Why it is not just about what you cut out

Patients often come to me after having seen multiple specialists and getting different opinions about what they should do to resolve their gut issues. With contrasting recommendations and many viewpoints, it can be confusing for patients — and understandably frustrating.

"Elimination diets" make sense on the surface, but as we get better at understanding the microbiome and the interaction of the diverse bacterial species in the colon, we realise that we are dealing with a complex adaptive system. The responses to changes in diet are more nuanced than simply removing a trigger, because the microbial species in the colon will vary accordingly. This is why elimination diets often produce short-term improvements that may not last. A more durable change involves first trying to understand the existing bacterial composition and then making changes to the diet and sometimes the microbiome — via probiotics — concurrently.

Why diversity matters

Our body requires many different post-biotics, such as short-chain fatty acids, to regulate its function. These are produced by the bacteria in our gut when they break down the foods we eat. The types of short-chain fatty acids produced from a narrow ecosystem tend to be more limited than if we had a more diverse one. If we are lacking in certain fatty acids, our body is not going to be able to function at its optimum, nor would it be able to handle the stress to different parts of the body.

The issue with "sensitivities"

By and large, we remove things from our diet because we think we are "sensitive" or "allergic" to the food item. But in reality, the situation may not be that clear cut.

Sometimes we do indeed develop a sensitivity to certain foods, but in many situations, these are not the typical reactions that involve the allergy cascade. Rather, it may be a lack of certain probiotics to process the food beneficially. Instead, we might have other bacteria that process the food differently and produce different end-products — resulting in more methane, for instance — and this might lead to more bloating.

Feeding the soil, not just planting seeds

The approach is similar to agriculture or gardening. Planting the seeds is only one part of the process. The factor that makes the most impact is actually ensuring a fertile soil for the seeds to grow. In the case of the gut microbiome, this means ensuring a consistent supply of diverse plant and fibre sources.

What I see in practice

Most patients have already restricted certain food products that they think do not agree with them, and I find that trying to change their minds at this stage is not easy.

Instead, I focus on improving the diversity of their diet to ensure adequate variety of fresh fruits and vegetables, and less processed foods. In the course of doing so, some patients end up taking certain foods that they had initially stopped eating — and they are surprised to find that they don't have the same reaction to those foods that they used to.

When to investigate further

The colon is more complex than what most of us realize and does more than simple waste management. The interaction of dietary fibre with the bacteria in the microbiome to produce various metabolites also influences the way the colon functions, as well as our overall health.

However, in spite of this multitude of processes occurring, when things are not going correctly, there are only a limited number of responses — constipation, diarrhoea, or pain. These symptoms can also be caused by other colonic issues such as infection, inflammation, or even tumours. So an important step is to ensure that the serious causes are excluded.

From there, we can then start on figuring out the best way to improve your gut and the microbiome it contains.

If you are experiencing persistent digestive symptoms and would like personalised advice on how diet may be contributing, contact our clinic to arrange a consultation and discuss a tailored approach to your gut health.