Eating for the gut

Hippocrates once claimed that "All disease begins in the gut".

The gastrointestinal tract is a tube-like structure that begins in the mouth, incorporating the organs the oesophagus, stomach, small intestine, large intestine & the anus.

Together, their goal is to extract and absorb nutrients from the food we consume and eliminate unwanted waste from the body as stools.

Among the many processes that ensure its efficient operation is maintaining a separation between the internal contents of the gastrointestinal tract & its external environment.

If the tract's walls are compromised & its contents leak into the bloodstream, strategically positioned receptors quickly identify this as a major issue & alert the immune system to take action (1).

There can be several causes for this, but the focus here will be on gut bacteria.

The protective and health-promoting properties depend on the concentration & diversity of bacteria.

Sufficient beneficial bacteria, means harmful bacteria may take over.

This leads to an imbalance known as dysbiosis, resulting in inflammatory bowel disorders such as Crohn's disease, ulcerative colitis or irritable bowel syndrome (IBS)

Unfortunately, it doesn't end there.

Asthma & cardiovascular disease can also develop (2), as can hypertension & atherosclerosis (3).

Additionally, obesity can occur, which alone can be the source of numerous other health problems such as diabetes, cancer, excessive fat accumulation & osteoarthritis (4).

This is an example of the cascade of ill health that may occur if the bacteria held within the gut is imbalanced indicating that Hippocrates' assertions were not too far off.

Preventing this imbalance is relative to the food that we eat & the particular food group that has the most positive influence is fibre.

Government dietary recommendations released by Public Health England in 2015 indicate that adults living in the UK should aim to consume 30g of fibre each day.

However, research carried out by the British Nutrition Foundation reveal that this is not being met; in fact, at 14g a day it is not even half the requirement (5).

One lecture I attended relating to the importance of fibre intake focussed on a series of studies comparing the intake of the Hadza Tribe of Northern Tanzania to the typical levels of fibre consumption of western societies.

The Hadza are thought to be one of the last hunter gatherer tribes in the World & were chosen specifically for their traditional way of life & eating habits.

Bacterial profiles were assessed through stool samples which revealed a greater number of bacteria in both numbers & diversity to that of a group of U.S. based subjects (6)

Vegetables rich in tough, indigestible fiber constitute 70% of the Hadza diet throughout the year & it is believed that this is where the difference is made.

There is little to no evidence of obesity among these people, their rate of cardiovascular disease is negligible & they do not suffer from the metabolic diseases common in industrialized nations.

In short, their daily fibre consumption typically ranges from 100-150g; approximately 8-10 times the current UK average intake.

While we cannot directly (or possibly need) to adopt similar eating habits we can significantly increase our daily fiber intake to improve our health & reduce the risk of the aforementioned illnesses.

The current UK recommendation of 30g per day can be achieved with adequate amounts of vegetables and legumes such as sweet potato and carrots (with skins, but ensure they are well washed), jerusalem artichokes, celeriac, whole grain cereals like rye and barley (if gluten-tolerant), oats, avocados, chickpeas, and Puy lentils.

Below are a few examples of high fibre dense dishes that are cheap, simple & easy to make.

Breakfast – celeriac & carrot rosti with avocado & poached egg

Lunch - savoy cabbage & puy lentil soup

Dinner - chicken & chickpea salad

The purpose of this article was to provide information as it relates to fibre intake, our current levels & how reduced amounts can affect our long-term health.

If the information highlighted here has prompted you to increase your fibre intake I would suggest you firstly seek further advice from a nutritional therapist like myself, a GP or a dietician.

References

1. Mu. Q, et al., (2017). Leaky gut as a danger signal for autoimmune diseases. Front Immunol, 2017. 8, 598.

2. Carding. S, et al., (2015). Dysbiosis of the gut microbiota in disease. Microbial Ecology in Health & Disease. 2015; 26:

3. Lau. L, et al., (2017). Bridging the gap Between Gut Microbial Dysbiosis and Cardiovascular Disease. Nutrients. 2017 Aug; 9(8): 859.

4. Bray. A, G. (2004). Medical Consequences of Obesity. The Journal of clinical Endocrinology & Metabolism. Volume 89, Issue 6, 1 June 2004, Pages 2583-2589.

5. Hooper. A, et al., (2015). 30g of fibre a day: An achievable recommendation? Nutrition Bulletin, 2015.

6. Smits, S, A, et al., (2017). seasonal Cycling in the Gut Microbiome of the Hadza Hunter Gatherers of Tanzania. Science 2017 August 25; 357(6353): 802-806.

7. Pontzer. H, et al., (2018). Hunter-gatherers as models in public health. Obesity Reviews 19 (Suppl1), 24-35 December 2018.