As Hippocrates, the father of modern medicine, said more than 2,000 years ago, ‘All disease begins in the gut’. And modern science is proving it as true today as it was then.
In this blog we outline the importance of gut microbiota and the use of diet to affect them to try to improve health and welfare.
For a detailed exploration of the topic, register for our free, CPD-accredited NutriWebinar. Led by experts Professor Glenn Gibson and Laura Tilt, it will give you both incredible insight into the science and practical tips on how to help balance gut microbiota for real health benefits.
The importance of the gut microbiome
We have more than 1,000 species of bacteria in our gut. And there’s been an increasing realisation among scientists that these can have a profound effect on our health – from Irritable Bowel Syndrome to infections, asthma and inflammatory disease right through to bone health and cognitive function.
This understanding has led researchers to investigate what we can do to affect the microbiota, to be applied to this wide range of health problems. A steady stream of scientific publications over the last 15 years address the topic, alongside research into probiotics and, more recently, prebiotics – which selectively fertilise the ‘good’ bacteria.
Our gut microbiome status changes throughout our lives. We acquire our gut bacteria mostly at birth. Moving through the milk years, there are differences in acquiring bacteria between breast-fed and infant formulae fed babies: human milk.
There is change again at the weaning stage, after which the gut microbiota remains fairly stable. As we get older there is then a decrease in the largely in beneficial bacteria like the bifidobacteria.
The gut microbiota can be susceptible to various challenges: stress, infection, antibiotics and poor diet all amongst the factor coming into play on a daily basis.
How does diet affect our gut microbiome and our health?
Carbohydrates, proteins, amino acids and lipids are all metabolised by microbiomes in different ways, with different outcomes for our health.
Carbohydrate metabolism – especially that of fibre – leads to organic acids, short chain fatty acids, that have shown to be beneficial in the gut. For example:
- Acetate is metabolised by the muscle, kidney, heart and brain
- Propionate, cleared by the liver, is an appetite regulator also said to be involved in cholesterol synthesis
- Butyrate is a fuel and regulates cell growth
Fibre itself can stimulate the growth of good bacteria. It’s been estimated that per 100g fibre fermented, 30g of bacteria is produced.
Metabolism of excess protein, on the other hand, leads to less positive end products:
- Ammonia induces quick cell turnover
- Phenols/indoles may act as co-carcinogens
- Amines are linked to migraine, cancer, schizophrenia
Balancing our gut microbiota
- Increased fibre intake
To help ensure balanced gut microbiota, our diet needs to include enough fibre. As discussed in our recent blog, government recommendations advise 30g per day for adults, representing a 60% increase in intake for most. Laura Tilt provides excellent advice on how this can be achieved in the NutriWebinar.
- Probiotic and prebiotics
Much work has been done into probiotic supplements: live ‘good’ bacteria that bring health benefits, especially lactobacilli and bifido bacteria.
More recently, scientists have found that prebiotics could have an even more profound effect on our health. They work by selectively proliferating beneficial bacteria, which in turn inhibit pathogens. They may also have a more general effect, including dampening inflammatory issues.
Prebiotics are found naturally in human breast milk and in fructans and inulins in vegetables including asparagus, onion, banana and leeks. They can also be taken as supplements, especially in GOS forms.
As our understanding of the link between gut microbiota and our health has grown, researchers have increasingly looked to see where we can have the most impact.
We’re in a position where health and nutrition professionals can advise clients on what they can do to improve their gut health and therefore overall wellbeing. We look forward to our research widening and deepening further to improve our understanding in this vital area.
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