Jejunal Villus Health: Function & Support

What Is Jejunal Villus Health?

The jejunum is the middle section of the small intestine and plays a central role in the digestion and absorption of nutrients. Its inner surface is lined with tiny finger-like projections called intestinal villi (villi intestinales), which dramatically increase the absorptive surface area of the gut. These villi are responsible for the efficient uptake of vitamins, minerals, carbohydrates, fats, and proteins. Jejunal villus health refers to the structural and functional condition of these villi and is a key indicator of overall intestinal well-being.

Anatomy and Function of the Jejunal Villi

The villi of the jejunum are between 0.5 and 1.5 millimetres in length and consist of a connective tissue core covered by specialised epithelial cells known as enterocytes. These cells are themselves covered with tiny projections called microvilli (the brush border), which multiply the absorptive surface area even further. Healthy jejunal villi are slender, well-vascularised, and have an intact epithelial lining. Each villus contains:

• Blood capillaries for the transport of water-soluble nutrients (e.g. glucose, amino acids)
• Lymphatic capillaries (lacteals) for the absorption of fats and fat-soluble vitamins
• Nerve endings of the enteric nervous system

Causes of Impaired Jejunal Villus Health

Various diseases and factors can negatively affect the structure and function of the jejunal villi. The most common causes include:

• Coeliac disease: An autoimmune condition in which gluten triggers an immune response that leads to flattening and destruction of the intestinal villi (villous atrophy).
• Crohn's disease: A chronic inflammatory bowel disease that can affect all layers of the intestinal wall and damage the villous structure.
• Infectious enteritis: Certain bacteria, viruses, or parasites (e.g. Giardia lamblia) can inflame the mucosa and the villi.
• Malnutrition: Deficiencies in essential nutrients such as zinc, folate, or vitamin A impair the renewal of the intestinal mucosa.
• Radiation and chemotherapy: Oncological therapies can damage the rapidly dividing epithelial cells of the intestinal lining.
• Medications: Certain drugs such as methotrexate or non-steroidal anti-inflammatory drugs (NSAIDs) can irritate the intestinal mucosa.

Symptoms of Impaired Jejunal Villus Health

When the jejunal villi are damaged, malabsorption typically occurs, meaning a reduced uptake of nutrients. Possible symptoms include:

• Chronic diarrhoea or pale, fatty stools (steatorrhoea)
• Abdominal pain, bloating, and intestinal cramps
• Unintentional weight loss
• Fatigue and general weakness (due to nutrient deficiencies)
• Anaemia (often due to iron or folate deficiency)
• Bone loss due to calcium deficiency (osteoporosis)
• Skin changes and impaired wound healing

Diagnosis

The assessment of jejunal villus health is carried out using various diagnostic methods:

• Endoscopy with biopsy: A gastroduodenoscopy allows a tissue sample to be taken from the jejunum and examined histologically. This is the gold standard for diagnosing coeliac disease and other villous disorders.
• Blood tests: Detection of specific antibodies (e.g. tissue transglutaminase IgA in coeliac disease), nutrient levels, and inflammatory markers.
• Stool analysis: Detection of fats, blood, or pathogens in the stool.
• Video capsule endoscopy: A small camera capsule swallowed by the patient provides images of the entire small intestine.

Promoting and Maintaining Jejunal Villus Health

A healthy intestinal mucosa and intact jejunal villi can be supported through various measures:

Diet

• High-fibre diet: Dietary fibre (e.g. from vegetables, legumes, whole grains) promotes a healthy gut microbiome and indirectly nourishes epithelial cells through the production of short-chain fatty acids (e.g. butyrate).
• Gluten-free diet: In coeliac disease, a strict gluten-free diet is the only effective therapy for villous regeneration.
• Adequate micronutrient intake: Zinc, vitamin A, folate, and glutamine are particularly important for the renewal of the intestinal mucosa.

Probiotics and the Gut Microbiome

A balanced gut microbiome supports the integrity of the intestinal lining. Certain probiotics (e.g. Lactobacillus and Bifidobacterium strains) can promote villous structure and epithelial barrier function.

Medical and Therapeutic Measures

• Treatment of the underlying condition (e.g. immunosuppressive therapy for Crohn's disease)
• Eradication of pathogens (e.g. antibiotic treatment for bacterial overgrowth)
• Parenteral or enteral nutritional therapy in cases of severe malabsorption

References

1. Schuppan, D. & Zevallos, V. - Wheat amylase trypsin inhibitors as nutritional activators of innate immunity. In: Digestive Diseases, 33(2), 260–263. Karger, 2015.
2. World Health Organization (WHO) - Diarrhoeal disease. Fact Sheet. WHO, 2017. Available at: https://www.who.int/news-room/fact-sheets/detail/diarrhoeal-disease
3. Green, P.H.R. & Cellier, C. - Celiac Disease. In: New England Journal of Medicine, 357(17), 1731–1743. NEJM, 2007.