The gut microbiome

Trillions of microorganisms (bacteria, viruses, fungi) reside in our gut. These gut bugs are collectively known as the ‘gut microbiome’.

 The gut microbiome protects the gut barrier, regulates our immune system, and is linked with our metabolism, cardiovascular health, mental health, and even our exercise performance.

 It also produces an array of vitamins, amino acids, and molecules such as short chain fatty acids (SCFAs) – the latter being incredible little metabolites that both nourish the gut cells and perform a multitude of functions throughout the body.

In fact, the gut microbiome is often referred to as a ‘virtual organ’ due to its metabolic activities and influence on both the gut and the rest of the body.

For the gut microbiome to do its good work, it needs to be healthy.

The human gut microbiome is incredibly complex and diverse. And each person’s is unique – like a fingerprint.

Many factors help shape our gut microbiome – our genes, our age, the medications we’re taking, but the most influential is our habitual (long-term) diet. What we eat affects the composition and diversity of our gut microbiome.

Generally speaking, studies have shown that those with diets higher in fibre have gut microbiomes that produce a greater number of SCFAs, while those who follow a typical “Western diet” – high in saturated fat, processed foods, and sugar – have gut microbiomes that produce toxic metabolites. Certain gut microbiome profiles and presence of metabolites are associated with gut disorders, obesity, depression, and cardiovascular disease.

… and we’re all different  

Because each person’s gut microbiome is unique to them, it’s impossible to define the perfect microbiome. However, a healthy one would be typically described as having a high microbial diversity (many different types of gut bugs), being stable, and being absent of pathogens. It’s safe to say that everyone’s gut health would benefit from including certain types of foods and avoiding others.

The good..  

Eat a variety of plant foods

Research has shown that eating a diverse range of plant foods is good for your gut - people who eat more than 30 different plant foods per week have a more diverse microbiome than those who eat only 10. This isn’t as hard as it sounds, plant foods include all fruits, veggies, legumes, grains, nuts and seeds.

Eat foods that feed your gut bugs - prebiotics and resistant starch

Prebiotics are dietary fibres – these include non-starch polysaccharides, oligosaccharides, and resistant starch, which are known to confer a health benefit. They do this by resisting digestion and passing through to the large intestine where they become a food source for your gut bugs.

Regular prebiotic intake is crucial – research suggests that some microbial species in the gut may disappear completely if they’re starved of dietary fibres. Prebiotics occur naturally in most fruits, veggies, legumes, and grains (particularly leeks, asparagus, Jerusalem artichokes, garlic, onions, wheat, oats, and soybeans).

One kind of resistant starch is particularly interesting - it’s formed when starchy foods such as potatoes and rice, are cooked and then cooled. The cooling turns some of the digestible starches into resistant starches. Hello potato salad!

Probiotics are good for you…

Probiotics are live bacteria found in some fermented foods. Yogurt and cultured milk products (e.g. kefir) are probiotics. Other fermented foods such as kimchi and sauerkraut also provide probiotic benefits, but it’s important they are not pasteurised (this kills the bacteria). As a side note, at this stage there is not enough evidence to support the purported health benefits of kombucha, but there’s no harm in drinking it.

The bad..

Avoid excessive intake of sugar, alcohol and artificial sweeteners. These negatively alter gut microbiome composition and reduce diversity.

Extended use of some medications can also alter your gut microbiome. These include proton pump inhibitors which are often used to treat indigestion, and antibiotics (which kill both good and bad bacteria). So it’s even more important to nurture your gut while on these medications.

Irritable bowel syndrome (IBS)  

A growing number of people in the western world suffer poor gut health. In fact, did you know that 1 in 12 people suffer from IBS?

Symptoms like bloating, excessive gas, heart burn, constipation and/or diarrhoea can all indicate something is not right, especially if the symptoms are prolonged.

While the first call you should make is to your GP (please, not Dr Google) certain gut disorders such as IBS can be managed through a dietary approach. For example a low FODMAP (that stands for Fermentable Oligosaccharides, Monosaccharides, Disaccharides and Polyols) diet can be a successful treatment for IBS (for more on that read about our GOOD GUT PLAN or get in touch).

If you’re considering a low FODMAP diet to manage your gut symptoms, please seek advice from a registered nutritionist or dietitian. Because many FODMAPs are also good sources of dietary fibre, you’ll need the right guidance to ensure any dietary changes do not compromise gut health. We have developed the GOOD GUT PLAN to help guide you through a low FODMAP diet the healthiest and most effective way.

To find out more about how you can personally improve your gut health, get in touch at hello@benutrition.co.nz.