Inside Story: Gut Health

By: Dr Lauren Macdonald

You may have noticed the huge industry of yoghurt based health drinks which has emerged based on the idea that we should aim to support the “good” bacteria living in our guts. But what is all the fuss about? And is this more than just a passing health trend? What you need to know is that we are each home to about 100 trillion bacteria that normally inhabit a healthy small and large intestine. But whilst most of us are aware that “bad” bacteria can cause illness, scientists are increasingly revealing ways in which “good” bacteria impacts on our overall health and wellbeing. Indeed, what we have come to learn about the gut microbiome in just the past five years has revolutionised our understanding of the role of the digestive tract in body physiology, health, and disease outcomes.

Why is gut health a hot topic?

Improved digestion: Gut bacteria have a direct and important role in our digestive processes. The “good guys” help with our, ahem, movements, and also help reduce the incidence of digestive problems. This is partly through the process of fighting off the bad bacteria - things like Clostrodium Difficile and other pathogenic nasties - and partly through helping us directly in the digestive process (providing us with many essential nutrients along the way).

Supported immune system: In recent years there has been a particular renewed interest in the relationship between our microbiome and our immune system. It now appears that the bacteria in the gut are intimately involved in the systemic functioning of our immune system. In other words, the bacteria in your gut are having effects on the immune system globally, not just in the local environment of the gut. The implications of this are only just beginning to become clear.

Helps ward off illness: Unfortunately, evidence is mounting that over the course of human history the diversity of our microbiome has diminished. Unlike our genes, which have remained relatively stable, our microbiome has undergone radical changes in response to shifts in our diet, our antibiotic use, and our increasingly sterile living environments. It has been suggested that the dysfunctional gut ecosystem (aka dysbiosis) may turn out to have a role in a range of conditions ranging from, obesity, type II diabetes, inflammatory bowel disease, crohn’s disease, colorectal cancer, and irritable bowel syndrome. As well as being linked to cancer development, research has also suggested that gut bacteria may be important for improving the effectiveness of cancer treatment, however, more research is needed to support or refute these claims.

Supports mental health: Interestingly, a potential role for gut health in brain development, behaviour, and mood is currently being investigated.

Can gut health be improved?

The idea of boosting gut bacteria has been around for a very long time, but actual scientific research on whether it works or not is still in its relatively early stages. Since the gut microbiome is influenced by the food we eat and the environment around us, it makes sense that that there are simple ways to help make it healthier.

Eat a healthy, balanced diet. Researchers are looking into which kinds of bacteria are particularly beneficial for us, and then examining what foods we should eat to help give them a boost. It seems the proportion of carbohydrate and fat in our diet may affect the balance of bacteria in our gut, although more research is needed to identify how and why this is.

Hydrate. Water is one of those essential elements for a healthy digestive system. Adequate hydration gives your digestive system the moisture it needs to properly function. Also, sometimes our bodies mistake hunger for thirst, so stay hydrated to prevent unnecessary overeating. Try keeping water with lemon slices around to help boost your intake.

Increase your high-fibre foods. Fibre, which the body struggles to digest, ends up in the large intestine where it feeds bacteria. A lack of fibre in our diet means the good bugs go hungry and, as a result, are unable to flourish and work at their best. The easy solution is to eat plenty of high-fibre foods such as vegetables, fruit, nuts, seeds, chickpeas, beans, lentils and wholegrains, including oats and brown rice.

However... More fibre is not always the solution. The first thing a constipation sufferer tries is to increase fibre intake. But there is a type called slow transit constipation for which this is the worst solution - it will lead to more bloating, wind and pain. If you try raising your fibre intake and things get worse, then stop. First try eating only fruit-based fibre, which is easier to digest than harder fibres such as bran. If that still doesn’t work, seek advice. Eating regularly is as important as what is in your meals - eating triggers the bowel to move, so if you skip meals you are more likely to develop constipation simply because it’s not getting that stimulus.

Have probiotic yogurts or drinks, or take a supplement: Probiotics are gut-friendly strains of bacteria which improve the quality and diversity of our microbiome. However, in order to be able to say that probiotics definitely benefit our health, we’d have to first prove that the live bacteria from probiotic products survive being eaten and pass, still alive, through the stomach, which is highly acidic. They would then have to find a home in the gut where they could stay and breed, and would have to significantly boost the existing population there. Research is starting to emerge that supports these claims, although it is not yet conclusive. If in the meantime you are keen to try a probiotic, there are many probiotic yogurts and drinks available (such as Yakult, Actimel, Activia and Müller Vitality) as well as a variety of probiotic supplements. However, not all bacteria are equal. You need to ensure you are taking a species, strain and subtype that has shown good results. Lactobacillus GG has been shown to have effects at fighting inflammation and, may, help problems such as Crohn’s disease, colitis or IBS. Products containing many billions of bacteria are also not necessarily better. If you take a super-strength probiotic you are flooding your gut with new inhabitants. This can cause bloating and discomfort.

Take prebiotics naturally in food, or take a supplement: Prebiotics fertilise the gut's friendly flora. A few examples are asparagus, artichoke, beans, garlic, root vegetables, and other foods rich in fiber.

Include fermented foods: Traditionally these were always part of our diet: we would eat raw milk or cheeses that would re-inoculate our body with good bacteria that the gut needs to thrive. Now, though, we rarely re-establish this via our diets. The most commonly eaten fermented food in the UK is probably live yogurt, which is a good start, but actually contains relatively few desirable strains of bacteria. This is largely because commercial yogurt is not allowed to ferment for long enough. Add foods as sauerkraut, kimchi, kefir, kombucha, tempeh or fermented pickles to enhance the biodiversity of the gut micro biome.

Limit medications: Antibiotics wipe out gut bacteria. Do not make the mistake of taking antibiotics if they are not needed. Most flu bugs are viral and will likely clear up on their own. Ask your doctor if there is a way to prevent any drug you are taking from triggering gut problems.

The bottom line

Until we know more, having the occasional live yoghurt or trendy lactofermented juice could well be worth doing.