Milk intolerance and microbe-containing dairy foods

Area of Science:

• Gastroenterology
• Human Nutrition
• Biochemistry

Background:

• Primary adult lactase deficiency is prevalent worldwide, affecting approximately 70% of the population.
• Lactase-deficient individuals exhibit varying degrees of lactose malabsorption and intolerance symptoms.
• Symptom development is influenced by lactose dosage, meal composition, gastric emptying, and intestinal transit time.

Purpose of the Study:

• To investigate the relationship between primary lactase deficiency, dietary lactose, and intolerance symptoms.
• To evaluate the tolerance and malabsorption of lactose from yogurt in lactase-deficient individuals.
• To explore the role of microbial beta-galactosidase in lactose digestion and tolerance.

Main Methods:

• Comparison of lactose malabsorption and intolerance symptoms in lactase-deficient individuals consuming different forms of dairy products (milk, yogurt with viable culture, pasteurized yogurt, acidophilus milk).
• Assessment of lactose loads ranging from 12g to 20g.
• Measurement of lactose malabsorption and tolerance levels.

Main Results:

• Lactose loads of 15g or more typically induce symptoms in lactase-deficient persons, while loads up to 12g may cause minimal symptoms.
• Lactase-deficient individuals tolerate up to 20g of lactose in yogurt well, with significantly reduced malabsorption compared to milk.
• Improved lactose absorption with yogurt is linked to microbial beta-galactosidase, though tolerance to pasteurized yogurt suggests independence from malabsorption.

Conclusions:

• Yogurt consumption is associated with enhanced lactose tolerance in lactase-deficient individuals, potentially due to microbial enzyme activity.
• Tolerance to significant lactose amounts in yogurt may not solely depend on reduced malabsorption.
• Further research is needed to fully elucidate the mechanisms underlying enhanced lactose tolerance with yogurt consumption.