Digestion: understanding it better to digest better

In the mouth:

It all starts with chewing, which mechanically breaks down food and mixes it with saliva. Saliva contains digestive enzymes, including salivary amylase, which begins the breakdown of complex carbohydrates (such as starch). This is known as early enzymatic digestion. The mixture formed, called the bolus, is then propelled toward the esophagus and then the stomach through a reflex movement called swallowing.

In the stomach:

The stomach acts as a chemical and mechanical processing tank. It secretes highly acidic gastric juices (containing hydrochloric acid and pepsin) that break down proteins into simpler fragments. Regular muscle contractions mix the contents, transforming the food bolus into chyme, a semi-liquid substance ready to pass into the small intestine.

In the small intestine:

This is the most crucial stage for nutrient absorption. Here, the chyme is mixed with:

• Bile, secreted by the liver (and stored in the gallbladder), which emulsifies fats, facilitating their digestion.

• Pancreatic enzymes (lipases, proteases, amylases) that continue the breakdown of lipids, proteins, and carbohydrates.

The inside of the small intestine is lined with villi and microvilli: these microscopic folds significantly increase the surface area available for exchange. It is through this mucous membrane that nutrients (vitamins, minerals, fatty acids, amino acids, glucose, etc.) are absorbed into the blood or lymph, to be distributed throughout the body.

In the colon:

The colon (or large intestine) plays a role in recovery and fermentation. It absorbs water and certain electrolytes (such as sodium and potassium) and is home to a large part of the gut microbiota. The latter ferments undigested fiber, producing short-chain fatty acids that are beneficial to the intestinal mucosa. The residues are finally compacted into stool and then evacuated via the rectum and anus.

We often talk about "difficult" or "slow" digestion to describe occasional digestive discomfort. But according to the French health insurance system, dyspepsia is when digestive symptoms have been present for at least three consecutive months.

Listen to your body: These signals are often messages that it's time to take care of your digestion.

Warning signs to look out for:

• Persistent bloating
• Slow or irregular transit
• Stomach ache
• Reflux or heartburn
• Nausea, even vomiting

Dietary causes

• Meals that are too large or fatty
• Poor chewing
• High consumption of refined sugar and fats
• Excessive consumption of alcohol, coffee, or tea
• Low-fiber diet

Lifestyle-related causes

• Chronic stress (major impact on the digestive system)
• Insufficient or irregular sleep
• Eating meals too quickly or too late in the evening
• Hormonal periods (especially in women)
• Overweight (mechanical pressure on the stomach)
• Taking certain medications
  • (If you are taking medication that may affect your digestion, please consult your doctor or pharmacist).

Internal or physiological causes

• Imbalance in the gut microbiota (dysbiosis)
• Digestive hypersensitivity
• Mild enzyme disorders
• Food intolerances (lactose, gluten, etc.)

Focus on the microbiota

Our intestines are home to billions of microorganisms (bacteria, yeasts, viruses, etc.) that make up the gut microbiota. This veritable ecosystem plays an essential role in:

• Digestion of certain foods and absorption of nutrients
• The synthesis of certain vitamins
• Immune protection
• The overall balance of the body

An imbalance in the microbiota can lead to digestive problems, increased fatigue, and even a weakened immune system.

How to take care of your microbiota?

• Focus on a varied diet rich in fiber
• Consume natural probiotics (fermented yogurt, kefir, etc.)
• Avoid excessive consumption of processed foods, alcohol, and antibiotics (unless prescribed).
• Reduce stress and adopt a healthy lifestyle

On the plate

• Chew slowly and consciously
• Cut down on fatty, spicy, or overly sweet foods.
• Split meals if necessary
• Drink water regularly (between meals if you experience bloating).

Foods to prioritize

• Fiber: fresh fruit, green vegetables, legumes, whole grains
• Natural probiotics: yogurt, kefir, raw sauerkraut
• Oilseeds: walnuts, almonds (high in fiber and filling)
• Digestive plants: ginger (nausea), fennel (bloating)