The Gut Microbiome, Its Importance & The Best Probiotics for Improving Gut & Digestive Health

You’ll probably know that our bodies are home to millions upon millions of microorganisms — commonly referred to as the human microbiome.

These communities of bacteria, fungi, viruses and protozoa thrive in areas of particular warmth and moisture in our bodies: primarily the gut, but also the mouth and, for women, the vagina.

Let’s explore the importance of the gut microbiome. What’s its role and can consuming probiotics help our gut health?

What is the gut microbiome?

The gut microbiome refers to the communities of microorganisms living in the human intestinal tract. Within this part of our body, there are estimated to be over 300 species of bacteria. Many of these are beneficial, but some can be harmful in excessive amounts.

Why is the gut microbiome important?

The gastrointestinal system is incredibly complex and there has been very compelling evidence of the fundamental role that the gut's microbial composition plays in human health.

An unhealthy gut microbiome with too much bad bacteria leads to ‘dysbiosis’, known to affect the body’s nutrient absorption, sugar level regulation, nerve function — and can even place us at greater risk of obesity and other diseases.

Gut dysbiosis has also been associated with the development of inflammatory bowel disease, cancer, sleep problems and is even implicated in a weakened immune system. In children, exposure to a range of beneficial bacteria is particularly important for avoiding food intolerances.

If you’ve got trouble sleeping, it may also be worth tuning into your gut. Hormones produced by gut bacteria regulate sleep and mental states, placing those with poor gut health at greater risk of insomnia and depression. Researchers have also coined the idea of ‘gut-skin communication’ — it is understood that there is a link between gut microbiome and skin problems.

By the same token, having a healthy, balanced gut microbiome — with abundant ‘good’ bacteria present — enhances immune system function, boosts sleep, can prevent depression and reduces the risk of obesity.

What are the signs of poor gut health?

If your gut microbiome is a bit unbalanced, you might notice some of the following symptoms.

• Upset stomach & digestive issues: An unhealthy gut microbiome makes it harder for our bodies to process food and is associated with IBS symptoms — gas, bloating, stomach cramps, heartburn, constipation and even diarrhea.
• Weight fluctuations, sugar cravings & food intolerance: A microbial imbalance is known to interfere with nutrient absorption and blood sugar regulation, making us more likely to overeat and reach for a sugar-laden pick-me-up. You may experience trouble digesting some types of food.
• Skin problems: Dermatological problems have been linked to gut bacteria health. Protein leakage caused by inflammation from an unhealthy gut is associated with irritated, eczema-prone skin.
• Insomnia & sleep trouble: Did you know that most of the serotonin in our body — a hormone affecting mood and sleep — is produced in the gut? Reduced quality and quantity of sleep can make us feel more fatigued during the day.
• Mood fluctuations — Gut bacteria produce a range of neurochemicals that affect how we feel; the gut-brain axis is a real thing, with the right balance of microbes credited with improved mental health outcomes.

So, all in all, a healthy gut microbiome is essential. Naturally, this begs the question — what can I do to ensure good gut health?

How can you improve your gut health and digestion?

Intestinal health and digestion are fundamentally affected by the composition of bacteria within the gut. Consuming probiotics (those good, friendly bacteria) is known to help your microbiome and improve your gut health and digestion.

A healthy, balanced gut can be promoted by taking a number of other lifestyle steps. Restful sleep and low stress levels are all great for the gut, as is good hydration — drinking water benefits the mucosal lining of the intestine.

As well as checking for food intolerances, eating slowly can help with digestion, as can cutting down on refined, processed sugars and foods. These can damage the composition of your gut microbiome.

What are friendly bacteria?

There are over 300 strains of bacteria living within your intestines. Some of these strains can be harmful in too great a quantity, but others convey health benefits. These beneficial types are known as probiotics.

Two of the most common types of ‘friendly’ gut bacteria include strains of Lactobacillus and Bifidobacterium. These strains have been scientifically shown to help restore a natural balance within our gut.

How can probiotics help with gut health and digestion?

Probiotics are defined as live bacteria that convey human health benefits. It is thought that by consuming these good bacteria — the most well-researched probiotic strains being Lactobacillus and Bifidobacterium — we encourage them to colonise in our gut. They help to control harmful bacteria, protect the lining of the intestine and break down food.

Ways to consume these helpful bacteria include through natural sources like fermented food, or through dietary supplements that contain these bacteria — products often marketed themselves as probiotics. These are commonly available commercially as daily capsules, but can also be added to food, like yoghurts.

What are the benefits of taking probiotics for gut health and digestion?

Many people are drawn to probiotics because they may be suffering with IBS-like digestive symptoms — stomach cramps, bloating, diarrhea and constipation.

There is a strong, growing body of evidence attesting to their positive impact on gut health, keeping our digestive system running as smoothly as can be.

• A wide-ranging scientific review found that multi-strain probiotics can ‘have the potential to improve IBS’, with other overviews suggesting that alterations in gut bacteria caused by probiotics are responsible for alleviating IBS symptoms.
• Evidence points to the clear benefits of probiotics for the treatment of diarrhea and constipation.
• A comprehensive scientific review found that probiotic strains can improve intestinal health, immune response, cancer prevention, lactose intolerance and even coronary heart disease prevention.

What are the best probiotics for gut health and digestion?

The most popular, thoroughly-researched probiotic bacteria for gut health and digestion are species of bacteria within the Lactobacillus and Bifidobacterium genera.

Lactoballicus are commonly found in the small intestine and vaginal flora, producing lactic acid that keeps populations of bad microorganisms in check. Bifidobacterium, on the other hand, thrive in the large intestine, providing support to the immune system and helping with food absorption. Both of these beneficial types of bacteria break down lactose.

Examples of probiotic Lactobacillus species:

• L. rhamnosus: perhaps the most popular probiotic strain, shown to help support digestion and immune function. It is commonly added to dairy products.
• L. reuteri: a species of bacteria understood to prevent the growth of pathogenic microbes and guard against inflammatory disease.
• L. acidophilus: found in fermented foods like sauerkraut and miso, benefitting our immunity and breaking down lactose.
• L. casei: a species found in yogurts, fermented milk and types of cheese, shown to relieve diarrhea in some studies.

Examples of probiotic Bifidobacterium strains:

• B. bifidum: perhaps the most widely-acclaimed of the Bifidobacterium genus, a number of studies have shown it to help with IBS symptoms and immunity.
• B. longum: known to help support the large intestine stabilise our gut microbiota, guarding against gastrointestinal diseases, as well as improving immune dysfunction.
• B. infantis: this species is thought to provide particular benefit to small children, benefitting the digestive system and improving nutrient absorption from breast milk.

This is not an exhaustive list, of course — within each genus, there are many different species, each unique and providing different benefits to the body.

Probiotic dietary supplements are usually measured in colony-forming units (CFU). Those with higher doses of CFU — over 1 billion — have been shown to produce the best results.

When browsing for a probiotic product or supplement, check the CFU and look out for Lactobacillus and Bifidobacterium bacteria — some of the most well-researched out there.

What natural food sources contain probiotics?

For many people, modern life isn’t hugely conducive to a healthy gut microbiome. Stress, a lack of sleep and the ready availability of processed, sugary food can wreak damage on the composition of bacteria in our intestinal tract.

Refined sugar in our diet is associated with increased inflammation in the body, leading to other types of disease.

There are a number of fermented foods that naturally contain the beneficial species and strains of bacteria we mentioned earlier.

• Yoghurt: yoghurt has been fermented by friendly Bifidobacterium and lactic acid bacteria. It’s one of the most readily-available probiotic foods out there — but make sure to choose a low-sugar option that has plenty of live cultures.
• Kefir: by adding kefir grains to cow or goat milk, we can create kefir — a fermented probiotic drink that’s bursting with gut-friendly bacteria.
• Kimchi: this is a spicy fermented Korean dish that naturally contains Lactobacillus kimchii, understood to benefit our digestive system.
• Sauerkraut: this is shredded cabbage that has been fermented with lactic acid bacteria. As well as being rich in minerals and vitamins, unpasteurised sauerkraut contains a hearty helping of probiotic bacteria.
• Green olives: The fermentation process for table olives imbues them with plenty of gut-friendly Lactobacillus bacteria.
• Kombucha: This fermented tea is known to contain a range of beneficial probiotic bacteria.
• Soft and aged cheese: Some types of cheese, such as cheddar, are known to be able to deliver our bodies some gut-friendly bacteria.

Some other, popular fermented foods include miso, tempeh and natto — all shown by science to boast some incredible gut-boosting microorganisms.

Probiotics and gut health: a clear link becoming clearer

A balanced gut microbiome plays a huge role in our body’s natural immunity, digestion, weight management, mood, sleep and even skin health.

Scientists, researchers and nutritionists are growing increasingly confident about the positive role that probiotic supplementation plays in maintaining the health of the gut microbiome and, by extension, our general health.

There is particularly strong evidence attesting to the impact of probiotics on digestion and the alleviation of IBS symptoms. The mechanism and action of particular probiotic strains is a matter of ongoing research.

At Inspired Health, we offer products from a range of health brands that help people of all ages to live happier, healthier lives. Explore our leading range of probiotic supplements.