The intestines, the foundation of good health

The intestines, an extraordinary organ

The microbiota or intestinal flora, which have stolen the limelight in recent times, have almost caused the other parts of the intestines to be forgotten: the mucous membrane and its roles, its nervous system, its communication with the brain... It is these elements that we will be covering in this case file, even though they are all highly interdependent.

The small intestine: a chemical factory for digestion and a gateway for nutrients

No less than 5m long in order to complete the digestion of food (after being broken down in the mouth and homogenised in the stomach, all in a bath of specific enzymes). With the assistance of pancreatic and hepatic enzymes (bile), large food molecules continue to be broken up into small elements or nutrients (sugars, amino acids, fatty acids, vitamins, minerals).

But its role doesn't stop there: the nutrients must be absorbed, i.e. pass into the blood. A highly specific structure is required to achieve this: a mucous membrane, consisting of cells called enterocytes, which twist and fold, bristling with millions of villi, themselves covered with microvilli, known as the "brush border". Unfolded it will cover 400m², equivalent to the area of a basketball court. This is precisely what is required for the rapid and affective absorption of nutrients. The mucous membrane is constantly renewing itself, with the enterocytes living for between 2 and 6 days, it is also very thin (4/100 of a mm).

The small intestine: a protective barrier preventing the entry of certain molecules

The enterocytes are fixed to the upper part by proteins forming an impenetrable seal preventing the entry of undesirable molecules (toxins, allergens, bacteria) through the space between 2 cells to enter into the blood stream. Mucous cells complete this mechanical barrier of the intestine. To this can be added the protection provided by the immune system and intestinal microbiota.  The integrity of the intestine is therefore maintained by the trio of the mucous membrane, immune system and microbiota.

The large intestine

Just 1.5m from its start (the caecum) to its end (the rectum). Between these two points is the colon, which pushes waste to the exit. The colonocytes (or colon cells) have a brush border highly specialised for active water reabsorption. Colonic digestion is exclusively performed by the bacterial flora (of highest concentration in the colon) which, via the phenomena of fermentation and putrefaction, break down the food residues that escaped digestion, notably fibre, while producing useful substances such as vitamins, fatty acids and glucose.

The stomach: a second brain!

Over 100 million neurones (as many as in the spinal cord) and some twenty different messengers or neurotransmitters (the same as in the brain) - a comprehensive range of connections: it's the nervous system of the intestine (known as enteric) that covers the entire intestine and functions independently although it is connected by the vagus nerve to the brain.

Large quantities of messages are exchanged between the 2 brains. The microbiota also actively participate in these exchanges. But chronic stress and the emotions are able to modify the composition of the intestinal flora by releasing stress hormones and neurotransmitters. Modification of the digestive neurones can also be observed with lower sensitivity of the digestive tract, particularly the intestines. A churning stomach, a knot in the stomach, gut-wrenching... just some of the popular expressions that show the link between the 2 brains.

When the intestine becomes too permeable

Numerous environmental factors can have an impact on intestinal permeability (known as hyperpermeability):

• Chronic stress;
• Unbalanced diet (highly processed, too much animal protein, saturated fats and sugars, lack of vitamin D and zinc…), acting on the microbiota. Depending on the environment, casein, a protein from milk and dairy products, and gluten, can also be factors;
• Certain drugs (anti-inflammatories, antibiotics, antacids…);
• Chemicals (endocrine disrupters, pesticides…);
• Highly intensive sport or sport at high altitude.

Numerous people nowadays have many of these risk factors.

The intestinal mucous membrane poorly performs its absorption role, leading to:

• in the event of poor absorption of amino acids: a deficiency of neurotransmitters essential for the proper functioning of the nervous system;
• in the event of poor absorption of fatty acids: hormonal or vitamin D deficiency;
• in the event of poor absorption of carbohydrates: hypoglycaemia…
• in the event of poor absorption of minerals and trace elements: disrupted organ function.

And all with an over-reaction of the immune system linked to the entry of undesirable molecules. The consequences: reactions of intolerance, allergy, chronic inflammation leading to pain/irritable bowel syndrome, auto-immune diseases, fatigue due to the deficiency in micronutrients (here we will find the results of Dr Kousmine and Dr Seignalet).

A few tips for optimum digestion of food and management of emotions in order to maintain a healthy intestinal mucous membrane

1. Correct your diet to avoid excessive intestinal fermentation and putrefaction, which cause bloating, flatulence and distension. ("How to eat healthily") Yes to aromatics and fine herbs with antioxidant properties, packed with minerals and trace elements, especially when consumed fresh.

2. Maintain or re-establish the equilibrium of your intestinal flora by consuming food rich in lactic ferments (pickled cabbage, sourdough bread, olives…) or in prebiotic fibres. Make sure your diet includes leeks, parsnips, pulses, cabbage, Jerusalem artichokes, endives, bananas, apples, dried fruit…

3. Support the intestinal mucous membrane in its barrier and nutrient absorption functions:

• by consuming key nutrients:

• • Glutamine, found in meat, fish, eggs, seafood, pulses, spinach, parsley and oil seeds (walnuts, hazelnuts, almonds...)
    Be careful if you are on a diet that excludes dairy products and gluten, you risk inadequate consumption of glutamine.

    

  • Butyrate, a source of energy for the colon cells above all, but also an important factor in the maintenance of intestinal health: important for regulating the immune system and intestinal barrier, for reducing oxidative stress and regulating intestinal sensitivity*. This is produced by intestinal bacteria which ferment the prebiotic-effect plant fibres.
  • Vitamin B2: obtained from milk, eggs, lean meat... it helps to maintain normal mucous membranes, including those of the intestines.

• by restricting or eliminating anything that irritates the mucous membranes:

• • reduce consumption of sugar, saturated fats and red meat.
  • in fragile environments, reduce or eliminate potentially allergenic foods such as gluten or lactose and by favouring fermentation (the FODMAPs). Then reintroduce them progressively following your therapist's recommendations.

4. Encourage mental well-being by prioritising foods that favour the production by the intestine of "soothing" neurotransmitters:

• • Serotonin (90% is produced in the intestines): bananas, avocado, beetroot, almonds, broccoli, figs…
  • GABA for anti-anxiety, via the consumption of prebiotic fibres that increase the production of butyrate favouring higher levels of GABA.

*Butyrate: implications for intestinal function. Leonel AJ et al. Curr Opin Clin Nutr Metab Care. 2012.