Improved clinical tolerance to chronic lactose ingestion in subjects with lactose intolerance: a placebo effect?

Abstract

Background-Uncontrolled studies of lactose intolerant subjects have shown that symptom severity decreases after chronic lactose consumption. Adaptation of the colonic flora might explain this improvement. Aims-To compare the eVects of regular administration of either lactose or sucrose on clinical tolerance and bacterial adaptation to lactose. Methods-Forty six lactose intolerant subjects underwent two 50 g lactose challenges on days 1 and 15. Between these days they were given 34 g of lactose or sucrose per day, in a double blind protocol. Stool samples were obtained on days 0 and 14, to measure faecal -galactosidase and pH. Symptoms, breath H 2 excretion, faecal weight and electrolytes, and orofaecal transit time were assessed. Results-Except for faecal weight, symptoms were significantly milder during the second challenge in both groups, and covariance analysis showed no statistical difference between them. In the lactose group, but not in the sucrose group, faecal -galactosidase activity increased, pH dropped, and breath H 2 excretion decreased. Conclusion-Bacterial adaptation occurred when lactose intolerant subjects ingested lactose for 13 days, and all symptoms except diarrhoea regressed. Clinical improvement was also observed in the control group which displayed no signs of metabolic adaptation. This suggests that improved clinical tolerance may be just a placebo eVect. (Gut 1997; 41: 632-635)

Removing lactose from milk does not delay bowel function or harden stool consistency in lactose-tolerant women

“…It has been reported that lactose reduces faecal pH in both lactose-tolerant (Holtug et al, 1992) and -intolerant subjects ( Christopher and Bayless, 1971;Briet et al, 1997). However, Kleessen et al (1997) found no differences in faecal pH after ingestion of 20 or 40 g of lactose per day.…”

Effect of exogenous β-galactosidase in patients with lactose malabsorption and intolerance: a crossover double-blind placebo-controlled study

“…However, this restriction leads to a reduction of intake of substances such as calcium, phosphorus and vitamins, and may associate with decreased bone mineral density (Solomons et al, 1985a, b;Di Stefano et al, 2002). To overcome these limits, in the last years, several approaches have been studied: drugs that increase contact time between enzyme and substrate, either delaying orocoecal transit (ie loperamide) (Szilagyi et al, 1996(Szilagyi et al, , 2000 or delaying gastric emptying (ie propantheline) (Peuhkuri et al, 1999); continuous lactose consumption to induce colonic adaptation (Briet et al, 1997); substitutes for milk (Swagerty et al, 2002); yogurt and probiotics for their bacterial bgalactosidase activity (Onwulata et al, 1989;Saltzman et al, 1999); addition of exogenous lactase to the milk before its consumption (Solomons et al, 1985a, b;Barillas & Solomons, 1987;Corazza et al, 1992;Lin et al, 1993). In particular, replacement therapy resulted in an efficacious strategy; nevertheless, only few double-blind and/or placebo-controlled trials have been performed.…”

Tolerance of different dairy products in subjects with symptomatic lactose malabsorption due to adult type hypolactasia

“…If the results of this study could be extrapolated to the entire population of LI individuals, LI would not represent an appreciable clinical problem, provided that lactose was routinely ingested in divided doses with meals. Unfortunately, the findings of other authors indicate that much lower doses of lactose may cause gastrointestinal distress in people with LM, even if served in divided doses during the day (12-34 g) [24][25][26]. In the present study, the load of 400 ml of milk, kefir and yogurt served as a single dose without a meal provoked clinical symptoms in all of the examined subjects.…”