UNLOCKING THE IMPACT OF JUNK FOOD ON YOUR GUT HEALTH: THE RELATIONSHIP BETWEEN DIET AND DIGESTIVE WELLNESS
The human body is home to many tiny living organisms, such as bacteria, archaea, viruses, and eukaryotic microbes: the gut microbiome. In our belly alone, there are over 100 trillion of these tiny cells, creating a busy community that affects how our body works. Two main groups, Bacteroidetes and Firmicutes, dominate our gut neighbourhood.
These little residents have a big say in how our body functions. They influence our health, how we digest food, and how our immune system works. Think of them as managers of our body’s systems, playing important roles in keeping us well and defending us from sickness. They’re like tiny superheroes inside us, doing a lot behind the scenes.
What we eat, our stress levels and our lifestyle can all have an impact on our microbiome. While certain areas are more difficult to change, we can certainly have a huge impact on the food that we consume.
Junk food is processed food that is normally high in saturated fats, sugar, additives, preservatives and synthetic flavours. Unfortunately, is also low in fibre, vitamins and minerals. Foods like pre-package meals and baked goods, crisps, candies, many soft drinks and salty snacks all fall into this category.
Gut microbiome differences
A recent study (Shah et al. 2023), found foundamental differences between the microbiome of normal eater and junk food eaters. The 4 main areas of difference between the gut microbiome of healthy eaters and the one of junk food eaters:
- Reduced diversity
- Reduced beneficial organisms
- Overgrowth of harmful organisms
- Dysbiosis
The reduced diversity means that there are fewer different types of organisms that live in the microbiome, making us more prone to illness. A resilient microbiome should have an abundance of different organisms.
The reduced number of beneficial organisms means that specific beneficial species are low or absent. An important category of beneficial species that are low on junk food eaters is the short chain fatty acid producers, which help us to digest food, create energy, balance the immune system, keep the gut PH slightly acidic (to kill harmful bacteria) and maintain the intestinal wall fit and healthy. Other important organisms that are commonly low on a junk food diet are Bifidobacterium and Lactobacillus species.
The overgrowth of harmful bacteria can happen because the PH is too alkaline (therefore not able to kill the harmful bacteria), the beneficial bacteria are reduced, recent antibiotic use or food poisoning and more. When we continue eating junk food, we effectively nourish the harmful bacteria, and this can promote health issues like inflammation and metabolic disorders such as obesity. When having a diet high in animal protein, we also often see and increases bile-tolerant organisms like Bacteroides.
The dysbiosis is the degree of deviation from a healthy microbiome. When eating junk foods, there is a higher level of dysbiosis, which can lead to digestive problems as friendly organisms help us to break down food.
Healthy gut microbiome
There are some specific organisms that we want to inhabit our gut microbiome: short chain fatty acid producers are at the top of the list. Included in this list we have species such as Roseburia, Faecalibacterium prausnitzii and Eubacterium. As we explained before, this category of bacteria is pivotal in helping our body to function optimally, but also support our metabolism.
Another marker that is usually present in small amounts in a healthy microbiome is Akkermansia Muciniphila, which main job is to stimulate mucus production. In this case mucus is our friend, as it protects the intestinal wall from damage.
The microbiome has a far reaching effects on different organs of the body, and is also partially responsible for our sense of satiety, promoting healthy weight. Therefore, when living in a state of dysbiosis we can expect to see an increase of conditions such as obesity, autoimmune conditions, cardiovascular disease and faster aging.
Can I change the gut microbiome?
A small recent study (Zhu et al. 2020) found that the gut microbiome can change in as little as 4 days when moving from a junk food diet to a healthy mediterranean diet or the other way around. You can start making positive changes today and slowly decrease your junk food consumption towards unrefined food options such as whole grains, fruit, vegetables and legumes. Prebiotics and probiotics can really help to bring back balance and nourish the friendly bacteria colonies. Prebiotics are foods like Jerusalem artichokes, chicory, asparagus, onions and apples, while probiotics are food such as yogurt, kefir, sauerkraut and kimchi.
Please remember that if you have been diagnosed with a medical condition or if you take any medication, you should consult your healthcare provider before making changes to your diet. This is because diet is powerful and can impact how we absorb/excrete medications, but also how our body function.
Conclusion
Every day our food choices can help shape our gut microbiome, which in turn influence health and disease. Aim to implement any change very slowly and take the time to see how the body reacts, to minimise side effects such as bloating, which can happen when we make radical changes too quickly.
Although an increase of fruit, vegetables, beans and grains are usually beneficial to the majority of the population, we are all unique and require a personalised approach. Discussing your goals and health history with a qualified practitioner is the first step, but you might also want to consider testing if you have tried several approaches without positive results.
References
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10734656/
https://pubmed.ncbi.nlm.nih.gov/34444870/
https://pubmed.ncbi.nlm.nih.gov/32330749/
https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(21)00086-4/fulltext
https://www.nature.com/articles/s41467-020-18871-1
https://www.bmj.com/content/361/bmj.k2179
