and based on that you can decide the best course of action for an individual,” he said.

“If we understand what the key metabolites or metabolic output of a healthy microbiota is compared to an unhealthy one, you have an opportunity to replace what is missing or alter the levels of key things by putting certain types of microbes back into the person and that would be achieved via probiotics.”

There are also more drastic measures individuals can pursue such as microbiotic transplantation.

“Since the first reports of successful faecal microbiotic transplantation, there has been a tidal wave of interest at looking at the potential to use this approach to treat a variety of diseases,” Carding said.

“In five years from now, you could be looking at a much broader range of applications including treating diseases that affects the central nervous system or the treatment of some cancers.

“You should really consider your gut as a second brain.”