We naturally assume we should avoid contact with bugs of all kinds. That said, the friendly bacteria that live in your digestive system are highly beneficial and prove key to a healthy gut– provided you keep them in the right balance. They also need to be in sufficient numbers to prevent any potentially bad bacteria from overgrowing.
The benefits of positive bacteria
The one hundred trillion bacteria and other organisms in your gut have a wide variety of different functions, which we are discovering more about with every day. This new research is highlighting the numerous beneficial roles they may have on your body, including:
- Preventing illness: beneficial bacteria prevent disease-causing bacteria from colonising and causing traveller's diarrhoea and stomach bugs.
- Energy metabolism: our gut bugs are key to breaking down nutrients, including fat, protein and carbohydrates. Research is also showing that the balance of our gut bugs can affect how we lose weight, with specific strains linked to an increased risk of disordered metabolism and weight gain.1
- Nutrient production: our gut bacteria help to produce short-chain fatty acids such as propionate and butyrate which are beneficial fuel sources for gut lining cells and liver cells.
- Immune system: they form a key part of our immune system, preventing gastrointestinal upsets, balancing the allergy response and even directly helping to make immune system cells.
- Good digestive function: those with a healthy population of gut bacteria tend to have less tummy troubles, with these beneficial organisms supporting bowel movement, helping to keep our gut lining healthy and reducing the risk of leaky gut.
- Healthy cholesterol levels: your gut bugs have a role to play in helping to balance cholesterol levels and keeping your cardiovascular system healthy.2
- Hormone balance: the microflora in your gut can even help to maintain healthy hormone levels. For example, if certain gut bugs over populate, they release enzymes which can cause recirculation of excess oestrogen and prevent it from being excreted from the body.3
Which types of beneficial bacteria do I need?
There are so many different strains of bacteria and yeast in our digestive system, each playing a specific role. When combined they work together as a collective; it’s the delicate balance and variety of gut bugs working harmoniously that makes a healthy gut what it is.
Having said that, it’s also important to know we can have too much of a good thing. When levels of even the beneficial bacteria start to overgrow, it can lead to quite grievous health problems– the rampant fermentation and bloating of the small and large intestine, in particular.4
Provided we keep them at the right levels and they don’t overgrow, what are the most important healthy bacteria to promote in our gut? Well, there are two key strains, of which should be present at high levels in a healthy human digestive tract:
By producing the enzyme lactase, this beneficial bacteria is beneficial for the proper digestion of lactose and dairy products. Without sufficient lactobacillus, we can experience bad reactions to dairy, making it appear that we have a dairy intolerance. Lactobacillus bacteria also work with the bifidobacteria strain to maintain the correct pH in the bowel (acidity), which is key to supporting mineral absorption – particularly in the case of calcium, magnesium, copper, and iron. Not only that but the increased acidity in the gut prevents pathogens and yeast from growing. And on top of all that, Lactobacillus can also help to stop vaginal and urinary tract infections.5
This strain of bacteria is the main beneficial microflora found in babies and young children up to the age of 7. It lines the wall of the large intestine, helping to protect the integrity of the gut lining, maintain bowel pH, inhibit the growth of nitrate producing bacteria which may affect bowel health, manufacture B vitamins and Vitamin K, and also help regulate the movement of stools throughout the bowel. Alongside lactobacillus, these gut bugs help to ferment carbohydrates, which release short chain fatty acids. These feed the cells that line the digestive tract, helping to keep them healthy and supportive of good gut function.6
What about the bad bacteria?
We are continually exposed to potentially disease-causing bacteria. This is in addition to strains of bugs that are not considered pathogenic, though they may cause symptoms of bowel disturbances if left to grow in high numbers. This is known as dysbiosis: an imbalance of gut bacteria where a person has too many of a particular strain, not enough bacterial variety, or unbalanced ratio of beneficial to non-beneficial strains.
Whilst gut bacteria should ferment the fibre we eat, dysbiosis can cause an excess of fermentation, particularly when fed with too much sugar and refined white carbohydrate. The results are unpleasant: generally, lots of wind, bloating and abdominal discomfort, as well as a potentially higher risk of developing IBS, leaky gut syndrome, and other health issues.7
How to support the right balance of gut bacteria
There are many factors which can affect your gut’s microbial balance, including stress and the quality of your sleep. Start by looking at your lifestyle and sleeping patterns, and aim to get at least 7 to 8 hours quality sleep per night. If you struggle with stress, introduce more mindful breaks into your daily routine, with a few minutes of deep breathing several times per day, or some relaxing exercise such as yoga, walking outside, or a regular massage.
When it comes to your diet, once again it’s important to remember that variety will stimulate a varied gut microflora. Here are some key factors to consider:
- Include plenty of fibre in your diet, as this forms the main fuel for your gut microflora to grow in a balanced way. Eat a variety of different fibrous foods, especially brightly coloured vegetables and fruit. Their coloured pigments help to support the diversity of your gut bugs. Aim for minimum 2 fruits and 5 veggies per day, including lots of different colours. Also ensure a healthy amount of whole grains, beans, pulses, nuts, and seeds feature in your diet.
- Eat whole, unprocessed and low sugar foods. Too much sugar and refined white carbs can cause the wrong kind of bacteria to overgrow.
- Eat plenty of healthy fats, including olive oil, avocados, oily fish, nuts and seeds – to help modulate inflammation, essential for a healthy balance of gut bacteria.
- Include fermented foods daily, such as a teaspoon or two of sauerkraut, a glass of kefir or a few tablespoons of plain natural yoghurt. These contain bacteria which help to support your colonies of beneficial bugs.
- Take a daily probiotic supplement. Choose one that provides minimum five billion live bacteria, with well researched strains that support human health.
If you'd like to read more about the benefits of keeping a healthy gut, as well as find more information on how you can promote good gut health, then head over to our Gut Health advice centre.
1GM, M. (2018): Obesity and the microbiome. - PubMed - NCBI
2ED, LM, PR, SF. (2018): Gut microbiota role in irritable bowel syndrome: New therapeutic strategies
3Baker JM, e. (2018): Estrogen-gut microbiome axis: Physiological and clinical implications. - PubMed - NCBI
4D. Borchert, N. (2018): Prevention and treatment of urinary tract infection with probiotics: Review and research perspective
5European Review for Medical and Pharmacological Sciences (2018): The relationship between small intestinal bacterial overgrowth and irritable bowel syndrome
6Ruiz, L., Delgado, S., Ruas-Madiedo, P., Sánchez, B. and Margolles, A. (2018): Bifidobacteria and Their Molecular Communication with the Immune System.
7Rajilic-Stojanovic, M., Jonkers, D., Salonen, A., Hanevik, K., Raes, J., Jalanka, J., de Vos, W., Manichanh, C., Golic, N., Enck, P., Philippou, E., Iraqi, F., Clarke, G., Spiller, R. and Penders, J. (2018): Intestinal Microbiota And Diet in IBS: Causes, Consequences, or Epiphenomena?