Oral microbiome linked to Alzheimer’s dementia

The notion that bacteria in our mouth might mediate neurodegeration, stresses the importance of attending to what we we eat and the pollutants in our environment.

Could the oral microbiome be linked to neurodegeneration?
Could the oral microbiome be linked to neurodegeneration?

Gut well soon originally started life as a cheerleader for traditional fermented products such as kefir and sauerkraut. Simple fermented foods, easy to make at home, with a long association to health and wellbeing. Over time we have edged a lot closer to the wider discussion about the human microbiome more generally. Exactly why do fermented foods, containing large amounts of helpful bacteria, appear to boost human health quite so dramatically?

As part of this growing understanding, I want to highlight and link to a new scientific study that suggests a potential relationship between gum disease and Alzheimer’s dementia.  There is not yet sufficient evidence to claim that the oral microbiome has a causal role in dementia1, but this paper offers more support for the notion that our bacterial populations (good and bad) have a crucial role in our physical and mental health.

pain armchair dentist suffering

The general idea that many of our most challenging health problems can be mediated by the bacteria we carry in and on our bodies is still highly controversial. Not least because our healthcare systems are often based on a treatment rather than prevention paradigm. If some of these treatments, such as antibiotics, can cause other problems in the short and long term what then? It is estimated that lifestyle choices (including diet), are connected to 80% of health problems seen by GPs in the NHS. And yet UK medical schools offer almost no nutritional education to their students. It can be argued that our doctors have been taught for decades, to engage with treatment opportunities rather than prevention strategies.

Returning to the cited study discussed in New Scientist. It has been hypothesised that a gum disease bacterium (Porphyromonas gingivalis), may get into the brain and cause inflammation which could be a factor in neurodegeneration. People with Alzheimer’s dementia tend to have higher levels of this bacterium in their brains. A company has created an oral medicine that is intended to block the activity of the toxins established by the bacterium. An initial small trial has seen some positive preliminary results.

A second question arising from this new approach to Alzheimer’s dementia is what lifestyle and dietary choices are likely to improve the mouth microbiome and reduce harmful bacteria that attack the gums?

Notes:

1 https://www.newscientist.com

Parkinson’s disease linked to the gut

Evidence suggests the causes for Parkinson’s disease may originate in the gut.

Parkinson's disease may start in the gut
Parkinson’s disease may start in the gut

The Guardian1 ran a story yesterday, pulling together some of the latest evidence linking the origins of Parkinson’s disease to the gut. It has long been thought that when a protein called alpha-synuclein is misfolded and clumps together in the brain, it is associated with nerve damage and a reduction in dopamine. This, in turn, is presumed to be responsible for the deterioration in the control of speech and movement, two of the key symptoms of Parkinson’s disease. But recent research in this field has been looking at the gut as a potential point of origin for the misfolded alpha-synuclein.

clinic doctor health hospital

The direct two-way channel between the gut and brain (the gut-brain axis) is being seen as an increasingly important mediator of human health.  A recent study with mice has added weight to the hypothesis that the misfolded alpha-synuclein originates in the intestinal tract and use the vagus nerve to travel to the brain. This follows earlier findings that indicate having your appendix removed reduces the chances of developing Parkinson’s in later life. Taken together these studies signpost the possibility that prevention of  Parkinson’s disease could focus on the gut rather than the brain.

However, there are a number of further steps that need to be made, not least a convincing explanation of what causes the misfolding of alpha-synuclein in the gut. As such, it is premature to conclude that the primary cause of Parkinson’s disease originates in the digestive tract. But this latest evidence underpins the importance of the gut in human health more generally. Understanding how to maintain a healthy gut microbiome through the use of prebiotics and probiotics is entering the mainstream. In addition, science is also drawing our attention to the pressing need to avoid substances that degrade or limit gut health, such as the chemicals that are present in a wide range of foodstuffs.

 

Notes

1 https://www.theguardian.com

Could the glyphosate in your bread be harming you?

Could glyphosate in your bread be harming your health and gut microbiome? Time to switch to organic

Glyphosate in our bread
Is bread harming our health?

Bread is perhaps the oldest and most prominent of all man-made foods, it predates agriculture and there is evidence of its continuous use in some parts of the world for over 20,000 years. In essence, all you need to make bread is grains (flour) and a little water, the kneaded dough will rise (leaven) if left, because of the presence of naturally occurring sourdough microbes in the air.  Then all you have to do is bake, sounds simple, doesn’t it?

The problem is that to make a greater profit from bread production, some of the natural processes, used for tens of thousands of years, have to be modified. For example, greater mechanisation in bread production1 allows lower quality (lower protein) grains to be used, reducing the nutritional value of the bread we consume. Modern chemicals are also having an increasing role in our food production, including grain farming. The Government’s own figures show that the area treated with glyphosate in the UK increased by a quarter between 2014 – 20162.

So why the ‘glyphosate revolution’ in food production, what value does it add and what are the likely consequences to our health? Glyphosate is an active ingredient in some weedkillers, such as Roundup (developed by Monsanto). It is used on the soil to kill weeds before young plants emerge, and in the case of wheat, it is sprayed onto ripening crops to improve yields in a process called ‘drying’. We know that glyphosate is in the soil, the water, in our grain, in our bread and therefore in us3.

There was a time in our recent past when we generally believed in scientists and our government’s ability to regulate science for the common good. Health problems linked to human contact with glyphosate have been discussed for many years. In 2015 the World Health Organisation (WHO) found that the available evidence indicated glyphosate was ‘probably carcinogenic’ to humans4. Over a dozen countries have banned or limited the use of glyphosate, yet in many nations, it continues to be consumed by the wider population in different forms, despite evidence of its potential to harm.

So what’s all this got to do with Gut Well Soon? Unsurprisingly some organisations that make profits from the production, sale and use of glyphosate continue to maintain, that at the levels humans ingest the substance, there is no increased risk of developing cancer. However, courts are awarding billions of dollars in damages against Monsanto following claims that exposure to Roundup caused cancers5. There is also credible evidence that glyphosate has an impact on the microbiome, even at very low levels of ingestion. Meaning that our gut health may be declining because the food we eat has been tainted with chemicals.

So what can you do about this? There are suggestions that the explosion in wheat and gluten intolerance seen over the last 20 years, might be correlated with the increasing use of chemicals in grain production. No causal link has been proven but we do know that switching to sourdough bread has benefitted the health of a large number of people with digestive problems. It seems intuitive, that by eating bread with no traces of weedkillers our health (collectively) is likely to improve. This all inevitably leads us to a conversation about switching to organic, naturally produced bread including sourdough.

Notes

1 Chorleywood Bread Process
2 Soil Association
3 Concerns over use of glyphosate-based herbicides
4 IARC
5 The Guardian

Autism correlated with gut health

Autism correlated with guthealth. More evidence links gut bacteria to developmental disorders.

Our gut bacteria may play a role in Autism Spectrum Disorders (ASD)
Our gut bacteria may play a role in Autism Spectrum Disorders (ASD)

There is mounting evidence of a relationship between the microbiome and autism. Taken in isolation one study that challenges conventional thinking about any condition such as autism should be treated with suspicion. However, increasing scientific research into gut health and wellbeing is starting to shift the thinking about human health in a completely new direction.

A number of studies have observed abnormal gut microbiota correlated with a range of conditions including autism. However, the issue of causality is still uncertain. So what does this mean?  In short that the bacteria in the human gut demonstrates a different profile in people with autism than people without autism. The scientific term for a balance and blend of gut bacteria that fall outside of the ‘normal’ range is known as dysbiosis. Exactly how gut dysbiosis is linked to autism is still far from clear. There is the possibility that dysbiosis is the effect of a condition rather than the cause of it, although we know there is a two-way relationship between the gut and the brain through the gut-brain access.

A recent overview of research into gut microbiota and dysbiosis in autism found that gut microbiota probably has a mediating role in ASD. By logical deduction, we can be confident that diet at some level is likely to be connected to the development of ASD or the maintenance of its symptoms.

So while we are waiting for science to deliver ‘conclusive’ findings that will help us understand more about autism, what shall we do?

Clearly, we should attempt to establish a healthy gut. The list of health problems linked to dysbiosis grows almost every day, they currently include a range of cancers, heart disease and even dementia! Amongst the simple measures every person can engage with immediately to keep a healthy gut, are to avoid processed meats and eat more fermented foods.

It’s far too early to draw firm conclusions about diet and complex developmental conditions such as ASD. But a picture is starting to emerge were just as diet influences gut health, gut health influences physical and mental wellbeing, there was never a greater case for embracing the maxim ‘we are what we eat’.

Fibre and your health; time for a rethink

Fibre is an essential part of the human diet, strategic reviews indicate that consuming just 30g of fibre a day is correlated to reduced risk of colon cancer, type-2 diabetes, heart attacks and strokes.

Fibre and your health
Fibre and your health

For most of us, there is a simple thing we can do to improve our short and long-term health, eat more fibre! The role of fibre in regulating digestion has been understood by humans for hundreds of years. But the full benefits linked to fibre (also known as roughage) are only just starting to be understood. A recent study published in The Lancet1 analysed a wide range of research and found that a shortage of fibre in our diets is linked to greater risks of type-2 diabetes, bowel cancer, heart attacks and strokes. In addition, people that eat more fibre tend to have lower weight, lower blood pressure and reduced cholesterol levels. Amazingly the research suggested that consuming a mere 30g (1oz) of fibre a day was sufficient to deliver the full range of health benefits. To put this into some kind of perspective the 30g target can be reached by consuming four slices of brown bread, eating a handful of nuts and seeds in addition to the regulation five portions of fruit and veg a day. In essence, it is available to most of us with only a few small changes to our eating habits.

pile of sliced wheat breads

Fibre consumed through our diet can be divided into two types, soluble and insoluble. Soluble fibre is generally thought of as a prebiotic, which means it supports communities of helpful bacteria in the gut microbiome. Insoluble fibre does not dissolve in water and typically passes through the digestive system aiding bowel movements. Most fibre rich foods contain soluble and insoluble elements, today food science is more concerned with the total amount of fibre rather than the different forms (cellulose, pectins and beta glucans) we eat.

In summary; fibre is an essential part of the human diet, strategic reviews of the available evidence strongly suggest that consuming 30g of fibre a day is correlated to a reduced risk of colon cancer, type-2 diabetes, heart attacks and strokes. There is a growing body of evidence that fibre also plays an important role in maintaining helpful bacteria in the gut microbiome.

Foods rich in fibre2 include;

  • Wholegrains (wholegrain breakfast cereals, wholewheat pasta, oats, barley,  rye and wholegrain bread).
  • Fibre-rich fruits (berries, apple, pear, melon and orange).
  • Fibre-rich vegetables (broccoli, carrot and sweetcorn).
  • A wide range of pulses, peas and beans.
  • Nuts and seeds.
  • Root crops cooked with skins on (potatoes, sweet potatoes).

Notes

1www.thelancet.com
2www.nutrition.org.uk

Gut health: BBC radio documentary

The importance of the microbiome to human health is just starting to emerge, but our attitude to gut health hasn’t always been this enlightened.

Learn more about gut health
Gut health, a BBC review in five episodes

Just a heads up for anyone interested in learning more about the changing relationship between humans and gut health. A short series The Gut Instinct: A Social History has been broadcast on BBC Radio 4 this week over five 15 minute episodes. At the time of writing the transmissions were still available on the BBC iPlayer here.

The concept was to explore how humans related to digestive processes and gut health across culture and time. There’s a lot of general information linked to the microbiome, some directly relevant to us today. The programme was written and presented by restaurant owner Tim Hayward and it seeks to offer an account relevant to a general audience, setting out major historical landmarks as well as important contemporary issues. Unusually for a British show, we actually hear adults talking about bowel movements and human waste in a practical and informative manner. The five-episode titles reflect the general content of the series (Gut Culture, A Window into the Gut, The Language of the Gut, The Disease of Civilisation and The Gut Speaks). Don’t expect much detailed science but I’d imagine anyone who tunes in to pick up some new morsels of gut knowledge, total listening time is just 75 minutes.

Do probiotics work?

Do probiotics work? Research from 2018 suggests that some probiotic strains might struggle to find a home in our gut, being quickly forced out by the established microbes.

Do probiotics work
Do probiotics help the human microbiome?

Do probiotics work?

Research into the human microbiome is demonstrating that gut health is both complex and nuanced. Complex because of the sheer quality and quantity of microbes that we humans host. For example according to the Human Genome Project each of us has around 22,500 human genes, however it’s estimated that we also carry 100 times that number in microbial genes! Understanding the colonies of microbes (predominantly bacteria) inside our gut is further complicated because no two people have exactly the same gut flora. So therefore each of us has a unique bacterial ecosystem.

A research paper published in the journal Cell in September 2018 and highlighted by the BBC website, has made the claim that “Humans feature a person-specific gut mucosal colonization resistance to probiotics”. The study found that an 11-strain probiotic mix, administered for a month had almost no impact on the long term gut health of 25 participants. Either passing straight through the digestive tract or lingering for a short time before being forced out by the well established resident bacteria. Although provisional, the results are highly suggestive that the gut has a defence mechanism designed to protect itself from rapid colonization by new visitors. This is kind of intuitive, if any new bacteria that we ingested could quickly establish a foothold in our body then we would be much more vulnerable to harmful microbes.

Although this initial study hasn’t been replicated and is based on a relatively small number of people it suggests that probiotics might work best if they are tailored to each of us individually. That probiotics might offer the greatest benefit if they are designed to coexist with our unique resident populations. From a consumer’s point of view I am left thinking how might I be able to tell if the probiotics I consume are having a lasting effect without going down the road of expensive lab based testing? Hopefully further studies offering greater insight will follow.

 

Notes

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