The effect of dairy product ingestion on human immunodeficiency virus-related diarrhea in a sample of predominantly gay men: a randomized, controlled, double-blind, crossover trial.

BACKGROUND

In the highly active antiretroviral therapy (HAART) era, chronic diarrhea remains common in human immunodeficiency virus (HIV) illness. Empirical lactose avoidance is often advised despite lack of evidence of benefit in a population at risk for osteopenia and malnutrition.

METHODS

The a priori hypothesis was that moderate lactose ingestion would not worsen diarrhea in this population. We used a double-blind, noninferiority, randomized crossover trial in a community setting of primary and tertiary care HIV clinics. The participants all had chronic diarrhea and were a volunteer sample of 49 predominantly white HIV-infected men who have sex with men. They ingested 240 mL of low-fat milk (12 g of lactose) and lactose-free milk during 2 separate study periods. The primary outcome was mean difference in stool weight between the 2 study periods in the 8 hours after milk ingestion. Lactose was judged not to worsen diarrhea if this difference did not exceed 167 g in 8 hours with 95% certainty.

RESULTS

Forty-eight (98%) of 49 participants were male. Median age, CD4 cell count, and viral load were 42 years (range, 20-62 years), 390 cells/mL (range, 20-1100 cells/mL), and 112 copies/mL (range, <50 to >500,000 copies/mL), respectively. Thirty-nine participants (80%) were taking HAART medication. Ten participants (20%) were lactase deficient. The mean difference in stool weight between the 2 study periods was -41.3 g/8 h (upper 95% confidence limit, -13.5 g) for the entire group and +11.3 g/8 h (upper 95% confidence limit, +47.4 g) for the lactase-deficient group.

CONCLUSIONS

Moderate lactose ingestion does not worsen diarrhea in HIV-infected persons with chronic diarrhea, regardless of lactase status. Therefore, avoidance of modest quantities of milk may not be justified in this population.