From the Guidelines
Lactulose is unlikely to significantly affect blood glucose levels in most patients, including those with diabetes mellitus type 2, when used as directed. Lactulose is a synthetic disaccharide that is not digested in the small intestine and exerts an osmotic laxative effect in the colon 1. The use of lactulose in mildly constipated, noninsulin-dependent patients with diabetes mellitus type 2 may not lead to an increase in blood sugar levels 1.
Some key points to consider when using lactulose include:
- Typical dosing for lactulose in adults is 10–20 g (15–30 mL or 1–2 packets) daily, which may be increased to 40 g (60 mL or 2–4 packets) daily if needed 1
- Lactulose can cause bloating and flatulence, which are dose-dependent and considered very common side effects 1
- Patients with diabetes should monitor their blood glucose levels more closely when starting lactulose treatment or adjusting the dose
- It is essential for individuals with diabetes to inform their healthcare provider if they are prescribed lactulose, so they can help monitor and manage any potential effects on blood glucose levels 1.
Overall, the benefits of lactulose in managing constipation outweigh the potential risks, and its use can be considered in patients with diabetes who do not experience significant bloating or abdominal pain with lactulose use 1.
From the FDA Drug Label
Since lactulose solution contains galactose (less than 1.6 g/15 mL) and lactose (less than 1.2 g/15 mL) it should be used with caution in diabetics.
Lactulose may affect blood glucose levels in diabetics due to its galactose and lactose content. Therefore, it should be used with caution in diabetic patients. 2
From the Research
Lactulose and Blood Glucose Levels
- The effect of lactulose on blood glucose levels has been studied in various populations, including healthy individuals and those with type 2 diabetes mellitus (T2DM) 3, 4.
- Studies have shown that lactulose does not significantly affect blood glucose levels in healthy individuals 4 or those with T2DM 3, despite the presence of carbohydrate impurities in lactulose products.
- However, one study reported a minor increase in maximum blood glucose levels after intake of 30 g liquid lactulose in individuals with T2DM, although this increase was small (mean treatment difference of 0.63 mmol/L) 3.
- Another study found that changing the brand of lactulose syrup can lead to marked deterioration in glycemic control in diabetic individuals, possibly due to differences in the amount of absorbable sugars in the syrup 5.
Mechanisms of Action
- Lactulose is a prebiotic that can stimulate the growth of bifidobacteria and influence the metabolism of the intestinal microbiota 6, 7.
- The mechanisms of action of lactulose are not fully understood, but it is thought to have anti-inflammatory effects, nourish the gut epithelial cells, and provide a protective barrier from microorganism infection 7.
- Lactulose may also have a role in the management and prevention of type 2 diabetes via actions on the gut microbiota, including increasing the abundance of short-chain fatty acid-producing bacteria and suppressing potentially pathogenic bacteria 7.
Clinical Implications
- The available evidence suggests that lactulose is generally safe for use in individuals with impaired glucose tolerance, including those with diabetes 3, 4.
- However, the potential impact of lactulose on blood glucose levels should be considered, particularly in individuals with diabetes who are using lactulose for the treatment of constipation or other gastrointestinal disorders 3, 5.
- Further research is needed to fully understand the effects of lactulose on blood glucose levels and its potential role in the management and prevention of type 2 diabetes 7.