Exploring the gut brain super highway

A Guild of Health Writers meeting, sponsored by Optibac, looking at the increasingly clear links between the microbiota in the gut and the activities of the brain – with Professors Ted Dinan and Tim Spector, Dr Yoram Inspector and functional medicine practitioner, Lucinda Miller. Michelle Berriedale-Johnson took some notes.

Professor Ted Dinan is Professor of Psychiatry and a principal investigator in the APC Microbiome Institute at University College Cork.

Professor Dinan started by describing the sheer size and diversity of the microbiota in our guts: 1-2 kilos of bacteria weighing roughly the same as our brains and infinitely more diverse. The amount of DNA in our microbiota would simply not fit into our cells. But the interesting thing is that the DNA in the microbiota can be changed.

The main transport of chemicals from the gut to brain is via the vagus nerve running from the brain through the neck and thorax to the abdomen, although communication can also happen via fatty acids in the blood crossing the blood brain barrier. Disregulation of this communication is now thought to be involved in a number of conditions such as autism, Parkinsons, depression and various cognitive disorders. The microbiota of depressives show much less diversity that the microbiota of 'normal' people and are very different.

He described how, in their laboratories, they had raised rats that were entirely bacteria free and discovered that in those animals, the myelination patterns were abnormal, the synaptic formation was disregulated and there were abnormalities in the blood brain barrier.

They then transplanted the microbiota from both healthy and depressed humans into rats and found that the rats with the 'depressed' microbiota exhibited many of the symptoms of depression in humans - they were more anxious, took no enjoyment in normally enjoyable pursuits etc.

Question? In FMT (Faecal Microbiota Transplants) should the psychiatric health of the donor be checked as well as the physical health?

Professor Dinan's current work is focused on the Bifido Bacterium Longum 1714 which appears to reduce stress and improve cognitive skills in rats. They are currently running a cross over placebo controlled study in health individuals and it appears that those consuming the BB Longum 1714 are less stressed (their waking salivary cortisol levels are lower, for example) and have improved cognitive function in certain aspects (EEGs show increased frontal mobility in the brain).

The microbiota can be changed – through food, antibiotics, probiotics and FMT.

Up till now treatment for depression has focused on CBT (Cognitive Behavioural Therapy teaching the brain to 'think' differently) and drugs. Diet has been ignored. It should not be.

Professor Tim Spector is Professor of Genetic Epidemiology and head of the Department of Twin Research at Kings College London. He is also author of the best selling 'The Diet Myth'.

Professor Spector's position as head of the huge twins' research project has neatly enabled him to combine twins research with microbiota research, correlating, via their twins, microbial species with diseases. For the last seven years, this research has also, through the British Gut project, fed into their work sequencing the genetics of the microbiome. This has already revealed specific links between microbe types and at least 20 health conditions - such as obesity, allergy and many digestive issues.

It is not hard to change the composition of the microbiome – every food that you eat will change it, as will every drug that you ingest. And it can be changed in as little as three days.

Professor Spector described how, in the few days that he had spent with the Hazda tribe in Tanzania who still hunt and gather their foods from the local terrain, his own bacteriological profile changed dramatically. (The Hazda have on average 40% more diversity in their microbiota than we do, including more short chain fatty acids.) He also described how a 10 day diet of MacDonald hamburgers alone had reduced his son's microbial diversity by nearly 50%!

Speculation on why the hamburger only diet should have had such a dramatic effect included a lack of fibre (no food for the bacteria) and an excess of artificial sweeteners.

Fibre, found in abundance in polyphenols such as red wine, coffee, chocolates, berries, green and black tea, fruit, vegetables and olive oil, seems to be crucial for bacterial health. Ideally we should consume 30g per day although most people would not consume more than 20g.

Fibre and healthy bacteria also seem important in weight control. In the twins studies, the slimmer twin always appears to have a greater diversity of bacteria in their guts. Interestingly, it usually seemed to be a dearth of good bacteria that had deleterious effect on health rather than an overgrowth of harmful bacteria – such as Christensenella or akkenasia.

Fermented foods, especially with prebiotics, are particularly beneficial (kombucha has three times as many microbes as any other fermented food) and while probiotics seem helpful when you are unwell they seem to have little effect when you are well.

Personalising the diet is important as each in dividual reacts differently to different food. Thus, despite their similar glycaemic readings, potatoes, orange juice and rice can result in completely different glucose loads in different people.

Dr Yoram Inspector is a psycho-gastroenterologist, the consultant psychiatrist at St Mark's Hospital in Harrow, North London. St Marks provides psychiatric and psychological treatment for patients suffering from gastrointestinal disorders.

While Dr Inspector now focuses on the gut, his medical doctorate was received for research into psychiatric aspects of heart transplantation. (Interestingly, although heart transplant patients are completely aware that the heart is only a muscle, there is far more psychological fall out among heart transplant patients than among patients receiving any other transplanted organ – such as a liver.)

Fascinatingly, Dr Inspector traced the close connection between the gut and the brain/psyche from the ancient tale of Gilgamesh and the giant Humbaba whose intestines twine around his face, through the Greeks (the loneliness of Medusa, traumatised by her experiences, who will not speak of them lest she turn her listener to stone), the bible and right up to Michealangelo's Sistine ceiling.

In his work he has found that functional gut issues are frequently associated with trauma, especially physical abuse (62%), abandonment and neglect. The chronic inflammation of the gut associated with functional gut issues can directly affect the brain and often plays a role in depression.

He believes that in all psychological conditions, the gut's health should be a prime consideration.

Lucinda Miller, naturopath and functional medicine practitioner.

Lucinda sees listening to the patient as the most important task of any medical practitioner. She also sees most conditions, both physiological and psychological as being traceable to gut malfunctions. To quote Hippoctrates, all diseases begin in the gut...

So, an ear infection that is treated with antibiotics disrupts the gut flora and which will more often than not, result in behavioural disimprovement. One could also speculate whether in a condition such as eczema, it is actually the gut flora which are affecting the skin barrier. Or even whether the 'terrible twos' toddler temperament could actually have something to do with a disruption of the gut flora.

Lucinda stressed the importance of a varied diet (not easy to achieve with sick children who may already be fussy eaters) not only for children but for mothers both pre and post delivery.

She also pointed to the very strong link between gut issues in children on the autistic spectrum - well over 80% of children on the spectrum have gut issues, most often constipation.

Interventions mainly centre around building up the microbiome by increasing the ranges of fruits and vegetables eaten, adding probiotics and herbal antimicrobials such as oregano and garlic, introducing kefir (which is very child friendly) - and ensuring that they get dirty! Lucinda described two cases where these interventions had worked really well.

Ethan, aged eight, had suffered from tics, anxiety, OCD and hyperactivity. He stools were poor and while he had no lactobacillus in his gut, he had plenty of candida and streptococcus. Samy, aged three, was tiny, had high levels of anxiety and could not yet speak – and her microbiota was a disaster!

In both cases the children had improved dramatically when their microbiota issues were addressed.

The meeting ws sponsired by Optibac Probiotcs.

February 2018

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