What evidence is there for a connection between the microbiome and the chronic inflammation and mental health problems on the rise in western populations? Do we need to rethink hygiene practices to benefit from this new understanding?

In this episode we’re going to be getting our heads around the idea that while Hygiene has revolutionised health, too much hygiene, actually weakens our immune system’s development. To understand why, we need to understand how the complex community of microbes in our intestines, on our skin and in nature around us has evolved for thousands of years, in symbiosis with our immune system; we’ll be mapping out how, as our hygiene practices and food processing have increased, so the diversity of microbiota has dropped, eventually leading to the explosion of inflammatory disorders, mental health issues and auto-immune disfunction we’re now seeing in western communities. But how to solve this problem, without loosing the great advances in health care achieved by the application of Hygiene theory?

Who better to answer that question and explain these subtleties than professor of medical microbiology at University College London, Dr. Graham Rook. Rook is a specialist in infection and immunity, and has spent his career unfolding how the young immune system is ‘programmed’ by the microbial background, identifying all the medical conditions that have been worsened by the failing immuno-regulation associated with our impoverished biomes, and developing ways we can update our lifestyle to restore the diversity required to sustain healthy immune response.

In his new book ‘Evolution, Biodiversity and a Reassessment of the Hygiene hypothesis’ he explains all this and his 2003 Old-Friends hypothesis, which seeks to correct the over-stretching of the Hygeine hypothesis.

We have got a show from the second series with phytotherapist Alex Laird, about the dietary aspect of the microbiome and inflammation called ‘Mood Food: Inflammation, the gut and diet’ should anyone want to get into the food side of this.

What we discuss:

00:00 Intro

08:30 Bacterial diversity in the human body and the evolution of the immune system

12:00 The symbiotic co-evolution of internal bacteria and humankind

13:30 The ‘programming’ of the adaptive immune system by diverse bacteria: Lymphocytes

16:30 Most of our genes evolved in micro-organisms 

20:55 Modern western microbiomes compared to our hunter gatherer ancestors

21:40 Variety of diet and contact with nature

22:10 Microorganisms from mother and the natural environment

24:00 The socio-economic factor: Urban poverty VS exposure to microorganisms and diverse diet

26:00 Antibiotic over-use in children contributing to allergies and obesity

26:25 Immune regulation, and how it changes with hyper inflammation

30:00 Background high inflammation in the west

31:20 Microbiota transplants in mental health, allergies and obesity experiments

33:50 The difficulty in using biota transplants to treat biome related issues 

39:00 Microbiome/inflammation research into Autism, Parkinsons and Alzheimer’s 

46:00 ‘Trained Immunity’ - raising immune alertness epigenetically 

50:00 Reassessing the hygiene hypothesis, good diet and minimising antibiotics

References:

G. Rook, ‘Evolution, Biodiversity, and reassessing the hygiene hypothesis’ book

G. Rook, 'The Old Friends Hypothesis’ paper

‘Pediatrics Consequences of Caesarean Section-A Systematic Review and Meta-Analysis’, maternal microbiota paper

‘Association between antibiotic treatment during pregnancy and infancy and the development of allergic diseases’ paper

‘Gut microbiome remodelling induces depressive-like behaviour’ paper

‘Long-term benefit of Microbiota Transfer Therapy on autism symptoms and gut microbiota’ paper

'Pet-keeping in early life reduces the risk of allergy in a dose-dependent fashion’ paper