Copy of 2.8 Oligosaccharides & Lactose

Oligosaccharides

Oligosaccharides encompass fructans and galacto-oligosaccharides (GOS).

Fructans are long chains of fructose molecules with a glucose at the end, whereas GOS are long chains of galactose with a glucose at the end. Oligosaccharides are found in wheat products, certain nuts like pistachios and cashews, vegetables like garlic, onion, and green peas, and fruit like pomegranates and grapefruit.

Oligosaccharides travel through the gut unabsorbed, as we do not produce enzymes that are able to break them down. Upon reaching the colon, they are fermented, and can contribute to bloating, abdominal discomfort, and changes in bowel habits.

Lactose

Lactose is a naturally occurring disaccharide found in dairy products.

It is comprised of a glucose and galactose molecule which is broken down by the enzyme, lactase. Lactase is produced in the brush border of the small intestine. When lactose is broken down by way of lactase, glucose and galactose can be absorbed in the lumen of the gut.

In some individuals, the ability to produce adequate or any amount of lactase is lost. This causes the lactose to remain undigested and unabsorbed and pass its way through the gut to the colon where it can be fermented by bacteria. This fermentation process contributes to bloating, gas, and changes in bowel habits.

Lactose maldigestion occurs in about 65% of the population around the world, and varies greatly amongst different ethnicities, with prevalence being higher in African Americans, Hispanics/Latinos, and Asians, and less common in those of European descent.

In irritable bowel syndrome, use of a low lactose diet has resulted in mixed outcomes. While retrospective studies show that low lactose diets can be helpful, prospective studies find lactose restriction does not provide adequate symptom relief except upon ingestion of large loads of lactose. However, a low lactose diet as part of the low FODMAP diet can guide you in determining how lactose impacts your patients’ symptoms.

Where do Lactase Enzymes Fit?

Click on this link to listen to some practical tips regarding lactose and the low FODMAP diet.

Lactase enzymes can be trialled on the low FODMAP diet to allow for as much dietary variety and flexibility as patients desire. Lactase enzymes hydrolyze lactose in the gut and can help to reduce digestive distress.

Most enzyme supplements contain 7000-9000 lactase units (per recommended dose), to be taken with meals and snacks containing lactose. Results seem to vary patient to patient, so a short-term trial to see how they work in your individual patient could be considered.

In addition, lactose-free products are very readily available on the market – everything from milk, to yogurt, to cheese. Providing patients guidance on how to find these products and ensure they understand a low FODMAP diet isn’t a dairy-free diet can help them to maintain as much normalcy in their diet as possible.