Dr Libby Weaver

A concept within digestive health that is
not only fascinating but has wide-ranging effects on how we feel and
function—including gut transit time (how quickly food moves through the
digestive system), mood, concentration, behaviour and, potentially, food
addictions—is gut integrity, which when compromised is known as ‘leaky gut’ or,
in more technical terms, increased intestinal permeability.

The cells that line a healthy small
intestine look like a row of neatly stacked bricks with finger-like projections
(called villi). In a healthy gut, only nutrients (such as vitamins and
minerals) move through the gut wall into the blood, and this is the precious
process through which we are nourished and stay alive. However, the cells that
line the gut can move apart, as if the bricks are stacked with gaps. This is,
in fact, how we are born.

When we are born, the cells that line our
digestive system are a distance apart, which is why we can’t feed all foods to
newborns; foods must be gradually introduced to a child over time to prevent
reactions as the gut matures. The gut is immature when we are born, and it
slowly matures from birth until reaching full maturity somewhere between the
ages of two and five, depending on the individual child and their health and
life experiences in the early years. The cells that line the gut can, however,
also come apart during adulthood as a result of the exaggerated production of a
protein called zonulin, gastrointestinal infection, chronic excess alcohol
consumption or prolonged stress. The chronic production of stress hormones can
compromise the integrity of the gut cells and signal to them that they need to
move further apart so that more nutrition can get through to the blood, as
nutrient requirements increase during times of stress. Everything about us is
geared for survival. Trouble is, these days, we can get stuck in this stress
response.

When food travels through a gut with good
cell lining integrity, it can only go straight ahead. However, if it travels
through a gut in which the cells have come apart, it may go straight ahead, or
it may move out of the gut and into the blood. Fragments of food are not
intended to enter the blood. Nutrients from food are; but if actual fragments
of food enter the bloodstream, the immune system, which is what protects you
from infection, thinks that the food fragment is a germ and it mounts an immune
response against it. This is one mechanism through which adults can develop
food sensitivities.

In this case, you may notice that once you
were able to eat anything without a problem, and now certain foods seem to
cause you grief. This process can be healed by minimising the irritation to the
gut lining, which may mean avoiding some foods or ingredients for a period of
time while also working on nourishing the gut. Once we’ve worked out why
someone has ‘leaky gut’ symptoms in the first place (what I like to call ‘the
road in’) and this has been addressed, they will often be able to improve their
tolerability of the foods that caused them irritation. So, understanding what
had led the gut become ‘leaky’ is really important—for example, did the problem
begin as a result of stress or an infection? The power to heal the symptoms is
always in the why, so think about your road in.

It’s common to experience changes in your digestion and gut symptoms during and after a long flight, particularly so for those who experience irritable bowel syndrome (IBS). But have you ever wondered why this happens?

Partly it’s due to the atmospheric pressure in the cabin. If you’ve ever seen a plastic water bottle after take-off and landing, you’ll have noticed that the air pressure between the water and the lid changes – it swells up after take-off and compresses after landing. Your gastrointestinal tract doesn’t do this in quite the same way but it is a good example of how the atmospheric pressure does affect us in ways we might not be aware of. With the change in air pressure during a flight, any gas inside your gut expands and this adds more pressure to your system. If you add to this that most people are reticent to release the wind while seated so closely to other people, you’ve got a recipe for an expanding belly. 

This process doesn’t just occur for people who have IBS so others may also experience abdominal distention and bloating with air travel, depending on what they have eaten recently and how much gas is present in the gut. It is normal for there to be some gas within the gut, however as this expands with the change in air pressure, it takes up a larger volume in the gut and therefore creates a greater stretch on the wall of the intestine. People with IBS tend to have increased sensitivity to this stretch on the intestinal wall, and experience more uncomfortable tummy pain as a result.

So, what can you do to minimise this? Dressing comfortably for the flight and avoiding tight clothing around your tummy can be helpful, as this can exacerbate bloating and associated pain. If you have IBS and are aware of certain foods and drinks that trigger or exacerbate your symptoms, avoiding or minimising these in the lead up to the flight will also help to keep symptoms more manageable.

It also pays to consider what you are consuming throughout your travels. Avoiding carbonated drinks can help, yet these are typically offered regularly throughout flights. Make still water your main drink. When it comes to food, from a mindset perspective, it can be really easy to just think “oh it’s too hard” and to eat anything that is in front of us—but if nourishment remains a priority for you, you will almost always find a way. Of course, travelling isn’t the same as cooking your own meals at home but if you use nourishment as a guide simply choose the best option available to you. If it appeals to you, you might also like to do a bit of research of the meal options ahead of time and to have some nourishing snacks on hand that you know you normally tolerate well. It can make all the difference to how your gut fares along the way. And I can’t encourage you enough to only eat when you’re hungry—so often we just eat everything that’s offered to us on planes, and overeating will put additional pressure on your gut.

For those who are nervous flyers, also remember that stress can hinder our digestive processes, so if you feel you need to distract yourself while flying, I encourage you to use strategies like reading a book, listening to music or practising meditation, rather than using food or alcohol as a distraction, or snacking mindlessly. When you are hungry, you might also like to take some long, slow breaths before your meal, to help calm your nervous system and, in turn, support better digestion.

Given how common irritable bowel syndrome (IBS) is – around one in five women in Australia and New Zealand experience IBS symptoms – and the impact that it can have on quality of life, it’s no surprise that the low FODMAP diet has become hugely popular. But is adopting a low FODMAP way of eating the only way to address your IBS symptoms?

In short, no. It certainly can be an effective way of managing IBS symptoms, but it shouldn’t necessarily be the first place you start. This is primarily because it’s quite a restrictive way of eating and many nutritious foods are high in FODMAPs. If it is followed long-term without professional guidance, you may be at risk of nutritional deficiencies which has a lousy impact on your health.

Remember also, the low FODMAP diet is not a no FODMAP diet. Nor is it a forever diet – it is a tool intended to identify the foods exacerbating your IBS symptoms so reintroductions need to occur as part of this. As the diet isn’t curative (it is for symptom management only) work must continue to be done on the gut and digestion to help improve its function.

To that effect, let’s look at some of the other considerations that can lead to an unhappy tummy and measures you can take to address symptoms commonly associated with IBS—such as bloating, cramping, excessive flatulence, diarrhoea, constipation or intermittent bouts of both.

Chew your food properly

This may seem obvious, but thorough chewing can be a gamechanger for reducing IBS symptoms. The stomach doesn’t like to allow food to move into your small intestine for further digestion until it is well broken down. There are no teeth beyond our mouth, yet so many people eat as though their oesophagus is lined with teeth!

To help you slow down and chew properly, try not to take another mouthful until you have completely chewed and swallowed the previous one. If you find this difficult, putting your knife and fork down between each bite can be helpful.

Address your stress

The gut has its very own nervous system (often referred to as our second brain) and stress is known to exacerbate IBS symptoms—think bloating, constipation and diarrhoea, for example.

When we’re feeling anxious or stressed our body releases stress hormones (adrenaline and cortisol). Adrenaline is responsible for the ‘fight or flight’ response, which was originally designed to give you a better chance of escaping a threat to your life—think a tiger chasing you. Because digestion isn’t a priority if your life is in danger, the stress response hinders digestive processes by reducing the secretion of enzymes into the digestive tract that are required to digest and absorb nutrients, and altering the motility of the digestive tract. So, addressing your stress can also help you to manage IBS symptoms.

Reduce or eliminate caffeine

If you find things are moving through your digestive tract a little too quickly, you may like to consider your caffeine intake, as it is known to stimulate bowel motility which can lead to urgent, looser stools for some people. Caffeine also triggers the release of adrenaline which you now know can hinder our body’s ability to digest foods optimally. Some people are more sensitive to caffeine than others, so pay attention to how it affects you and your digestion.

Please note that if you are experiencing chronic gut symptoms and you haven’t yet seen your doctor to rule out other bowel conditions, it’s important to do this. If you have been diagnosed with IBS and are experiencing ongoing, significant symptoms, I encourage you to seek support from an experienced healthcare professional. There is always a reason/s behind what we experience and resolving IBS could have a huge impact on your overall health and happiness.