Having healthy, diverse bacteria in your gut is linked to many health benefits, including improving immune function, and lower incidence of heart disease, diabetes, asthma, depression, irritable bowel syndrome, and some allergies. But how quickly can your improve your microbiome?
Our microbiome is made up of trillions of cells, including bacteria, viruses and fungi, and the largest community of these is in the gut. In fact, there are more bacterial cells than human cells in the body. “Good gut health is linked to the health of pretty much every other organ”, says Dr Megan Rossi, AKA the Gut Health Doctor.
The British Dietetic Association lists important reasons why our microbiome helps us, including that gut bacteria has a role in digesting food, in particular breaking down fibre, and absorbing nutrients. The bacteria produce several vitamins, including folate, B2, B12 and vitamin K. They also produce short-chain fatty acids, which may reduce inflammation, protect against colon disorders, and lower cholesterol and blood-sugar levels. They stimulate infection-fighting cells in the blood stream, too.
How quickly can you improve your gut bacteria?
“We have the ability to shape our gut microbiome simply by how we treat it, and targeting our diet is one of the most effective ways to boost our microbiome diversity”, says Rossi. While some research suggests you can make alterations to your gut microbes within days (for better or worse), this could depend on a number of factors, including how drastic the changes you make to your diet and lifestyle are.
Long-term benefits may take several months to show, and the same research found gut microbes can return to their original make-up if you return to a less beneficial diet. “It requires regular and routine support to maintain long-term changes and benefits”, says clinician-scientist Dr Sunni Patel.
Everyone’s gut bacteria is very different (unrelated people reportedly share no more than 30 percent of the same bacterial strains), so “it can be very individualised in terms of how long it takes for changes to take effect”, says Rossi.
Every person is different, but if you want to improve your microbiome, some broad principles apply to all.
Eat a wide and varied range of plant-based foods. “I recommend aiming for 30 ‘plant points’ every week”, says Rossi, which means eating 30 different plants. These should include fruits, vegetables, wholegrains, legumes, nuts, seeds, herbs and spices. A healthy gut has a diverse community of microbes, each of which prefers different foods, so the more variety in your diet, the more diverse bacteria will thrive in your gut.
Eat more fibre. Most people eat less than they should. Fruit, vegetables, pulses, nuts and wholegrains feed healthy bacteria, which ferment the fibre and in the process produce substances thought to be “protective”, such as short-chain fatty acids. We are advised to eat at least 30g of fibre per day, but increasing fibre intake by as little as 6g a day (the amount in a bowl of high-fibre breakfast cereal or 2 thick slices of wholemeal bread) has been found to have an effect on gut bacteria. If your diet is low in fibre, a sudden increase can cause wind and bloating, so make gradual changes and drink extra water.
Avoid highly processed foods. They often contain ingredients that either suppress ‘good’ bacteria or increase ‘bad’ bacteria.
Probiotic foods – live bacteria found in fermented foods such as yoghurt, kimchi and sauerkraut – might encourage more microbes to grow. Eat them if you enjoy them. Find out how to make ferments on BBC Food.
Choose extra-virgin olive oil over other fats when you can. It contains the highest number of microbe-friendly polyphenols.
Antibiotics kill ‘good’ bacteria as well as ‘bad’. If you need antibiotics, make sure you eat lots of foods that boost your microbes afterwards.
How does lifestyle affect gut bacteria?
Sleep deprivation, even partial, has been shown to impact your microbiome. Establishing a routine and avoiding caffeine and alcohol in the evening can help you get a good night’s sleep. Managing stress levels and regular exercise are also key to a healthy microbiome, according to Rossi.
How do you know if you have a healthy gut?
“This has to be the most common question I get asked in my clinic and on social media, and it’s one I can never give a simple answer to”, says Rossi, adding that there’s no single measure to assess gut health. She does not recommend commercial gut microbiome testing kits. To establish a client’s likelihood of having a diverse microbiome, she asks them questions about their plant intake, sleep quality, stress levels and exercise pattern.
Your gut microbiota changes as you age, but a review suggests it is not clear if these changes are due to physiological changes, age-associated inflammation, gradual deterioration of the immune system, diet, medications, or chronic health conditions.
“Taking time for your gut will be a worthy investment”, says Patel, adding “you can never be too young or too old to ensure you are improving your microbiome”.